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Determination of vitamin C in tropical fruits: A comparative evaluation of methods

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Abstract

Two analytical methods for extracting vitamin C (l-ascorbic and l-dehydroascorbic acids) in tropical fruits [banana, papaya, mango (at three maturity stages) and pineapple] were evaluated. These methods used ion-pair liquid chromatography (LC) for detecting ascorbic acid, but differed in the preparation of the sample (extraction with 3% metaphosphoric acid −8% acetic acid or 0.1% oxalic acid). Results were validated by comparison with ascorbic acid content obtained by the AOAC’s official titrimetric method, by performing a recovery study and by the determination of within-day repeatability and inter-day reproducibility. There were differences in the efficiency of vitamin C extraction related to the fruit matrix and especially to the maturity stage in climacteric fruits. The LC-extraction method using 3% metaphosphoric acid −8% acetic acid shows high mean recoveries (99 ± 6%) for all matrices assayed, while the LC-extraction method with 0.1% oxalic acid proved to be unacceptable in some cases (unripe, half ripe and ripe banana and ripe mango) obtaining mean recoveries of 39.9 ± 9.1% and 72 ± 13% for banana and mango, respectively. The detection limit achieved with the metaphosphoric acid-acetic acid LC-extraction method for ascorbic acid (0.1 mg/l) allowed the determination of this vitamin in fruits analysed with good precision (5.94–12.8%), making its use as a routine analysis method perfectly valid. Recommendations about storage temperature, methods of thawing l-ascorbic acid extracts and the addition of antioxidants to extracts were made.

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... Carotenoids are also responsible for fruit colors ranging from yellow to red hues; many of these nonpolar pigments show vitamin A activity and all of them have antioxidant activity in polar and nonpolar systems (Astrid Garzon et al., 2012;Burns, Fraser, & Bramley, 2003;Ferreira-Zielinski et al., 2014;Mariutti et al., 2013;Muller, 1997). Vitamin C, comprising ascorbic and dehydroascorbic acid, is also a powerful polar antioxidant and fruits are the main source of vitamin C in common diets (Hernandez, Lobo, & Gonzalez, 2006;Proteggente et al., 2002;Ramful et al., 2011). Vitamin C can provide antioxidant activity in vitro, as well as actively restoring vitamin E in vivo (Proteggente et al., 2002;Thaipong, Boonprakob, Crosby, Cisneros-Zevallos, & Hawkins Byrne, 2006). ...
... There is no simple universal method to measure the antioxidant activities of bioactive compounds, since there are many free radicals and many classes of antioxidants with a range of polarities (Huang, Ou, Hampsch-Woodill, Flanagan, & Prior, 2002;Kajdzanoska et al., 2011;Proteggente et al., 2002;Xu & Chang, 2007). Such complexity demands extraction of antioxidants using different solvents, resulting in a range of responses in different assays in vitro, which often hinders comparison of results (Hernandez et al., 2006;Kajdzanoska et al., 2011;Prior, Wu, & Schaich, 2005;Thaipong et al., 2006;Xu & Chang, 2007). To address this, standardized microplate methods for measuring the antioxidant activities of polar and nonpolar compounds, such as the determination of Trolox equivalent antioxidant activity (TEAC), oxygen radical absorbance capacity (ORAC), and β-carotene bleaching assays were revisited and standardized (Huang et al., 2002a, b;Prieto, Rodriguez-Amado, Vazquez, & Murado, 2012;Prior et al., 2005). ...
... Extraction of vitamin C was performed according to Hernandez et al. (2006), with slight modifications. Freeze-dried sample (1 g) was homogenized with 10 mL cold (8 • C) aqueous solution (H 2 O:OA, 99.5:0.5, v/w) in a 15-mL argon-filled centrifuge tube for 60 sec and subsequently stirred for 15 min in dim light. ...
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This study measured the total levels of phenolic, anthocyanin, carotenoid, and tocopherol compounds, and vitamin C in ten fruits from the Brazilian Cerrado: araçá-boi, bacaba, bacupari, biribá, cajuí, curriola, marmelada-espinho, mirindiba, murici, and puçá-preto. Five extracts were prepared from each fruit using solvents with different polarities. The Trolox equivalent antioxidant activity, oxygen radical absorbance capacity, and inhibition of β-carotene bleaching were determined for each extract. Scott-Knott test and principal component analysis showed that the analyzed fruits were rich sources of different classes of bioactive compounds, with levels comparable to those in commonly consumed fruits such as guavas, and various berries and citrus fruits. To our knowledge, this is the first comprehensive study of the bioactive compounds and antioxidant activities of biribá, cajuí, marmelada-espinho, and mirindiba. Moreover, mirindiba was found to be a rich source of vitamin C and phenolics, with an average level of carotenoids and tocopherols.
... The highest level of starch un staining was exhibited by 1-MCP untreated (9.33) fruits that were kept inside the standalone corrugated cardboard boxes (P3). This is an indication of high rate of respiration and the subsequent onset of the climacteric peak and ripening stage that brought about a more rapid deterioration in shelf life of banana fruits (Hernandez et al., (2006). Table 7 shows Total Soluble Solids (TSS) content was gradually but consistently increased throughout the storage period irrespective of treatments. ...
... 0 Brix) was recorded on the 22 nd day of the storage period from 1-MCP untreated fruits that kept inside the standalone corrugated cardboard boxes without inner PEP (P3). This could be an indication of the rapid deterioration in shelf life of the fruits as a result of the onset and progress of the climacteric peak caused by the higher rate of respiration (Hernandez et al., 2006). The lowest TSS (8.00 0 Brix) at the end of the 36 days long storage period was on the contrary recorded from fruits treated with the highest concentration of 1-MCP (17.5µl/L) and kept inside the non-perforated inner PEP (P1). ...
... The results are in agreement with the findings reported by Tourky et al. (2014) in that as the storage period or ripening process advances, total acidity could increase resulting in a decrease in fruit pH. A similar result was reported by Hernandez et al. (2006) that as the storage period progresses, the evolution of ethylene and respiration rate may increase with a subsequent decrease in pulp p H . ...
Article
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The effect of four concentration levels of 1-methylcyclopropene-1-MCP (17.5µl/L), 10.5µl/L, 3.5 µl/L and 0 µl/L or untreated control) in combination with three levels of export standard banana packaging materials with modified atmosphere (MA) storage effect was investigated under ambient conditions (22+1 °C and 80 + 5% RH) on shelf life and physicochemical quality attributes of Cavendish banana (Musa AAA Group, Cavendish Subgroup, cultivar 'Poyo', syn: 'Robusta'). 1-MCP treatment with increased levels of concentration and increased levels of modified atmosphere packaging (MAP) generally extended shelf life and maintained better quality of fresh banana fruits when applied separately and in combination. The longest shelf life (36 days) with the lowest changes in physicochemical properties was obtained when fruits were kept in corrugated cardboard boxes with inner sealed or non-perforated polyethylene bags (PEP) after treatment with the highest concentration of 1-MCP 17.5µl/L. This could be credited to the higher inhibitory effect of 1-MCP on both the synthesis and action of ethylene when applied at the stated level of concentration and the stronger modified atmosphere (MA) condition created by the inner non-perforated PEP kept within the corrugated cardboard boxes. Thus, this technique could be considered as a less sophisticated and less costly postharvest handling alternative (storage and transportation) under ambient conditions to the temperature controlled (14 o C) reefer container-based system currently employed in Ethiopia and elsewhere for fresh banana exports.
... Fruits and vegetables are important sources of fruits and vegetables (Odriozola-Serrano, Hernández-Jover & Martín-Belloso, 2007) [120] . Hernández, Lobo, & González (2006) [60] reported that it is an important source of nutrition for human. Vitamin C was an additive for processed foods according to Rios & Penteado (2003) [140] . ...
... Fruits and vegetables are important sources of fruits and vegetables (Odriozola-Serrano, Hernández-Jover & Martín-Belloso, 2007) [120] . Hernández, Lobo, & González (2006) [60] reported that it is an important source of nutrition for human. Vitamin C was an additive for processed foods according to Rios & Penteado (2003) [140] . ...
... The volume of the reaction mixture was recorded at the endpoint. 45 The reaction mixture was discarded into a waste beaker, then the graduated cylinder was rinsed with about 1 mL of citrus juice. 44 The titration was then repeated, and if the total volume of the reaction mixture for two titrations was in agreement to within AE0.2 mL, then a different juice was tested. ...
... 44 The titration was then repeated, and if the total volume of the reaction mixture for two titrations was in agreement to within AE0.2 mL, then a different juice was tested. 45 If the total volume of the reaction mixture for the two titration was not within AE0.2 mL, then a third titration was carried out. 44,45 2.8.5. ...
Article
Preparation of a thin film of polyvinyl alcohol (PVA)/myrrh natural resin using a low gamma irradiation dose (1 kGy) was investigated towards increasing the post-harvest time of lemon fruit. Different analytical techniques, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and mapping techniques were used to characterize the prepared thin film. This investigation was carried out to evaluate the effect of different concentrations of myrrh as an edible coating in prolonging shelf life and preserving the quality of lemon fruits (Citrus aurantifolia). Lemons were immersed directly in PVA solution containing 1%, 2%, and 3% concentrations of myrrh and then stored at ambient (25 ± 1 °C) and low (4 ± 1 °C) temperatures. The disease severity, acidity, total soluble solids (TSS), and ascorbic acid contents were tested after the coating with the PVA/myrrh thin film at different temperatures (4 °C and 25 °C) for different storage times (7 and 14 days). The application of different concentrations of the synthesized PVA/myrrh thin film (1%, 2%, and 3%) significantly reduced green mold disease symptoms and disease severity in the lemon fruits. The acidity value (pH value) was the lowest for the 2% myrrh treatment after 7 °C days at 25 °C, followed by the 1% myrrh treatment under the same conditions. The highest TSS was observed after the treatment for 7 days at 25 °C, with a value of 8.1 g dL-1. A high ascorbic acid concentration (33.5 mg dL-1) was noted after coating the lemons with the 1% PVA/myrrh thin film for 7 days at 25 °C. The results show that the application of a PVA/myrrh thin film extends the shelf-life and maintains the quality of lemon fruits by decreasing the levels of evaporation from the fruits and loss of weight due to the delay of the complete ripening stage of the lemon fruits.
... Results in the same Table 1 illustrated that TSS of mango pulp and blanched sweet potato were 15.7 and 15.3%, respectively. Meanwhile, it was 9.8,5.3,5.07 and 9.57% for papaya pulp, pumpkin, blanched pumpkin and sweet potato, respectively, as reported by Yurena et al. (2006), El-Fiky et al. (2007) and Mayor et al. (2008). Data in Table 1 appeared that Mango had the lowest pH value 4.26 while, it was 4.83,6.02,7.62,5.80 and 5.83 for papaya pulp, pumpkin, blanched pumpkin, sweet potato and blanched sweet potato, respectively. ...
... 0.21 and 0.08% for papaya pulp, pumpkin, blanched pumpkin, sweet potato and blanched sweet potato respectively, as reported by Cano et al. (1996) and Gliemmo et al. (2009) (2000), Ali (2006) and El-Fiky et al. (2007). Ascorbic acid content of mango and papaya pulp was 161.92 and 400.28 mg /100g, respectively Meky (1999).While, it was decreased from 200.85 to 114.80 and from 68.71 to 46.14 mg/100g for pumpkin, blanched pumpkin, sweet potato and blanched sweet potato, respectively (Hiroshi et al., 2000, Yurena et al., 2006and Zaki et al., 2006. The carotenoids content (as β-carotene) of mango and papaya pulp was 43.02 and 34.35 mg /100g, respectively. ...
Conference Paper
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Continuous biological H2 production from pre-treated rice straw waste using a mesophilic up- flow anaerobic staged reactor (UASR) at different organic loading rates (OLRs) was investigated. OLR was varied from 7.1 to 26 g COD/l. d. A steady improvement in H2 yield (HY) was recorded from 7.1 g COD/l. d. (95.5 mmol/d.) up to 21.4 g COD/l. d. (117 mmol/d.), and showed a decreasing trend of 107.1 mmol/d. at OLR of 26 g COD/l. d. Likely, H2 production (HP) revealed a gradual improvement in concurrence with OLR from 7.1 to 21 g COD/l.d and decreased thereafter. Carbohydrate degradation and COD conversion efficiency vary also with an increase in OLR. When the OLR was from 7.1 to 21.4 g COD/l.d., the COD and carbohydrate removal was over 70 and 80 %. At higher OLR of 26 g COD/l.d., the COD conversion and carbohydrate degradation efficiency was declined.
... The total soluble solids were determined in the fruit juice using a digital refractometer (Lacey et al., 2009). The titratable acidity was recorded by titration with 0.1 M NaOH of pH 8.3 (Hernández et al., 2006). Ascorbic acid was measured by following the method of Roe et al. (1948). ...
Article
Penicillium digitatum and Penicillium italicum are potentially important post-harvest pathogens of citrus fruit causing huge economic loss. In this study salicylic acid (SA) and Cinnamomum verum were tested to control the infection of P. digitatum (green mold) and P. italicum (blue mold) as an alternative to chemical control. In an in vitro assay methanolic extracts of five plants were tested for antifungal activity where C. verum exhibited the highest colony growth inhibition 74.6 and 76.4 % of green and blue mold respectively. Moreover, during In Planta assay the combination of C. verum and SA produced the lowest disease incidence (20 and 33.3%) and severity (13.1 and 6.1%) of green and blue mold respectively compared to stand-alone treatments without affecting the fruit quality considerably. Furthermore, an upsurge in the the activity of polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia lyase (PAL) encoding genes of citrus fruit was recorded during transcriptional profiling. The highest gene expression was recorded in fruit treated with C. verum and SA in combination compared to healthy control. Similar results were observed during quantification of corresponding gene products. This unveils the fact that the enhanced expression of defense-linked genes might be associated with the disease suppression. Conclusively, our findings indicate that C. verum and SA in combination can suppress green and blue mold of Citrus by modulating the expression of defense-linked genes. The combined use of plant extracts and resistance inducers is a safer alternate to chemicals to suppress green and blue mold during storage.
... Vitamin C (ascorbic acid) is one of the water-soluble vitamins (Julijana et al., 2018), and its composition in mammals depends on glucose content in the liver (Comb, 2008). It is available in two forms of biological importance, one of which is reduced and called L-Ascorbic acid and is the most biologically active form, and the other is the oxidizing form L-dehydroascorbic acid, which has a biological value as well (Hernandez et al, 2006). In ruminants, as a result of the intense oxidation process in the rumen, a large part of vitamin C is converted to diketogulanic acid which has no vital functions, making them more susceptible to diseases associated with vitamin C de ciency such as scurvy and mastitis (MacLeod et al., 2003). ...
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A study was conducted at Deir Al-Hajar Research Station for Shami Camels, Administration of Livestock Research, General Commission for Scientific Agricultural Research (GCSAR) in the years 2019 and 2020 to describe the associations between vitamin C concentrations in milk, and either stage of lactation, parity or the presence of mastitis. For this purpose, thirty lactating Shami camels from different parities were used. Milk samples were collected monthly over one entire lactation season lasting 11 months. The concentration of vitamin C was 35.01±9.81 mg/l milk and ranged between 33.01 and 36.80 mg/L milk during considered parities without significant differences in its concentration .However, vitamin C concentration was affected by lactation month P<0.0.5, and the values ranged between 18.99 and 53.03 mg/l milk during the course of lactation. An evident decline in vitamin C concentration in camel milk appeared with positive interactions for California test by 20-50%. The average concentration of vitamin C in milk produced from healthy and infected udders was 35.01±9.81 mg/l and 22.99±1.30 mg/l, respectively.
... Molecules 2021, 26 dimercaptopropanol [5,6], mercaptoethanol [7,8], cysteine [9], homocysteine [10,11], and recently the most frequently used dithiothreitol [12][13][14][15][16]. These reagents are stable and active only in neutral or slightly acidic pH. ...
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The analysis of total vitamin C content in food is most frequently performed by reducing dehydroascorbic acid to ascorbic acid, which is then assayed with the technique of high-performance liquid chromatography combined with spectrophotometric detection. Tris(2-carboxyethyl)phosphine is currently the only agent in use that efficiently reduces dehydroascorbic acid at pH < 2. Therefore, there is a continued need to search for new reducing agents that will display a high reactivity and stability in acidic solutions. The objective of the study was to verify the applicability of unithiol and tris(hydroxypropyl)phosphine for a reducing dehydroascorbic acid in an extraction medium with pH < 2. The conducted validation of the newly developed method of determining the total content of vitamin C using tris(hydroxypropyl)phosphine indicates its applicability for food analysis. The method allows obtaining equivalent results compared to the method based on the use of tris(2-carboxyethyl)phosphine. The low efficiency of dehydroascorbic acid reduction with the use of unithiol does not allow its application as a new reducing agent in vitamin C analysis.
... Ascorbic acid (AA) and dehydroascorbic acid (DHA) contents were determined as described by Hernández et al. (2006), Lykkesfeldt (2000) and Wechtersbach and Cigié (2007) to quantify the total vitamin C content in the orange juice. A fresh juice sample was weighed (5-10 g) and mixed with 15-20 ml 0.04% metaphosphoric acid. ...
Article
Ultrasound is a useful alternative to thermal processing that can be applied to many food products and juices to aid with enzymes and microorganism inactivation and to improve the efficiency of unit operations generally applied in the food industry. The aim of this study was to evaluate the effect of a high-intensity sonication treatment (frequency 20 kHz; intensity 39.4 W/cm2) applied for treatment times from 0 to 105 min on the content of polyphenols, vitamin C, organic acids, and carotenoids, and on the hydrophilic and lipophilic antioxidant capacity and color of orange juice. Treatments were performed in triplicate and data was statistically analyzed. Sonication time did not have a significant effect (P > 0.05) on total polyphenols, total vitamin C, organic acid, and carotenoid contents, lipophilic antioxidant capacity, or juice color. The hydrophilic antioxidant activity and the lutein content increased significantly (P < 0.05) with increased sonication time. These results may be useful as a baseline for the development of sonication treatments that could be used in combination with other traditional and emerging processing approaches to protect the most important bioactive compounds and quality properties of orange juice.
... An Abbe refractometer was used to calculate percentages of total soluble solids (T.S.S %.) (Sparks et al. 2020). Ascorbic acid was measured as mg/100 g fresh weight using the dye 2, 6-dichlorophenol indophenol technique (Hernández et al. 2006). Dubois calculated total sugars as g/100g dry weight (Dubois et al. 1956). ...
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Bacillus amyloliquifaciens (BA), Bacillus megaterium (BM), and Cyanobacteria have all been identified as effective biofertilizers that positively impact various crops. Two successful field experiments were conducted at Al-Azhar University's Experimental Farm during the summer season 2020 and 2021 growing seasons to assess the effect of Bacilli strains and Cyanobacteria inoculation on the vegetative growth and growth parameters and plant chemical content of sweet pepper (Capsicum frutescens). In addition, the study investigates the ability of isolated bacterial strains from soil samples to improve plant growth, which is indicated by analyzing phytohormone production and phosphate solubilization. The obtained results indicated that mixed inoculation with both Bacillus strains and Cyanobacteria improved vegetative growth, plant chemical contents, and positive microbial activity in the soil Rhizosphere compared to un-inoculated plants. In addition, soil available nutrients (N, and K) increased significantly when BA and BM were combined with Cyanobacteria, while available phosphorus gave the most increase with BM.
... Percentages of total soluble solids (%T.S.S.) were determined by Abbe refract meter [35]. The dye 2,6-dichlorophenol indophenol method was used to determine ascorbic acid as mg/100 g fresh weight [36]. Total sugars were determined as g/100g dry weight according to Dubois [37]. ...
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Two successful field experiments were carried out during 2020and 2021 growing seasons to evaluate the effect of bio fertilizers; Bacillus amyloliquifaciens (BA), Bacillus megaterium (BM) and cyanobacteria inoculation on the vegetative growth, growth parameters and plant chemical content of Cucurbita pepo (Squash) crop. The study of mixed inoculation with both Bacillus strains, and cyanobacteria was found to improve vegetative growth, plant chemical contents and positive microbial activity in the soil Rhizosphere in comparison to un-inoculated plants. Soil available nutrients (N and K) increased significantly with BA and BM combined with cyanobacteria while available phosphorus gave most increase with BM.
... The obtained values agree with those reported for sub-Saharan Africa and India (Stadlmayr et al. 2013). In the case of tubers of D. cayenensis and D. prehensilis, although their vitamin C content is high, their dietary contribution is difficult to calculate, as vitamin C content is greatly affected by temperature (Hernández et al. 2006). In this line, reductions in vitamin C due to cooking have been reported in Amaranthus spp. ...
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Ethiopia is confronted with the paradox of hosting hundreds of edible plants and having high food and nutritional insecurity. Meals are mainly made up of staples and often lack of protein and micronutrients. Therefore, a large section of the population, particularly children and women, are malnourished. We hypothesize that wild edible plant species can contribute to fulfil the micronutrient demands of local people. Hence, we assessed the nutritional potential of underutilized edible plant species growing in understories of coffee agroforestry systems of southwestern Ethiopia. An ethnobotanical household survey (n = 300) documented the edible existing plants; and a promising subset of them (n = 12) was analysed for nutrient and antinutritional factor content in the lab. All 12 species, except fruits, have higher calcium, iron and zinc contents compared to regularly cultivated crops. Vitamin C was high in Syzygium guineense (330.72 mg/100 g edible parts or EP) and Rubus apetalus (294.19 mg/100 g). Beta-carotene ranged from 9.2 to 75 µg retinol activity equivalent (RAE) /100 g 25 among all species, but was exceptionally high in Rubus apetalus (161.7 µg RAE/100 g). Concerning the antinutritional factors, phytate content varied from 31.06 to 601.65 µg/100 g, being lower in Dioscorea prehensilis (31.06 µg/100 g) and D. alata (90.17 µg/100 g) compared to Carissa spinarum (601.65 µg/100 g) and Solanum nigrum (536.48 µg/100 g). Thus, we conclude that the assessed underutilized species are potential sources of dietary nutrients locally needed, and are notable Amaranthus graecizans, Portulaca oleracea and Dioscorea cayenensis as providers of Ca, Fe and Zn, and the fruit Rubus apetalus of provitamin A.
... Vitamin C (ascorbic acid) was measured by HPLC (Thermo Fisher Scientific) (Hernandez, et al., 2006). Briefly, about 0.12 g of sample was weighed. ...
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To document indigenous knowledge and farmers’ know-how related to the leafy vegetables Launaea taraxacifolia, Bidens pilosa and Alternanthera sessilis, an ethnobotanical investigation using participatory approach research methods and tools, was conducted in 19 villages randomly selected across ethnic and agro-morphological zones of southern and central Benin. The geographical distribution of the three species was established and the southern area appeared suitable for an in situ conservation programme of genetic diversity of these leafy vegetables. Respectively, 11.11%, 55.56% and 90% of the respondents reported that Launaea taraxacifolia Bidens pilosa and Alternanthera sessilis are still harvested from the wild (level 0 of domestication) while 22.22% and 16.67% of respondents reported that L. taraxacifolia and B. pilosa are being cultivated (level 4 of domestication). Uprooting and cutting plant stems were the most common harvesting methods. The study revealed the existence of morphotypes resulting in the identification of different varieties of L. araxacifolia (three varieties), B. pilosa and A. sessilis (two). The frequency of consumption of each of the leafy vegetables and its consumption method varied according to the ethnic group. Regarding methods of preparation, sauce made from fresh leaves was reported only for L. taraxacifolia while precooked leaves were otherwise used. The respondents also reported that these leafy vegetables possessed, in addition to their culinary value, several medicinal virtues. L. taraxacifolia was the most valued medicinally and is used for the prevention or healing of 21 diseases with 16 possible pharmacological functions. Further research is required on the biochemical and phytochemical characterization of the genetic diversity of these species as well as the effects of processing methods on their nutritional value.
... Cette méthode n'est pas applicable à toutes les matrices. Par exemple, dans le cas des fruits, le dosage peut être faussé du fait de la présence en quantité de tannins et de minéraux tels que le cuivre, le fer, le manganèse ou le cobalt qui peuvent êtres oxydés par le réactif (Hernandez et al., 2006). (Vermeir et al., 2007). ...
Thesis
La consommation régulière de fruits, sous forme fraîche ou transformée, est largement préconisée pour son effet bénéfique sur la santé. Les polyphénols contenus dans les fruits suscitent un intérêt croissant de la part des nutritionnistes, des industriels et des consommateurs, du fait de leurs propriétés antioxydantes et de leur rôle dans la prévention de certaines formes de cancers et des maladies cardiovasculaires. La pomme est naturellement riche en polyphénols et sa consommation courante la rend très intéressante en termes d'apports journaliers. Néanmoins, l’impact des procédés de transformation sur le devenir des composés antioxydants est peu étudié.Au cours de cette thèse, deux procédés, la déshydratation-imprégnation par immersion (DII) et le séchage convectif, ont été examinés séparément et combinés. Différentes variétés de pommes de table (Belchard®, Royal Gala et Reinette grise du Canada) et de pommes à cidre (Avrolles, Guillevic et Marie Ménard) ont été sélectionnées, sur trois années consécutives. Pour chacun des procédés, les cinétiques de déshydratation et de dégradation de l’acide ascorbique et des différentes classes de polyphénols ont été suivies, les concentrations en antioxydants étant mesurées par CLHP-UV-BD ; pour la DII, deux températures (45 et 60 °C) ont été étudiées. L’évolution des teneurs en sucres (fructose, glucose et saccharose) au cours de la DII a également été mesurée, par CLHP-IR.Après avoir mis au point les méthodes analytiques permettant de quantifier l’acide ascorbique et les composés phénoliques sur produits sucrés, ces composés ont été suivis en fonction du temps de procédé. En DII, un impact significatif de l’année de récolte a été observé sur les transferts, plus important que celui attribuable à la variété. Les transferts s’intensifient avec la température qui a aussi un impact négatif sur la rétention en antioxydants. Toutefois, les résultats font ressortir des différences de comportement significatives entre les polyphénols et l’acide ascorbique. La perte en acide ascorbique est très rapide, essentiellement due à l’oxydation et l’entraînement par l’eau. En ce qui concerne les polyphénols, leur rétention diffère selon leur structure chimique. Les procyanidines, composés polymérisés et capables de créer des interactions avec les composés des parois cellulaires, subissent très peu de pertes. Par contre, les acides hydroxycinnamiques, substrats préférentiels de la polyphénoloxydase et de faible masse moléculaire, enregistrent une perte plus importante. Par comparaison, le séchage convectif préserve mieux l’acide ascorbique et les composés phénoliques, sans différences marquées selon leur structure chimique. De plus, la variété semble avoir une faible incidence sur les transferts. Lors de l’enchaînement de DII / Séchage proposé, la DII, même si elle ne représente que 10% du temps de traitement, est responsable d'environ la moitié des pertes finales en polyphénols, avec des différences entre composés similaires à celle déjà décrites en DII et en séchage convectif. L’imprégnation en saccharose peut être néanmoins intéressante pour masquer l’astringence des procyanidines et améliorer les qualités gustatives des pommes séchées.
... 'Hongkong' [27] and cv. 'Baixinho do Santa Amalia' [28]. The decrease in firmness with maturity and ripening could be related to the degradation of cell wall pectin [29]. ...
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Papaya fruits have great nutritional and economical values. The ripening stage of papaya fruits at the time of harvesting massively impacts the quality and shelf-life of fruits. Volatile organic compounds (VOCs) emitting from the papaya fruits during the ripening process could be used as a real-time non-invasive biomarker to characterize the ripening stage. This paper reports identification of VOCs as non-invasive ripening biomarkers of papaya fruits based on solid-phase micro-extraction coupled with gas chromatography–mass spectrometry (GC–MS) analysis of VOCs emitted from the papaya fruit cv. ‘Red Lady’. Three ripening stages were studied, viz., green unripe (UR), yellowish-green intermediate ripe (IR), and yellow full ripe (FR). GC–MS analyses and the subsequent statistical studies identified a total of 35 VOCs. Partial Least Squares Discriminant Analysis (PLS-DA) of VOCs from the three ripening stages identified six biomarker VOCs, which can efficiently distinguish between ripening stages. Among the six ripening biomarkers, three VOCs (methyl hexanoate, 3-carene and longifolene) showed a remarkable correlation with the ripening-associated changes in the fruit nutritional profile. The biomarkers reported here could be used as a viable technology for non-invasive monitoring of ripening stages and the nutritional value of papaya fruits.
... The extraction for ascorbic acid estimation was followed as described by Hernández et al. (2006). Briefly, 10 g sample was crushed and extracted in 50 mL of 3% metaphosphoric acid-8% acetic acid solution. ...
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Fresh-cut fruits are susceptible for microbial contamination during handling and storage. Hence, there is a need for minimal processing of such foods using non-thermal technology that can inactivate both bacterial pathogens and undesirable enzymes while retaining the quality. In this regard, synergistic effect of light emitting diode (LED) based blue light (BL) and natural exogenous photosensitizer- curcumin (PS) on the inactivation of bacterial pathogens (Escherichia coli, Staphylococcus aureus), and enzymes (polyphenol oxidase, peroxidase, bromelain) of fresh-cut pineapple slices were evaluated. The effect of photodynamic treatment (PS+BL) on quality attributes like color, phenolics, flavonoids, ascorbic acid content and antioxidant activity was also investigated. The PS+BL treatment at optimized conditions resulted in 3 and 4 log reduction of E. coli and S. aureus, respectively. PS(100 μM)+BL treatment led to partial inactivation of polyphenol oxidase (33.5%) and peroxidase (25.7%), synergistically, but preserved desired enzyme bromelain. The PS+BL didn’t show any significant (p<0.05) consequence on color, phenolics, flavonoids and antioxidant activity, while it affected the ascorbic acid content negatively (reduced by ~30%). The current investigation showed that the photodynamic inactivation of E. coli and S. aureus using LED-based photosensitization in fresh-cut fruit slices could be used as a potential method for microbial control although some phytochemical losses. Graphical abstract
... The vitamin C content in ripe fresh mangoes used for canning was 21.6 ± 1.2 mg/100 g. The value is within the previously reported range (19.7 ± 9.1-38.7 ± 1.4 mg/100 g) [32,33]. The vitamin C content in pineapple (24.3 ± 1.1 mg /100 g) was similar to that reported previously [34,35]. ...
Article
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The effect of thermal processing on health-promoting phytochemicals was investigated in relation to the canning of mango and pineapple. The cans were retorted at four different temperatures for varying amounts of time. Vitamin C, β-carotene, polyphenols, flavonoid content, and antioxidant capacity in canned fruit pieces and sugar syrup were determined. The diffusion and leaching of phytochemicals were determined through mathematical modelling. Retention of vitamin C in canned pineapple pieces was higher than in canned mango pieces. Thermal treatment had an effect of rapidly reducing leached vitamin C. The activation energy required for the degradation of vitamin C and β-carotene in mango was higher than that required in pineapple. Trolox equivalent antioxidant capacity (TEAC) values at 130 °C (40 min) were 3.1 and 1.9 μmolTrolox/g FW in mango pieces and syrups, respectively, indicating that antioxidant leaching had occurred. The degradation constants of the phytochemicals studied were comparable but were slightly higher in pineapple than in mango. The investigated health-promoting phytochemicals in canned products were present in substantially lower concentrations than in fresh mango and pineapple.
... 2.3.4.2. Vitamin C. Ascorbic acid was determined as described by Hernández et al. 21 using a Thermofisher HPLC (Thermo Scientific, Germany). The samples containing zobo were diluted twice, while samples containing just water and turmeric were not diluted. ...
Article
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Street-vended foods are cheap, readily available and have been currently identified as possible means for micronutrient fortification in an effort to prevent malnutrition in developing countries. The effect of enriching street-vended zobo drink (Hibiscus sabdariffa) with turmeric (Curcuma longa) was studied to assess the potential to increase health-supporting properties for its consumers. Two processing methods were tested: boiled turmeric root in zobo and addition of fresh turmeric paste to zobo in different concentrations. Vitamin C in turmeric-fortified zobo ranged from 496-725 μg/100 mL, delphinidin-3-sambubioside from 52-69 mg/100 mL, and cyanidin-3-sambubioside from 21-27 mg/100 mL. Micronutrients ranged from 10.9-14 mg/L and 2.19-2.67 mg/L for iron and zinc, respectively. Folic acid, vitamin C, anthocyanins and iron showed the highest amounts in the 2% boiled turmeric zobo samples. Ferulic acid (0.16-2.03 mg/100 mL), and chlorogenic acid (20-24 mg/100 mL) did not show the same statistically significant improvement for 2% boiled turmeric-fortified zobo. The zobo samples with turmeric paste consistently had lower values of vitamins, polyphenols and minerals in comparison with the boiled turmeric-fortified zobo samples. Turmeric-fortified zobo can play a role in a healthy diet by its health-supporting properties. Consumption of a typical one serving of 500 mL (representative packaged bottle size of zobo drink by the street vendors in Nigeria) of turmeric- fortified zobo would contribute 63-88% DV and 18-23% DV of iron and zinc. Overall, fortification with boiled turmeric improves the antioxidant and nutritional quality of zobo, specifically regarding vitamin C, delphinidin-3-sambubioside and iron.
... This variation could be due to wild harvesting of fruits occurring in different geographical locations, climatic and soil conditions and seasonality. However, it is also important to determine the accurate content of vitamin C in foods to better understand the relationship of dietary intake and human health (47). National Health and Medical Research Council Australia has recommended the Recommended Dietary Intake (RDI) of vitamin C for healthy adult males and females as 45 mg/day and a upper level of intake (UL) is not possible to establish with certainty for supplementary vitamin C however a 1,000 mg/day can be a prudent limit (48). ...
Article
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Oxalic and phytic acid are phytochemicals considered to be anti-nutritional factors as they are predominantly found as oxalates and phytates bound to minerals like calcium and potassium. Studies have associated excessive oxalate consumption with increased urinary excretion of oxalate (hyperoxaluria) and calcium oxalate kidney stone formation, and excessive phytate consumption with decreased bioaccessibility and bioavailability of certain minerals and reduced utilization of dietary protein. However, other studies suggest that dietary consumption of phytate may be beneficial and inhibit formation of calcium oxalate kidney stones. In light of these conflicting reports, dietary intake of oxalate and phytate enriched plants should be considered in relation to potential health outcomes following consumption. Terminalia ferdinandiana is one such plant and is investigated here with respect to oxalate, phytate, and mineral contents. Assessment of oxalate and phytate contents in T. ferdinandiana fruit, leaf, and seedcoat tissues through hydrolysis into acid forms revealed oxalic acid contents ranging from 327 to 1,420 mg/100 g on a dry weight (DW) basis whilst phytic acid contents ranged from 8.44 to 121.72 mg/100 g DW. Calcium content in the different tissues ranged from 131 to 1,343 mg/100 g. There was no correlation between oxalic acid and calcium, however a significant, positive correlation was observed between phytic acid and calcium ( r = 0.9917; p < 0.001), indicating that tissues rich in phytic acid also contain higher levels of calcium. The high content of phytic acid in comparison to oxalic acid in T. ferdinandiana fruit found in this study and the dietary significance of this in terms of calcium bioavailability, needs to be investigated further.
... Titratable acidity (%): Standard methodology proposed in (Hernández et al., 2006) was applied for determining titratable acidity of fruit sample. ...
... To conduct all the operations beneath reduced lightweight and at a temperature of 4° C, many precautions were taken. Also, the addition of one millimeter TBHQ is suggested to stabilize vitamin C within the extract solutions [17]. ...
Conference Paper
Infectious disease that affect virtually fifty thousand individuals daily still unfold and became a serious world drawback and also the key rationalization is that the emergence of multi-drug resistance in microorganism strains. This perturbing scenario has led to seek for new and natural antimicrobial substances with bigger bioactivity and no aspect effects. In practical foods, bioactive compounds exist and might defend the United States of America through many mechanisms against diseases to safeguard against diseases associated with aerophilous stress, the anti-oxidant properties of many BaCs area unit necessary. Fruit consumption provides the United States of America with anti-oxidants that may work to safeguard synergistically. Solely the pulp is employed in mango fruit, whereas all alternative items area unit discarded and cause environmental pollution. Because of its high nutraceutical and dedicative worth, the recognition of mangos is on the rise. Polyphenolic compounds area unit is higher in pulp and better in mango leaves and stem barks and associated bioactivity in fruit. Their area unit varied Polyphenols in mango, however, Mangiferin is bioactive. So to produce bigger insights into their medical, nutritionary, and industrial applications, yet as their role(s) in defensive the plant, all bio-active constituents in mango have to be compelled to be studied. The high nutritional value of ripe mango has been shown to have high matter and anti-carcinogenic effects, with high quite Polyphenols and distinctive supermolecule contents, making it a high potential candidate for nutraceutical usage. The technology at intervals that freeze-dried mango powder retains identical quality as recent ripe mango pulp has already been developed. The goal of this analysis is to assist with the proper use of mangoes to enhance nutrition and health, as well as to improve our understanding of the plant defense mechanisms that depend on these compounds. There is also great potential for use of alternative drying techniques for the popularization of fruit bar processing.
... Ascorbic acid is an important vitamin for human nutrition that is supplied by fruits (especially citrus and some tropical) and vegetables (Hernández et al., 2006). The effect of CEO and CEO-loaded NLC on the ascorbic acid content in tangerine fruit is shown in Fig. 5. Figure 6 reveals that a significant decrease in the ascorbic acid content of tangerine fruits during storage has occurred. ...
Article
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In this study, the effect of cinnamon essential oil (CEO) at 0.3 and 0.6 mg/mL concentrations loaded in the nanostructured lipid carriers (NLC) against Penicillium citrinum and Penicillium expansum involved in tangerine decay was investigated. The minimum inhibitory concentrations (MIC) of the CEO and CEO-loaded NLC against both P. citrinum and P. expansum were about 0.425 and 1 mg/mL, respectively. Moreover, the minimum fungicidal concentrations (MFC) of the CEO and CEO-loaded NLC were 0.675 and 1.5 mg/mL, respectively, and the values were approximately the same for P. citrinum and P. expansum. According to the chemical and sensory analysis during 25 days of storage at 25 °C, the CEO-loaded NLC reduced the weight loss (from 30.7 to 26.3% and 27.1% at 0.3 and 0.6 mg/mL CEO, respectively) and there was no detrimental effect on the organoleptic and chemical properties such as titratable acidity, pH, TSS, and ascorbic acid content due to the treatment with CEO-loaded NLC. The tangerines were inoculated with P. citrinum and P. expansum spores and the percentage of the infected wounds were evaluated during 25 days of storage at 25 °C. The fungal spoilage of tangerine fruits reduced during storage, significantly (from 100% on the 10th day to 31% and 33% on day 25 for P. citrinum and P. expansum, respectively). Therefore, CEO-loaded NLC has the potential to be introduced as a new treatment for increasing tangerine shelf life.
... Phosphate buffer (0.05 M, pH 3.2) and acetonitrile at the ratio of 90:10 was used as isocratic mobile phase with 1 ml/min flow rate. A Thermo Scientific BDS Hypersil C18 column (250 × 4.6 mm; particle size, 5 µm) was used as stationary phase, and ascorbic acid was detected at 244 nm using PDA (Ekinci and Kadakal, 2005;Hernandez et al., 2006;Phillips et al., 2010). ...
... For the determination of vitamin C, each peach sample was extracted according to [29] with a few modifications. Frozen pulp (2 g) was mixed with 2 mL of 0.1% formic acid in order to avoid L-ascorbic acid oxidation. ...
Article
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Cold storage is used to extend peach commercial life, but can affect quality. Quality changes are assessed through the content of nutritionally relevant compounds, aroma, physical characters and/or sensorially. Here, six peach and nectarine cultivars were sampled at commercial harvest and after 7 days of 1 °C storage. A trained panel was used to evaluate sensorial characters, while carotenoids, phenolics, vitamin C, total sugars, and qualitative traits including firmness, titrable acidity and soluble solid content were integrated with volatile organic compound (VOC) analysis previously reported. The different analyses reveal interesting patterns of correlation, and the six cultivars responded differently to cold storage. Sensory parameters were correlated with 64 VOCs and seven intrinsic characters. Acidity, firmness, and 10 VOCs were strongly negatively correlated with harmony and sweetness, but positively correlated with bitterness, astringency, and crunchiness. In contrast, Brix, b-carotene, and six VOCs were positively correlated with harmony and sweetness.
... Therefore, this study was carried out to determine AA content in red and yellow flesh juice of C. lanatus using RP-HPLC. (10)(11)(12). Watermelon flesh was cut into smaller pieces prior to homogenization in a HESSTAR blender in the dark and kept in ice. The homogenized mixture was thoroughly mixed and weighed at 2 g into a 50 mL centrifuge tube. ...
Article
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Introduction: Ascorbic acid (AA) is a significant micronutrient known for its potent antioxidant properties beneficial to health. AA acts as a cofactor in various physiological reactions including improving endovascular function, modifying immunologic and inflammation functions, and aiding in scavenging free radicals. Different methods have been performed to quantify AA in fruits. However, there is limited data for AA analysis in red and yellow crimson watermelon using RP-HPLC, with a simple sample preparation process. Thus, the present study was conducted to detect the quantification of AA in the juices of local red and yellow crimson watermelon (Citrullus lanatus) flesh. Methods: The detection was carried out using the reversed-phase high-performance liquid chromatography (RP-HPLC) by injecting 20 µl samples into a C-18 column with a temperature set at 25˚C. The overall analysis was conducted using 0.1 % ortho-phosphoric acid and acetonitrile (95:5, v/v) as mobile phase with a flow rate of 1 mL/min at a detection wavelength of 254 nm. Results: The results show that the retention time of AA was eluted at 2.8 min in both juice samples. This method was then validated using linearity (0.9838), limit of detection (LOD) (0.47 µg/mL) and limit of quantification (LOQ) (1.43 µg/mL). The concentration of AA in red and yellow watermelon samples were found at 19.88 µg/mL and 19.05 µg/mL, respectively. Conclusion: The present study concludes that AA content in red and yellow crimson watermelon was successfully detected and quantified using the RP-HPLC method. The results were reliable and successfully validated using linearity, LOD and LOQ.
... Drying time and total soluble sugars (TSS) in terms of degrees Brix were recorded following the method of Ouaabou et al. [29] and Bozkir et al. [30], respectively. Titrable acidity, pH, and ash contents were measured according to methods devised by International [31], while vitamin C was determined according to Hernández et al. [32]. ...
Article
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Poor postharvest handling, microbial infestation, and high respiration rate are some the factors are responsible for poor storage life of perishable commodities. Therefore, effective preservation of these commodities is needed to lower the damages and extend shelf life. Preservation is regarded as the action taken to maintain desired properties of a perishable commodity as long as possible. Persimmon ( Diospyros kaki ) is perishable fruit with high nutritive value; however, has very short shelf-life. Therefore, effective preservation and drying is needed to extend its storage life. Drying temperature and preservatives significantly influence the quality of perishable vegetables and fruits during drying. The current study investigated the effect of different temperatures and preservatives on drying kinetics and organoleptic quality attributes of persimmon. Persimmon fruits were treated with preservatives (25% honey, 25% aloe vera, 2% sodium benzoate, 1% potassium metabisulfite, and 2% citric acid solutions) under different drying temperatures (40, 45, and 50°C). All observed parameters were significantly affected by individual effects of temperatures and preservatives, except ash contents. Similarly, interactive effects were significant for all parameters except total soluble sugars, ash contents, and vitamin C. Generally, fruits treated with citric acid and dried under 50°C had 8.2% moisture loss hour ⁻¹ , 14.9 drying hours, 0.030 g H 2 O g ⁻¹ hr ⁻¹ , 1.23° Brix of total soluble solids, 6.71 pH, 1.35% acidity, and 6.3 mg vitamin C. These values were better than the rest of the preservatives and drying temperatures used in the study. Therefore, treating fruits with citric acid and drying at 50°C was found a promising technique to extend storage life of persimmon fruits. It is recommended that persimmon fruits dried at 50°C and preserved in citric acid can be used for longer storage period.
... Phosphate buffer (0.05 M, pH 3.2) and acetonitrile at the ratio of 90:10 was used as isocratic mobile phase with 1 ml/min flow rate. A Thermo Scientific BDS Hypersil C18 column (250 × 4.6 mm; particle size, 5 µm) was used as stationary phase, and ascorbic acid was detected at 244 nm using PDA (Ekinci and Kadakal, 2005;Hernandez et al., 2006;Phillips et al., 2010). ...
Article
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Millets are nutritionally superior indigenous staple crops packed with high protein, vitamins, and minerals. However, anti-nutrients such as phytic acid, tannins, and polyphenols present in the millets tend to reduce the bio-accessibility of minerals (iron and zinc), due to which the millet diets are greatly compromised. Although most of the cereals, such as wheat flour, brown rice, and barley, contain phytic acid to a level far more than that of the millets, it is important to develop feasible household methods to reduce the level of phytic acid so as to enhance nutrient absorption. The present study was carried out to investigate the effect of traditional processing on nutrient and anti-nutrient retention of three majorly consumed millets, namely, sorghum, finger millet, and pearl millet. These millets were traditionally cooked and then fermented overnight with water and curd. The results show that this type of simple, traditional household-level process significantly reduced the phytic acid content by 62.9% in sorghum, 34.1% in finger millet, and 29.35% in pearl millet. There is a considerable decrease in phytic acid–zinc molar ratio by 71.38, 61.15, and 33.47% and in phytic acid–iron molar ratio by 73.52, 48.07, and 66.39% in sorghum, finger millet, and pearl millet, respectively. Among the macronutrients, the protein and ash contents were significantly increased. A high retention of water-soluble vitamins was observed in the processed millets. Overall, the traditionally cooked millet, fermented overnight and then added with curd, enhanced many essential macro- and micronutrients and concurrently reduced phytic acid, thus forming a sustainably simple household method for improving dietary nutrients.
... The uniqueness of this nanoprobe system was regaining the fluorescence intensity that is turned on for the JB-CDs/Cr(VI) fluorescence through selective introduction of AA. AA is a vital antioxidant, which plays an important role in our daily life, 67 and it is also used for the removal of AA. 68 Cr(VI) and AA react together resulting in a redox reaction, where AA acts as a strong reducing agent of Cr(VI). In the redox reaction, the enediol group in AA undergoes oxidation, accompanied by the production of Cr(III) or other lower oxidation numbercontaining chromium compounds. ...
Article
Currently, the technologies accompanying the usage of waste materials for the fabrication of innovative useful materials have been significantly advanced. For the same purpose, a possible sustainable approach was demonstrated for the utilization of jute caddies, known as jute industry waste. From the industrial waste, carbon dots (CDs) were sonochemically prepared, followed by their surface modification with benzalkonium chloride (BZC) to yield waste jute-derived fluorescent surface-quaternized CDs (JB-CDs), which exhibit excellent water solubility, excitation-dependent emission, and good photostability, and were utilized as a fluorescent nanoswitch to detect inorganic pollutants, such as chromium (VI) [Cr(VI)] ions, in aqueous solutions. JB-CDs can detect Cr(VI) concentrations as low as 0.03 μM through luminescence quenching ("turn-off") and further recover their fluorescence ("turn-on") selectively for sensing ascorbic acid (AA), compared with other metal ions and biomolecules tested. The present technique has the advantages of fast response time and high selectivity and sensitivity in practical applications. JB-CDs were tested against a Gram-negative bacterium, Escherichia coli, and a Gram-positive bacterium, Staphylococcus aureus, to confirm their bactericidal activity. The results indicated that JB-CDs substantially inhibited the growth of the tested bacteria. Besides this, JB-CDs played the role of a nanovehicle to exemplify the release study of a model drug ciprofloxacin. It was observed that the surface-quaternized JB-CDs showed a pH-responsive release behavior, where the release behavior was found to be better controlled at pH 7.4 than at pH 5.2 and 6.8. The synthesis of such a fluorescent nanobutton, stimuli-responsive drug release, and antibacterial nanomaterial using a sustainable material such as jute industrial waste can pave the path for a smart multifunctional material.
... The initial vitamin C content of carambola was 44.03 mg/100 g. However, some other researchers have reported different ascorbic acid content in carambola fruit: 74 mg/100 g (Hernández et al., 2006), 25.2 mg/100 g for green fruit, 25.9 mg/100 g for half-ripe, and 23.4 mg/100 g for ripe (Narain et al., 2001). This difference in ascorbic acid content could be related to the stage of maturity and agricultural practices. ...
Preprint
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Carambola is an excellent C-vitamin source and other healthy nutrients; unfortunately, because its high moisture content is a very perishable fruit. Solar drying is a feasible solution for its preservation. However, the optimal drying conditions depend on the dryer material. A natural convection sun-dryer was modified using four di�erent materials: glass, acrylic, polycarbonate, and polyethylene. The moisture content of carambola slices was reduced from 89.23% to final moisture content between 2.2% and 5.9% in a maximum time of 650 min. The final water activity of dried samples ranged from 0.310 to 0.414. The color analysis of carambola indicated a decrease in lightness while a and b parameters increased; the mix of red and yellow resulted in an orange product which turned slightly brown as lightness decreased. In addition, the ascorbic acid reduced from 338.46 mg/100 g (d.b) to 159.50 mg/100 g- 124.37 mg/100 g (d.b), depending on the cover material. In general, polycarbonate dryers show less degradation of components due to the lower temperatures reached in their drying chamber. However, the solar drying of carambola with all the covers is technically, economically, and environmentally feasible compared to conventional technologies, such as the electric oven used in this work.
... Al analizar los valores de grados Brix obtenidos en el presente estudio, resalta que el banano muestreado presentó un contenido total de sólidos solubles similar a valores reportados para banano maduro, de acuerdo con los resultados obtenidos por Hernández et al. (2006) en el cultivar Gran enana (22,8 ± 1,2 °Brix) y con Yánez Bustamante et al. (2020), autores que determinaron un rango de 19,33 a 24,5 °Brix en banano maduro cultivado en Ecuador. El contenido de sólidos solubles es una característica que posiciona al banano como una fruta con un perfil muy favorable para procesos industriales, como por ejemplo la elaboración de bebidas fermentadas (Carvalho et al., 2009). ...
Article
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Introducción. El consumo de frutas y vegetales correlaciona inversamente con la incidencia de enfermedades degenerativas como diabetes, enfermedades cardiovasculares, ciertos tipos de cáncer y cataratas asociadas al envejecimiento, dada la acción de compuestos bioactivos como vitamina C, polifenoles y carotenoides. Objetivo. Evaluar el perfil nutricional de once frutas cultivadas en Costa Rica. Materiales y métodos. Este estudio se realizó en el Centro Nacional de Ciencia y Tecnología de Alimentos de la Universidad de Costa Rica, en el 2010. Se determinó el contenido de fibra dietética, polifenoles totales, reportados como equivalentes de ácido gálico (EAG), carotenoides totales expresados como µg β-caroteno y la capacidad hidrofílica de absorción de radicales de oxígeno (H-ORACFL) de once frutas tradicionales o subutilizadas: banano (Musa AAA subgrupo Cavendish cv. ‘Grand Naine’), mora tropical de altura (Rubus adenotrichos cv. ‘vino con espinas rojas’), melón (Cucumis melo cv. ‘Veracruz’), higo (Ficus carica cv. ‘Brown-Turkey’), mango (Mangifera indica cv. ‘Tommy Atkins’), papaya (Carica papaya híbrido ‘Pococí’), pejibaye (Bactris gasipaes H.B.K), piña (Ananas comosus cv. híbrido MD-2 ‘Gold’), membrillo (Cydonia oblonga), jocote (Spondias purpurea cv. Tronador) y tomate de árbol rojo (Solanum betaceum). Las frutas fueron recolectadas en localidades de San José, Cartago, Alajuela, Guanacaste y Limón. Resultados. Seis de las frutas estudiadas presentaron contenidos de fibra dietética entre 4,2 y 6,6 g 100 g-1. La mora tropical de altura presentó el mayor contenido de compuestos fenólicos totales (538 ± 97 mg EAG 100 g-1) y la mayor actividad antioxidante (62,1 ± 4,0 μmol equivalentes de Trolox g-1), y el pejibaye cocido presentó el mayor contenido de carotenoides (72 ± 4 µg β-caroteno g-¹). Conclusión. Se evidencia los altos contenidos de compuestos bioactivos en frutas comúnmente cultivadas en Costa Rica, características nutricionales asociadas a beneficios para la salud, respaldados por estudios clínicos y epidemiológicos.
Article
The effects were investigated of edible coating and drying temperature (50, 65 and 80 °C) on the properties of dehydrated pineapple cubes. A comparative study was performed using mathematical models, multiple linear regression (MLR) and artificial neural networks (ANNs) to predict moisture ratio (MR) and drying rate (DR). Kinetic drying, effective moisture diffusion (Deff) and activation energy were examined. Midilli et al. model was the best fit to predict MR. Higher air temperature reduced drying time and moisture content, while Deff increased for uncoated and coated dried pineapples of 1.69 × 10⁻⁹ to 5.57 × 10⁻⁹ m²/s and 1.60 × 10⁻⁹ to 5.95 × 10⁻⁹ m²/s with the activation energy (Ea) of 37.68 and 41.61 kJ/mol, respectively. Interestingly, the edible coating did not significantly affect Deff and Ea, but it retained ascorbic acid. Moreover, ANNs model was appropriate for the prediction of the MR and DR of dehydrated pineapple cubes, as this model had the highest R² and accuracy with the lowest RMSE and MAE. The ANNs models with topology of 3–14-14-1 for MR and 3-7-7-1 for DR predictions were the optimal to estimate the drying process of uncoated and coated fruits with satisfactory accuracy and benefit for food industry.
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p class="Abstrak">Mangga ( Mangifera indica, L.) cv. Gedong merupakan salah satu kultivar unggulan Jawa Barat,dengan daya saing tinggi di pasar domestik dan internasional. Sulitnya mendapatkan kematangan serempak merupakan tantangan yang harus diatasi dengan teknologi pascapanen yang tepat. Penggunaan karbit sebagai pemacu kematangan buah tidak lagi dianjurkan dan perlu diganti dengan bahan lainya seperti etilen. Penelitian ini bertujuan untuk mendapatkan konsentrasi gas etilen dan lama paparan serta kondisi pemeraman terbaik untuk menghasilkan buah mangga Gedong matang sempurna dengan mutu yang baik. Penelitian dilakukan dengan Rancangan Acak Lengkap Faktorial. Perlakuan yang diterapkan adalah konsentrasi gas etilen (0, 30, 60 dan 90 ppm) selama 24 jam pada kondisi ambient dan dalam ruangan berpendingin (AC). Hasil penelitian menunjukkan bahwa, perlakuan terbaik untuk mendapatkan mangga cv. Gedong matang sempurna dengan mutu yang baik yaitu penggunaan etilen 30 ppm. Dengan perlakuan tersebut kematangan buah mangga tercapai 2 hari pada suhu berpendingin dan 4 hari pada kondisi ambient lebih cepat dibandingkan mangga tanpa paparan gas etilen. Suhu ruangan pemeraman lebih berpengaruh terhadap mutu buah mangga Gedong matang yang dihasilkan. Pemeraman dengan gas etilen meningkatkan kadar TPT (89,55%), vitamin C (71,31%), dan total fenol (167,23%) serta menurunkan total asam (92,62%) dan total flavonoid (71,67%) dari buah mangga Gedong matang. Konsentrasi gas etilen tidak berpengaruh terhadap kadar air, TPT, total asam dan vitamin C pada buah mangga Gedong matang hasil pemeraman. Gas etilen tidak menyebabkan penurunan mutu berdasarkan parameter fisikokimia yang diamati. Ripening of Mango ( Mangifera Indika L.) CV. Gedong Using Ethylene Gas Mango ( Mangifera indica, L.) CV. Gedong is one of the leading cultivars in West Java, with high competitiveness in the domestic and international markets. The difficulty of obtaining simultaneous ripe fruits is a challenge that must be overcome with the right postharvest technology. The use of carbide as a ripening booster is no longer recommended and needs to be replaced with ethylene gas which has been practiced internationally. This study aims to obtain the best ethylene gas concentration and exposure time and ripening conditions to produce perfectly ripe Gedong mangoes with good quality. The research was conducted with a completely randomized factorial design. The treatment applied was the concentration of ethylene gas (0, 30, 60 and 90 ppm) for 24 hours in ambient conditions and in an air conditioned room. The results showed that, the concentration of 30 ppm ethylene gas was the best treatment to produce fully ripe mangos with good quality, where maturity was obtained 2 days (air-conditioned room) to 4 (ambient condition) days earlier compared to those without ethylene gas exposure. The temperature of the ripening room has more effect on the quality of the ripe Gedong mango produced. Ripening with ethylene gas increased levels of TPT (89.55%), vitamin C (71.31%), and total phenols (167,23%) and decreased total acid (92.62%) and total flavonoids (71.67%) from ripe Gedong mangoes. Ethylene gas concentration had no effect on water content, TPT total acid and vitamin C in ripened mango Gedong. Ethylene gas did not cause deterioration based on observed physicochemical parameters. </p
Article
Ascorbic acid, known as vitamin C, is an important antioxidant and food ingredient, and highly sensitive to environmental conditions, which makes its incorporation into food, cosmetic and pharmaceutical products more difficult. The evaluation of its nano/microencapsulation enables the improvement of its stability and controlled release. There are various investigations regarding ascorbic acid encapsulation; however, a deep study related to the scale-up of encapsulation process, its application into food products and digestibility study are still needed. This review highlights the main physicochemical and health properties of vitamin C, recent advances of its encapsulation into micro/nanocarriers, and application in food products. Also, the controlled release and bioavailability of encapsulated forms within different carriers is underlined. The results of published studies clearly show that vitamin C can be successfully protected within micro/nanoencapsulation systems and it can be applied as an efficient ingredient in the formulation of various food products such as bakery goods.
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Alicyclobacillus acidoterrestris can cause spoilage in orange juice that leads to consumer rejection. Six different orange juices were physiochemically characterized (pH, total soluble solids, titratable acidity, total polyphenols and vitamin C). A bottle for each sampling point per juice was filled (headspace: 40% volume) and inoculated with 102 – 103 CFU ml–1 of A. acidoterrestris ATCC® 49025™ (heat shocked before inoculation: 75°C, 20 min). Samples were stored for 21 d at 45 ± 1°C and plate counted periodically on acidified YSG agar (pH 3.7) incubated at 45 ± 1°C for 3 d. The effect of headspace (6% versus 40% volume) on A. acidoterrestris growth was also evaluated. The effect of nisin (0.006%, 0.003%, 0.0015%, and 0.00075%), sodium benzoate (0.1%), potassium sorbate (0.1%), and a mix of benzoate and sorbate (0.05% each) on A. acidoterrestris was additionally addressed. A. acidoterrestris reached up to 107 CFU ml–1 in five of the six juices in less than one week. Headspace significantly impacted (P<0.05) A. acidoterrestris maximum population, which reached the critical value of 5 log CFU ml–1 at 40% headspace. All preservatives, regardless of concentration, showed a bacteriostatic effect during 22 d of storage with no significant differences among treatments (P>0.05).
Article
In order to investigate the light quality of LED lamps on some of the composition of leaf lettuce, an experiment was conducted in randomized complete block with 3 replications. Lettuce transplants for 35 days were exposed to irradiation of six light spectra [red (R), blue (B), white (W), 1red:1blue (RB), 1Red: 1Blue: 1White (RBW) and Fluorescent (FL) (control)]. The results showed the quality of light was significant at 1% level on soluble sugars, starch, soluble proteins, nitrate concentration, total phenol, total flavonoid, total antioxidant capacity, anthocyanin and vitamin C levels. The maximum dry weight plant (13.8 g), soluble sugars (14.3 mg/g) and starch (13.0 mg/g) were observed in R treatment. The maximum protein (0.39 mg/g), total phenol (19.78 mg/100 g,), total flavonoid (17.68 mg/100 g), total antioxidant capacity (78.66%), anthocyanin (30 mg/100 g) and vitamin C (0.19 mg/100 g) appeared in B treatment. The highest and lowest nitrate concentration were observed in the R (85.5 mg/kg FW) and B (354.44 mg/kg FW), respectively. According to the results, it can be said that red light produces the necessary materials for the growth of the aerial part of the plant, and blue light produces the most secondary metabolites.
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'Seolhyang' strawberries are popular in Asian markets owing to their bright-red color and desirable flavor. However, Seolhyang strawberries have a fragile outer layer and a short shelf-life. Therefore, 'Seolhyang' strawberries are often treated with CO2 to prolong their shelf-life. However, the effects of high CO2 treatment on the quality of Seolhyang strawberries are unclear. Herein, the effects of a short-term high CO2 treatment on the decay rate, firmness, color, targeted metabolite profile, and antioxidant activity of Seolhyang strawberries in two ripening stages (i.e., half-red and bright-red) were investigated during a 9-day cold storage period. Targeted metabolites (i.e., sugars, organic acids, and anthocyanins) were investigated using HPLC and/or UHPLC-qTOF. CO2-treated strawberries exhibited lower (although not significantly) decay rates than untreated strawberry samples. The bright-red samples contained higher levels of anthocyanins than the half-red samples, regardless of CO2 treatment, during storage. High CO2-treated half-red and bright-red strawberries exhibited firmness, color, and metabolite profiles similar to those of their controls at the final storage time. Interestingly, CO2-treated half-red strawberry samples showed higher antioxidant activity than the control. Thus, CO2 treatment may prolong the shelf-life of Seolhyang strawberries without loss of quality based on improving their targeted metabolite profiles and antioxidant activity.
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The present study is aimed to evaluate the effect of fermentation and gastrointestinal digestion of three kinds of fermented kiwifruit pulps with different lactobacillus (Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus casei). The changes of bioactive substances (total phenolic acid, total flavonoid, Vitamin C and the viable count), anti‐oxidant capacity (DPPH, ABTS, hydroxyl radical and superoxide anion radical scavenging activity) and phenolic profiles (protocatechuic acid, protocatechualdehyde, chlorogenic acid, caffeic acid and p‐coumaric acid) were detected. The result showed compared to non‐fermented kiwifruit pulp, fermentation with LP and LA had higher content of TPA, TF and VC, as well as anti‐oxidant capacity. Fermentation with LP, the content of protocatechualdehyde, p‐coumaric acid, and chlorogenic acid were increased. However, after digestion, LP showed more effect in maintaining the content of anti‐oxidants, anti‐oxidant capacity and the viable count rather than LA. During digestion, the content of protocatechualdehyde and p‐coumaric acid were increased in fermented samples compared with non‐fermented samples. Overall, comparing with LA and LC, LP more suitable for the fermentation of kiwifruit pulp.
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Nearly 30 varieties of banana (Musa spp.) are grown in Sri Lanka while it is the most produced and traded fruit in fresh form in the world. In the present study, five banana varieties commonly grown in Sri Lanka were evaluated for their nutritional composition. Fruits were collected using stratified random sampling design from all agro-climatic zones, sorted and cleaned. Composite samples were prepared by oven drying a portion of the sample at 45 °C while the rest was freeze-dried. Proximate composition, fatty acid profile and vitamin composition were determined using standard procedures and presented on fresh weight basis. Total carbohydrate, protein and dietary fibre contents of studied banana varieties were 13.46-26.46, 0.14-0.2 and 1.97-2.49%, respectively. Major fatty acids observed in Musa spp. were palmitic, linoleic, α-linolenic, oleic, stearic, palmitoleic and myristic acids. Vitamin A and E contents were higher than other fat-soluble vitamins. Among studied banana varieties, the nutritional significance of Puwalu was upheld by the highest quantities of fat-soluble vitamins and polyunsaturated fatty acids while the nutritional significance of Kolikuttu was upheld by the highest quantities of protein, dietary fibre, thiamine and riboflavin. Ambul kesel was observed to contain the highest vitamin C content among studied banana varieties.
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Refractance Window (RW) is a relatively new drying technique for producing dried powders, slices or leathers from fruits and vegetables. In the present study, the effect of temperature (70, 80 and 90 °C) and thickness of puree (2 and 3 mm) on drying characteristics, mass transfer and quality attributes of RW dried banana puree were investigated. Results showed that drying at 90 °C reduced drying time (∼61-64%) and energy consumption (∼30-44%), as compared to drying at a lower temperature (70 °C) for both the thickness. The effective diffusion coefficient (Deff) values obtained (2.89×10⁻⁹ to 8.84×10⁻⁹ m²/s) using Dincer and Dost analytical approach had higher R² (0.980-0.991) and lower RMSE (0.029-0.053) values. RW drying at 90 °C resulted in higher ascorbic acid retention (∼76-78%) with the least total colour change (3.4-6.9) compared to other studied conditions. Besides, retention of total phenolic (10.3 mg GAE/g dm) and flavonoid contents (3.4 mg QE/g dm), as well as antioxidant capacity (58.8 mM TE/g dm), were also better in samples dried at 90 °C. The study suggested that drying at a higher temperature during RW not only reduces drying time but also improves retention of quality attributes.
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چكیده میوه توتفرنگی (ananasa Fragaria (در صنایع غذایی کاربرد بسیاری داشته، بخصوص اسانس و عصاره بهدستآمده از این میوه در بسیاری از فراوردههای غذایی استفاده میشود. در این پژوهش، تغییرات صفات کیفی و بیوشیمیایی دو رقم توت فرنگی کاماروزا و پاروس در طی پانزده روز نگهداری در دمای 0 درجه سانتیگراد مورد بررسی قرار گرفت. نتایج مقایسه این دو رقم در روز اول نشان داد که سفتی بافت، میزان مواد جامد محلول و شاخص طعم در رقم کاماروزا به طرز معنیداری بیشتر از رقم پاروس بود. مقایسه تغییرات صفات در این دو رقم در طی پانزده روز نشان داد میزان pH در هر دو رقم افزایش داشت، درحالیکه در طی این پانزده روز میزان مواد جامد محلول و شاخص طعم در رقم پاروس، به طرز معنیداری افزایش یافت. سفتی بافت و درصد کاهش وزن در هر دو رقم طی پانزده روز کاهش معنی داری نشان داد ولی این کاهش در رقم کاماروزا بیشتر بود. صفات کیفی و بیوشیمیایی مورد مطالعه و نیز شاخص طعم در دو رقم توتفرنگی طی پانزده روز به طور موثری تحت تاثیر نوع رقم و مدت نگهداری تغییر کردند. این بررسیها نشان داد نوع رقم توتفرنگی عامل تعیینکنندهای به لحاظ حفظ ارزش غذایی و نیز محتوای ترکیبات طبیعی در طی نگهداری و شرایط پس از برداشت میباشد، بهطوریکه رقم کاماروزا از این جنبهها برتری ویژهای نسبت به رقم پاروس نشان داد. بهنظر میرسد ذخیرهسازی در دمای پایین روشی کارآمد برای نگهداری میوه توتفرنگی است
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Objectives: Canary Islands bananas represent the only native cultivar of Musa spp. present in Spanish territory. Since 2013, it has the Protected Geographical Indication label, which confers an additional value to this fruit. Bananas from the Canary Islands have certain organoleptic properties that make them stand out from among other commonly consumed Musa spp. However, to date, no studies have been reported including an extended nutritional composition of this product. Methods: the present work shows the main nutritional components of bananas from the Canary Islands as determined by different analytical techniques (mainly liquid chromatography, spectroscopy, spectrophotometry, and polarimetry) when at their best in terms of ripeness (grade 6). Moreover, potential nutrition claims relating to their composition were proposed using the current legislation. Results: the fruit's remarkable content in vitamin B6 (0.52 g/100 g), dietary fiber (2.22 g/100 g), potassium (419.9 mg/100 g), and vitamin C (12.35 mg/100 g) should be highlighted. Additionally, these components could appear on nutritional labeling as claims, according to current European regulations. Conclusions: a daily consumption of one Canary Islands banana contributes to the recommended dietary intake of vitamin B6, vitamin C, potassium, and dietary fiber. The high nutritional value of this fruit enhances its presence in the Mediterranean eating pattern, being remarkable as a local product with excellent nutritional properties.
Chapter
Berries are small fleshy fruits, which are cultivated and commonly consumed in fresh and processed forms. This group includes, among others, strawberries ( Fragaria spp.) and blackberries ( Rubus spp.). This chapter aims to review the impact of different washing and/or disinfection methods on the bioactive compounds of strawberries and blackberries. There are different techniques for brining the fruit and the sanitizing agent into contact: immersion, spraying, and fogging. In each one of these techniques, the right combination of operational variables should be determined that allows the desired disinfection to be achieved without loss of quality or healthy potential. All the techniques required process optimization to find the conditions that allow achieving surface decontamination, without losing the healthy potential of the fruits. In short, the fogging of berry fruits (strawberries and blackberries) using the ecological peracetic acid sanitizer could be a promising option to extend the post‐harvest life of these fruits without compromising their general appearance.
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A novel natural method was developed to preserve the freshness quality of Prunus salicina Lindl. cv. ‘Shazikongxinli’ fruit during post-harvest storage. The fresh-keeping paper soaked in different solutions containing chitosan and natamycin was developed and applied to the ‘Shazikongxinli’ fruit for physiochemical, biochemical, and enzymatic activities. Chitosan-natamycin interaction provided an excellent protective effect on ‘Shazikongxinli’ fruit quality during post-harvest storage compared to other treatments. This result could be confirmed by the lowest browning index, polyphenol oxidase activity, and weight loss percentage. Besides, vitamin C, peroxidase, and titratable acid were recorded highest in the chitosan-natamycin treated group, which is 0.32 mg 100 g⁻¹, 6.0 U min g⁻¹, and 4.50 mol L⁻¹ at 15 days, respectively. Furthermore, interlinkages between phenolic content, polyphenol oxidase (PPO) activity, and browning index were also recorded, which played an influential role in maintaining fruit quality. The study results could have commercial applications for preserving qualities and extending the shelf-life of fruits.
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This study investigated the effect of LED illumination on the inactivation of Rhizopus stolonifer and Botrytis cinerea on strawberries and physicochemical properties of the strawberries. Twelve days of illumination resulted in an antifungal effect of 3.4 and 1.9 log CFU/g on R. stolonifer and B. cinerea, respectively. The illumination caused no significant effect (P ≥ 0.05) on the mass, color and texture of strawberries. Furthermore, total phenol content, trolox equivalent antioxidant capacity and anthocyanin content of the illuminated strawberries significantly increased (P < 0.05). Vitamin C content of illuminated strawberries was only significantly different (P < 0.05) from the control starting from Day 9. These results show that 405 nm LED illumination can potentially complement temperature and humidity control in preventing mold spoilage and preserving physicochemical quality of strawberries during refrigerated storage.
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As a natural enzyme, alkaline phosphatase (ALP) plays an essential role in clinicopathological examinations and biomedical research, which is capable of hydrolyzing the phosphate group of L‐ascorbic acid‐2‐phosephate (AAP) to yield L‐ascorbic acid (L‐AA). While L‐AA could reduce cobalt oxyhydroxide (CoOOH) nanoflakes to Co2+, leading to a smaller size and weaker light scattering, which could be monitored by electron microscopic images and optical spectra. Hereby, the indirect detection of ALP was achieved by the reduced light scattering signal of CoOOH nanoflakes. Under the optimal conditions, the decrease in the scattering intensity was proportional to the concentration of ALP in the range of 0.1~160 U/L and the detection limit was 0.034 U/L (3σ/k). Compared with the other assays, the proposed light scattering method were more convenient and economic for ALP sensing. The method was successfully applied to ALP analysis in human serum samples, which was similar to the result obtained by the commercial kits.
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Summary Chemical composition in different parts of banana pulp was determined. Ash and protein mean concentrations in the central part of the pulp were higher than in the me- dium part, and these were higher than those in the external part. The mean concentrations of the fiber (total and non-soluble) in the central part were higher than those found in the other parts. Ascorbic acid behaved inversely; the mean concentration significantly decrea- sed from the external part to the central part. The central part contained the highest mean concentrations of the analysed minerals (Na, K, Ca, Mg, Fe, Cu, Zn and Mn), with statisti- cally significant differences for Cu, Zn and Ca. A tendency to differentiate the pulp sam- ples of banana as a function of the part considered was observed after using factor anal- ysis. The samples from the central part were different from those from the external part. The samples of the medium part overlapped with those of the other two parts.
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A new method for determination of ascorbic acid using gas chromatography was developed and compared to the high-performance liquid chromatography (HPLC) one. The analysis was performed after simple clean up techniques and a freeze drying step. Total ascorbic acid was analyzed after reduction of dehydroascorbic acid by dithiothreitol as in some HPLC methods. These conditions can be employed only for ascorbic acid or for multi-compound assay.
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A storage study of orange juice packed in oxygen scavenging (OS) film and oxygen barrier film was conducted to determine the extent of ascorbic acid loss due to oxygen as a function of time and temperature. The initial concentration of ascorbic acid in the orange juice was 374 mg/l and this was found to decrease by 74 and 104 mg/l after 3 days of storage at 25 °C in the OS and oxygen barrier film, respectively. This rapid loss in ascorbic acid correlated well with the amount of oxygen initially present in the headspace and that dissolved in the juice. The loss of ascorbic acid also correlated with an increase in the browning of the juice, where the extent of browning was found to be lower for the juice packed in the OS film than that packed in the oxygen barrier material. The rapid removal of oxygen was found to be an important factor in sustaining a higher concentration of ascorbic acid over long storage times.
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Physical (weight, size, shape, texture and colour), physicochemical (pH, titratable acidity, soluble solids, moisture content, total solids), chemical (soluble sugars, vitamin C, starch, pectic substances, volatile compounds) and biochemical (polyphenol oxidase and peroxidase activities, soluble proteins) characteristics and sensory attributes (appearance, flavour, odour, colour, firmness, acceptability) of banana (Musa cavendishii L.) fruits were studied in order to assess possible differences between nutritional properties and consumer acceptability of the local (Canarian) cultivars Enana and Gran Enana and the Latin-American (Colombian) Enana cultivar. Significant differences (P ≤ 0·05) were found between size and length of fruit, and between other objective measurements (lightness, yellowness, acidity, moisture content, starch, peroxidase and polyphenol oxidase activities, soluble sugars—sucrose, fructose, glucose). Also there were significant differences in vitamin C and protein content which established the higher nutritional value of the Spanish banana cultivars. The main compositional differences between the banana cultivars in terms of flavour were quantified. Purge and trap (head-space) analysis of the Spanish Enana cultivar showed it was the richest in the characteristic banana volatile aroma compounds. Sensory descriptive analysis discriminated between banana cultivars in terms of flesh colour and flesh sweetness; although panellists liked all cultivars, they preferred the Spanish Enana fruits (overall acceptability test).
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The importance of vitamin C to the human body is widely acknowledged throughout the globe. The deficiency of this vitamin leads to various diseases. In view of its importance, numerous methods including spectrophotometric ones have been developed for its determination in pharmaceuticals, foods and biological samples. A comprehensive review of the available spectophotometric methods for the determination of ascorbic acid is presented.
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Ascorbic acid content of commercial fruit juices and its rate of loss with respect to time and temperature of storage were determined. Ascorbic acid content of commercial fruit juices ranged from 2.4 to 43 mg/100 ml of juice. Storage of commercial fruit juices in closed containers at room temperature for 4 months resulted in ascorbic acid losses ranging from 29 to 41%. Commercial orange juice when stored in open containers in the refrigerator for 31 days lost 60 to 67% of its ascorbic acid while fresh orange juice lost ascorbic acid at the much slower rate of 7 to 13%. Open containers of commercial fruit juice, when stored outside the refrigerator for 10 days, lost 12.5% of their ascorbic acid content, while refrigerated for the same period, the ascorbic acid losses amounted to 9%.
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High performance liquid chromatography combined with laboratory robotic extraction procedures was utilized to determine the ascorbic acid and the dehydroascorbic acid content of the principal sources of vitamin C in the American diet. Variation of the vitamin content from sample to sample and source to source is studied and it is concluded that human diet studies should be accompanied by nutrient composition studies to determine reliable vitamin C intake. A case study on broccoli provided guidelines for the proper storage conditions required, if necessary, in order to obtain reliable data on vitamin C intake.
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Humans are unable to synthesise L-ascorbic acid (L-AA, ascorbate, vitamin C), and are thus entirely dependent upon dietary sources to meet needs. In both plant and animal metabolism, the biological functions of L-ascorbic acid are centred around the antioxidant properties of this molecule. Considerable evidence has been accruing in the last two decades of the importance of L-AA in protecting not only the plant from oxidative stress, but also mammals from various chronic diseases that have their origins in oxidative stress. Evidence suggests that the plasma levels of L-AA in large sections of the population are sub-optimal for the health protective effects of this vitamin.Until quite recently, little focus has been given to improving the L-AA content of plant foods, either in terms of the amounts present in commercial crop varieties, or in minimising losses prior to ingestion. Further, while L-AA biosynthesis in animals was elucidated in the 1960s,1 it is only very recently that a distinct biosynthetic route for plants has been proposed.2 The characterisation of this new pathway will undoubtedly provide the necessary focus and impetus to enable fundamental questions on plant L-AA metabolism to be resolved.This review focuses on the role of L-AA in metabolism and the latest studies regarding its biosynthesis, tissue compartmentalisation, turnover and catabolism. These inter-relationships are considered in relation to the potential to improve the L-AA content of crops. Methodology for the reliable analysis of L-AA in plant foods is briefly reviewed. The concentrations found in common food sources and the effects of processing, or storage prior to consumption are discussed. Finally the factors that determine the bioavailability of L-AA and how it may be improved are considered, as well as the most important future research needs.© 2000 Society of Chemical Industry
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Food levels of vitamin C and flavonoids not only vary greatly depending on species and variety, growing location, harvesting time, storage, processing, and other conditions, but also with respect to methodological differences. For accurate dietary exposure determination and in support of future studies on the effects of dietary vitamin C and flavonoids, we determined ascorbic acid, and the major dietary flavones (apigenin, luteolin), flavonols (kämpferol, quercetin, myricetin), flavanones (hesperetin, naringenin and their glycosides), and anthocyanidins (pelargonidin, cyanidin, delphinidin) in fruits and vegetables commonly consumed in Hawaii. After optimization of extraction procedures to avoid loss of these sensitive analytes, high-pressure liquid chromatography with electrochemical, diode-array and/or mass spectrometric detection revealed concentrations ranging in foods as eaten from 4 to 801 mg/kg for ascorbic acid and 172 to 905 mg/kg for citrus flavanones to as high as 259 mg/kg for flavones/flavonols and 1168 mg/kg for anthocyanidins. Storage and processing, especially when heat was applied, led to significant losses of all analytes. The high variability in the levels of these antioxidants, in part caused by culturally diverse food preparation techniques, indicates that food level determinations are a prerequisite for accurate human diet studies.
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The antioxidant capacity of a group of fruits obtained in the Singapore markets was investigated. A total of 27 fruit pulps were tested for their general antioxidant capacity based on their ability to scavenge 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical. The contribution of l-ascorbic acid (AA) to the total antioxidant activity of fruits was investigated by using RP-HPLC. The antioxidant capacity of the fruit pulp was measured by monitoring the change of absorbance of the free radical solution at 414 nm in the test reaction mixture following addition of the fruit extract, as compared with AA. The results were expressed as mg of AA equivalents per 100 g, i.e. the quantity of AA required to produce the same scavenging activity as the extract in 100 g of sample (l-ascorbic acid equivalent antioxidant capacity, AEAC). Total antioxidant capacities of AA acid, trolox, hydroquinone, pyrogallol and several fruits were also evaluated based on its ability to scavenge the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Results obtained were compared with those of ABTS assay. Every mol of AA, trolox or hydroquinone, was found to reduce about 2 mol of ABTS+ or DPPH. However, 4 mol of DPPH or 7 mol of ABTS+ were scavenged by every mol of pyrogallol. A good correlation of AEAC was observed between the two methods. Both methods have been recommended to be useful tools to evaluate antioxidant capacities of fruits. According to the AEAC value of binary extract solution of fruits in the ABTS model, ciku shows the highest antioxidant capacity, followed by strawberry, plum, star fruit, guava, seedless grape, salak, mangosteen, avocado, orange, solo papaya, mango, kiwi fruit, cempedak, pomelo, lemon, pineapple, apple, foot long papaya, rambutan, rambutan king, banana, coconut pulp, tomato, rockmelon, honeydew, watermelon and coconut water. The AA contribution to AEAC of fruits varied greatly among species, from 0.06% in ciku to 70.2% in rambutan.
Article
The application of capillary zone electrophoresis with UV–VIS and diode array detection for simultaneous analysis of l-ascorbic and d-isoascorbic acids was investigated. The method of analysis was simple, fast and its performance was tested in terms of linearity, sensitivity and detection limit. Twenty-six samples representative of three types of apricot commercial juices (organic, integrated and conventional) were analysed for their ascorbic acid content and data were reported (range n.d.–486 mg/l).
Article
Vitamin C, including ascorbic acid and dehydroascorbic acid, is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. The content of vitamin C in fruits and vegetables can be influenced by various factors such as genotypic differences, preharvest climatic conditions and cultural practices, maturity and harvesting methods, and postharvest handling procedures. The higher the intensity of light during the growing season, the greater is vitamin C content in plant tissues. Nitrogen fertilizers at high rates tend to decrease the vitamin C content in many fruits and vegetables. Vitamin C content of many crops can be increased with less frequent irrigation. Temperature management after harvest is the most important factor to maintain vitamin C of fruits and vegetables; losses are accelerated at higher temperatures and with longer storage durations. However, some chilling sensitive crops show more losses in vitamin C at lower temperatures. Conditions favorable to water loss after harvest result in a rapid loss of vitamin C especially in leafy vegetables. The retention of vitamin C is lowered by bruising, and other mechanical injuries, and by excessive trimming. Irradiation at low doses (1 kGy or lower) has no significant effects on vitamin C content of fruits and vegetables. The loss of vitamin C after harvest can be reduced by storing fruits and vegetables in reduced O2 and/or up to 10% CO2 atmospheres; higher CO2 levels can accelerate vitamin C loss. Vitamin C of produce is also subject to degradation during processing and cooking. Electromagnetic energy seems to have advantages over conventional heating by reduction of process times, energy, and water usage. Blanching reduces the vitamin C content during processing, but limits further decreases during the frozen-storage of horticultural products.
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In view of the widespread use of Vitamin C, a large number of methods have been developed for quantifying Vitamin C contents in natural and fortified food samples and pharmaceuticals. It is therefore essential to assess these methods. Accordingly, this paper reviews non-spectrophotometric methods.
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Tolerances of peach and nectarine fruits to insecticidal controlled atmospheres were determined by the time before occurrence of visual injury and/or off-flavor. The tolerances of ‘John Henry’ peaches, ‘Fantasia’ nectarines, ‘Fire Red’ peaches, ‘O'Henry’ peaches, ‘Royal Giant’ nectarines, and ‘Flamekist’ nectarines to 0.25% O2 (balance N2) at 20°C were 2.8, 4.0, 4.0, 4.4, 5.1, and 5.2 days, respectively. ‘Fairtime’ peaches tolerated 0.21% O2 + 99% CO2 at 20°C for 3.8 days, 0.21% O2 + 99% CO2 at 0°C for 5.0 days, 0.21% O2 at 20°C for 6.0 days, and 0.21% O2 at 0°C for up to 19 days. Soluble solids content, pH, titratable acidity, and vitamin C content of ‘Fairtime’ peaches were not significantly influenced by the low O2 and/or high CO2 treatments. There was a good correlation between tolerances of peaches and nectarines to the insecticidal atmospheres and the accumulation rates of acetaldehyde (r = −0.94, P < 0.01) and ethanol (r = −0.88, P < 0.01). The lower tolerance of ‘John Henry’ peaches to 0.25% O2 was associated with a higher respiration rate, a more mature and larger fruit, and faster accumulation rates of acetaldehyde, ethanol, and ethyl acetate. Generally, accumulation rates of anaerobic volatiles were higher in more mature and larger fruits of ‘O'Henry’ peaches and ‘Fantasia’ nectarines kept in 0.25% O2, air + 35% CO2, or 0.25% O2 + 35% CO2 at 20°C. Comparison of fruit tolerance and published information on the time to reach 100% mortality of some insects suggests that 0.25% O2 at 20°C is probably not feasible for postharvest insect disinfestation while 0.21% O2 with or without 99% CO2 at 0°C merits further investigation.
The total vitamin C amount in different food and plasma samples was determined by a dual detection system, after HPLC separation, with direct detection of ascorbic acid and indirect fluorimetric detection of dehydroascorbic acid after a post-column O-phenyldiamine derivatisation. The two active forms of vitamin C and their D-isomers were separated within 10 min. The repeatability was determined by measurement of several fruits and vegetables and ranged from 0.3 to 1.9% (relative standard deviation) for vitamin C. The reproducibility, based on double determinations, ranged from 1.9 to 3.6% for vitamin C, depending on the matrix. The reproducibility, based on several determinations of reference materials, ranged from 2.4 to 3.7% for ascorbic acid and from 4.3 to 5.8% for dehydroascorbic acid, again depending on the matrix.
Article
A liquid chromatographic method has been described for the determination of total vitamin C, ascorbic acid (AA) and dehydroascorbic acid (DHAA) in fruits and vegetables. The complete separation of AA and DHAA could be achieved on a C18 column using 0.2 M KH2PO4 (pH adjusted to 2.4 with H3PO4) as the mobile phase at a flow-rate of 0.5 ml/min. Since the detection sensitivity was poor for DHAA even at 210 nm, it was estimated as the difference between the total AA after DHAA reduction and AA content of the original sample, using dithiothreitol (DTT) as the precolumn reductant. The reaction times for the complete conversion of DHAA to AA at room temperatures were 150, 120, 90 and 75 min for 1, 2, 4 and 8 mmol DTT per mmol of DHAA, respectively. The percentage recovery ranged from 81.7 to 105.9. AA contents of some selected fruits and vegetables were analyzed comparatively by liquid chromatography and enzymatic assay to validate the method.
Article
Dehydroascorbic acid (DHA) is an important, interesting but somewhat enigmatic compound in biological systems. DHA has many unique properties that set it apart from ascorbic acid (AA), and DHA has functions that may be very important beyond that in the AA:DHA cycle. Future studies should help to better clarify chemical activity of DHA and related products that form from DHA, as well as to highlight the role DHA plays in normal cellular homeostasis.
Article
Vitamin C (ascorbic acid (AA)) is very popular for its antioxidant properties. Consequently, many other important aspects of this multifaceted molecule are often underestimated or even ignored. In the present paper, we have tried to bring to the foreground some of these aspects, including the peculiarities of the AA biosynthetic pathway in different organisms, the remarkable function of AA as a co-substrate of many important dioxygenases, the role of AA-regenerating enzymes and the known pathways of AA catabolism, as well as the intriguing function of AA in gene expression.