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Thermal characteristics, chemical composition and polyphenol contents of date-pits powder

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... Al-Mawali et al. [27] observed the oil-melting peak at 2.8 • C, which was close to the structural relaxation. Similarly, they observed the onset of glass transition temperature of air-dried whole date-pits at 138 • C. In the case of freeze-dried date-pits, Suresh et al. [47] observed lower glass transition within 43-50 • C. However, Rahman et al. [25] were unable to observe a shift in the case of roasted date-pits and they explained that this could be due to the complexity of glass transition in the case of very compact rigid biomaterial. ...
... This could cause the difference or absence of the Same letter in a column shows no significant differences (P > 0.05). glass transition in the date-pits biomaterial containing a complex structure [47]. ...
... The onset and peak solids melting-decomposition temperatures of WDP was observed at 179 • C and ended at 200 • C, which was lower as compared to the values as observed in the current study [27]. Suresh et al. [47] observed the onset, peak and end solids-melting temperatures of freeze-dried date-pits at 59, 106 and 197 • C, respectively. These temperatures were much lower as compared to the WDP a prepared by air-dried in this study. ...
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The objective of this study was to develop functional date-pits by mold digestion for the potential use in food products. Whole date-pits (WDP) and defatted date-pits (DDP) were digested by mold Trichoderma reesei at 20 °C. T. reesei consumed date-pits as nutrients for their growth, and DDP showed higher growth of molds as compared to the WDP. The mold digested WDP and DDP samples showed an increased water solubility and hygroscopicity as compared to the samples prepared by autoclaved. This indicated that the mold digestion transformed date-pits to hydrophilic characteristics. Thermal analysis indicated a structural change at −3.2 °C for the untreated WDP and it was followed by a glass transition shift (i.e. onset: 138 °C and a specific heat change: 295 J/kg oC), and an endothermic peak at 196 °C with enthalpy of 68 J/g for the solids melting-decomposition. Similar characteristics were also observed for treated samples with the two glass transitions. The total specific heat changes for WDP, autoclaved-WDP, and digested-WDP were observed as 295, 367, and 328 J/kg oC, respectively. The total specific heat changes for DDP, autoclaved-DDP, and digested-DDP were observed as 778, 1329, and 1877 J/kg oC, respectively. This indicated that mold digestion transformed more amorphous fraction in the DDP. The energy absorption intensities of the Fourier Transform Infrared (FTIR) spectra for the selected functional groups decreased by the mold digestion.
... The addition of DSP into beef meatballs at levels (0, 4, 8, 12 and 16%) replaced of animal fat by levels (0, 20, 40, 60 and 80%) which was designed in this study to prepared beef meatballs enriched by phenolic compounds which it were known with have healthy benefit characteristics in human body as antioxidants, ant carcinogenic and other healthy benefit characteristics. It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. ...
... It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. The phenolic compounds (total polyphenols and total flavonoids) and antioxidant activity (ORAC assay) of DSP and prepared beef meatball samples before and after cooking were determined and these results were listed in Table (6). ...
... In the same way , it could be showed that the total polyphenols, total flavonoids and antioxidant activity were showed a significant increase (p<0.05) by increasing of replacement levels fat by DSP at levels (4 to 16%) in produced uncooked and cooked beef meatballs samples, it were recorded ranged about (169.29 to 681.47 mg/100g) for total polyphenols, and ranged about (20.80 to 84.09 mg/100g, respectively) for total flavonoids and (38.80 to 155.20 μmol trolox /g) for antioxidant activity as comparison to control sample (0.8 and 0.10 mg/100g, and 1.01 μmol trolox /g, respectively). These results were accordance with [16,30,36,21]. ...
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The aim of this study is evaluation the quality and antioxidant properties of beef meatballs as affected by addition of date seeds powder (DSP) at different levels (0, 4, 8, 12 and 16%) from total formula of beef meatballs. The chemical composition (moisture, crude protein, fat, ash, crude fiber and total carbohydrates), antioxidant properties (total polyphenols, total flavonoids and antioxidant activity), physical properties (water holding capacity, PH and color properties (lightness (L), redness (a) and yellowness (b) values), cooking quality (cooking yield, cooking loss, moisture retention and fat absorption), sensory evaluation of meatball samples were measured. It could be noticed that the DSP have a higher content of crude fiber, total phenolic contents and Antioxidant activity led due to a higher increase theses contents in beef meatballs by increasing replacement levels (4 to 16%). Also caused improvement in water holding capacity, a and b values, cooking yield and moisture retention, while caused reduced in fat content, L values, cooking loss and fat absorption of beef meatball samples containing DSP. Also, the addition of DSP up to 12% in produce beef meatball samples noticed any negative effects on the organoleptic criteria. General, it could be observed that, the DSP has a good sources of crude fiber, antioxidant properties and useful addition of DSP in ingredients up to 12% for fortification of produced the beef meatball and other meat products without any negative effects on the organoleptic characteristics. For these reasons, it can be provide various benefits in meatballs production.
... Fig. 1 shows sigmoid shape (i.e., type II according to the International Union of Pure and Applied Chemistry, IUPAC) isotherms of the whole and date-pits fractions as a function of temperature (Brunauer, Deming, Deming, & Troller, 1940;Alothman, 2012;Zheng et al., 2018). Similar sigmoid shape was observed for the freeze dried date-pits isotherm (Suresh et al., 2013, Belarbi et al., 2000. The sigmoidal sorption isotherm was also commonly observed for foods, plant products and different types of plant leaves and biomaterials (Mulet et al., 1999, Rahman and Al-Belushi, 2006, Siripatrawan and Jantawat, 2006, Peng et al., 2007, Staudt et al., 2013, Alamri et al., 2018Arslan & Togrul, 2006;Sinija & Mishra, 2008;Bahloul et al., 2008;Mohamed et al., 2005;Argyropoulos et al., 2012;Lo´pez-Vidan˜a et al., 2021;Lo´pez-Vidan˜a et al., 2016). ...
... At 10°C the M b values were 5.75 and 5.67 g/100 g for the DDP and REP, while WDP and SUP M b values were 4.49 and 4.32, respectively. M b value of freeze dried date-pits were estimated as 4.30 g/100 g ds at 20°C (Suresh et al., 2013) and 4.27 g/100 g ds at 25°C (Belarbi et al., 2000), while in this study it was observed as 4.49 g/100 g ds at 30°C (Table 2). The BET-monolayer value indicated the active polar sites in the solid matrix. ...
... BET and GAB), monolayer moisture increased with the removal of oil, as this trend was also observed by De Jong et al. (1996) for whole and defatted foods. In the case of freeze dried date-pits, Suresh et al. (2013) estimated the M g value as 4.1 g/100 g ds, while Belarbi et al. (2000) found M g of Deleget-Nour date-pits as 4.89 g/100 g ds. In this study, the M g values were higher as compared to the reported values. ...
Article
Moisture sorption properties of whole date-pits (WDP) and three fractionated date-pits; defatted date-pits (DDP), residue (REP) and supernatant (SUP) fractions were studied. Sorption isotherms were measured using Differential Thermal and Humidity chamber at different temperatures (10, 30, 50, 70 and 90 °C) and relative humidity ranged from 0.05 to 0.9. Crossovers of isotherm curves were observed for all fractions between different temperatures. At 30 °C, BET-monolayers of WDP, DDP, REP and SUP were 4.9, 4.2, 3.8 and 3.2 g/100 g ds, respectively. The complete isotherms (i.e. 0.05–0.90 water activity) were modelled by GAB with high coefficient of determination (i.e. 0.944 to 0.999). In the cases of WDP and DDP, the isosteric heat plots showed increasing trends with the decreased moisture and peaks at moisture 0.025 and 0.040 g/100 g ds. Unlike all fractions, DDP isokinetic temperatures Tis (i.e. 97.4 °C) was lower than isobound temperatures Tib (i.e. 145.0 °C) indicating complete removal of bound water occurred at higher temperature as compared to the temperature when all reactions reached at the same. The moisture sorption isotherm characteristics could be used in determining the end point of drying and storage stability as well as packaging design of the date-pits and their fractions.
... The addition of DSP into beef meatballs at levels (0, 4, 8, 12 and 16%) replaced of animal fat by levels (0, 20, 40, 60 and 80%) which was designed in this study to prepared beef meatballs enriched by phenolic compounds which it were known with have healthy benefit characteristics in human body as antioxidants, ant carcinogenic and other healthy benefit characteristics. It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. ...
... It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. The phenolic compounds (total polyphenols and total flavonoids) and antioxidant activity (ORAC assay) of DSP and prepared beef meatball samples before and after cooking were determined and these results were listed in Table (6). ...
... In the same way , it could be showed that the total polyphenols, total flavonoids and antioxidant activity were showed a significant increase (p<0.05) by increasing of replacement levels fat by DSP at levels (4 to 16%) in produced uncooked and cooked beef meatballs samples, it were recorded ranged about (169.29 to 681.47 mg/100g) for total polyphenols, and ranged about (20.80 to 84.09 mg/100g, respectively) for total flavonoids and (38.80 to 155.20 μmol trolox /g) for antioxidant activity as comparison to control sample (0.8 and 0.10 mg/100g, and 1.01 μmol trolox /g, respectively). These results were accordance with [16,30,36,21]. ...
Article
The aim of this study is evaluation the quality and antioxidant properties of beef meatballs as affected by addition of date seeds powder (DSP) at different levels (0, 4, 8, 12 and 16%) from total formula of beef meatballs. The chemical composition (moisture, crude protein, fat, ash, crude fiber and total carbohydrates), antioxidant properties (total polyphenols, total flavonoids and antioxidant activity), physical properties (water holding capacity, PH and color properties (lightness (L), redness (a) and yellowness (b) values), cooking quality (cooking yield, cooking loss, moisture retention and fat absorption), sensory evaluation of meatball samples were measured. It could be noticed that the DSP have a higher content of crude fiber, total phenolic contents and Antioxidant activity led due to a higher increase theses contents in beef meatballs by increasing replacement levels (4 to 16%). Also caused improvement in water holding capacity, a and b values, cooking yield and moisture retention, while caused reduced in fat content, L values, cooking loss and fat absorption of beef meatball samples containing DSP. Also, the addition of DSP up to 12% in produce beef meatball samples noticed any negative effects on the organoleptic criteria. General, it could be observed that, the DSP has a good sources of crude fiber, antioxidant properties and useful addition of DSP in ingredients up to 12% for fortification of produced the beef meatball and other meat products without any negative effects on the organoleptic characteristics. For these reasons, it can be provide various benefits in meatballs production.
... The addition of DSP into beef meatballs at levels (0, 4, 8, 12 and 16%) replaced of animal fat by levels (0, 20, 40, 60 and 80%) which was designed in this study to prepared beef meatballs enriched by phenolic compounds which it were known with have healthy benefit characteristics in human body as antioxidants, ant carcinogenic and other healthy benefit characteristics. It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. ...
... It was found by many studies that the phenolic compounds (polyphenols and flavonoids) could be player these roles in human body [16,36,21].The date seeds content has an excellent sources of phenolic compounds ranged about (3102-4430 mg /100g date seeds weight) and antioxidants activity ranged about (580-929 μmol trolox equivalents/g date seeds weight). Therefore this a great potential to be used of date seeds as a supplement for antioxidant characteristics in food, and medicine products [16,30,36]. The phenolic compounds (total polyphenols and total flavonoids) and antioxidant activity (ORAC assay) of DSP and prepared beef meatball samples before and after cooking were determined and these results were listed in Table (6). ...
... In the same way , it could be showed that the total polyphenols, total flavonoids and antioxidant activity were showed a significant increase (p<0.05) by increasing of replacement levels fat by DSP at levels (4 to 16%) in produced uncooked and cooked beef meatballs samples, it were recorded ranged about (169.29 to 681.47 mg/100g) for total polyphenols, and ranged about (20.80 to 84.09 mg/100g, respectively) for total flavonoids and (38.80 to 155.20 μmol trolox /g) for antioxidant activity as comparison to control sample (0.8 and 0.10 mg/100g, and 1.01 μmol trolox /g, respectively). These results were accordance with [16,30,36,21]. ...
Article
The aim of this study is evaluation the quality and antioxidant properties of beef meatballs as affected by addition of date seeds powder (DSP) at different levels (0, 4, 8, 12 and 16%) from total formula of beef meatballs. The chemical composition (moisture, crude protein, fat, ash, crude fiber and total carbohydrates), antioxidant properties (total polyphenols, total flavonoids and antioxidant activity), physical properties (water holding capacity, PH and color properties (lightness (L), redness (a) and yellowness (b) values), cooking quality (cooking yield, cooking loss, moisture retention and fat absorption), sensory evaluation of meatball samples were measured. It could be noticed that the DSP have a higher content of crude fiber, total phenolic contents and Antioxidant activity led due to a higher increase theses contents in beef meatballs by increasing replacement levels (4 to 16%). Also caused improvement in water holding capacity, a and b values, cooking yield and moisture retention, while caused reduced in fat content, L values, cooking loss and fat absorption of beef meatball samples containing DSP. Also, the addition of DSP up to 12% in produce beef meatball samples noticed any negative effects on the organoleptic criteria. General, it could be observed that, the DSP has a good sources of crude fiber, antioxidant properties and useful addition of DSP in ingredients up to 12% for fortification of produced the beef meatball and other meat products without any negative effects on the organoleptic characteristics. For these reasons, it can be provide various benefits in meatballs production.
... Date pit should therefore be explored for economic value in food industry and other sectors such as nutraceutics and pharmaceutics [6,7]. Averages of chemical compositions of date pit as reported in most researches was 7.5% dry matter, 6% moisture, 8.5% protein, 8% fat, 15% crude fiber, 60% carbohydrates and 1.5% Ash [8,9]. Regardless fibers The Date pit have bioactive components such as polyphenols which make it a potential value adding and functionality in food products [10]. ...
... The functionality and structural properties of date pit are promising and potential for many value added as for oil contents [11], fibers and bioactive components such as phenolic compounds [12]. On the other hand, date pit potentiality have thermal characteristics [8], antioxidant activities [13,14,15], antiviral activities [16], and nutritional values [10,17]. The functional and constituent features of date pit have also given it promising applications in the field of some food industries. ...
... Date pit powder was prepared according to [8,10]. Khalas type of date pit were washed, and oven dried at 50°C for 48 hours, crushed, and milled using (Guangzhou Mingyue -China) grinding mill, then sieved into 300 μm filter. ...
Article
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Abstract Date pit powder (DPP) as a promising by-product additive from date palm (Phoenix dactylifera L.) was recovered as a novel fat replacer fiber source in processed cheese block type (PCB). Four concentrations of cheese fat replaced by DPP (0, 5, 10, 15, and 20%) in PCB were conducted and its impact on chemical composition, microstructure, rheological and sensory properties was evaluated. The inclusion of DPP was improved the fiber content and texture properties of PCB. The DPP stabilized the cheese hardness, adhesiveness, and springiness with fat replacement in cheese. The microstructure of replaced fat PCB with DPP showed lesser numerous fat globules and has a smooth and homogenous protein embedded and distributed uniformly throughout the cheese structure compared to the control. The replacement of 5% fat in PCB by DPP recorded the closest rated sensorial evaluation comparing with control in all criteria and acceptance scores. Regarding the obtained results, date pit as a novel by-product from dates may have a potential texture property and could enrich fiber content and bioactivity of PCB. (PDF) Effects of Date Pit Powder Inclusion on Chemical Composition, Microstructure, Rheological Properties, and Sensory Evaluation of Processed Cheese Block. Available from: https://www.researchgate.net/publication/346382329_Effects_of_Date_Pit_Powder_Inclusion_on_Chemical_Composition_Microstructure_Rheological_Properties_and_Sensory_Evaluation_of_Processed_Cheese_Block [accessed Dec 01 2020].
... The onset of oil melting of date pits was observed at − 17.3 °C with a peak at 2.8 °C, and ended at 29.2 °C, and the enthalpy of the peak was 8.9 J/g sample (Fig. 1b). Suresh et al. [50] observed an endothermic peak and melting of oil in the case of freeze-dried date pits powder (moisture content 6.7 g/100 g sample). The onset of oil melting was observed at − 10.7 °C with a peak at 2.7 °C, ended at 17.2 °C, and the enthalpy of the peak was 2.8 J/g sample. ...
... A sharp shift in the thermogram caused the same mid and end temperature. Suresh et al. [50] observed a shift in the case of freezedried date pits (moisture 6.7 g/100 g date pit) sample at heating rates of 5, 30, and 40 °C/min. The onset, mid, and end points of the glass transition were observed as 43.0, 44.4, and 51.0 °C at 5 °C/min. ...
... This could be due to the fact that roasting transformed more compact ordered (i.e., rigid) molecules and causing low specific heat change at the glass transition, and therefore, it was difficult to trace using the conventional thermal analysis [39], [40]. The absence and variation of glass transition in the date pits indicated that date pits was a complex biomaterial, which possessed varied rigidity due to the existence different types of amorphous components [50]. ...
Article
Full-text available
Thermal characteristics and proton mobility of date pits and their alkaline-treated fibers were measured by differential scanning calorimetry (DSC) and low-field nuclear magnetic resonance (LF-NMR). The DSC thermogram of date pits showed three endothermic peaks: first one for oil melting, second one after glass transition, and third one for the solids-melting and a shift indicating glass transition. The residue from the alkaline-treated fibers (F1) showed an exothermic peak and an endothermic peak for solids-melting. The exothermic peak before solids-melting indicated that more molecular order was progressed in the fibers before its melting. The exothermic shift could be due to the crystallization or molecular ordering in the sample and the endothermic peak was due to the solids-melting. The precipitated alkaline-soluble fibers (F2) at a medium pH (i.e., 5.5) showed mainly solids-melting, while precipitated fibers (F3) at very low pH (i.e., 1.5) showed an absence of glass transition and solids-melting. The residue fibers and fibers precipitated at pH 5.5 were mainly crystalline, while precipitated fibers at pH 1.5 were non-crystalline rigid amorphous. However, the precipitated fibers at pH 1.5 showed less structural bonding between the crystallites as compared with the precipitated fibers at pH 5.5. The three pools of proton were identified in the date pits, and these were linked to the protons in the lignin, holocellulose (i.e., cellulose and hemicellulose), and oil. The protons in the fibers F1, F2, and F3 as a function of temperature varied differently, which indicated structural diversity of the fibers. Therefore, fibers having different structural characteristics could be developed from the date pits.
... The total phenolic content of fresh-cut eggplant was measured according to the F lin-Ciocalteau method [23]. A total of 0.1 mL of extract was added into the tube with mL of water. ...
... The total phenolic content of fresh-cut eggplant was measured according to the Folin-Ciocalteau method [23]. A total of 0.1 mL of extract was added into the tube with 3.9 mL of water. ...
Article
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The growing demand for fresh-cut products has led to an increasing interest in the study of enhancing the quality of ready-to-eat products. Eggplants are consumed as fresh-cut vegetables, which represent an increasing consumption rate. To extend the shelf life of the product, combination treatments have been proposed to inhibit the browning index (BI). Moreover, the storage temperature (4, 16, 25 °C), the concentration of ascorbic acid (AA) (1, 2, 3, and 4 g/L), and modified atmosphere packaging (MAP) (MAP-1, O2: 80 Kpa + CO2: 0 Kpa; MAP-2, O2: 5 Kpa + CO2: 15 Kpa; MAP-3, O2: 10 Kpa + CO2: 10 Kpa; MAP-4, O2: 15 Kpa + CO2: 5 Kpa; MAP-5, O2: 0 Kpa + CO2: 80 Kpa) are screened through the BI of fresh-cut eggplant. Then, the effect of AA combined with MAP on the BI, phenolic content, and polyphenol oxidase (PPO) of fresh-cut eggplants is investigated over four days. In particular, two different areas of fresh-cut eggplant with seed and without seed were chosen to measure the BI. The result shows that the proper temperature (16 °C) maintains the BI of fresh-cut eggplant with seed during two days through screening. The screening of AA demonstrates that AA of 2 g/L is the better concentration to protect the color of fresh-cut eggplant with seed and without seed. AA of 2 g/L shows lower BI for fresh-cut eggplant with seed and without seed in MAP-2, MAP-3, MAP-4. The combination of AA (2 g/L) and MAP-2 significantly inhibited the browning of fresh-cut eggplants with seed. The application of AA (2 g/L) combined with MAP-2 inhibits the PPO and total phenol content activity over two and three days. Taken together, using AA combined with MAP may constitute a potential approach for maintaining the quality and inhibiting the browning of fresh-cut eggplants.
... The aw data is also required to predict the moisture migration since aw is the driving force behind moisture transfer to or from the food product [14] . Also, thermal characteristics study (solids melting characteristics) using differential scanning calorimeter (DSC) is required for understanding the physicochemical characteristics of paprika as a function of temperature and MC [15] . In literature, such data for paprika has not been reported. ...
... The enthalpy of solids melting was determined by software (NETZSCH, Proteus Thermal Analysis, 5.2) which showed an increase from 76.69 to 279.60 J g -1 with an increase in MC (6.93 to 23.05% db) and aw (0.42 to 0.78). The increase in melting enthalpy may be due to the transformation of solids matrix structure and higher density of hydrogen bond [15] . ...
... oil [31,32]. DPs are class of lignocellulosic resources in which cellulose, hemicellulose, and lignin are the main components [32,33]. Thus, date pit is a suitable low cost source of cellulose in these countries to be used as slid phase extractors towards DBPs. ...
... Thus, cellulose isolated from DP has high structural integrity and mechanical properties [26,27]. The D-MCC has also a degree of crystallinity higher than the MCC isolated from jute and soybean hulls [33,41]. The computed values of CI for MCC and D-MCC by XRD provided a qualitative or semi-quantitative evaluation of the amounts of amorphous and crystalline cellulosic components in a sample. ...
Article
The sorption characteristics of phosphate ions from aqueous molybdate solution of pH ≤ 2 onto malachite green (MG) impregnated thiophenol (TP) functionalized Au nanoparticles based polyurethane foam (PUF) solid platform (MG-AuNPs-treated PUF) was studied. Phosphate uptakes followed Langmuir and Freundlich models. Based on the retention profile, a dual mechanism involving a “weak base anion exchanger i.e. solvent extraction” and a “surface adsorption” of phosphate retention as complex ion associate {[MG]⁺.[H2PMo12O40]⁻}PUF is anticipated. Complete retention of phosphate at various concentrations (0.01–100.0 μg mL⁻¹) onto the sorbent packed column at 3–5 mL min⁻¹ flow rate was achieved. A highly sensitive strategy for enriching, quantitative recovery and trace determination of phosphate in water using the sorbent packed column was developed. Under the optimized parameters, a linear concentration range of 0.07–25 μg L⁻¹ and limits of detection (LOD) and quantification (LOQ) of 0.02 and 0.07 μg L⁻¹ phosphate were achieved, respectively. The proposed and reference methods for analysis of phosphate in water samples were subjected to statistical treatment (student's t and F tests) at 95% confidence with no significant difference indicating the precision and accuracy of the proposed assay. The settled sorbent in flow mode was robust sufficient to be reused for five times without significant decrease in its performance. The intraday repeatability and interday stability of the established sorbent packed column towards phosphate (10.0 μg L⁻¹) determination was studied. An estimated coefficient of variation less than ±5% was achieved revealing the suitably of the modified PUFs in column mode. The established column enabled multiple enrichment of phosphate from water and expanded the range of phosphate level which can be determined in water.
... P < 0.05 (significant); **: P < 0.01 (very significant) and *** P < 0.001 (extremely significant). the data reported by (Suresh et al., 2013) and (Zakir Hossain et al., 2014). The amounts of water extractable and protein in O were in agreement with the values reported by (Siles López et al., 2010). ...
... Phenols and DPPH contents in O.P were similar with those reported by (Lafka et al., 2011). The phenol content in D.K and O was quite similar to that reported by (Suresh et al., 2013) and (Dibanda Romelle et al., 2018). In this study, A. S&L extracts were found to have lower levels of phenolic compounds but similar DPPH percentage compared to the results reported by (Peschel et al., 2006). ...
Article
The integration of easily available and under-exploited biomasses is considered a sustainable strategy in biorefining approaches. Mediterranean countries, especially Algeria, Morocco, and Tunisia, offer such under-exploited waste of different origins. This study revealed the chemical composition and phytochemical characteristics of various agri-food side-products, marine residues, and wild grasses collected in the Maghreb region. Results showed that these wastes contained variable proportions of polysaccharides, lignin, constitute molecules (proteins, lipids, and inorganic molecules) and, various secondary metabolites, mainly flavonoids and condensed tannins. Based on this, the Mediterranean waste was divided into three categories. The first category included waste with high lignin content (40 wt%). The second category contained waste with lignin content below 10 wt% and structural carbohydrate content below 50 wt%. Additionally, the waste in this category comprised noticeable amounts of flavonoids and condensed tannins, particularly from thistle, speedwell, and spurge. Finally, the third category included waste with lignin content above 15 wt% and carbohydrate content in the range of 45-55 wt%. The results also showed that the waste in the third category has a chemical composition similar to that of raw materials envisioned for use in European or North American commercial biorefineries. The findings of this study indicate that the biomass waste employed in this study can be used to develop marketable bioproducts and may be a potential raw material for a biorefinery facility.
... oil [31,32]. DPs are class of lignocellulosic resources in which cellulose, hemicellulose, and lignin are the main components [32,33]. Thus, date pit is a suitable low cost source of cellulose in these countries to be used as slid phase extractors towards DBPs. ...
... Thus, cellulose isolated from DP has high structural integrity and mechanical properties [26,27]. The D-MCC has also a degree of crystallinity higher than the MCC isolated from jute and soybean hulls [33,41]. The computed values of CI for MCC and D-MCC by XRD provided a qualitative or semi-quantitative evaluation of the amounts of amorphous and crystalline cellulosic components in a sample. ...
Article
A low-cost and selective solid phase extractor (SPE) for complete removal of chromium (VI) sp cies from aqueous media has been developed. The proposed method was based upon formation of chlorochromate [CrClO3]⁻ aq oxyanion in aqueous HCl (≥ 0.5 mol/L) medium followed by complete extraction onto the ion pairing 2,3,5-triphenyltetrazolium chloride (TZ⁺Cl⁻) modified α-Fe2O3 nanoparticles treated polyurethane foam (PUFs) (TZ⁺Cl⁻/α-Fe2O3 NPs/PUFs) solid phase platform. The sorption data fitted well pseudo-second-order kinetic with an overall rate constant (k2) of 0.010 g (mg. min)−1. The values of ΔH (−78.2 ± 2.1 kJ mol ⁻¹ ) and ΔG (−3.51 ± 1.1 kJ mol ⁻¹ ) revealed that, the [CrClO3]⁻ aq sorption onto the solid sorbent are spontaneous and exothermic process, respectively. The value of ΔS (223.5 ± 2.5 J mol ⁻¹ K ⁻¹ reflects the sorption of [CrClO3]⁻ aq onto the TZ⁺Cl⁻/α-Fe2O3 NPs/PUFs sorbent proceeded in a more random fashion. The nanocomposite sorbent packed column was successfully used for complete removal of trace levels of chromium (VI) species from environmental water samples. The retained chromium (VI) species were recovered with NaOH (0.5 M) and analysed by ICP-OES. Sorbent packed column was also used for rapid and complete retention of chromium(III) after oxidation with H2O2 in KOH. The sorbent packed column can be reused for 3–4 times without decrease (±5%) in column performance.
... It is rich in phenolic compounds (21.0-62.0 mg GAE/100 g of date seeds) and antioxidants (580-929 mL Trolox equivalents/g) (Al-Farsi et al., 2007;Suresh et al., 2013). These bioactive molecules, polyphenols, are healthpromoting substances, such as antibacterial, antioxidant, anti-inflationary, and anticancer activity, and have protective effects against the onset or delay of cardiovascular alterations, inflammation, and aging. ...
... Date seeds are continuously distinguished by a high concentration in phenolic compounds despite the fact that many standards have been utilized for phenolic measurement. More phenolic constituents are found in date seeds than other by-products of date (17). A previous study supports our findings, where phytochemicals of three date kinds (Shahal, Um-sellah, and Mabseeli) have been reported (7). ...
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The date palm (Phoenix dactylifera L.) fruit contains variety of bioactive constituents including phenolic compounds. This research aimed to analyze the phenolic constituents and antioxidant potential of crude methanol extract samples from seeds of different date varieties, Aseel (As), Ambar (Am), Ajwa Saudi (AJS), Ajwa Khairpur (AJK), Khipro (KP) and Karblyan (KB). Date seeds are regarded as waste product. However, it contains secondary chemicals of biomedical significance. Colorimetric methods were used for the evaluation of phytochemical and antioxidant capacity. The Folin-Ciocalteu method was used for the assessment of phenolic content. The antioxidant potential was evaluated through phosphomolybdenum test, potassium ferricyanide test, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate scavenging test methods. All samples differ significantly in terms of antioxidant activities and quantity of secondary metabolites (phenolic and flavonoid contents). When all samples were compared, As was shown to have the highest amount of phenolic and flavonoids, while AJ(S) had the lowest content. The KP sample had the highest overall antioxidant and reducing potential, while the AJ(K) and Am samples showed the lowest, respectively. Significant DPPH scavenging capacity has been demonstrated in all samples. In order to extend the shelf life of food products, date seeds may consequently provide ideal material for the bio-functional food industry.
... The dates contain a seed referred to as pits, pips, stones, kernels, etc. The seed constitutes 10 % of total weight of the fruit (Suresh et al., 2013). The seed are mostly light to dark brown in colour, odourless and tasteless with slight bitterness. ...
... These bioactive phytoconstituents, such as flavonoids, have the potential to serve as a basis for the development of dietary supplements. Few alterations in known compounds, derived from natural sources, can change the biological activity of the native compound (Suresh et al., 2013). ...
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Testing natural antihyperlipidemic substances is necessary due to the increasing prevalence of diabetes mellitus, which leads to chronic hy-perglycaemia and poses a significant threat to public health and well-being worldwide. The present study investigated the anti-diabetic effect of black pepper , turmeric, and ajwa date pulp + seed and their mixtures as hypolipidemic, antioxidant and protective agents on the liver and kidney by examining histo-logical changes in alloxanised diabetic rats. Eleven groups consisting of eighteen males and eighteen females were divided into a normal control (non-diabetic), a positive control (diabetic), positive groups receiving glibenclamide (10 mg kg-1 body weight), black pepper (BP), turmeric (T), ajwa pulp (AP), ajwa seeds (AS) aqueous extracts and their various combinations. The dose of BP aque-ous extract was 50 mg kg-1 body weight, while the dose of the other materials was 500 mg kg-1 body weight. The aqueous extracts were administered orally once daily for eight weeks. Our phytochemical screening detected the presence of fla-vonoids, tannins, saponins, steroids, and alkaloids in these extracts. The results pertaining to serum levels of glucose, lipids, glycosylated haemoglobin, and anti-oxidant biomarkers revealed significant improvements after administration of AS, BP + AS, and the mixture of all extracts. Moreover, histological analyses demonstrated the protective effects of these extracts. In conclusion, all tested materials, especially ajwa seeds administered alone and in combination with black pepper extract, exerted significant antihyperlipidemic and weight-stabilising effects in alloxanised diabetic rats. Therefore, these natural substances hold promise as potential herbal medicines for managing diabetes mellitus.
... Dates are the primary source for creating date pastes and date syrup, which are used in the confectionery and fermentation industries [6]. It is also a good source of vitamins A and C, as well as B vitamins like thiamine and riboflavin [1,7], and studies have shown that dates induce antioxidant [8,9], anti-cancer [10], and antiviral [11] activities. Date fruits have a relatively high percentage of carbohydrates (71.2-81.4% of total energy content) and ash (1.68-3.94%) ...
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With the increasing global nutritional bar market, developing and formulating innovative high-energy and protein bars to compensate for nutrients using date fruits is beneficial for health-conscious individuals. The current research was undertaken to study the composition and physicochemical characteristics of innovative high-energy and high-protein bars using two combinations of Sukkari dates or fruit mixtures as a base. Fifty percent of either Sukkari date paste or dried fruit mixture (25% raisin, 12.5% fig, and 12.5% apricot) combined with other different ingredients was used to produce a date-based bar (DBB) or fruit-based bar (FBB). Proximate composition, sugar content, amino and fatty acid profiles, minerals and vitamins, phytochemicals, antioxidant activity, and visual color parameters of the DBB and the FBB were determined and statistically compared. Proximate analysis revealed higher moisture and fat content in the FBB than the DBB, while ash and crude fiber were higher in the DBB than the FBB. The protein content in the DBB and the FBB was not statistically different. Both prepared bars exuded around 376–378 kcal 100 g−1 fresh weight. Sugar profile analysis of the DBB and the FBB showed dependable changes based on date or fruit content. Fructose, glucose, and maltose contents were higher in the FBB than in the DBB, while sucrose content was higher in the DBB than in the FBB. The DBB showed significantly higher content in Ca, Cu, Fe, Zn, Mn, and Se and significantly lower content in Mg, K, and Na than the FBB, with no variation in phosphorus content. The DBB and the FBB contained both essential (EAA) and non-essential (NEAA) amino acids. The DBB scored higher Lysine, Methionine, Histidine, Threonine, Phenylalanine, Isoleucine, and Cystine contents than the FBB, while the FBB scored only higher Leucine and Valine contents than the DBB. Seventeen saturated fatty acids were identified in the DBB and the FBB, with Palmitic acid (C16:0) as the predominant fatty acid. Oleic acid (C18:1n9c) was predominant among seven determined monounsaturated fatty acids. Linoleic fatty acid (C18:2n6c) was predominant among eight identified polyunsaturated fatty acids. In addition, α-Linolenic (C18:3n3) was detected in a considerable amount. However, in both the DBB and the FBB, the content and distribution of fatty acids were not remarkably changed. Regarding phytochemicals and bioactive compounds, the FBB was significantly higher in total phenolic content (TPC), total flavonoids (TF), and total flavonols (TFL) contents and scavenging activity against DPPH and ABTS free radicals than the DBB. The DBB and the FBB showed positive a* values, indicating a reddish color. The b* values were 27.81 and 28.54 for the DBB and the FBB, respectively. The DBB is affected by the lower L* value and higher browning index (BI) to make its color brownish. Sensory evaluation data showed that panelists significantly preferred the DBB over the FBB. In conclusion, processing and comparing these bars indicated that using Sukkari dates is a nutrient-dense, convenient, economical, and better sugar alternative that helps combat the calorie content. Thus, scaling up the use of dates instead of fruits in producing high-energy and protein bars commercially is highly recommended.
... Meanwhile, several extraction times were optimized. In a preliminary study, we studied several combinations of ratio (DP-Ethanol) and extraction times on extraction yield and biological (antibacterial and antioxidant) activities of DSEE [18][19][20]. In our study, the DSEE yield and bioactivity decreased with the extraction time. ...
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This study explored the impact of date palm seeds ethanolic extract (DSEE) on the microbiological, physicochemical, and sensory qualities of chicken breast meat kept refrigerated at 4 °C. DSEE was applied at 0.156% (DSEE1), 0.312% (DSEE2), and 0.624% (DSEE4). Microbiological parameters, chemical stability, and sensory features of DSEE were monitored for 14 days at refrigerated conditions (4 °C). DSEE considerably (p < 0.05) decreased lipid/protein oxidation processes. Interestingly, at 14 days, DSEE at 0.624% delayed microbial growth. Moreover, the addition of 0.312% (DSEE2) and 0.624% (DSEE4) and storage time substantially affected the sensory (appearance, odor, color, and overall acceptability) parameters of chicken breast meat. By expertly employing chemometric techniques such as principal component analysis (PCA) and heat maps, the acquired evidence brought useful information to regroup all samples and to associate microbiological and oxidation characteristics to organoleptic attributes using correlation models. PCA and heat maps provided effective information to differentiate all samples and relate lipid and protein oxidative processes and microbiological properties to sensory parameters. The obtained findings contribute to a better knowledge of the impact of chemical and microbial alterations on sensory quality in fortified meat products. This study displayed the potential functional and economic benefits of using DSEE as an encouraging component in chicken meat preservation.
... Morphological analyses were carried out on all the pomace varieties with a scanning electron microscope (JSM-6610 JEOL PLUS / LA, Tokyo, Japan), operated at 10 kV and a working distance of 20 mm in high vacuum mode (Suresh et al., 2013). All samples were placed on adhesive carbon tape, fixed in the SEM stub, and coated with gold in a sputter coater under vacuum in the presence of inert gas. ...
Article
Date fruit pomace (DFP), an abundant byproduct of the date syrup industry, is currently underutilized. It is either fed to animals or landfilled where it ferments, causing serious environmental issues. Proper waste management through valorization strategies is required to reduce the environmental impact of date waste and foster the transition of the date processing industry towards sustainability. The implementation of valorization strategies requires characterizing the DFP composition. Herein, four DFP samples of Emirati varieties were characterized in terms of compositional and functional properties. The fresh DFPs contained moisture (∼60.0 g/100 g). On a dry matter basis, DFPs contained total dietary fiber (∼45.5 g/100 g), residual sugars (∼35.3 g/100 g), protein (∼10.6 g/100 g), ash (∼4.1 g/100 g), and fat (∼1.3 g/100 g). They were also rich in nutritionally important elements such as potassium (∼145.7 ppm), calcium (∼46 ppm), phosphorus (∼28.7 ppm), and magnesium (∼26.7 ppm). The total phenolic content varied from 170 to 260 mg gallic acid equivalents GAE/100 g, making DFP a good source of antioxidants. Scanning electron microscopy measurements revealed the presence of fibrous bundle-like structures, whose thermal stability was confirmed by thermogravimetric analysis, showing the dominance of insoluble over soluble fiber. Higher water- and oil-holding capacities were found for dried desugared pomace. The high fiber, phenolic, and elemental content highlight the high nutritional value of DFP, which can be used as dietary supplement, while its sugar content can be used to produce value-added biochemicals via fermentation. Thus, DFP may represent a valuable bioresource for food and non-food applications.
... oil (9-13.5%), and ash (0.9-1.8%) [12]. We postulated that such a chemical composition of date seeds would be a good candidate for CQD fabrication. ...
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Multifunctional carbon quantum dots (CQDs) were synthesized hydrothermally from vinasse (CQD-V) and date seeds (CQD-P) as wastes of bioethanol and date fruit processing industries, respectively. The particle size, morphological and structural characteristics, fluorescence properties, antioxidant and antimicrobial activity, and cytotoxicity of CQDs were investigated. Both CQDs had a narrow size distribution plot with an average particle size of 2.37 and 6.82 nm in CQD-P and CQD-V, respectively. The CQDs emitted intense green fluorescence under the excitation of UV light (380 nm). The quantum yield of CQD-V (20.64%) was higher than that of CQD-P (5.16%). However, transmission electron microscopy approved the formation of uniform spherical-shaped nanoparticles. The ATR–FTIR and EDX analyses confirmed the synthesis of naturally occurring N and P-doped CQDs from both precursors. The antioxidant power of CQDs-P (IC50 = 3.6 mg/mL) was stronger than that of CQDs-V (IC50 = 4.5 mg/mL). In addition, CQD-P represented antimicrobial performance on all microbial strains (Listeria monocytogenes, Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli) compared to CQD-V, with high activity on P. aeruginosa. The cytotoxicity of the synthesized CQDs on L929 cell lines was quite low, and they could be considered potentially non-toxic nanomaterials. This study demonstrated that the agro-industrial waste of vinasse and date seeds are excellent candidates for the synthesis of CQDs with high fluorescence activity and antioxidant potential, which could be suggested for a wide range of applications. Graphical Abstract
... g / 100 g date-pit) together with oil (9.9-13.2 g / 100 g date-pit) (Suresh et al., 2013). Date seeds are waste from processing dates that have not been utilized optimally. ...
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The study aimed to evaluate the production performance of male Limousine Crossbreed cattle with different feed levels with the addition of RD flour. It used nine male Limousine crossbreed cattle, aged <1-3 years, with an average initial weight of 335±29,09kg. The method used is an experimental method using CRD with 3x3: T0= Ad libitum corn straw + concentrate without RD powder, T1= Ad libitum corn straw + concentrate containing 7,5% RD, T2= Ad libitum corn straw + concentrate containing 15% RD flour. The variables measured included Daily gain, Average daily gain, feed conversion ratio, and Income over feed cost. Data were analyzed by ANCOVA. Cattle were fed for eight weeks from (March 26 to June 8, 2021), in the Livestock Group of Kucur Village, Dau District, Malang Regency. The result showed that using feed with the addition of RD at different levels of male Limousine crossbreed cattle had a significant effect on FCR (P>0,05) and on Daily gain, Average daily gain, and IOFC (P<0,01) had a different significant effect. This study concluded that the treatment of T1 feed (7.5% "RD" flour) showed the best results for Daily gain (70,67±5,43 kg), Average daily gain (1.26±0.09 kg), FCR (5.85±0.19),, IOFC Rp. 36586.50.
... 36,37 Previously, Ali, Al-Hattab, and Al-Hydary 38 stated that Iraqi date seed oil was regarded as an oleic-palmitic type. In another study, Suresh et al. 39 reported that Omani date seeds oil was dened as an oleic-myristic type. Fatty acids content and composition in date seed oil are strongly dependent on the variety of dates and their ripening stage as well as the method used for oil extraction. ...
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Novel composite films made of sodium caseinate (NaCas) and two functional compounds from date seed co-products, i.e. furfural and date seed oil (DSO), were produced. The effects of furfural and DSO contents on the barrier, mechanical and optical properties of NaCas films were assessed using a two-factor, five-level central composite design. Increasing DSO content increased contact angle values of NaCas films and decreased their solubility indicating an increase in their hydrophobicity. Moreover, increasing furfural concentration increased tensile strength (TS) of NaCas films due to crosslink formation between furfural and NaCas' primary amine groups. On the other hand, furfural and DSO incorporation conferred good light barrier properties to the resulting films. Overall, a furfural content of 0.69% and 1.76% DSO were selected as the optimum factor levels producing maximum contact angle (69.85°) and TS (36.47 MPa) and minimum solubility (16.95%) with overall desirability of 0.98.
... depending on the geographical origin [46]. Apart from this, the reason for the observed differences in results from previous studies is the difference in the extraction procedures used [42,47]. Several previous studies used several solvents for extraction, especially organic solvents or organic and aqueous solution mixtures. ...
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Utilising major waste products from the food industry can have both a great environmental impact and be a means to improve consumer health. Date seed is a food industry byproduct that has been proven to have high nutritional value. The aim of this work was to measure the total polyphenolic content (TPC), flavonoids, and antioxidant activity of the seeds of six date fruit varieties, Fard, Khalas, Khinaizi, Sukkary, Shaham, and Zahidi, and to use those seeds to enhance the antioxidant value of cookies by partially substituting flour with ground date seed. Date seed powder (DSP) was extracted at three levels of sample to solvent ratio (5:1, 10:1 and 15:1 mg/mL). Cookies were prepared using three substitution levels of wheat flour (2.5, 5.0, and 7.5%, w/w) by DSP and two types of flour (white and whole wheat), and were baked at two different temperatures, 180 and 200 °C. The composite cookies were found to contain a significant amount of TPC and flavonoids, and showed increased antioxidant activity compared with the control samples.
... Thus, the utilisation of date waste is important for date cultivation and to increase the income in date-processing units. Currently, seeds are used mainly for animal feed for various livestock and sometimes as a soil additive [2,21]. The prevailing global trends aim for a more circular economy. ...
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Date seeds are a major waste product that can be utilised as a valuable and nutritional material in the food industry. The aim of the present study was to improve cookies quality in terms of functional and textural value and assess the effect of date seed powder flour substitution on the physical and chemical characteristics of cookies. Three substitution levels (2.5, 5 and 7.5%) of flour by fine date seed powder from six varieties locally named Khalas, Khinaizi, Sukkary, Shaham, Zahidi and Fardh were prepared. Two types of flour were used (white flour and whole wheat) at two different baking temperatures: 180 and 200 °C. The incorporation of date seed had no or slight effect on moisture, ash, fat and protein content of the baked cookies. On the other hand, incorporation significantly affected the lightness and hardness of cookies; the higher level of addition, the darker and crispier the resulting cookies. The sensory analysis indicated that the produced cookies were acceptable in terms of smell, taste, texture and overall acceptability. The results indicate that the most acceptable cookies across all evaluated parameters were produced using whole wheat flour with 7.5% levels of date seed powder using Khalas and Zahidi varieties. Overall, the analysis indicated that cookies with acceptable physical characteristics and an improved nutritional profile could be produced with partial replacement of the white/whole wheat flour by date seed powder.
... These values are in range with those for Deglet Nour and Allig date seed oil as reported by Besbes et al. [17]. Suresh et al. studied the thermal properties of Khalas date seed with particle size ranging from 132 to 400 µm [85]. They examined the effect of moisture content as well as heating rate and they concluded that melting enthalpy increases with increasing moisture content, while the heat rate was found to affect the melting enthalpy based on the moisture content in the sample. ...
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Date palm (Phoenix dactylifera) is an agricultural crop, which plays an important role as a source of nutrition in the day-to-day life of people. Date palm cultivation, processing industries, and consumption generate tons of wastes. One of these wastes is date seed, which represents 10% of the total weight of date fruit. The utilization of date seed waste is a research topic of interest for many applications such as cosmetic, nutritional, and engineering. In this review, the different methods used for preparing date seeds' powder and extracting its oil are surveyed. A comprehensive review of the physical and chemical properties of the date seed powder and oil is provided in addition to the employed characterization methods. This paper also reviews the utilization of date seed waste in the most common engineering applications including biofuels, composites, and adsorbent applications. The paper also highlights the research limitation and future research potentials of the utilization of date seed for several engineering applications.
... Results of the chemical composition of DP in this study (Table 2) were within the range values of different varieties of DP formerly determined by many researchers (Mohebbifar and Torki 2011;Suresh et al. 2013). Only result of ash content was higher (2.05%), but also within the range values (1.3-3.2%) reported by Feedipedia (2017) and (1.68-3.94%) ...
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This study was performed to investigate the effect of feeding different levels of date pits (DP) to growing Japanese quails on growth performance, diet digestibility, blood parameters, carcass traits, and economical value of the farm production. A total of 204 1-day-old quail chicks were randomly divided into 4 groups (three replicates each). DP was chemically analyzed and used as 0%, 2%, 4%, and 6% to formulate 4 balanced experimental diets (control, DP-2, DP-4, and DP-6, respectively). The feed and water were given ad libitum. Feed intake (FI) and body weight gain (BWG) were recorded weekly, and the feed conversion ratio (FCR) was calculated. A digestibility trial was conducted, and the digestion coefficient (DC) was calculated for diet dry matter (DM) and nutrients. At the end of the experiment, carcass traits were measured and blood samples were collected for blood picture analysis. Economical evaluation of the test diets was carried out to determine the net return (NR) of feeding DP to quails. Results showed significant (P < 0.05) change in FI and final body weight among treatments. FCR of DP-6 group was the best in all treatments. DC of diet DM and nutrients were reduced with increasing DP level except for nitrogen-free extract (NFE). Carcass traits and blood parameters were within the normal range with no adverse effects. From the economic point of view, quail selling return values were significantly higher (P < 0.05) for all the groups supplemented with DP than the control one. Total return (TR) and NR values showed insignificant (P > 0.05) differences among the experimental groups; they were higher for DP-fed groups compared with the control. The present results demonstrated a beneficial effect of DP inclusion in the diet of quails in terms of growth performance, blood profiles, carcass traits, and economic value.
... Results of the chemical composition of DP in this study (Table 2) were within the range values of different varieties of DP formerly determined by many researchers (Mohebbifar and Torki 2011;Suresh et al. 2013). Only result of ash content was higher (2.05%), but also within the range values (1.3-3.2%) reported by Feedipedia (2017) and (1.68-3.94%) ...
... The defatted date-pits powder (F1) showed that fibers (i. e. holocellulose) are covered by lignin (Fig. 1A, low magnification and Fig. 1B, high magnification), which is similar to the previous report as shown by Suresh et al. (2013). In the case of lingo-cellulosic eucalyptus, de Lima et al. (2020) also observed smooth surface of lignin coating and after alkaline digestion surface showed rough porous after removal of lignin. ...
Article
Four types of fibers (i.e. defatted, F1; residue after alkaline digestion, F2; precipitated fibers at pH 5.5, F3; and pH 1.5, F4) were prepared from date-pits. The date-pits were first defatted and then digested by an alkaline solution. The fibers F2 showed the highest amount of cellulose (i.e. 46.0 g/100 g sample), while fibers F3 and F4 showed the lowest amount of cellulose (i.e. F3, 9.3 g/100 g sample). The visual structures of the fibers were determined by Field Emission Scanning Electron Microscope (FESEM). Fibers F1 (i.e. defatted date-pits) showed that lignin was coated over holocellulose, however alkaline digestion clearly showed lignin-coating was removed and fibers (F2) contained two main types of structural matrix (i.e. micro-size trapezoidal particles were embedded in nano-size fine interconnected fibers). Fibers F3 showed highly porous particles, while F4 showed that spherical particles were imbedded in an interconnected fiber matrix. Infrared Fourier Transform (FTIR) peaks within the wave number 400-4000 cm−1 showed different molecular structures of the fibers. X-ray (XRD) patterns showed different crystallinity of the fibers. The crystallinity of the F2 and F4 were 76.7 and 95.5%, respectively and fibers F3 was mainly amorphous in nature.
... Tunisia [3]. The world production of dates reached 7.5 million tons in 2011 [4], dominated by the variety called 'Deglet Nour' which constitutes about 60% of the total production with a well appreciated sensory quality and high marketing values. ...
Article
Large amounts of secondary date waste (pulp and seeds) are produced and discarded in Tunisia without proper valorization methods. To study the possibility of valorizing different varieties of Tunisian date waste (pulp and seeds) via anaerobic digestion, batch biochemical methane potential (BMP) tests were carried out under mesophilic temperature. The bio-methane production curves were fitted to the model of modified Gompertz in search of the kinetic parameters. The bio-chemical characterization of the substrates from different varieties (total and volatile solids, COD and contents in carbohydrates, proteins, lipids, polyphenols) was realized. Principal component analysis (PCA) was used to investigate the correlations between the model parameters and biochemical variables. Results show that the biochemical compositions of date pulp and seeds strongly depend on the varieties. The BMP are in the range of 0.295-0.345 and 0.267-0.327 Nm³ CH4·kg COD⁻¹ for pulp and seeds respectively, resulting from the significant biochemical variance among the varieties. The BMP of date seeds was significantly correlated with their VS/TS ratio, carbohydrate and protein contents (p < 0.05). For the pulp, significant correlation was found between BMP, carbohydrate and lipid contents. PCA shows that certain varieties (like pulp and seeds of Deglet Nour and seeds of Bejou) are most suitable for being valorized by anaerobic digestion. The most suitable date varieties for this innovative approach were revealed. This research provided useful knowledge for bioconversion of waste date pulp and seeds to biomass energy.
... In another study, Iranian date seed oils were defined as oleic-lauric type [19]. Suresh et al. [20] reported that Omani date seeds oils can be considered as oleic-myristic type. ...
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The cultivation of the date palm (Phoenix dactylifera L.) is the main activity and source of livelihood for people from arid and semiarid regions of the world. Date production is increasing every year. In addition, pitted date exportation is rising and great amounts of date seeds are produced. This biomass represents a problem for manufacturing companies. At the moment, date seeds are normally discarded or used as animal feed ingredients. However, this co-product can be used for many other applications due to its valuable chemical composition. Oil is one of the most interesting components of the date seed. In fact, date seeds contain 5–13% oil. Date seed oil contains saturated and unsaturated fatty acids with lauric and oleic as the main ones, respectively. Tocopherols, tocotrienols, phytosterols, and phenolic compounds are also present in significant amounts. These phytochemicals confer added value to date seed oil, which could be used for many applications, such as food product formulations, cosmetics, and pharmaceuticals. This review provides up-to-date data on the different extraction techniques and the chemical composition of date seed oils. The applications of date seed oil have also been reviewed.
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Background: Date seeds are a significant waste product of the date business that might provide potentially valuable material for the development of important culinary components. This study aimed to examine the nutrients in parboiled date seed powder and develop various value-added products from it. Materials and methods: The current study evaluated the proximate composition, vitamins, minerals, and bioactive components of date seed powder. Fibre, ash, moisture, calcium, ascorbic acid, iron, and tannin were among the nutrients studied. The samples were also sent for GCMS analysis. The current study created four value-added items. These include chapatti, kinnathappam, pakkavada, and gulab jamun. Results and Conclusion: According to this study, date pits have higher levels of nutrients (Calcium-30 mg/100g, Iron-3.2 mg/100g, Ascorbic Acid-11.76 mg/100g, Tannin-38.4 mg/100g), fibre (77g/100g), ash (0.4g/100g), moisture (3,48g/100g), and polyphenols. According to the findings of this investigation, adding 5% date seed powder to value-added products has no significant effect on their qualities.
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The date palm holds immense significance in the socio-economic fabric of the countries where it is extensively cultivated. The plant and its derivatives boast diverse nutritional and functional properties, contributing to a substantial global production surge. Despite various initiatives to convert date processing waste into value-added products, a significant proportion of waste persists in the form of date seeds, date pomace, and lost dates. The physicochemical and nutritional profiling of date seeds and pomace reveals functionalities that, if properly utilized, could transform them into economically viable, natural, and sustainable ingredients across various sectors. Although ample literature exists on date palms and their industrially relevant waste products, this review distinctly focuses on date seed and pomace as pivotal by-products of date processing. The objective is to furnish comprehensive and updated insights into the valorization of date seeds and pomace, emphasizing their applications in the food industry. This review also endeavors to illuminate approaches for minimizing the wastage of these industrial by-products and highlights the bioactive components inherent in them.
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In this study, wild jujube pit (WJ) was used to compose with hydroxyapatite (HA) and poly(lactic acid) (PLA) based on 3D printing. The properties of WJ and its alkali/silane treatments (WJS), PLA/WJS/HA composites powder and their 3D-printed samples were investigated by a Fourier transform infrared spectrometer, simultaneous thermal analyzer, a melt flow tester, a scanning electron microscope, and a universal mechanical testing machine. The results showed that few amounts of WJS or HA enhanced the reactivity of PLA. The 3D-printed PLA/WJS/HA composite showed much higher water absorption than PLA, indicating its enhanced hydrophilicity and biodegradability. The inputting of HA and WJS increased the tensile strain of PLA, indicating better plasticity. Finally, porous PLA/WJS/HA scaffolds with interconnected pores in size of 0.8 mm and rougher surface were fabricated. The scaffold with the lowest compression strength did not crack after being compressed 75% of its height, demonstrating an excellent stiffness. Those values suggested that the biomass waste, WJ, can be effectively utilized to prepare PLA/WJ/HA composite, which has the potential to be used as bone scaffolds and other lighter weight structural parts.
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Thermal (differential scanning calorimetry, DSC), proton (low-frequency nuclear magnetic resonance, LF-NMR), and mechanical (differential mechanical thermal analysis, DMTA) relaxations were measured for defatted date-pits as a function of temperature. DSC showed three types of relaxations, lower one structural relaxation (i.e. − 5 °C), followed by a glass transition (i.e. 136 °C) and solids melting–decomposition (i.e. 171 °C). LF-NMR showed three pools of protons, rigid, semi-rigid and mobile. Rigid protons showed two types of relaxations, first one low temperature increase (− 80 to − 40 °C), plateau region (− 60 to − 40 °C) and a positive peak at 120 °C, and semi-rigid showed maximum peak at − 5 °C and minimum peak at 150 °C. Mobile protons showed low relaxation (− 80 to − 40 °C), a maximum peak at 70 °C and a minimum peak at 130 °C. The maximum peak (i.e. − 5 °C) of semi-rigid protons was similar to the DSC structural change, while the maximum peak of rigid protons (120 °C) was similar to DSC glass transition (i.e. 136 °C). The minimum peak of the semi-rigid protons (i.e. 150 °C) was similar to the solids melting–decomposition (171 °C). DMTA showed five regions of mechanical relaxations, glassy region (i.e. onset at 32 °C), glass transition (i.e. 32–85 or 87 °C), first reaction region with a plateau or peak (85–140 °C), second reaction region (87–174 °C), and softening or decomposition region (223 or 242 °C). Mechanical glass showed completely different relaxation as compared to the protons and thermal relaxations. This study showed that LF-NMR, DSC and DMTA could be used to explore the relaxations of a material at nano-, micro- and macro-levels.
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The date palm (Phoenix dactylifera L.) grows in the world's arid and semi-arid regions, particularly in the majority of Middle Eastern countries. It has played an important role in the survival of many ancient civilizations. It is regarded as a valuable nutrient, but it also plays an important role in the economies of date-producing countries. Date palm seeds are commonly described as waste after consuming their pulp by industries or individuals. However, date pits contain a valuable source of edible oil characterized by a high content of unsaturated fatty acids, sterols, tocopherols, and tocotrienols. The main purpose of this study was to analyze the chemical composition and quality parameters of Date Seed Oil (DSO) extracted from ten native date palm seed (Phoenix Dactilifera L.) varieties and compare them to the literature results. The choice of the seed variety was based on popularity and quality. The lipid extraction was carried out by a soxhlet apparatus using a standard solvent with a seed isolated from a matured date. The yield ranged from 2.94% to 8.06% depending on the variety. Gas chromatography coupled to mass spectroscopy (GC/MS) and high-performance liquid chromatography (HPLC) were used to determine the composition of the fatty acids, sterols, and tocols (tocopherols and tocotrienols) in the extracted oil. Our results indicate that DSO is rich in poly and unsaturated fatty acids (PUFA+MUFA = 48.89% to 60.77%) with oleic acid (C18:1) as the predominant fatty acid (from 52.60% to 42.13%). On other hand, eight sterols were identified and the mean content ranged from 346.97 to 816.60 mg/100g of oil. Also, a high amount has been recorded in tocols ranging from 1937.14 µg/g to 3844.06 µg/g. Indeed, the predominant tocols in DSO were alpha-tocotrienols and alpha-tocopherols. Likewise, the quality parameters indicate that DSO has excellent thermal and oxidative stability and is generally safe to consume. In fact, the peroxide value (PV) recorded a mean of 3.96 to 6.33 meq O2/kg. The iodine value of DSO samples goes from 48.84 to 60.59 g I2/100 g oil. The saponification value (SV) changed between 214.85 and 225.59 mg KOH/g of oil. However, the coefficients of extinction K232 and K270 were lower than the specified limitations. According to the findings, date seed has the potential to be used as a renewable resource while also adding value to pharmaceutical, cosmetic, food, and agricultural products.
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Date-pits are waste from date fruit processing industry and their valorisation as a lignocellulose biomaterial could generate economic gain. In this work, defatted date-pits (DDP) from whole date-pits (WDP), was soaked in alcohol-water followed by pressure-cooking. Two fractions of date-pits were developed, one as residue fraction (REP) and another one was supernatant fraction (SUP). REP showed higher level of hemicellulose and lower level of lignin (P < 0.05) compared to SUP. Similar water absorption, increased hygroscopicity, and decreased solubility were observed for REP compared to SUP. SEM showed that REP with bigger size particles as compared to the SUP fraction. SUP fraction showed two glass transitions, while REP showed single glass transition. Total specific heat changes of REP, and SUP fractions were 149 and 1032 J/kg oC, respectively, which indicated that SUP is mainly amorphous in composition. This was also supported by XRD data having Ruland-crystallinity of 52.0% (i.e. REP) and 9.6% (i.e. SUP), respectively. FTIR analysis indicated different molecular structure of SUP as compared to REP fraction as evidenced from the highest energy absorption for all selected functional groups. Overall, the results showed that this extraction method was effective to produce two distinctive fractions of date-pits with varied crystallinity.
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Holo-cellulose fibers were prepared by pre-treatments (i.e., water, ethanol, microwave and pressure cooker) followed by alkaline-acid digestion of defatted date-pits. Ethanol pre-treated fibers showed the highest content of hollo-cellulose (i.e., 76.1 g 100 g−1 sample−1) and the lowest content of lignin (0.8 g 100 g−1 sample−1). Low lignin content in lignocellulosic fibers is required when it is used for biofuel production and food products. Thermal analysis of defatted date-pits showed a structural relaxation at 267.7 K followed by an onset glass transition at 403 K and solids melting-decomposition endothermic peak at 456 K with enthalpy of 125 kJ kg−1. However, all treated defatted date-pits showed a cold crystallization as indicated by exothermic peak (i.e., 423–433 K). Ethanol pre-treated sample showed the highest specific heat change (i.e., 380 J kg−1 K−1) at their glass transition temperature (i.e., the highest fraction of amorphous component) and the highest solids melting-decomposition peak at 460 K and enthalpy of 239 kJ kg−1 (i.e., more energy needed to decompose molecular networks). Microwave pre-treated sample showed the highest crystalline lignocellulosic fibers. High crystalline lignocellulose is required when it is used as fillers in bio-composites and as ingredients to form crust in food products, while amorphous lignocellulose is required in breads to make it more soft crumb and bioplastic films for their flexibility. Fourier Transform Infrared (FTIR) spectra of all treated date-pits showed higher absorptions, and this indicated more interlinking ability with other components.
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In order to explore the effect and the corresponding physiological mechanismes of UV‐C irradiation on browning of fresh‐cut apples, both whole and sliced apple were irradiated with UV‐C (254 nm) for 5 min before or after processing. The browning index (BI) of slices was immediately measured, while other relevant physiological parameters were evaluated on quick‐frozen samples during refrigerated storage. Results indicated that both pre‐processing and post‐processing UV‐C treatment effectively delayed browning of apple slices, nevertheless, post‐processing UV‐C treatment was more efficient. Browning index (BI) significantly negatively correlated with non‐enzymatic capacities, and activities of Catalase (CAT), Ascorbate peroxidase (APX) and Glutathione reductase (GR). BI was positively correlated with the contents of H2O2 and Malondialdehyde (MDA). These findings suggested that UV‐C treatment delayed browning of apple slices during cold storage by improving the antioxidant system. Post‐processing UV‐C treatment was more efficient than pre‐processing.
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Camel milk and dates are well-known for their great nutritional and therapeutical benefits. Therefore, the study aimed to combine the benefits of fermented camel milk (FCM) and Sukkari date (SKD) in a naturally sweetened FCM. Six treatments of FCM using ABT-5 cultures with 0, 5, 7.5, 10, 12.5, and 15% SKD were carried out. Chemical, physicochemical, rheological properties were studied, while organoleptical attributes and probiotic strains viability were monitored during cold storage (4 °C) up to 15 days. Results showed that fortification with SKD increased total solids (TS), ash, dietary fiber, and carbohydrate content compared to plain FCM. Water holding capacity (WHC) values increased with low and medium SKD levels then decreased with high SKD levels. Minerals such as K, P, Mg, Zn, Fe, and Cu were significantly increased, while Na was significantly decreased. Increased SKD levels in FCM resulted in significant increases in total phenolic content (TPC), total flavonoids (TF), total flavonols (TFL), and antioxidant activity (AOA). Instrumental color analysis exhibited a significant change in L*, b*, BI, and ∆E due to adding SKD in a dose-dependent manner. The viability of Streptococcus thermophiles, Lactobacillus acidophilus, and Bifidobacterium bifidum was increased by adding low and medium SKD levels, resulting in a higher number than the accepted threshold for a probiotic effect. Adding 10 and 12.5% SKD recorded the best-balanced flavor score at the beginning and after up to 15 days of storage, respectively. Conclusively, the current study revealed that fortification with SKD at 7.5–12.5% improved the nutritional quality without adverse effects on the technological, organoleptic characteristics, and probiotics viability and provided acceptable, nutritious, and healthy benefits to FCM.
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Fruits and vegetables play an important part in the diets of global human population. During processing, the unused residues such as peels, stalks, rinds, stem, leaves etc. come out as waste. Due to the high moisture content of these perishable wastes, they undergo rapid decomposition that leads to foul odour and growth of pathogens. Almost, 30% of the loss occurs at the supply, retail, consumer, post-harvest and processing level. The perishable waste like peels, pomace, seeds etc. act as threat for the environment and degrade pollution-free model. The wastes are rich in protein, carbohydrates, minerals, vitamins and other phytochemicals and bioactive compounds such as pigments, dietary fibre, essential oils etc. Recent researches have shown that there is an increase in the utilization of these wastes for the extraction of value-added products such as bioactive compounds, bio-colorants, organic acids, Single cell protein (SCP), organic minerals, enzymes and others. The present review paper deals with the recent studies conducted on valorisation of the fruit & vegetable waste.
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The changes in consumer preferences and the increasingly competitive global market have demanded that food entrepreneurs engage in innovative value-added activities. The date is a delicatessen fruit known by its content of active compounds (e.g., dietary fiber and antioxidants) and its biological activity which has a vast potential in the design of new products such as bioactive ingredients, sugar substitutes, dietary supplements, functional foods, among others. In the current paper, innovative approaches to the value addition to date fruits and their processing by-products have been reviewed from recent high-quality scientific works. New processes such as ultrafiltration and hydrothermal treatments are shown as a useful alternative to obtain differentiated date-based ingredients (e.g., fiber concentrates, sap syrups, and date powders). Moreover, the use of date fruits and their byproducts as natural sources of value-added active compounds in the preparation of dairy, meat, and bakery and cereal products is also presented.
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Background: Conventional food additives were associated with potential harm. Palm seeds are an interesting source of high-added value bioactive compounds, regarding their potential use in food industries. Aim: Date seeds extract (DSE) of Algerian Phoenix dactyliefra L. was studied for its phytochemical, antioxidant, and antibacterial activity and to identify its potential uses in foods. Material and methods: A total soluble solid of DSE (°Brix) was determined by refractometry. The total phenolic contents (TPCs) were determined according to the Folin-Cioclateu method and the total flavonoid and flavonols were also estimated with colorimetric method. The DPPH method was used to determine the antioxidant activity of DSE. The IC50 values were also calculated and the antioxidant activity index (AAI) was determined. The agar well diffusion method was employed for the antibacterial activity of the aqueous DSE against various pathogens. Results: Moisture, ash, and fat contents (%) determined were 11.06, 1.33, and 7.06, respectively. The physicochemical analysis of the extract showed a pH value of 4.67, titratable acidity value of 0.64 citric acid/100 g, °Brix value = 3%, sugars values of 0.12, 0.47, and 0.35 g/L for reducing sugar, total sugar, and sucrose, respectively. The determination of phenolic compounds was carried out on three groups, namely total phenols = 229.67 mg GAEq/g, flavonoids = 201.12 mg QEq/g, and flavonols = 173.03 mg QEq/g, respectively. The DSE demonstrates to be effective as an antioxidant “in vitro” and showed a strong antibacterial activity with different inhibition levels, depending on the bacterial strains. Conclusion: The current investigations present knowledge about the possible role of palm industry by-products as a novel perspective for the development of new foods. We suggest that date seeds can be exploited in some food applications utilizing their high levels of bioactive molecules.
Chapter
In arid and semiarid areas, date palm is an essential fruit crop. Date is considered an ideal food with numerous nutritional and medicinal properties. Date is rich in sugar, protein, dietary fiber, minerals, and some vitamins. Its pulp, pit, pollen, and spathe extracts were used to prevent a wide range of chronic diseases. It contains a broad range of secondary metabolites, including anthocyanins, carotenoids, flavonoids, phenolic acid, procyanidins, and sterols. Date bioactive compounds are antioxidants, antimicrobial, anticancer, anti-inflammatory, and hepatoprotective. Biosynthesis of these compounds is influenced by several factors such as sunlight, irrigation, cultivar, tissue type, pollination, thinning, and maturity stage. This chapter discusses the medicinal and nutritional value of dates with an emphasis on secondary metabolites and various factors influencing their biosynthesis, pharmaceutical benefits, and potential use in functional food. Recent advances in metabolomics are also discussed.
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Background: Conventional food additives were associated with potential harm. Palm seeds are an interesting source of high-added value bioactive compounds, regarding their potential use in food industries. Aim: Date seeds extract (DSE) of Algerian Phoenix dactyliefra L. was studied for its phytochemical, antioxidant, and antibacterial activity and to identify its potential uses in foods. Material and methods: A total soluble solid of DSE (°Brix) was determined by refractometry. The total phenolic contents (TPCs) were determined according to the Folin-Cioclateu method and the total flavonoid and flavonols were also estimated with the colorimetric method. The DPPH method was used to determine the antioxidant activity of DSE. The IC50 values were also calculated and the antioxidant activity index (AAI) was determined. The agar well diffusion method was employed for the antibacterial activity of the aqueous DSE against various pathogens. Results: Moisture, ash, and fat contents (%) determined were 11.06, 1.33, and 7.06, respectively. The physicochemical analysis of the extract showed a pH value of 4.67, titratable acidity value of 0.64 citric acid/100 g, °Brix value = 3%, sugars values of 0.12, 0.47, and 0.35 g/L for reducing sugar, total sugar, and sucrose, respectively. The determination of phenolic compounds was carried out on three groups, namely total phenols = 229.67 mg GAEq/g, flavonoids = 201.12 mg QEq/g, and flavonols = 173.03 mg QEq/g, respectively. The DSE demonstrates to be effective as an antioxidant “in vitro” and showed a strong antibacterial activity with different inhibition levels, depending on the bacterial strains. Conclusion: The current investigations present knowledge about the possible role of palm industry by-products as a novel perspective for the development of new foods. We suggest that date seeds can be exploited in some food applications utilizing their high levels of bioactive molecules. Keywords: Phoenix dactylifera L., Degla-Baïda, seeds extract, bioactive molecules, biological activity, in vitro, novel perspective.
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Diabetes is a chronic metabolic disorder triggered by disturbances in carbohydrate, protein, and lipid metabolisms, where either reduced secretion or sensitivity of insulin is observed coupled with poor glucose control. Date palm fruits are one of the fruits reported to have good potential in diabetes treatment due to its presence of polyphenols exerting strong antioxidant activities. Other possible mechanisms of action include the polyphenolic compounds, which can inhibit enzymes like α-amylase and α-glucosidase. Flavonoids in dates can stimulate β-cells by increasing the number of islets and β-cells, recovering endocrine pancreatic tissues, reducing β-cell apoptosis, activating insulin receptors following the increase in insulin secretion, in addition to improving diabetes-induced complications. In this review, the in vitro, in vivo, and human study-based evidence of date palm as an anti-diabetic fruit is summarised.
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It is a major challenge to synthesis a cost – effective, efficient and reliable solid phase extractor with exceptional selectivity, capacity and reproducibility for removal of disinfection by-products (DBPs) in drinking water. Thus, the current study extends the analytical utility of microcrystalline cellulose (MCC) as a novel solid extractor against the underexplored bromate ions at trace levels as one of DBPs in drinking water. The proposed MCC platform was prepared via acid (HCl) hydrolysis of cellulose that was isolated from date pits (DPs). Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM) and thermal gravimetric analysis (TGA) were used for characterization of MCC sorbent prepared from DPs (D-MCC). Disappearance of the distinct FTIR peaks of hemicellulose and lignin were observed. The particle size of D-MCC ranged from 2.5 to 4 µm and rougher. SEM micrographs exhibited clear, smooth and stretched polymer structures on the surface and confirmed from the energy dispersive X-ray (EDX) spectra. SEM, TEM images and XRD data also revealed surface agglomeration in microstructures with a satisfactory crystallinity index of 80.81%. High stability of D – MCC was confirmed as compared to raw DPs A dual retention mechanism of bromate involving an ion association interaction of “weak base anion exchanger” and an added component of “surface adsorption” by the available surface area of the D-MCC is proposed. The D – MCC sorbent was successfully used for complete removal of BrO3- ions from environmental water samples. The sorbent presented extraordinary sorption capacity towards bromate ions in comparison to the frequently available extractor counterparts. D MCC can be packed in column for complete separation of trace levels of bromate ions from water from large volumes of water samples without decrease in its performance. Thus, this system can be utilized for ultra-trace determination.
Book
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A food property is a particular measure of the food’s behavior as a matter or its behavior with respect to energy, or its interaction with the human senses, or its efficacy in promoting human health and well-being. An understanding of food properties is essential for scientists and engineers who have to solve the problems in food preservation, processing, storage, marketing, consumption, and even after consumption. Current methods of food processing and preservation require accurate data on food properties; simple, accurate, and low-cost measurement techniques; prediction models based on fundamentals; and links between different properties. The first edition was well received, secured bestseller from the publisher, and received an award. Appreciation from scientists, academics, and industry professionals around the globe encouraged me to produce an updated version. This edition has been expanded with the addition of some new chapters and by updating the contents of the first edition. The seven chapters in the first edition have now been expanded to 24 chapters. In this edition, the definition of the terminology and measurement techniques are clearly presented. The theory behind the measurement techniques is described with the applications and limitations of the methods. Also, the sources of errors in measurement techniques are compiled. A compilation of the experimental data from the literature is presented in graphical or tabular form, which would be very useful for food engineers and scientists. Models can reduce the numbers of experiments, thereby reducing time and expenses of measurements. The empirical and theoretical prediction models are compiled for different foods with processing conditions. The applications of the properties are also described, mentioning where and how to use the data and models in food processing. Chapter 1 provides an overview of food properties including its definition, classification, and predictions. Chapters 2 through 4 present water activity and sorption isotherm including its terminology, measurement techniques, data for different foods, and its prediction models. Chapters 5 through 12 present thermodynamic and structural characteristics including freezing point, glass transition, gelatinization, crystallization, collapse, stickiness, ice content, and state diagram. Chapters 13 through 15 discuss the density, porosity, shrinkage, size, and shape of foods. Chapters 15 through 23 present the thermophysical properties including specific heat, enthalpy, thermal conductivity, thermal diffusivity, and heat transfer coefficient. Chapter 24 provides the acoustic properties of foods. This second edition will be an invaluable resource for practicing and research food technologists, engineers, and scientists, and a valuable text for upper-level undergraduate and graduate students in food, agriculture and biological science, and engineering. Writing such a book is a challenge, and any comments to assist in future compilations will be appreciated. Any errors that remain are entirely mine. I am confident that this edition will prove to be interesting, informative, and enlightening.
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The efficient methods for extracting phenolics from grape seeds have been of great interest to many investigators, due to the special health promoting and disease preventing effects of polyphenols. In this study, extractions were performed by using aqueous ethanol. The effects of single factors such as the concentration of ethanol, the ratio of liquid to solid (L/S), extraction temperature, extraction time, and number of extractions on the extraction efficiency were studied. Total phenol was measured by the Folin-Ciocalteu procedure to monitor the efficiency of the extraction under different experimental conditions. High pressure liquid chromatograph (HPLC) analysis was applied to identify and quantify some specific dimeric and trimeric phenolics in grape seeds. The concentration of ethanol and the extraction temperature showed the most significant impact on the yield of total phenolics. At room temperature, the extract with highest total phenolics was obtained with 50% ethanol. A higher extraction yield was obtained at higher temperature. When ethanol concentration and temperature were kept constant, 1.5 hr extraction time and liquid to solid ratio of 7.5:1 resulted in the best yield. In all cases, the phenolics extracted by first and second stage consisted of 90-97% of the total phenolics of the sum of the three stages. Therefore, two-stage extraction would be more cost efficient than three-stage extraction.
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Studies were conducted on properties of seed oils extracted from three date palm (Phoenix dactylifera) varieties Shahabi, Shekar and Kabkab, grown in Bushehr-Iran. The primary objective of this study was to extract seed-oil from the three native date varieties and then analyzed their fatty acids (FAs). Also the chemical parameters of PV, AV, p-anisidin, and Totox values of oils, as indicators of the quality and safety, and oxidative status of edible oils, as well as refractive index as an objective method for evaluation of rancidity were also evaluated. Date seeds are approximately 10% of the fruits weight. Seeds contained about 8.5% fat that can serve as a useful source of fatty acids to replace other vegetable oils. The following mean of values from the three varieties were obtained from samples: peroxide value (1.05), acid value (1.4), p-anisidine value (2.54), Totox (4.64) and refractive index (1.46). Also, flame ionization based detection gas chromatography (GC-FID) revealed that oleic acid was the primary fatty acid in all varieties. It was followed by lauric, myristic, palmitic, linoleic and stearic acids and trace amounts of the other fatty acids like undecylic, capric, nonanoic (pelargonic) and caprylic acids. Depending on the regional industry, these data suggest that the potential applications of date seed oil for humans and animals are feeding, cosmetic formulations such as in body creams, shaving soap and shampoos, and pharmaceutical products.
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Oil characteristics and fatty acid profile of seeds from three varieties of date palm (Phoenix dactylifera) cultivars in Bushehr-Iran Akbari, M.1, Razavizadeh, R.2, Mohebbi, G. H.3* and Barmak, A.3 1Department of Biology, Faculty of Sciences, Payam Noor University of Najafabad, Najafabad, Iran. 2Department of Biology, Faculty of Sciences, Payame Noor University. Tehran, Iran. 3Food and Drug Department, Bushehr University of Medical Sciences, Bushehr, Iran. Accepted 8 June, 2012 Studies were conducted on properties of seed oils extracted from three date palm (Phoenix dactylifera) varieties Shahabi, Shekar and Kabkab, grown in Bushehr-Iran. The primary objective of this study was to extract seed-oil from the three native date varieties and then analyzed their fatty acids (FAs). Also the chemical parameters of PV, AV, p-anisidin, and Totox values of oils, as indicators of the quality and safety, and oxidative status of edible oils, as well as refractive index as an objective method for evaluation of rancidity were also evaluated. Date seeds are approximately 10% of the fruits weight. Seeds contained about 8.5% fat that can serve as a useful source of fatty acids to replace other vegetable oils. The following mean of values from the three varieties were obtained from samples: peroxide value (1.05), acid value (1.4), p-anisidine value (2.54), Totox (4.64) and refractive index (1.46). Also, flame ionization based detection gas chromatography (GC-FID) revealed that oleic acid was the primary fatty acid in all varieties. It was followed by lauric, myristic, palmitic, linoleic and stearic acids and trace amounts of the other fatty acids like undecylic, capric, nonanoic (pelargonic) and caprylic acids. Depending on the regional industry, these data suggest that the potential applications of date seed oil for humans and animals are feeding, cosmetic formulations such as in body creams, shaving soap and shampoos, and pharmaceutical products. Key words: Seed oil (Phoenix dactylifera), fatty acid, gas chromatography.
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Pomegranate peels were dried by freeze drying at 20�C; air and vacuum drying at 40, 60, and 90�C; and sun drying. The moisture sorption isotherm was measured and modeled using the Brunauer– Emmett–Teller (BET) and Guggenheim–Anderson–De Boer (GAB) models. Two solvents (methanol and ethanol) and water were used to extract the phenolic compounds in pomegranate fruit peel. Fresh peels contained 5,990, 4,530, and 8,460 mg gallic acid equivalent (GAE)/100 g dry-peel solids for methanol, ethanol, and water extracts, respectively. The total phenolic content of ethanol extracts of freeze-dried peels was comparable to that of fresh peels (4,900 mg GAE/100 g dry-peel solids), whereas air- and vacuum-dried peels had significantly lower phenolic contents. Peels air dried at 60�C had the highest phenolic content (2,320–4,650 mg/100 g dry-peel solids) compared to samples air dried at 40 or 90�C (1,160– 4,480 mg/100 g dry-peel solids), whereas vacuum-dried peels did not show any trends with temperature. In general, methanol had a higher capacity for extracting phenolic compounds from dried pomegranate peels than water, and ethanol showed a low extraction capacity. In all cases, phenolic compounds were significantly lower in ethanol extracts compared to methanol or water extracts (p<0.05). In addition, phenolic compounds soluble in water and ethanol were more sensitive to all drying methods except freeze drying.
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The aims of this study are to determine and compare the antioxidant levels and activities (i.e. primary and secondary) between selected seeds of Malaysian tropical fruits - guava (Psidium guajava), mango (Mangifera indica L.) and papaya (Carica papaya L.). Seeds are among byproducts from the processing of fruitsbased products. Instead of discarding seeds as waste, seeds with high potential as antioxidants could be utilised for commercial purposes. Accordingly, the selected seeds of Malaysian tropical fruits were tested in this study for total phenolic content (TPC), free radical scavenging activity by 1, 1- diphenyl-2-picrylhydrazyl (DPPH) assay and metal ion chelating effect by ferrous ion chelating (FIC) assay. Extraction of antioxidant compounds from sample was done with 70% ethanol. TPCs of the seeds were expressed as gallic acid equivalents (GAE) in mg per 100 g fresh seed weight. TPC assay showed that mango seeds had the highest TPC (i.e. 32 ± 0.001 mg GAE) followed by guava seeds (i.e. 20 ± 0.001 mg GAE) and papaya seeds (8 ± 0.003 mg GAE). For DPPH assay, IC50 data showed that mango seed extract scavenged 50% DPPH radicals at the lowest concentration (0.11 ± 0.01 mg/mL) followed by the positive control BHA (0.13 ± 0.01 mg/mL), guava seed extract (0.26 ± 0.01 mg/mL) and papaya seed extract (0.34 ± 0.01 mg/mL). Interestingly, all seed extracts showed higher free radical scavenging activities than BHA after sample concentration of 0.60 mg/mL. However, FIC assay indicated that metal ion chelating effects of all seed extracts were weaker than BHA suggesting that the fruit seeds are not sources of good metal ion chelators. Overall, present results suggest that TPC of the seeds show strong negative correlation with their primary antioxidant activity (r= -0.985, R2= 0.970), and not all compounds in extracts which could scavenge DPPH radicals are good metal ion chelators. Mango seeds relatively showed the highest antioxidant level and primary antioxidant activity followed by guava seeds and papaya seeds.
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In this paper, we report on the water vapour desorption isotherms, at 25°C, of eleven date (Phoenix dactylifera) varieties, from different locations, collected at full ripeness: Mech-Degla, Deglet-Nour and Haloua (Algeria), Barhi, Fardd, Khadrawi, Khalass, Madjol, Rizaz (Saudi Arabia), Madjhoul (Israël) and Kentichi (Tunisia). The static gravimetric method was used, according to the COST 90 recommendations. The overall shape of the curves describing the water content as function of the water activity was typical of sugar-rich materials. Experimental data were analysed using the Guggenheim–Anderson–Brunauer (GAB) and Brunauer–Emmett–Teller (BET) models, through direct non-linear regression without any transformation of data. Both models correctly fit the whole set of data, for water activity ranking from 0.11 to 0.90, but the BET model was preferred since the values of its parameters were more realistic.
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Three native sun-dried date varieties from Oman (namely Mabseeli, Um-sellah, and Shahal), as well as their syrups and by-products (press cake and seed) were examined for their proximate composition, dietary fibre, total phenolics, and total antioxidant activity. Carbohydrate was the predominant component in all date varieties, syrups, and their by-products, followed by moisture, along with small amounts of protein, fat, and ash. Press cakes had the highest protein content, ranging in concentration from 3.62 g/100 g in Shahal to 5.23 g/100 g in Mabseeli, whereas fat was the highest in seeds and ranged from 5.02 g/100 g in Mabseeli to 5.90 g/100 g in Um-sellah. Seeds and press cakes were found to be good sources of dietary fibre, varied between 77.75 and 80.15 g/100 g fresh weight and between 25.39 and 33.81 g/100 g fresh weight, respectively. Among dates, syrups, and their by-products, seeds had the highest contents of total phenolics (3102–4430 mg of gallic acid equivalents/100 g fresh weight) and antioxidant activity (580–929 μmol of Trolox equivalents/g fresh weight). The results obtained suggest that date by-products (particularly seeds) serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient.
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State diagram is a map of the different states of a food as a function of water or solids content and temperature. The main advantage of drawing map is in identifying different states of a food, such as freezing point and glass transition, which helps in understanding the complex changes when food's water content and temperature are changed. it also assists in identifying food's stability during storage as well as selecting suitable conditions of temperature and moisture content for processing. This paper provides an overview and critical assessment on the basic concepts of the state diagram with their terminologies, selected measurement techniques, and their use. Glass transition alone could not be considered as generic rules for food stability criteria since numbers of instances, such as pore formation, diffusion, microbial stability, non-enzymatic browning, other factors or mechanisms play important role. However, it is definitely one of the factors affecting the stability, and a future challenge to combine the glass concept with other mechanisms or factors.
Article
A fully automated-continuous flow 40-sample/ hour procedure was adapted from the Singleton-Rossi method of analysis for total phenols in wine and other plant extracts. It was compared with small-volume manual and semiautomated versions of this analysis. The agreement in mg of gallic acid equivalent phenol (GAE) per liter among a series of dry wines was excellent by all three procedures. The coefficients of variation in replicate analyses averaged 5.8% for the manual, 6.2% for the semi-automated and 2.2% for the automated procedure. This greater reproducibility, plus savings of about 70% in labor and up to 40% in reagents, makes the automated procedure attractive for laboratories doing enough total phenol analyses to recoup the cost of the automating equipment. For continuous flow, color development with the Folin-Ciocalteu reagent in alkaline solution must be hastened by heating compared to slower room temperature development for the manual methods. Heating of sugar-containing samples in the alkaline solution gives interference presumably from endiol formation. Examples are given of corrections which were used successfully to estimate the true phenol content of sweet wines.
Article
Glass transition and other thermal characteristics of gelatin from different sources were studied by differential scanning calorimetry (DSC) and modulated DSC (MDSC). The initial glass transition temperatures of equilibrated gelatin samples at 11.3% relative humidity, determined from reversible heat flow thermogram of MDSC, were 23, 75 and 59°C, respectively, for tuna skin, bovine and porcine gelatin. When gelatin samples were equilibrated at higher relative humidity of 52.9%, glass transition temperature of fish skin and bovine gelatin decreased to -3 and 57°C, respectively. Further increase of equilibration relative humidity to 75.3% showed increased value in the case of tuna skin, whereas bovine and porcine did not show any significant change. DSC and MDSC results indicated that tuna gelatin showed lower glass transition compared to mammalian source gelatin equilibrated at the same constant relative humidity. In general glass transition measured by DSC was found lower than the values measured by MDSC. The results in this study showed that the degree of plasticization varied with the source of gelatin as well as their extraction methods. Copyright © 2007 Elsevier Ltd. All rights reserved.
Article
The levelling-off extent of crystallization and crystallization behaviour in corn starch were studied using an X-ray diffraction technique, taking into account the glass transition temperature range of amorphous corn starch. Amorphous corn starch samples at 60, 70, or 80% solids were stored at various temperatures giving various temperature differences between storage temperature and glass transition temperature (T − Tg). Corn starch was observed to crystallize into the same crystal form, independent of water content and storage temperature and, therefore, of theT − Tg. The Avrami equation was found to be useful in modelling of crystallization kinetics in starch. The data obtained can be used in prediction of stability during storage of starch-containing products with various water contents.
Article
Thermal characteristics of freeze-dried whole and skimmed camel milk, and its major components were measured by differential scanning calorimetry (DSC). The thermogram of whole milk showed three endothermic peaks (two for fat-melting and the other for non-fat solids-melting) and three shifts. Two shifts at low temperature were related to the glass transitions. The shift at higher temperature after melting of non-fat solids could be related to the structure ordering in milk after solids-melting. It was difficult to identify which components in the milk were providing these transitions and to trace the glass transitions of each component in the milk due to the complex interactions of the components’ phases. For this reason, different major components of the camel milk (fat, cream, casein, whey protein, and lactose) were separated and then measured its thermal characteristics. The thermogram of camel milk fat showed two endothermic peaks, one wide and the other sharp. The shape of the endotherm for fat was related to the melting of different fractions of fatty acid. The glass transitions of the isolated casein, whey and lactose were also determined separately.
Article
The qualitative and quantitative thermal analyses of crystalline and amorphous d(−)-fructose were studied utilising methods of standard differential scanning calorimetry (DSC), quasi-isothermal temperature-modulated differential scanning calorimetry (quasi-isothermal TMDSC), and thermogravimetric analysis (TGA). Advanced thermal analysis of fructose was performed based on heat capacity. The apparent total and apparent reversing heat capacities, as well as phase transition parameters were examined on heating and cooling. The melting temperature, Tm, of crystalline d(−)-fructose shows a heating rate dependency, which increases with raising the heating rate and leads to superheating. The equilibrium melting temperatures: Tm∘(onset) = 370 K and Tm∘(peak) = 372 K, and the equilibrium enthalpy of fusion ΔfusH° = 30.30 kJ · mol−1, of crystalline d(−)-fructose were estimated on heating for the results at zero heating rate. Anomalies in the heat capacity in the liquid state of d(−)-fructose, assigned as possible tautomerisation equilibrium, were analysed by DSC and quasi-isothermal TMDSC, both on heating and cooling. Thermal stability of crystals in the region of the melting temperature was examined by TGA and quasi-isothermal TMDSC. Melting, mutarotation, and degradation processes occur simultaneously and there are differences in values of the liquid heat capacity of d(−)-fructose with varied thermal history, measured by quasi-isothermal TMDSC. Annealing of amorphous d(−)-fructose between the glass transition temperature, Tg, and the melting temperature, Tm, also leads to crystallization of the sample and shows changes in the total apparent heat capacity. The experimental, apparent heat capacity of fully crystalline and fully or partially amorphous d(−)-fructose was analysed with reference to the solid (vibrational) and liquid heat capacities based on the ATHAS scheme.
Article
Different drying methods were investigated for efficient dehydration of fenugreek (Trigonella foenum-graecum) greens for optimal retention of color and its constituents. Accordingly, hot air (HA, 40°C, 58–63% RH), low humidity air (LHA, 40°C and 28–30% RH), and radiofrequency (RF, 40°C, 56–60% RH) were explored for efficient drying of fenugreek greens. The three single-layer drying models (Exponential, Page, and Modified Page) tested showed excellent fit (R = 0.92–0.99) for all three drying methods. The time required for drying with LHA and RF was less (∼27%), as compared to HA drying. LHA-dried fenugreek had superior green color and a more porous and uniform structure than those obtained from RF and HA drying. Aqueous methanolic (60:40) extract of fenugreek greens dehydrated by LHA exhibited the highest radical scavenging activity. Dehydrated fenugreek greens showed good consumer acceptance as well as shelf life.
Article
This study reports on the enthalpy relaxation and water sorption behaviors of ball-milled potato starch. Ball milling converts the semi-crystalline state of starch to an amorphous state, and a prolonged procedure promotes enthalpy relaxation. It has been reported that prolonged treatment leads to a decrease in starch water sorption. In the present study, ball milling of potato starch was carried out for up to 90h. The relaxed enthalpies and water sorption isotherms were measured by differential scanning calorimetry and equilibrium sorption of water vapor. Enthalpy was found to increase and water sorption to decrease with milling time. The time-dependant increase in enthalpy was found to follow the Kohlrausch–Williams–Watts (KWW) equation. The sorption isotherms were analyzed with a dual-mode sorption model and the concentration, CH′, of Langmuir type sorption sites was found to decrease with time. This decrease was also found to follow the KWW equation. Moreover, a linear relationship was found between the decrease in CH′ and the increase in enthalpy.
Article
The liquid crystal formation of sodium cellulose sulphate (NaCS)-water systems was investigated by differential scanning calorimetry (DSC), polarizing light microscopy (POL) and wideangle X-ray diffractometry (WAXS). The liquid crystalline state was observed at a water content (Wc) ranging from 0.4 to 1.5(g water)/(g NaCS) (g/g), and at a temperature ranging from 260 to 310 K depending on Wc. DSC and WAXS data indicated that each sodium ion is sandwiched by two cellulose molecules coexisting with 4–20 water molecules in the liquid crystalline state. When Wc exceeds the critical value, free water molecules enhance the molecular movement of NaCS and molecular chains are arranged in a random form.
Article
The kinetics of gelatinization of potato starch (starch:water weight ratio, 1:1) were investigated using differential scanning calorimetry (DSC). In the first stage, two isoconversional (Ozawa-Flynn-Wall and Friedman) methods were applied. It was found that the value of the activation energy (E) changes with 0 < α < 1 from approximately 75 to 138 kJ/mol. Further analysis using non-linear regression methods revealed that the best fit was found for a competitive double-step reaction, whereby the first step was attributed to the “n-order reaction” scheme and the second step was described by three-dimensional diffusion of Jander's type. The first step was attributed to the gradual formation of interchain and intrachain hydrogen bonding which restricts chain mobility and led at elevated temperature to the second diffusion-based ratelimiting step. For this model function, a spherical shape for the reacting bodies is the best stereogeometrical approximation; this corresponds well with observations concerning starch alignment at different microstructural levels and its behaviour during gelatinization.
Article
The mechanical properties of aligned tapes and monofilaments of a random copolyester, containing 17.5% of biphenol (COTBP), were investigated using macroscopic and X-ray techniques on both unannealed and annealed samples. The results were compared with similar studies of a random copolyester of hydroxybenzoic acid and hydroxynaphthoic acid (BNA/HNA). Whereas in the HBA/HNA copolymer on the scale observed by X-ray diffraction, the chain is sinuous, with an increasing sinuosity upon annealing, the COTBP is straight and no effect is seen upon annealing. The macroscopic moduli of both polymers increases with annealing. This is attributed to an increase in the shear modulus caused by an increase in the packing density of the chains. © 1997 Elsevier Science Ltd.
Article
Cereal Chem. 65(6):443-446 Starch gelatinization was defined as the melting of starch crystallites, as granule fatty acids. Formation of these complexes partly explains determined by X-ray diffraction, in which the complete destruction of differences reported for heat of gelatinization values of amylose/lipid- crystallite integrity was observed as a function of moisture content and bearing starches because of competing melting and crystallizing effects. temperature. Melting occurred over a range of temperatures, and melting X-ray analysis failed to confirm differential scanning calorimetry evidence temperatures increased as starch moisture content decreased. For moisture of starch melting in samples at moisture contents lower than about 30% and contents of 30% and higher, endothermic transitions determined by heated to temperatures as high as 1750 C. A glass transition was postulated calorimetry were confirmed as reflecting loss of starch crystalline structure. to account for reports of apparent differential scanning calorimetry The wide range of melting temperatures was attributed to different degrees endotherms in such low-moisture starches. In the absence of an of crystallite perfection within the granule and to their respective intermediate amorphous melt, the B to A or C structure changes observed interaction with granule moisture content. For normal maize starch, in heat and moisture treated potato starches were interpreted as solid-state heating caused formation of crystalline V-type complexes of amylose with transitions. There is widespread interest in the process of starch gelatinization, in which the organized granule structure is disrupted, often the first step in starch applications (Zobel 1984). Although the phenomena of gelatinization are readily apparent, the various ways (optical, Theological, calorimetric) used to determine gelatinization have made it difficult to formulate a precise and common definition. In addition, gelatinization thermograms obtained by differential scanning calorimetry (DSC) have been interpreted differently (Donovan 1979, Eberstein et al 1980, Biliaderis et al 1980, Evans and Haisman 1982, Zobel 1984, Maurice et al 1985, Hoseney et al 1986). On the other hand, the observed first-order endotherms are generally interpreted to mean that gelatinization is a melting process. Identification of the (DSC) transitions by X-ray diffraction, however, is critical to a comprehensive understanding of starch thermograms. Kugimiya et al (1980), for example, used complementary X-ray data to show that their 110120°C endotherms were caused by the melting of crystalline V-type amylose-lipid complexes. Application of the term "melting" to starch gelatinization is based on X-ray and synthetic polymer technologies. Thus, from diffraction studies, crystalline specimens yield reflections from crystal planes. After melting, these reflections disappear and a broad halo appears, indicating a change from a crystalline to an amorphous (molten) state. Accordingly, the material is no longer a rigid solid but rather exhibits the properties of a liquid. In this state, polymeric materials may show low fluidity, and as such, fit into the classic definition of a melt. High molecular weight materials, however, impart high viscosity or rubberlike qualities to the molten-liquid state (Mandelkern 1964). In this report, X-ray diffraction was used to characterize transitions that produce endothermic DSC peaks when starches are heated after having been equilibrated to different moisture contents (Donovan 1979, Eberstein et al 1980, Eliasson 1980). Potato starch was used to illustrate typical starch-water interactions because of available DSC data and its purity with respect to granule lipids. Some of the data reported here are unique in that the X-ray diffraction patterns were recorded as the starch was maintained at its gelatinization (melt) temperature. This differs from past studies in which samples were gelatinized and then cooled before X-ray analysis. As a consequence of the cooling process, moist gels could display crystalline artifacts. In this study, samples that were first heated, cooled, and then subjected to X-ray analysis were in sealed tubes and were limited to 20% or less moisture to avoid recrystallization. Maize (corn), potato, and waxy maize starches were investigated to cover granules with a range of crystal structure, amylose/amylopectin ratio, and lipid content. Maize has an A- type structure, 27% amylose, and polar lipids that can complex with the amylose fraction to form V crystals. These V structures are formed from collapsed amylose helices in which chemical adjuncts are trapped inside. Complex formation has been established by X-ray studies and investigated by DSC; the effect on thermograms of starch, however, has been subjected to speculation (Hellman et al 1954, Kugimiya et al 1980, Stute and Konieczny-Janda 1983, Zobel 1984, Biliaderis et al 1985). Waxy maize also has an A structure and lipids similar to those in maize, but amylose is absent for complex formation. Potato starch has a B structure and 22% amylose but lacks a lipid fraction for complex formation. The C form is native to certain root and tuber starches. From the standpoint of this study, C is formed when potato starch is heat and moisture treated (Sair 1967). X-ray patterns of starch structures are diagrammed in Figure 1 (Zobel 1964, 1988a).
Article
The food polymer science (FPS) approach has been effectively used to investigate the physical stability of amorphous food materials. The glass transition, a key FPS parameter, has traditionally been determined using thermal techniques that scan temperature while holding the plasticizer (moisture) content constant. Moisture sorption isotherms provide information about the physical properties of food as the plasticizer level is adjusted and temperature is held constant. New automatic isotherm generators can be used to produce high resolution, dynamic isotherms much faster than traditional static methods. Dynamic isotherms for a small selection of amorphous materials have been investigated and shown to experience distinct inflection points in the water activity region where the glass transition temperature is close to the experimental temperature. Several studies on amorphous spray dried milk powder and amorphous polydextrose indicate very good agreement between glass transitions determined using thermal techniques and dynamic isotherm methods. This agreement suggests that dynamic isotherms are a viable alternative to traditional thermal methods for investigating glass transitions of amorphous foods.
Article
The empirical dielectric decay function γ(t)= exp –(t/τ0)β may be transformed analytically to give the frequency dependent complex dielectric constant if β is chosen to be 0.50. The resulting dielectric constant and dielectric loss curves are non-symmetrical about the logarithm of the frequency of maximum loss, and are intermediate between the Cole-Cole and Davidson-Cole empirical relations. Using a short extrapolation procedure, good agreement is obtained between the empirical representation and the experimental curves for the α relaxation in polyethyl acrylate. It is suggested that the present representation would have a general application to the α relaxations in other polymers. The Hamon approximation, with a small applied correction, is valid for the present function with β= 0.50 in the range log(ωτ0) > –0.5, but cannot be used at lower frequencies.
Article
Corn, wheat, and potato starches were annealed at 20 and 50°C, and the gelatinization phenomena were observed with differential scanning calorimetry (DSC). Amylose content and amylopectin chain length distribution were not changed by the annealing treatment. The DSC endotherm associated with gelatinization of amylopectin shifted to a higher temperature, and became narrower and deeper after annealing at 50°C; however the conclusion temperature and enthalpy of gelatinization were similar. The ordered structures of amylopectin, formed by a varying number of links by hydrogen bonds, were cleft at the gelatinization temperature. Model calculation suggested that more links (N) would be generated in each ordered amylopectin region, and the number of ordered regions (M) would be reduced by annealing at a higher temperature. However, the total number of links in amylopectin, represented by the product (N×M), was similar for cereal starches and only slightly increased for potato starch.
Article
Crystallization of amorphous polymers is affected by their physical state and molecular mobility. In the present study, crystallization behaviour of amorphous corn starch was related to its physical state and glass transition. Amorphous corn starch was produced by freeze-drying a gelatinized 5% (w/w) starch suspension. State diagram and sorption properties were determined to characterize the material. Amorphous corn starch samples containing 60, 70, and 80% solids were stored at various temperatures that gave various temperature differences between storage temperature and glass transition temperature (T − Tg). The melting behaviour of crystallites formed was determined using differential scanning calorimetry. Crystallization in starch samples occurred with a rate that was dependent on storage temperature, water content, and T − Tg. In addition, the melting temperature and the extent of crystallization were affected by storage temperature, water content, and T − Tg. The data reported allow the prediction of crystallization in starch, as a physical state-dependent phenomenon and, therefore, stability of starch-containing products during storage.
Article
Cereal Chem. 79(3):349-353 Thermomechanical analysis (TMA) and differential scanning calori- metry (DSC) were used to investigate the thermal transitions of long-grain rice kernels. Three distinct thermomechanical transitions were identified as rice kernels were heated from 0 to 200°C. The identified transitions were a low temperature transition with onset at ≈45°C, an intermediate tem- perature transition at ≈80°C, and a high temperature transition at ≈180°C. Low temperature transition with onset from ≈60°C at 5% moisture content (MC) to 30°C at 20% MC was identified as the glass transition of the rice kernels. Intermediate temperature transition from 60 to 100°C, depending on MC, may be caused by rapid evaporation of moisture in the rice kernels. High temperature transition was associated with melting of the crystalline structure of rice starch. The temperatures of all three transitions decreased as MC increased, confirming that moisture acted as a plasticizer in rice kernels.
Article
Enthalpy relaxation and fragility of selected carbohydrates were correlated with their molecular weight. Anhydrous glucose and its oligomers (i.e. maltose and maltotriose) were selected to represent amorphous carbohydrates with increasing molecular weight. The enthalpy relaxation behavior of glucose, maltose and maltotriose was determined at 5 ◦C below their respective glass transition temperatures using differential scanning calorimetry (DSC). The non-exponential behavior of enthalpy relaxation was fitted with the Kohlrausch–Williams–Watts (KWW) equation. The mean relaxation time constants (�) for glucose, maltose and maltotriose at (Tg −5) were 16.9, 38.4 and 128.6 h, respectively. The fragility indices (m) of glucose, maltose and maltotriose, determined using the DSC glass transition width approach, were 105, 88.1 and 97.6, respectively. The glass transition temperature andmeanenthalpy relaxation time increased with increasing molecular weight for the selected carbohydrates studied herein. The greater glass transition temperature and enthalpy relaxation time of maltotriose are attributed to the decreased specific volume, segmental mobility and increased entanglements resulting from its higher molecular weight. Maltotriose may be preferred as an encapsulant or food ingredient to reduce structural relaxation in food formulations during storage.
Article
Unlike inorganic and organic molecules, in semicrystalline polymers melting gets complicated because of the requirement of conformational transformation of the chain segments, where part of the same chain resides in the crystal and also in the amorphous phase. The chain segment residing in the amorphous part can be constrained, either due to adjacent or nonadjacent re-entry leading to a different nature of chain folding, and arising differences are observed in local chain mobility due to differences in topological constraints. Thus, different conformational possibilities in the amorphous region of the semicrystalline polymer has implications on melting temperature and the processes involved in the order to the disorder phase transformation. With a series of experiments on ultra high molecular weight polyethylene, where the topological constraints are tailored by adopting a different synthesis route, it is shown that melting behavior cannot be fully explained by Gibbs–Thomson equation only. Nonlinearity in melting temperature on heating rate invokes kinetics in the melting process, where depending on the heating rate melting can occur either via successive detachment of chains and their diffusion in the melt or by cluster melting. The role of superheating on melting process is also addressed.