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Extraction of natural antioxidants from hazelnut (Corylus avellana L.) shell and skin wastes by long maceration at room temperature

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Abstract

The feasibility of obtaining antioxidant phenolic extracts from hazelnut by-products was investigated by long maceration at room temperature. The hard shells and defatted skins of both whole and chopped roasted hazelnut kernels were studied. Three solvent systems were employed and these included aqueous methanol, ethanol and acetone. Extraction yields as well as phenolic contents varied according to the by-product and the solvent used. Among the studied samples, the skin of whole roasted hazelnuts gave remarkably high extraction yields (about 30%) and extracts with the richest phenolic content (up to 502 mg/g, expressed as gallic acid equivalents).Extracts were screened for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidation of linoleic acid in vitro model systems. The extracts from the skin of whole roasted hazelnuts manifested the strongest antioxidant activity, similar or superior to butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) and α-tocopherol, at equivalent concentrations. The presence of hazelnut fragments in the skin residue lowered the yield and the antioxidant activity of the extract. All the extracts were found to be very rich in tannins.

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... Recent research by Ozyurt et al. [10], determined total phenolic content to identify the total antioxidant activity to characterize the phenolic profile of hazelnut skin. Additionally, Contini et al. [12] verified the presence of tannin compounds obtained from phenolic extracts of hazelnut shell and skin wastes. Therefore, the usage of hazelnut skin as a source of antioxidants and dietary fiber may offer beneficial supplements to the food, medicine, and cosmetic industries [7]. ...
... The content of total phenols ranged from 155.3 ± 2.1 mg GAE /g DW in Giffoni hazelnut skin to 153.3 ± 3.9 mg GAE /g DW in Romana hazelnut skin; the content of total flavonoids ranged from 27.2 ± 0.7 mg RE /g DW in Giffoni skin to 27.8 ± 2.3 mg RE /g DW in Romana skin (Table 1). Del Rio and coworkers (2011) [22] reported that the phenol content in aqueous extracts was 8.7 ± 0.3 g/100 g in Giffoni skin and 9.0 ± 0.0 in Romana skin; Contini and collaborators (2008) [12], showed that phenol content in methanol extract carried out on different varieties (Italian Tonda Gentile Romana, Tonda di Giffoni, Tonda Gentile delle Langhe, Turkish Tombul) was 426.7 ± 4.6 mg GAE/g. Since the antioxidant compounds in foods are chemically different and structurally complex, no single assay is suitable to accurately determine the antioxidant activity for all compounds. ...
... The antioxidant capacity ranged from 13.2 ± 0.1 mM TE in Giffoni hazelnut skin to 13.1 ± 0.2 mM TE in Romana hazelnut skin with the TEAC method and to 23.3 ± 5.8 mM TE in Giffoni skin to 23.1 ± 6.2 mM Te in Romana skin with the FRAP method (Table 1). Contini and collaborators (2008) [12], showed that the antioxidant capacity in methanol was 68 ± 1.2 mg GAE/ mg DPPH); Del Rio and coworkers (2011) [22] reported that antioxidant capacity was 1321.1 ± 54.4 mmol Fe 2+ Equivalent/kg in Giffoni and 1229.9 ± 47.0 Fe 2+ Equivalent /kg in Romana. The difference in phenolics content and antioxidant capacity could depend on the extraction methods/solvents used and on environmental factors. ...
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Agro-wastes are one of the major sources for nutritional and therapeutic benefits along with other beneficial properties. Dark brown pellicular pericarp (skin or testa), covering the hazelnut seed, is removed before consumption after the roasting of a kernel. Defatted skins of both hazelnut varieties, Tonda Gentile Romana and Tonda di Giffoni, were profiled by a metabolomics-based approach and this was used to discriminate between these two different hazelnut cultivars. In particular, an untargeted metabolomic extract from hazelnut by-products was investigated by UHPLC-Mass spectrometry followed by multivariate statistics analysis, and significant qualitative and quantitative metabolic differences were observed between them. Samples were also assessed for their total phenolic and antioxidant capacity using two different assays. Although no significant differences were found in total phenolic contents and antioxidant capacity, the Flavone, Flavonol, Flavonoid, and Phenylpropanoid Biosynthesis pathway was significantly higher in the Romana rather than in the Giffoni variety, whereas Myricetin and Syringetin compounds were more representative in Giffoni cultivars. These results indicated that hazelnut skin, especially from the Romana variety, could potentially be used as an ingredient in healthy food. Healthy food is a new food category with an expanding demand from future generations.
... In addition, hazelnut contains phytochemicals described as calori-free, natural bioactive compounds such as phenolic compounds (Alasalvar and Shahidi, 2009). Several studies indicated total phenolic content and also phenolic compounds (Solar and Stampar, 2011;Güner et al., 2017) identified as phenolic acids acting as antioxidant (Altun et al., 2011;Arcan and Yemenicioğlu, 2009;Contini et al., 2008;Li and Parry, 2011). Recently, the total antioxidant capacity and antioxidant active compounds in hazelnut have been reported (Altun et al., 2011;Arcan and Yemenicioğlu, 2009;Contini et al., 2008;Delgado et al., 2010;Ghirardello et al., 2013;Li and Parry, 2011;Miraliakbari and Shahidi, 2008;Shahidi et al., 2007;Yang et al., 2009). ...
... Several studies indicated total phenolic content and also phenolic compounds (Solar and Stampar, 2011;Güner et al., 2017) identified as phenolic acids acting as antioxidant (Altun et al., 2011;Arcan and Yemenicioğlu, 2009;Contini et al., 2008;Li and Parry, 2011). Recently, the total antioxidant capacity and antioxidant active compounds in hazelnut have been reported (Altun et al., 2011;Arcan and Yemenicioğlu, 2009;Contini et al., 2008;Delgado et al., 2010;Ghirardello et al., 2013;Li and Parry, 2011;Miraliakbari and Shahidi, 2008;Shahidi et al., 2007;Yang et al., 2009). ...
... were similar to those reported by Firestone (2013). It was shown previously that hazelnut has high antioxidative activity analysed by several methods such as TAC, ORAC, CUPRAC, TOSC, ABTS/ persulfate, AAPH-linoleic acid assay, and DPPH (Altun et al., 2011;Arcan and Yemenicioğlu, 2009;Contini et al., 2008;Delgado et al., 2010;Ghirardello et al., 2013;Li and Parry, 2011;Miraliakbari and Shahidi, 2008;Shahidi et al., 2007;Yang et al., 2009). In this study, we evaluated the antioxidant capacity of hazelnut kernels, hazelnut oils and defatted hazelnut kernels using the DPPH-radical assay (Figure 1). ...
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Hazelnut providing the macro-and micronutrients is a constituent of the healthy diet. Hazelnut, one of the most consumed treenut, is produced in the different countries. The geographical origin influences the chemical composition and the biological activity in the several plant foods. The purpose of this study is to evaluate the chemical composition, the antioxidative capacity and total phenolic content of the hazelnut kernels obtained from the different countries, including Azerbaijan, Chile, Italy, and Turkey. The hazelnut kernels were examined for crude oil, ash, moisture, and protein contents. The refractive index, iodine value, and fatty acid composition of the hazelnut oils were identified. In addition, the hazelnut oil, the kernels, and the defatted kernels were tested for their antioxidative activities and total phenolic contents. Protein contents of the hazelnuts from different countries were similar. The largest oil yield was determined in the hazelnut kernels from Chile and Turkey (62.35 ± 0.51 % and 62.29 ± 0.46 %, respectively). While the oil from Turkish hazelnut kernels showed the highest oleic acid content (84.09 ± 0.17 %), Azerbaijan hazelnut oil had the lowest oleic acid content (78.10 ± 0.48). The highest phenolic content was detected in the hazelnut kernels from Azerbaijan. Although the lowest phenolic content was observed in the hazelnut kernels from Turkey, the most potent antioxidative capacity was determined in the Turkish hazelnut kernels, their oil, and their defatted form. It can be concluded that the Turkish hazelnut kernels could contain high amounts of the fat-soluble antioxidants in addition to the water-soluble phenolic antioxidants. The results suggested that the hazelnuts exhibited different chemical composition, antioxidant capacity, and phenolic content depending on their origin. Keywords: Hazelnut oil, Geographical origin, Fatty acid composition, Antioxidant capacity, Total phenolic content
... The extraction yield of the shell ranged from 3.00 ± 0.45 to 14.81 ± 0.92, and the extraction yield of the kernel ranged from 8.19 ± 1.26 to 24.23 ± 0.78. Similar results have been obtained for other plant species, such as pecan [25] and hazelnut [26]. * Mean within a row followed by the same lower case letter are not significantly different at 5% level by Tukey test. ...
... The results of a reducing power assay (Figure 4) indicated that the shell extract obtained using 95% ethanol had the highest reducing capacity. In agreement with the results of a previous study about Corylus avellana L. [26], the antioxidant activity decreased with the water content in the extraction ...
... The results of a reducing power assay (Figure 4) indicated that the shell extract obtained using 95% ethanol had the highest reducing capacity. In agreement with the results of a previous study about Corylus avellana L. [26], the antioxidant activity decreased with the water content in the extraction solution; however, the extraction yield increased. As the water content in the extraction solution decreased, the antioxidant capacity of the shell extract increased considerably from 18.81 ± 4.50 (0% ethanol) to 695.14 ± 27.04 (95% ethanol) µg AAEs/mg of extract. ...
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The purpose of this study was to determine the antioxidant activity of the seed shells and kernels of Jatropha curcas L. The extracts obtained from five solutions (0%–95% ethanol) were tested and compared. Overall, the antioxidant capacity of seed shell extracts was higher than that of seed kernel extracts. The seed shell extract obtained using 95% ethanol exhibited the best antioxidant activity among the five solutions. The half-maximal inhibitory concentration (IC50) of 1,1-diphenyl-2-picrylhydrazyl and free radical scavenging ability of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) were 13.63 ± 0.15 and 6.75 ± 0.51 μg/mL, respectively. The reduction ability and total phenol content were 95.14 ± 27.04 μg ascorbic acid equivalents/mg of extract and 536.33 ± 8.62 μg gallic acid equivalents/mg of extract, respectively. In in vitro cytotoxicity assays, solutions with less than 250 μg/mL of seed shell extract had no major cytotoxicity. The seed shell of Jatropha curcas L. can be used as an antioxidant material and has potential for biomedical applications.
... Hazelnuts (Corylus avellana L. Betulaceae) and walnuts (Juglans regia L. Juglandaceae) are important commercial crops worldwide, which generate a large amount of shells as by-products from the processing industry [4,5]. On the one hand, hazelnuts are well-known nuts with an average annual production of about 55,8500 tons (with shell), out of which 75% is produced in Turkey, followed by 15% in Italy [6]. ...
... The TPC of HS crude polar extract was significantly higher (41.75) than the one observed for WS hydrophilic extract (13.14 mg GAE/g extract). The reported data from this type of lignocellulosic extracts vary greatly since the chemical composition is highly influenced by the isolation method and solvent type employed [5,34,36,38]. However, similar results were found for hydrophilic extracts from hazelnut shells isolated by methanol (56.6), ethanol (59.6), and acetone (72.2 mg GAE/g) [5]. ...
... The reported data from this type of lignocellulosic extracts vary greatly since the chemical composition is highly influenced by the isolation method and solvent type employed [5,34,36,38]. However, similar results were found for hydrophilic extracts from hazelnut shells isolated by methanol (56.6), ethanol (59.6), and acetone (72.2 mg GAE/g) [5]. Moreover, for extracts derived from walnuts shells lower TPC values were found ranging from 13.4 to 30.1 mg GAE/g extract [39], which is in agreement with the results of the present work. ...
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Hazelnut (HS) and walnut (WS) shells, an abundant by-product of the processing industries of these edible nuts, are traditionally considered as a low-value waste. However, they are a source of valuable compounds with an interesting chemical profile for the chemical and pharmaceutical sectors. In this study, the lipophilic and hydrophilic extracts present in HS and WS were quantified and identified, then the polar fractions were chromatographically separated, and their antioxidant capacity was studied. The experimental work includes the isolation of crude lipophilic and hydrophilic extracts by an accelerated extraction process, chromatographic analysis (gas chromatography-flame ionization (GC-FID), GC-mass spectroscopy (GC-MS), high-performance size-exclusion chromatography (HPSEC), thin-layer chromatography (TLC)), and quantification of the components. In addition, a thorough compositional characterization of the subgroups obtained by flash chromatography and their antioxidant capacity was carried out. The gravimetric concentrations showed different lipophilic/hydrophilic ratios (0.70 for HS and 0.23 for WS), indicating a higher proportion of polar compounds in WS than in HS. Moreover, the lipophilic extracts were principally composed of short-chain fatty acids (stearic, palmitic, and oleic acid), triglycerides, and sterols. The polar fractions were screened by thin-layer chromatography and then separated by flash chromatography, obtaining fractions free of fatty acids and sugar derivatives (97:3 in HS and 95:5 in WS), and mixtures richer in phenolic compounds and flavonoids such as guaiacyl derivatives, quercetin, pinobanksin, and catechin. The most polar fractions presented a higher antioxidant capacity than that of the crude extracts.
... Bacchetta, Tronci, and Aramini (2015) identified a total of 18 phenolic compounds and quantitatively determined them in 57 hazelnut cultivars. Furthermore, hazelnut skins can be considered an inexpensive source of natural antioxidants (Alasalvar, Karamać, et al., 2009a;Alasalvar, Amaral, Satir, & Shahidi, 2009b;Contini, Baccelloni, Massantini, & Anelli, 2008;Boccacci et al., 2013) when nuts are consumed as natural products. ...
... The radical scavenging ability or hydrogen-donating of the hazelnut extract was monitored using the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), following the method described by Contini et al. (2008) with slight modifications as follows: liquid extract (100 µL), 80% ethanol (100 µL) or 6-hydroxy-2,5,7,8 tetramethychroman2-carbossylic acid (Trolox, Sigma-Aldrich, USA) used as referent antioxidant, in triplicate, was mixed in a 1 cm disposable cuvette with 2.9 ml of freshly prepared ethanol solution of DPPH (0.06 mM) and incubated in dark conditions for 15 min. At this time, the decrease in absorbance was measured at 517 nm against a blank of ethanol (Beckman DU530 UV/ VIS" spectrophotometer). ...
Article
Corylus avellana L. is known for its healthy properties, and yet previous studies have not dealt with its effects on human innate response. The aim of this study is to assess if C. avellana has an immune adjuvant effect. Human macrophages were pre-treated with hazelnut liquid extract, found to be rich in phenylpropanoids, and subsequently infected with Staphylococcus aureus. Based on the intracellular bacteria CFU reduction and on the treatment doses used, the donors were divided into High-Dose and Low-Dose-Responders. Expression profile for inflammatory and Iron metabolism genes, both for Peripheral Blood Mononuclear Cells and Macrophages, highlighted that Low-Dose-Responders came from a more pronounced pro-inflammatory milieu as compared with High-Dose-Responders. Blood test results revealed that Low-Dose-Responders had higher LDL C and Triglycerides and lower HDL C. Overall, our results suggest that the effect of the extract on Macrophage immune response is influenced by the intracellular inflammatory status of the donor.
... In this work, when comparing the performances of extraction solvents, it was confirmed by all methods that the antioxidant efficacies of the extracts obtained with the CC-PG was quite high (approximately three times) compared to that of the ethanol:water mixture. Phenolic fraction of hazelnut extracts contains polymerized polyphenols like tannins (Contini et al., 2008), dimeric B type procyanidins (Monagas et al., 2009) oligomeric flavan-3-ol contents (Del Rio, Calani, Dall'Asta, & Brighenti, 2011). As supposed by Shahidi et al. (2007), tannins represented the principal fraction of the phenolic substances of the extracts, amounting to nearly 60 to 65% of the total phenols. ...
... In the study of Alasalvar et al. (2009), it was evaluated that 80% (v/v) acetone was a more effective solvent than 80% (v/v) methanol for the extraction of condensed tannins in hazelnut skin samples. Contini et al. (2008) demonstrated that acetonic solvent was able to produce the highest amount of crude extract from hazelnut skin waste samples compared to methanol and ethanol. Condensed tannins with high antioxidant ability could be better extracted into acetone of low polarity. ...
Article
An environmentally friendly method using natural deep eutectic solvents (NADES) and microwave-assisted extraction (MAE) for the recovery of bioactive compounds from hazelnut pomace (a hazelnut oil process by-product) was developed to contribute to their sustainable valorization. Eight different NADES were prepared for the extraction of antioxidant constituents from hazelnut pomace, and choline chloride:1,2-propylene glycol (CC-PG) was determined as the most suitable NADES, considering their extraction efficiency and physicochemical properties. After selecting suitable NADES, operational parameters for the MAE process of antioxidants from hazelnut pomace were optimized and modeled using response surface methodology. For the highest recovery of antioxidants, the operational parameters of the MAE process were found to be 24% water, 38 minutes, 92 °C and 18 mL/0.1 g-DS. Under optimized conditions, extracts of both pomace as a by-product and unprocessed hazelnut flours of three different hazelnut samples (Tombul, Çakıldak, and Palaz) were prepared, and their antioxidant capacities were evaluated by spectrophotometric methods. Antioxidant capacities of CC-PG extracts of all hazelnut samples were 2-3 times higher than those of ethanolic extracts. In addition, phenolic characterization of the prepared extracts was carried out using the UPLC-PDA-ESI-MS/MS system. The results of this study suggest that hazelnut by-products can potentially be considered an important and readily available source of natural antioxidants. Furthermore, the modeled MAE procedure has the potential to create an effective and sustainable alternative for pharmaceutical and food industries.
... The PC have lower values for fourteen Turkish varieties ranged between 51.9 and 203.1 mg GAE/g [7], while for HS using aqueous methanol (80/20, v/v), aqueous ethanol (80/20 v/v) and aqueous acetone (80/20, v/v) for extraction, the obtained values are 499.7, 588.2 and 546.6 mg CE/g, respectively [39]. Total flavonoid contents (TFC) of HS extracts I-III, expressed as mg of CE per gram sample are very similar as it is shown in Table 3 and Figure 1. ...
... The TPC values are similar with reported results of 638 and 706 mg GAE/g for medium roasted and high roasted HS samples, respectively, by using the same solvent ethanol [26].The TPC have lower values for fourteen Turkish varieties ranged between 51.9 and 203.1 mg GAE/g [7], while for HS using aqueous methanol (80/20, v/v), aqueous ethanol (80/20 v/v) and aqueous acetone (80/20, v/v) for extraction, the obtained values are 499.7, 588.2 and 546.6 mg CE/g, respectively [39]. Total flavonoid contents (TFC) of HS extracts I-III, expressed as mg of CE per gram sample are very similar as it is shown in Table 3 and Figure 1. ...
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The present study evaluates natural composition of Serbian roasted hazelnut skins (HS) with potential role in application as functional nutrient of various food products. Total phenols (TPC) and flavonoids contents (TFC) in HS extracts obtained with different ethanol concentrations (10%—I, 50%—II and 96%—III) and their antioxidant activities were investigated. The highest total phenols content (706.0 ± 9.7 mgGAE/gextract) was observed in 96% ethanol HS extract. Ethanol HS extracts showed very high antioxidant activity with effective concentrations (EC50) ranged between 0.052 and 0.066 mg/mL. The phenol and flavonoid content of roasted HS extracts I–III was determined by HPLC-ESI-MS/MS analyses. Contents of lipids, proteins, carbohydrates, metals, and C, H, N, S elements in roasted HS were also determined. Relatively high C/N, C/P and C/N/P ratios, rich metal contents and fatty acids composition indicated that hazelnut skin might be a good candidate for use as either human or fungal functional nutrient. In addition, possible application of phenolic HS extracts as UV booster was studied by recording UV spectra (220–440 nm) of 10 mg/L of HS extracts I–III combined with 10 mg/L of chemical sunscreen agent benzophenone-3 and in vitro sun protection factor (SPF) was calculated.
... They are highly appreciated for their organoleptic properties and are also very nutritious and healthy due to their favourable nutritional composition. A study carried out on 17 different varieties of hazelnut cultivated in Turkey, in fact, reported a moisture content of 2-5%, a fuels and chemical feedstocks [33], or fibreboards [34], but also to exploit its content in phenolic compounds [35][36][37][38]. However, in recent years many studies have focused their attention on the hemicellulosic fraction extracted from HS, pointing out the presence of very interesting compounds that could reveal new possible uses of this by-product. ...
... Foods 2021, 10, x FOR PEER REVIEW 3 of 20 metals from the environment, such as lead [21,22], chromium, cadmium, zinc [23,24], nickel [25], copper [26], arsenic [27], but also dyes [28] and CO2 [29]. Other studies have investigated the possible use of HS to produce hydrogen [30,31], ethanol [32], renewable fuels and chemical feedstocks [33], or fibreboards [34], but also to exploit its content in phenolic compounds [35][36][37][38]. However, in recent years many studies have focused their attention on the hemicellulosic fraction extracted from HS, pointing out the presence of very interesting compounds that could reveal new possible uses of this by-product. ...
Article
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Hazelnuts are one of the most widely consumed nuts, but their production creates large quantities of by-products, especially shells, that could be upcycled into much more valuable products. Recent studies have shown that hazelnut shell hemicellulose is particularly rich in compounds that are potential precursors of xylooligosaccharides and arabino-xylooligosaccharides ((A)XOS), previously defined as emerging prebiotics very beneficial for human health. The production of these compounds on an industrial scale-up could have big consequences on the functional foods market. However, to produce (A)XOS from a lignocellulosic biomass, such as hazelnut shell, is not easy. Many methods for the extraction and the purification of these prebiotics have been developed, but they all have different efficiencies and consequences, including on the chemical structure of the obtained (A)XOS. The latter, in turn, is strongly correlated to the nutritional effects they have on health, which is why the optimization of the structural characterization process is also necessary. Therefore, this review aims to summarize the progress made by research in this field, so as to contribute to the exploitation of hazelnut waste streams through a circular economy approach, increasing the value of this biomass through the production of new functional ingredients.
... The determination of the total phenolic content of the extracts were determined by Folin Ciocalteu method (Contini et al., 2008;Slinkard et al., 1977). The extracts were dissolved in EtOH (1000 ppm) and, 500 μL and 1000 μL samples were taken from the extracts. ...
... Determination of Radical Scavenging Capacity Using DPPH Method DPPH method was used for verifying the antioxidant capacity of the extracts (Contini et al., 2008;Slinkard et al., 1977). The extracts were kept in the dark and ambient conditions for 30 min. ...
... Consequently, much research has delved into cleaner tanning systems that are more eco-friendly and less hazardous to both the environment and human health [10,[12][13][14]. Many of the adopted technologies involve the use of eco-benign natural plant products either synergistically or using singular essence extracts [15][16][17][18][19][20][21][22][23]. Natural plant tannins contain polyphenols that can be categorized into hydrolysable or condensable tannins [13]. ...
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The stringent environmental regulations and compliance regarding leather tanning has compelled leather industry to seek alternative cleaner ingredients that have the capacity to minimize or prevent pollution caused by hazardous chemicals. Practical measures have so far involved replacing the current use of synthetic chemicals such as chromium salts, dyes, fatliquors and surfactants or minimizing their usage by incorporating agro-based organic components. Numerous papers have documented the use of different plant extracts at different stages of leather processing such as tanning, retanning, dyeing and fatliquoring. This present article details the specific plants and the leather processing stage at which they are applied and eventually the quality of the resulting leather. This article attempts to compile a considerable number of investigations published on physical properties of leather that is processed using natural plants. It has been shown that there are striking similarities in leather properties of leather processed using natural plants and using synthetic chemicals. This could help in compiling a database that details works on natural plants, stages of application and the corresponding physical properties which could provide a crucial assistance to research focusing on environmental protection and physical properties of leather which would in turn improve the quality of the resulting leather.
... Ayrıca yapılan çalışmalar antioksidan özelliğini kanıtlamıştır. 29 Crataegus monogyna Jacq. (Adi alıç): Adi alıçın UV ışınlarına karşı iyi koruma sağladığı ve güçlü antioksidan aktivite gösterdiği bildirilmiştir. ...
... In literature, antioxidant capacity and phenolic content have been reported about hazelnut kernel, green leafy cover, and brown skin in many studies [3,4,17,18]. For example, antioxidant capacity and phenolics from hazelnut by-products (shells and defatted skins) have been reported by using solvent maceration at room temperature with extraction yield of 30% and 502 mg g -1 GAE phenolic content in ethanol/water (80/20 v/v) mixture [3]. ...
... Total phenolic content (PC) was determined by using Folin-Ciocalteu's method as described by Contini et al. (2008) with slight modification. The tannic acid solution was used for calibration. ...
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This research was intended to evaluate the effect of packaging materials on the physicochemical stability of ground roasted coffee during storage at room temperature (28 ± 2°C) and relative humidity (RH) 80% for 12 months. The packaging material used was aluminium laminated poly ethylene (ALP) and poly ethylene terephthalate (PET). The physicochemical characteristic observed was non-volatile fraction consisted of moisture, crude fibre, ashes, the alkalinity of ashes, pH, microbiological load, total phenolic content and caffeine content. The result showed that the moisture content of ground coffee was below 5.0 % for both packaging materials. The overall adsorbed moisture of ground coffee was significantly (p<0.05) different for both packaging materials, whereby the moisture content of ground roasted coffee packaged in PET was 4.15% while of those packaged in ALP was 3.38% by the end of 12 months storage. There was no significant decrease in the ashes, the alkalinity of ashes, crude fibre, pH, total phenolic content and caffeine content for both packaging materials. The total plate count (TPC) decreased from an initial of 1.2 x 103 to be 1.7 x 102 CFU/g. Both packed ground roasted coffee were microbiological safe as it had TPC less than 105 CFU/g at the end of 12 months storage, the results indicated that the ground coffee packaged in ALP and PET was with acceptable qualities and stability. Thus both ALP packaging and PET packaging were able to preserve ground roasted coffee during storage.
... Eshkevarat region Yaghobifar, Sh. 1 , Rabiei, V. 2 , Razavi, F. 3 , Javadi, D. 4 , Hassani, A. 5 ...
... The total polyphenols (TP) were estimated as per Folin-Ciocalteu method (Contini et al., 2008). The CGA (0.1-0.8 mg/ml) was used to plot a calibration curve. ...
Article
The present work aimed to valorize green coffee spent (GCS) as a food ingredient and its application in food products. About 70% of GCS was obtained after processing green coffee for Chlorogenic acid. The cookies fortified with roasted green coffee spent (RGCS) and unroasted green coffee spent (UGCS) were evaluated for physicochemical properties and food safety. The UGCS and RGCS flour had dietary fiber ranging from 3.3 ± 1.08 and 2.6 ± 0.21%, total polysaccharides with 8.29 ± 0.05 and 16.34 μg/Mg along with fair amount of ash and protein. They also recorded 36.4 and 32.6 mg/100g of polyphenols and 0.32 and 1.25% Trolox equivalent antioxidant activity The UGCS and RGCS contained 4.76 and 8.29 μg/Mg oligosaccharides respectively. The UGCS and RGCS recorded The acrylamide in UGCS and RGCS cookies was 23.4–37.8 ± 0.3 lg ACR/kg d.m. The cookies formulations of RGCS had better sensory attributes such as color and aroma. Thus, RGCS enriched with prebiotic oligosaccharide represent novel functional food supplement.
... It has been reported that hazelnut is rich natural antioxidants (Alasalvar and Shahidi, 2009). Previous studies have shown that hazelnut exhibits high antioxidative activity in several assays (Altun et al., 2013;Arcan and Yemenicioğlu 2009;Contini et al., 2008;Delgado et al., 2010;Miraliakbari and Shahidi 2008;Li and Parry 2011;Yang et al., 2009). In the present study, the antioxidant capacity of hazelnut samples was analyzed by DPPH radical scavenging assay. ...
... The extraction process aims at providing a maximum yield of substances of the highest quality. Literature about the most effective methods and the solvents to extract soluble compounds is abundant, but is to some extent contradictory (Contini et al., 2008). Considering the structure of the matrices and their physicochemical properties, it would be impossible to propose a universal extraction protocol. ...
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Oil recovery, retention index, and thermodynamic parameters of green coffee beans (GCB) and its press cake (PC) extraction using bio-based solvents were investigated. The extraction parameters investigated were temperature (35 to 55 °C), type of material (coffee beans and press cake), and type of solvent (ethanol, acetone, and ethyl acetate), at a fixed solvent to solid mass ratio (5:1) (w/w). The fatty acid profile of the ethanolic extract was assessed for both GCB and PC, and compared to the oil obtained from the mechanical pressing. It was observed that higher temperatures affected positively the extraction yields, especially when acetone and ethanol were employed, allowing a recovery up to 90% and 56.7% for GCB and PC, respectively. The solution retained in the raffinate phase from the GCB extraction was greater than that for the PC. For all operational levels, the ∆H and ∆S were positive. ∆G decreased with increasing temperature. Palmitic and linoleic acids were predominant in all types of oil. The oil obtained by pressing showed higher content of linoleic acid (45.32%), while the solvent-extracted oil from GCB had more palmitic acid (34.79%), and the PC oil presented intermediate levels of all the methyl esters.
... The extract was freeze-dried (Thermo-Electron Corporation -Heto power dry LL300 Freeze Dryer, France). The dried extract was weighed to determine the yield and stored at -20 °C until further use, according to Contini et al. (2008). ...
... The hazelnut tree belongs to the Betulaceae family and has worldwide distribution. Its positive effects on human and animal health have been documented regarding the antioxidant activity and phenolic constituents of HS (30)(31)(32)(33). It follows then that extracts of natural antioxidants from HS could find potential use as nutraceuticals and dietary supplements for animals. ...
Article
Rabbits in groups of eight were fed for nine weeks with diets containing linseed, rich in polyun-saturated fatty acids (LS), linseed plus hazelnut skins, with antioxidant function (LS+HS), or palm oil, rich in saturated fatty acids (PO). The aim of this work was to compare the effects of aforementioned diets on serum biochemical parameters related to nutritional and inflammatory status, immune function and oxidative balance [triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lysozyme, reactive oxygen species and antioxidant power, respectively]. At the end of the study redox imbalance (with a significant increase in oxidative stress and decrease in antioxidant defenses) was greatest in rabbits fed the LS diet (without additional antioxidant protection) compared to the other two groups (P<0.05). Also the blood value of lysozyme, an immune parameter linked to inflammatory phenomena, was greater in the LS compared to the other two groups (P <0.05). ALT remained unchanged in all three groups, while a significant increase in AST, triglycerides, and cholesterol was noted in the group fed the PO diet as compared to the other two groups (P<0.05). In conclusion, the most favorable and healthy values were found in rabbits fed with diets containing linseed and supplemented with hazelnut skins (LS+HS group).
... For phenolic compounds analysis in liquid IC beverages (4 mg/mL and 10 mg/mL), Folin-Ciocalteu method was adapted to a micro-method format [28]. Folin-Ciocalteu reagent (Sigma-Aldrich, St. Louis, MO, USA) and chlorogenic acid (CGA) (Sigma-Aldrich, St. Louis, MO, USA) standard solution (0.1-0.9 mg/mL) were prepared. ...
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Our research aimed to evaluate the formation of Maillard reaction products in sun-dried coffee cascara and their impact on the safety and health promoting properties of a novel beverage called “Instant Cascara” (IC) derived from this coffee by-product. Maillard reaction products in sun-dried coffee cascara have never been reported. “Instant Cascara” (IC) extract was obtained by aqueous extraction and freeze-drying. Proteins, amino acids, lipids, fatty acid profile, sugars, fiber, minerals, and vitamins were analyzed for its nutritional characterization. Acrylamide and caffeine were used as chemical indicators of safety. Colored compounds, also called melanoidins, their stability under 40 °C and in light, and their in vitro antioxidant capacity were also studied. A safe instant beverage with antioxidant properties was obtained to which the following nutritional claims can be assigned: “low fat”, “low sugar” “high fiber” and “source of potassium, magnesium and vitamin C”. For the first time, cascara beverage color was attributed to the presence of antioxidant melanoidins (>10 kDa). IC is a potential sustainable alternative for instant coffee, with low caffeine and acrylamide levels and a healthy composition of nutrients and antioxidants.
... Hazelnut skins were pulverized mechanically with a blender, and phenolic compounds were extracted according to the procedure reported by Del Rio et al., with some modifications [5]. Two different extraction procedures were applied: one using a 1% (v/v) aqueous formic acid solution as an extractive solvent to obtain an aqueous extract and one using methanol/water (75: 25, v/v) as an extractive solvent to obtain a methanolic extract. ...
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The advanced glycation end-products (AGEs) arise from non-enzymatic reactions of sugar with protein side chains, some of which are oxido-reductive in nature. Enhanced production of AGEs plays an important role in the pathogenesis of diabetic complications as well as in natural aging, renal failure, oxidative stress, and chronic inflammation. The aim of this work is to study antiglycation effects of polyphenol compounds extracted by hazelnut skin that represents an example of polyphenols-rich food industry by-product, on AGEs formation. AGEs derived from incubation of bovine serum albumin (BSA) and methylglyoxal (MGO) were characterized by fluorescence. The phenolics identification and total polyphenol content in hazelnut skin extracts were analyzed by HPLC-MS and the Folin–Ciocalteu method, respectively. Antioxidant efficacy was evaluated by monitoring total antioxidant activity to assess the ABTS radical scavenging activity of samples by TEAC assay and oxygen radical absorbance capacity (ORAC) assay, expressed as millimoles of Trolox equivalents per gram of sample. Data here presented suggest that phenolic compounds in hazelnut skin have an inhibitory effect on the BSA-AGEs model in vitro, and this effect is concentration-dependent. The putative role of the hazelnut skin antioxidative properties for hindering AGEs formation is also discussed. Because of AGEs contribution to the pathogenesis of several chronic diseases, foods enriched, or supplements containing natural bioactive molecules able to inhibit their production could be an interesting new strategy for supporting therapeutic approaches with a positive effect on human health.
... It has been reported that hazelnut is rich natural antioxidants (Alasalvar and Shahidi, 2009). Previous studies have shown that hazelnut exhibits high antioxidative activity in several assays (Altun et al., 2013;Arcan and Yemenicioğlu 2009;Contini et al., 2008;Delgado et al., 2010;Miraliakbari and Shahidi 2008;Li and Parry 2011;Yang et al., 2009). In the present study, the antioxidant capacity of hazelnut samples was analyzed by DPPH radical scavenging assay. ...
... The yield of this extraction strongly depends on the nature of the solvent and the extraction method. However, it also depends on the plant material and the richness of bioactive compounds 25 . The comparison of our results with those of the literature shows that the polyphenol contents of our extracts are lower than that obtained by Ammor 26 (71.39 ± 1.13 mg/g with ethanolic extracts of Herniaria hirsuta). ...
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Plants are a large source of new bioactive molecules with therapeutic potentials. However, only a small amount of worldwide plants has been phytochemically investigated. The ethanolic extracts from leaves and flowers of Paronychia argentea were evaluated for their antilithiasic activity in vitro. The effect of extract (0.1, 0.2, 0.3, 1, 2, and 5mg/mL) was studied by the measurement of turbidity in presence or absence of extract at 620 nm using UV/Vis spectrophotometer. Total phenol and flavonoid contents were also evaluated. Polyphenol content was found to be more present in the leaves extract (9.29±0.009mg of Gallic acid equivalent (GAE)/g) compared to the flowers extract (5.92±0.14mg GAE/g). Flavonoids content was also found to be more present in the floral extract that is estimated at 0.18±0.01mg QE/g compared to the flowers extract (0.47±0.0035mg QE/g). For the antilithiasis activity, the results clearly shown that P. argentia extracts inhibited calcium oxalate crystallization by concentration-dependent manner. The maximum percent inhibition of calcium oxalate by flowers extract was found to be 70.97% at 5mg/mL. Further, P. argentea leaf extract has shown antilithiasic properties and may be used for the prevention of kidneys stones.
... The seeds were dried at room temperature (23-25 • C approx.) and reduced to powder (1700-425 µm) by grinding in a seed disintegrator (Severin, Sundern, Germany). Then 100 g of the powder was extracted with 750 mL of analytical grade methanol as previously described [26], with some modifications. ...
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The “Kurugua” (Sicana odorifera) is a native fruit that demonstrates attractive nutritional, coloring, flavoring, and antioxidant properties. The main by-products from the processing and consumption of kurugua fruit are epicarp and seeds. In this work, the properties of the seeds of S. odorifera were evaluated. The nutritional composition of the fruit seeds was determined through AOAC official methods and UHPLC-ESI-MS/MS profiling. The antioxidant activities were determined using in vitro methods, and the acute toxicity and hepatoprotective properties were investigated in Swiss albino mice. Quercetin derivatives and cucurbitacins were the main phytochemicals in the seeds’ methanolic extract and demonstrated some biological activities. GC-MS analysis revealed the essential fatty acids linolenic and linoleic as the main compounds present in seeds oil. The methanolic extract significantly reduced the serum levels of glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) in mice with induced hepatotoxicity (GPT p < 0.05; GOT p < 0.001) at the minor concentration tested (100 mg/kg EMSo). The results suggest that the S. odorifera seeds as by-products show potential use as a source of phytochemicals and in the production of oils with application in food supplements and nutraceuticals. Their integral use could contribute to waste reduction from kurugua fruits processing within the food safety and environmental sustainability framework.
... Solvent extraction process has been considered a crucial step for the use of the extract to further apply in food or pharmaceutical industries (Luengo et al., 2013). The variation of process parameters in the extraction process showed a great influence on the extraction yield (Contini et al., 2008). Around 120 million tons of citrus peels, which wastes valuable resources, have been annually discarded, whereas the orientation of "green recovery" is one of the most promising solutions (Mahato et al., 2020). ...
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Abstract Pomelo peels have been well known as a valuable source of phenolic compounds mainly flavonoids. In this study, the influences of extraction conditions of three extraction methods on the polyphenols yield, flavonoids yield, and antioxidant activity of resulting pomelo flavedo extract (PFE) were evaluated. As a result, the suitable process parameters for the ultrasound assisted extraction were selected at an applied power of 120 W, the temperature of 60 oC for 20 min. Meanwhile, the microwave assisted extraction was operated at an applied power of 150 W for 25 min and the Soxhlet extraction was carried out up to 4 reflux cycles (35 min per cycle) at 80 oC. Among three methods, the microwave assisted extraction was considered as the most efficient method to obtain the high yield of polyphenols (80.56%) and flavonoids (86.58%). Naringin and hesperidin determined by high-performance liquid chromatography showed the value of 64.42 ± 2.90 mg/g DW and 0.97 ± 0.02 mg/g DW, respectively. The PFE extracted by the microwave assisted extraction could be a potent nutraceutical in further application on food or pharmaceutical industries.
... Phenolic compounds possess the antioxidant activity through free radicals scavenging by donating hydrogen atoms or electron or by chelating metal ions [4,5]. In the ever-changing scenario, awareness toward healthy and balance eating habit to cope with stressful everyday life has attracted people towards natural antioxidant-rich foods instead of synthetic antioxidants [6,7]. ...
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Calligonum polygonoides L. (Phog) is an endemic perennial herb with highly resistant to all type of abiotic stresses and dominant biomass as well as phytochemicals producer in its natural habitat of the 'Thar Desert' of Rajasthan, India. The present study was conducted to evaluate effect of extremes of environmental conditions on the phenolic, flavonoids, tannin content, and total antioxidant activities of C. polygonoides foliage harvested during different months. It exhibited a significant variation in the content of phenolic compounds, flavonoids, tannins and antioxidant activity with harvesting time and all parameters are positively correlated to each other. The highest phenolic compounds and antioxidant activity was observed during severe winter and summer months, when monthly average environmental temperature was lowest and highest of the year, respectively. On the basis of results, two harvests of C. polygonoides foliage during June and December is advised to maximize the phenolic compound production wit highest antioxidant activity. These results demonstrate C. polygonoides which is a dominant biomass producer under the harsh climatic conditions can be an important source for the development of the functional foods rich in antioxidants in hot arid regions.
... Eshkevarat region Yaghobifar, Sh. 1 , Rabiei, V. 2 , Razavi, F. 3 , Javadi, D. 4 , Hassani, A. 5 ...
... Several studies have been conducted in order to enhance and valorize this waste by-product with the aim to obtain new materials, chemical compounds, and bioactive ingredients. In particular, HS were found to be suitable for the production of particleboard and Medium Density Fiberboard (MDF) [12,13], activated carbons capable of adsorbing and removing different heavy metals and CO 2 [14][15][16][17][18][19][20][21][22], antioxidant phenolics [6,[23][24][25][26], fermentable sugars and xylooligosaccharides [11,27], hydrogen production [28,29], ethanol [30] and some prebiotic compounds [31]. ...
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Recently, the cultivation of hazel is undergoing a large expansion. Italy is the world’s second largest producer of hazelnuts, with a production of around 98,530 tons in 2019. The processing of hazelnuts produces large amounts of waste, especially woody pericarps, due to the cracking process, generally used for domestic heating, causing air pollution. The high lignin content present in the pericarps makes them a suitable substrate for the cultivation of edible and medicinal mushrooms. To this aim, Ganoderma lucidum, Lentinula edodes, and Pleurotus cornucopiae were grown and cultivated on different hazelnut-shell-based substrates: Hazelnut Shell (HS), Hazelnut Shell and Wheat Straw (HS-WS), and Wheat Straw mixed with Beech Chips (WS-BC) as control. In vitro mycelial grow rate, the degradation capacity of the lignocellulosic fraction, the biological efficiency, and the qualitative differences between mushrooms growing on different substrates by using Attenuated Total Reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy were investigated. Our results suggested the ability of G. lucidum, L. edodes, and P. cornucopiae to grow and decay the lignocellulosic fraction of HS. Cultivation trials showed a similar biological efficiency but a different Fruiting Body Production (FBP) in the presence of HS with respect to the control. ATR-FTIR analysis provided a chemical insight for the examined fruiting bodies, and differences were found among the substrates studied. These results provide attractive perspectives both for more sustainable management and for the improvement of mushroom cultivation efficiency.
... Among the analyzed samples, the skin of whole roasted hazelnuts presented incredibly high extraction yields (about 30%) and extracts with the richest phenolic content (up to 502 mg/g, stated as gallic acid equivalents). The extracts from the skin of whole roasted hazelnuts documented the solidest antioxidant activity, similar or larger to butylated hydroxyanisole, butylated hydroxytoluene, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, and α-tocopherol, at equal concentrations, because they are rich in tannins [32]. ...
... Recent literature cites new valuable substances extractable from the shells, with particular attention to phenolic compounds. Their antioxidant, antiallergenic and antimicrobial effects on human bodies which may trigger several pathological conditions and/or age-related chronic diseases [130][131][132][133], together with an increasing interest and predilection of natural antioxidant compounds over the synthetic ones, is leading the cosmetic, pharmaceutical, and food and construction industries [134][135][136] to increase their research and development of new products containing such natural substances [137]. Regarding the construction sector, as an example, because of their lignocellulosic composition, hazelnut shells could be used to produce lower cost rigid polyurethane foams, commonly used as lightweight thermal insulating construction materials [138]. ...
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Corylus avellana L. is one of the most cultivated species in the world. Mainly utilized with the purpose of obtaining food material, hazel trees cannot guarantee constant kernels productions given the threats related to pathogens and to adverse conditions, especially in a globalisation and global changes scenarios. This matter led us to consider the opportunity of using hazel tree in all its parts and for several purposes, due to its multifunctional characteristics. As a pioneer species, it is a precious plant useful for forest restoration purposes and for forest successions/wildlife facilitation. Its roots enter into symbiosis with truffles making this species exploitable for hazelnuts and truffles production. The precious elements contained in what is considered “waste” deriving from hazel crops (i.e., leaves, skins, shells, husks and pruning material), could be reused and valorised in the perspective of a circular economy that is opposed to a linear one. In particular, a list of several phenolic compounds detected in hazelnut shells has been reported in literature to prevent and delay many human diseases due to their antioxidant properties and to free radical scavenging activities, with implications potentially useful even in the fight against COVID-19. All this makes hazel crop by-products interesting to be valorised as a chemical compound source for human health, even more than a biomass fuel or for bio-char applications. The multiple possible uses of the hazel tree would lead to alternative productions than the only nut productions, avoiding significant economic losses, would decrease the cost of disposal of crops residues and would increase the sustainability of agro-ecosystems by reducing, among other things, the production of wastes and of greenhouse gases deriving from the usual burning of residues which often happens directly in fields.
... The extraction yield of C. micranthum phenolic compounds obtained from maceration using ChLa, ChAa, ChTa, water, methanol and ethanol was shown in Table 2. Maceration is a traditional and one of the most ancient extraction processes applied for the extraction of bioactive substances such as phenolic compounds. Although maceration is a time-consuming method, it has been reported to be adequate and subsequent for the recovery of antioxidants from various plant materials (Contini et al., 2008;Ć ujic´et al., 2016). Based on the experimental results, the type of the examined solvents significantly influenced the phenolic compounds of the extracts (p < 0.05) suggesting a great variation among the extraction yields ( Table 2). ...
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Kinkeliba (C. micranthum) is a tropical plant widely used for its tremendous phytochemicals and biological activities. In the present study, three green carboxylic acid-based natural deep eutectic solvents (NADESs) were used to assess the extraction of phenolic compounds in terms of total phenolic content (TPC), total flavonoid content (TFC), individual phenolic compounds and antioxidant capacity (DPPH and FRAP assays) from dried C. micranthum leaves. For the synthesis of NADESs choline chloride was used as hydrogen bond acceptors (HBA) in combination with lactic acid (ChLa), acetic acid (ChAa) and tartaric acid (ChTa) as hydrogen bond donors (HBDs). The conventional solvents including distilled water, pure methanol and pure ethanol were used for comparison. Three extraction methods including maceration extraction (ME), homogenate-assisted extraction (HAE) and ultrasound-assisted extraction (UAE) were tested to determine the best extraction conditions. The solvents combined with the extraction methods were successfully applied for the recovery of phenolic compounds from C. micranthum leaves. ChLa exhibited the highest performance giving the TPC (21.12±0.13-23.62±0.58 mg GAE/g, followed by ChAc (15.49±0.13-18.85±0.39 mg GAE/g), water (17.08±0.32-18.13±0.13 mg GAE/g), ChTa (14.49±0.26-17.44±0.19 mg GAE/g), methanol (7.46±0.45-11.64±0.32 mg GAE/g) and ethanol (2.88±0.39-4.60±0.39 mg GAE/g), respectively. For TFC, ChLa (4.38±0.09-5.01±0.09 mg ECE/g) was the most prominent solvent, followed by ChAc (2.84±0.04-5.01±0.36 mg ECE/g), methanol (1.93±053-4.85±0.04 mg ECE/g), ethanol (1.49±0.36-4.16±0.04 mg ECE/g), ChTa (1.09±0.04-3.22±0.13 mg ECE/g) and water (1.15±0.04-1.37±0.44 mg ECE/g), respectively. The acidic NADESs especially ChLa and ChAa exhibited the best efficiencies compared to the conventional solvents. Furthermore, UAE and HAE provided good extraction efficiency in a short extraction time (30 min) in terms of the TPC, TFC, individual phenolic compounds and the antioxidant capacity compared to ME which gave a similar yield with 12 h of extraction time. Principal component analysis (PCA) showed that C. micranthum extracts could clearly be discriminated in terms of phytochemical compounds and antioxidant capacity and UAE, HAE or ME combined with ChLa ChAc or ChTa were the best choices to higher extraction efficiency.
... is is a branch of phytonanotechnology, which has been shown as a new field for the synthesis and utilization of nanoparticles as an ecofriendly, simple, and cost-effective technology. Different techniques have been applied to extract certain antioxidants from their plant parts, such as shaking with a suitable extractor solvent, homogenization at high speed, and ultrasound-, maceration-, stirring-, and microwave-assisted extraction [7][8][9][10]. Some of these plant extracts containing antioxidant compounds are greatly affected by the extraction technique used in their preparation. ...
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)ere is a need to synthesize eco-friendly nanoparticles with more effective and potent antibacterial activities. A green and costeffective method for the synthesis of silver nanoparticles (AgNPs) using 4ymus vulgaris, Mentha piperita, and Zingiber officinale extracts was developed. )e analytical instrumentation, namely, UV/Vis, absorption spectroscopy, FTIR, and scanning electron microscopy (SEM), was used to determine the developed AgNPs, confirming the functional groups involved in their reduction. Acidic molybdate, DPPH, and FRAP regents were reacted with AgNPs extract to evaluate their antioxidant, scavenging, and oxidative activities. )e agar well diffusion method was used to determine the antibacterial potential of AgNPs extracts using clinical isolates. )e developed AgNPs showed peaks at 25 cum\Diff, 50 cum\Diff, and 75 cum\Diff, respectively, of 16.59 ± 0.78, 45.94 ± 1.07, and 81.04 ± 0.98 nm, for 4ymus vulgaris, Mentha piperita, and Zingiber officinale. SEM revealed uniform prepared and encapsulated AgNPs by plant extracts matrix. )e FTIR shows the involvement of amide (-CO-NH2), carbonyl (-CO), and hydroxyl (-OH), which resulted in the reduction of AgNPs. )e AgNPs extract showed significantly higher TAA, DPPH, and FRAP values than free AgNPs and plant extract (p < 0.05). Antibacterial of AgNPs extracts revealed various degrees of inhibition zones against Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. )e developed AgNPs extract showed acceptable antioxidant activities and noticeable antibacterial potential. )e prepared green synthesized AgNPs showed a promising antibacterial activity against four multidrug-resistant clinical isolates, Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. Further, fractionated extracts other than crude extracts will be utilized in the preparation of AgNPs to get more efficient antibacterial activities for future work.
... In addition, Kornsteiner et al. [30] showed that removing skin significantly reduces the amount of phenolic content in almonds from 239 to 47 mg gallic acid equivalents (GAE)/100 g. Contini et al. [31] and Shahidi et al. [32] also confirmed that the European hazelnut by-products had stronger antioxidant activity than the kernel. Furthermore, Pelvan et al. [33] reported that the highest phenolic compounds, as well as antioxidant activity, were found in roasted hazelnut skin, followed by natural hazelnut, and were the lowest in roasted hazelnuts without skin. ...
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Consistent with the massive production of pine nuts, a huge amount of by-products such as shell and skin has also been generated and led to environmental pollution without proper handling. As the implementation of the circular economy concept, their bioactive compounds that may potentially become a source of valuable co-product were evaluated. Pine nut shell and skin samples from two Korean pine nut cultivars, subjected to low (130 °C), medium (150 °C), and high temperatures (180 °C) with different roasting durations (10, 20, and 30 min), were used to evaluate the possibility to improve their bioactive compounds as a result of different roasting conditions. This study demonstrated the improvement of total phenolic content, total flavonoid content, and total proanthocyanidin content, as well as antioxidant activities measured by FRAP, ABTS, and DPPH assays. The results also indicate that the bioactive compounds and antioxidant capacity of skin was higher than that of shell. The most representative phenolic compounds responsible for antioxidant activity were quantitatively analyzed by HPLC-UV, including phenolic acids and flavonoids. In general, low or medium roasting temperatures for a short time could be favorable to provide more bioactive compounds, and suggesting could be further developed as antioxidant resources. Graphic Abstract
... Notwithstanding, citrus peels are an excellent source of phenolic acids and flavonoids, vitamin C, folate, and potassium with several biological benefits (anti-inflammatory, anticarcinogenic, antidegenerative, antioxidant, and antimicrobial properties;Oboh & Ademosun, 2012;Rafiq et al., 2018). Conventional extraction methods, such as cold pressing, heating reflux, and Soxhlet, are timeconsuming and have safety hazards and high energy input (Contini et al., 2008;Mandal et al., 2007). To increase the exploitation of citrus peels, an ecofriendly extraction method can be applied to recover bioactive compounds from citrus waste. ...
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The current study focused on optimizing the extraction conditions of bioactive compounds from orange peels using response surface methodology (RSM) to decrease the number of experimental trials and increase the yield of bioactive compounds. Ultrasonic extraction time, extraction temperature, and ethanol concentration have been optimized. Twenty experimental trials have been carried out to optimize the extraction conditions. The response surface methodology (RSM) results showed that the extraction temperature and ethanol concentration had a remarkable effect on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. The optimal ultrasound‐assisted extraction conditions were 44 min extraction time, 50°C extraction temperature, and 57.7% ethanol concentration. Under these optimal conditions, TPC and TFC were 292.158 µg GAE/g and 191.144 µg catechol/g, respectively, whereas antioxidant activities were 5.199 and 2.96 µg/mL for 2,2‐diphenyl‐1‐picrylhydrazyl and 2,20‐azino‐bis(3‐ethylbenzothiazoline‐60‐sulfonic acid) diammonium salt, respectively. response surface methodology RSM saves the extraction time and effective for optimizing extraction conditions with the highest efficiency and yield.
... Another Italian researchers M.Contini et al. studied the phenolic content of extracts from hazelnut shells using three solvent systems -ethanol, methanol and 80% acetone solution, and found that the extract obtained with 80% acetone had the richest phenolic content. The extract has been shown to have a high percentage of tannins and antioxidant activity [10]. ...
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The article provides a comparative analysis of data on the content of macro-and micronutrients, as well as the determination and identification of biologically active substances in the bioextracts obtained with distilled water (BE-I) and 70% ethanol (BE-II) from the shell of the common hazelnut (Corylus avellana L.) plant widespread in the northwestern region of Azerbaijan. It was established that the bioextracts BE-I and BE-II have the same mineral composition and contain 25 mineral elements. The bioextracts obtained by extraction with distilled water and 70% ethanol contain 28.51% and 14.61% mineral elements respectively. The amount of macronutrients (K, Na, Mg, Ca, Fe, P) in BE-I is 22.97%, micronutrients (Ti, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Sn, Sr, Y, Al, S, Se, Si, Ba, Pb, Rb, V)-5.54%; in BE-II 11.60% and 3.01%, respectively. It was established that the BE-II contains 85.4% biologically active substances (BAS) and 28 major therapeutic substances, while the BE-I contains 71.5% BAS and 14 major therapeutic substances. Phenolic compounds with high antioxidant, anticancer and antibacterial properties were found among the BAS, of which the following components dominate: 2-methoxy phenol (C7H8O2), 2,3-dihydrobenzofuran (C8H8O), 2-methoxy-4-vinylphenol (C9H10O 2) , 4-Hydroxy-3-methoxybenzaldehyde (C8H8O3), 2-methoxy-4-propyl-phenol (C10H14O2), 4-((1E)-3-hydroxy-1-propenyl)-2-methoxyphenol (C10H12O3), dibuthyl phtalate (C16H22O4), 1-naphtalenamin (C10H9N), 5-cholestene-ol, 24-methyl-(C28H48O), γ-sitosterol və β-sitosterol (C29H50O), stiqmast-4-en-3-one (C29H48O), 4H-pyran-4-one-, 2,3-dihydro-3,5-dihydroxy-6-methyl-(C6H8O4), trans-4-fluoro-4'-(methyltio) chalcone (C16H13FOS). The bioextracts obtained by the proposed methods contain vital macro-and microelements and BAS with high therapeutic effect, which allows them to be used as a therapeutic agents in the treatment and prevention of many diseases. Based on the results of the study for obtaining bioextracts rich in mineral elements, BAS, coloring pigments and flavorings the optimal regime was determined using two-stage extraction by 70% ethanol and distilled water.
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Nuts contain a vast array of phenolic compounds having important biological properties. They include substances allocated into the five major groups named phenolic acids, flavonoids, tannins, phenolic lignans and stilbene-derivatives. The complexity in composition does not allow setting a universal extraction procedure suitable for extraction of all nut phenolics. The use of non-conventional extraction techniques - such as those based on microwave, ultrasound and compressed fluids – combined with GRAS solvents is gaining major interest. Regarding these latter, ethanol, water, and ethanol-water mixtures have proved to be effective as extracting solvents and allow clean, safe and low-cost extraction operations. In recent years, there has been an increasing interest on biological properties of natural phenolic compounds, especially on their role in the prevention of several diseases in which oxidative stress reactions are involved. This review provides an updated and comprehensive overview on nut phenolic extraction, their chemical profiles and bioactive properties.
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To the best of our knowledge, there have been no phytochemical studies concerning the wild plant Leontodon hispidulus Boiss. (Asteraceae). Optimization of the green extraction process of the plant aerial parts, identification of main phenolic compounds, evaluation of antioxidant, anti-inflammatory and anticancer activities of the optimized extract have been carried out. HPLC-analysis was performed using 95% ethanolic extract. 3-Level Box-Behnken Design was applied for optimization of extraction yield and total phenolic content using 3-factors (ethanol/water ratio, material/solvent ratio and extraction time). Antioxidant, anticancer and anti-inflammatory activities were evaluated by ABTS-assay, prostate and cervical carcinoma human cell lines and carrageenan-induced rat paw edema model, respectively. HPLC-analysis showed the presence of quercetin, rutin, kaempferol, chlorogenic and ρ-coumaric acids. Increasing both ethanol/water ratio and material/solvent ratio decreased the yield, while, it increased by prolongation of the extraction time. High material/solvent ratio increased the phenolic content. The optimized extract showed high total phenolic content (104.18 µg/mg) using 201 ml of 74.5% ethanol/water at 72 h and good biological activities. Antioxidant activity was found to be 41.89 mg Trolox-equivalent/gm, with 80% free radicals inhibition. For anti-inflammatory activity, 100 mg/kg of the extract inhibited the edema in rats by 83.5% after 4 h of carrageenan injection as compared to 81.7% inhibition by indomethacin. Prostate carcinoma cell line was more sensitive to the anticancer activity of the extract than cervical carcinoma cell line (IC50 = 16.5 and 23 μg/ml, respectively). The developed extraction procedure proved to be efficient in enriching the extract with phenolic compounds with promising anticancer, anti-inflammatory and antioxidant activities.
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The environmental and economic impacts of food wastage are of increasing concern in the functional food sector—approximately a third of cereals and nearly half of fruits and vegetables go to waste worldwide. Food Wastes and By-products is a comprehensive survey of food wastage, covering the physical properties, supply, processing, and potential health benefits of recovered food waste and its reconstituted by-products. Written by leading researchers in the field, this innovative text focuses on the nutraceutical factors and bioactive compounds found within fruit, vegetable, and cereal waste. The text provides essential information on the supply of waste and its composition, identifies foods rich in valuable bioactive compounds, and explores innovative methods and technologies for the extraction and processing of high-value by-products from fruit, vegetable, and seed waste. The authors discuss the nutraceutical properties of value-added by-products and their uses in the manufacturing of dietary fibers, food flavors, supplements, pectin, and others.
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The essential nutrients of 23 wild hazelnuts (Corylus heterophylla) grown in northeast China were analyzed in order to sieve good species and study the factors effected on nut quality. Hazelnut kernels contained 45.76–62.78% fat similar to Corylus avellana and main fatty acids were oleic acid (79.75%), linoleic acid (15.42%), palmitic acid (3.29%), and polyunsaturated fatty acids ranged between 10.37% and 25.88%. Average protein, soluble sugar, starch, and ash contents of hazelnut kernels were 25.12%, 4.98%, 2.03%, and 3.04%, respectively. The amount of amino acids, mostly as glutamic acid, arginine, and aspartic acid, was also determined by the hazelnut varieties. The abovementioned variation was explained by growing environmental differences. Among them, the 11th sample was highest in protein content (30.21%) and 18th sample highest in fat content, while the 5th and 14th samples had relatively balanced nutrients. So, when planning to select new cultivars, we primarily considered different hazelnut qualities.
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Hazelnut represents a relevant agro-food supply chain in many countries worldwide. Several biological adversities threaten hazelnut cultivation, but among them bacterial blight is one of the most feared and pernicious since its control can be achieved only by prevention through the observation of good agricultural practices and the use of cupric salts. The aim of this work was to evaluate the lignocellulosic biomasses obtained from hazelnut pruning and shelling residues as a renewable source of cellulose nanocrystals and lignin nanoparticles and to investigate their antimicrobial properties against hazelnut bacterial blight. Cellulose nanocrystals were obtained through an acid hydrolysis after a chemical bleaching, while lignin nanoparticles were synthesized by a solvent–antisolvent method after an enzymatic digestion. Both collected nanomaterials were chemically and morphologically characterized before being tested for their in vitro and in vivo antibacterial activity and biocompatibility on hazelnut plants. Results indicated the selected biomasses as a promising starting material for lignocellulosic nanocarriers synthesis, confirming at the same time the potential of cellulose nanocrystals and lignin nanoparticles as innovative tools to control hazelnut bacterial blight infections without showing any detrimental effects on the biological development of treated hazelnut plants.
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This study deals with biotechnological transformation of oat bran using ultrasound processing and enzymatic hydrolysis of oat bran into functional ingredients with antioxidant and prebiotic properties. The results on changes of polyphenol concentrate antioxidant activity during storage did not reveal changes within 8 months at a temperature of 20 ± 1 °C and a relative humidity of 70 ± 5%. The study of the growth dynamics of Lactobacillus acidophilus and Bifidobacterium bifidum confirm the presence of prebiotic effect of xylooligosaccharides (XOS) from oat bran and their selectivity. It is noted that the accumulation of biomass of prebiotic cultures occurs faster with the use of XOS and lactulose as compared to milk. In order to protect sensitive bioactive compounds the capsules were prepared with a whey protein concentrate (WPC) and maltodextrin (MD) as wall materials. The highest encapsulation efficiency of 95.28% was recorded at WPC:MD ratio of 60:40. A digestion protocol that simulates conditions of the human gastric and intestinal tract was designed to investigate the effect of the structural characteristics of capsules on release kinetics. The release percent of polyphenols coated in capsule was ranged between 70 and 83% after 2 h of digestion. Thus, the feasibility of oat bran biotechnology into functional ingredients has been confirmed, which will further allow utilizing them in novel products with bifidogenic properties. It is also proved that utilization of WPC can be beneficial for polyphenols encapsulation as a wall material.
Article
Olive leaves (OL) are considered a potential source of bioactive compounds mainly due to its high content of phenolic compounds, widely known as natural antioxidants. The main objective of this study was to compare the performance of three OL extracts obtained by different extraction techniques in protecting canola oil against oxidative damage. The technologies evaluated were maceration with ethanol/water 75:25 (v/v), supercritical fluid extraction with CO2 (SC–CO2) and SC-CO2 with 10% ethanol as modifier (SC–CO2/EtOH). Each extract was analyzed as for total phenolic compounds (TPC), antioxidant activity (ABTS assay) and phenolic composition by reversed phase liquid chromatography-quadrupole-time of flight mass spectrometry. The oxidative stability of canola oil with or without the incorporation of 250 mg/kg of each extract was assessed during five weeks of storage at 60 °C. Peroxide, K232, K270, and Rancimat values, besides tocopherols content were determined. Macerated extract showed the highest TPC and antioxidant activity, but both SC-CO2 extracts were more effective in preserving tocopherols. In addition, SC-CO2 extracts delayed the oxidation progress as they lead to higher induction periods than control and macerated extracts, and a slower increase in peroxide values. Results obtained reinforce the use of supercritical fluid technology to obtain antioxidants compounds from natural sources.
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In recent years, the use of natural substances such as essential oils and extracts has been emphasized in place of chemical preservatives in the food industry. Green walnut skin is an agricultural waste that, due to its phenolic compounds, can be considered a natural combination containing biological properties, reduces many incurable diseases, prevents the oxidation of lipids, and is used as antimicrobial factors. In this study, the content of phenolic compounds, antioxidant, and anti-bacterial properties of methanolic extracts of green walnut skin was investigated. Extraction was carried out using both soaking and soxhlet methods in 60% and 80% methanol solvent. The number of phenolic compounds of the extract was determined by the spectrophotometric method. The anti-radical activity of the extract was evaluated by DPPH radical inhibitory test. The anti-bacterial activity of the extract was investigated by the disc diffusion method against Salmonella typhimurium, Shigella dysentery, and Listeria monocytogenes. Collected data were analyzed using SPSS software and the Duncan test. Results: The total phenol content for soaking and soxhlet methods was respectively 17.81 and 89.07, according to Gallic acid equivalent, based on mg / g of sample. EC 50 amount of green walnut skin was 0.15 mg/ml. Remarkable antimicrobial activity was observed against all studied bacteria. MIC was between 1.625 and 1.25 and MBC between 1.2 and 2.5 mg/ml. The results of this study showed that methanolic extracts of green walnut skin are a potential source of bioactive compounds with antioxidant and antimicrobial properties that can be used in the food and medicine industry to protect human health.
Article
The aim of this study was to valorize hazelnut (Corylus avellana L) cake (HC), which is a by-product of hazelnut oil industry, in compound chocolate (HCC) as a partial replacer of sugar and milk originated powders (MOP: skimmed milk and whey powder in equal amounts). D-optimal mixture design was used to optimize HCC formulation. The optimum sugar, MOP, and HC amount were selected as 25.0–40.0, 6.0–21.0, and 0.0–15.0 g/100 g, respectively. The Casson model with high R² values (0.9882–0.9948) was used to determine yield stress and plastic viscosity values of samples which were varied between 1.47 and 2.35 Pa, and 1.17–1.42 Pa s, respectively. Furthermore, particle sizes and water activity were determined between 25.67 and 78.20 μm and 0.31–0.38, respectively. Total phenolic content in HCC samples, their digestibility, and bioaccessibility ranged from 1389 to 3367; 2601–3955 mg GAE/kg, and 112–187% respectively. Also, hardness and brittleness were ranged between 7.85 and 11.55 N and 0.52–1.02 mm, respectively. The sensorial characteristics of the samples along with flow behavior and physico-chemical properties indicated that HC may be used as a healthy and low-cost ingredient in HCC formulation to partially substitute sugar and MOP.
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Hazelnut belongs to the genus Coryllus and family Betulaceae. Hazelnut contains 10–22% carbohydrate, 1–3% cellulose and pectin, protein content of 10–24%, 50–73% fat and ash content of 2.4–2.8%. It is a good source of phytochemicals, fatty acid especially monounsaturated fatty acids, and fat-soluble bioactive compounds (tocopherol, phytosterols). It also contains essential amino acids, antioxidant phenolics, minerals, vitamins, and dietary fibers. These have ability to reduce risk of cardiovascular diseases, decrease cholesterol levels, and prevent metabolic syndrome. Major by-products of hazelnut (hard shells) are rich in phenolic compounds like catechin, epicatechin, epicatechin gallate, and gallic acid. Hazelnut may be consumed either naturally or in roasted forms. Roasting improves its texture, flavor, or color depending upon time and temperature.
Article
An extraction method based on a multivariate analytical approach was developed for enhancement of the phenolic compounds in cashew nut extracts. The different extractor solvents (acetone, water, ethanol, and methanol) and their binary, ternary, and quaternary combinations were evaluated using a simplex-centroid design and surface response methodology. The special cubic model exhibits no lack of fit and explains 89.2% of the variance. The total phenolic measurements by the Folin-Ciocalteu method revealed the highest values for ethanol (5.93 mg GAE g−1) and acetone–methanol–ethanol ternary mixture (5.92 mg GAE g−1) extracts. ESI (−)-Q/TOFMS analyses combined with PCA and HCA revealed the presence of fatty acids, phospholipids, and sugars in the ternary mixture cashew extract, while for the ethanol extract only phenolic compounds, such as anacardic acids and derivatives, were found. The proposed approach was adequate to reach the optimal extractor which ethanol, a low-toxicity solvent, enabled the selective extraction of a high content of phenolic compounds from cashew nuts.
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In order to characterize the influence of nut composition on quality, seventeen cultivars grown in Viterbo were analysed in 2000-2001. Quantitative and qualitative determinations of sugars, organic acids, lipids and vitamins were carried out. Total polyphenols in the pellicle and in the seed were measured. The sensory profiles of six cultivars ('Tonda Gentile delle Langhe', 'Tonda di Giffoni', 'Tonda Gentile Romana', 'Mortarella', 'Nocchione' and 'Tombul') were examined. Fatty acid composition and level of tocopherolic and non tocopherolic antioxidant confirmed the nutritional and dietetic value of the nuts. Polyphenols were mainly concentrated in the perisperm. Sensory analysis was able to reveal varietal differences for attributes related to taste and flavour. A positive relationship between sweetness scores and sugar concentration was observed.
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Antioxidant activities of ethanolic extracts of whole almond seed, brown skin, and green shell cover were evaluated using different free radical trapping assays. Trolox equivalent antioxidant capacity assay revealed that the total antioxidant capacities of brown skin and green shell cover extracts were 13 and 10 times greater than that of the whole seed extract at the same extract concentration. The free radical-scavenging activity of extracts of brown skin and green shell cover also exceeded that of the whole seed. The scavenging activity of superoxide radical by different almond extracts ranged from 76 to 97% at 100 ppm and 85 to 99% at 200 ppm. The corresponding reduction of hydrogen peroxide concentration was 59–66% (100 ppm) and 86–91% (200 ppm). The hydroxyl radical-scavenging capacities at 100 and 200 ppm were 16 and 42% for whole seed, 57 and 100% for brown skin, and 40 and 56% for green shell extracts, respectively. A 100% scavenging activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was observed for brown skin and green shell extracts at 100 and 200 ppm concentrations, respectively, and whole seed extracts scavenged 21 (at 100 ppm) and 73% (at 200 ppm) of the DPPH radical.
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In this study, six common tests for measuring antioxidant activity were evaluated by comparing four antioxidants and applying them to beverages (tea and juices): Trolox equivalent antioxidant capacity assay (TEAC I-III assay), Total radical-trapping antioxidant parameter assay (TRAP assay), 2,2-diphenyl-l-picrylhydrazyl assay (DPPH assay), N,N-dimethyl-p-phenylendiamine assay (DMPD assay), Photochemiluminescence assay (PCL assay) and Ferric reducing ability of plasma assay (FRAP assay). The antioxidants included gallic acid representing the group of polyphenols, uric acid as the main antioxidant in human plasma, ascorbic acid as a vitamin widely spread in fruits and Trolox as water soluble vitamin E analogue. The six methods presented can be divided into two groups depending on the oxidising reagent. Five methods use organic radical producers (TEAC I-III, TRAP, DPPH, DMPD, PCL) and one method works with metal ions for oxidation (FRAP). Another difference between these tests is the reaction procedure. Three assays use the delay in oxidation and determine the lag phase as parameter for the antioxidant activity (TEAC I, TRAP, PCL). They determine the delay of radical generation as well as the ability to scavenge the radical. In contrast, the assays TEAC II and III, DPPH, DMPD and FRAP analyse the ability to reduce the radical cation (TEAC II and III, DPPH, DMPD) or the ferric ion (FRAP). The three tests acting by radical reduction use preformed radicals and determine the decrease in absorbance while the FRAP assay measures the formed ferrous ions by increased absorbance. Gallic acid was the strongest antioxidant in all tests with exception of the DMPD assay. In contrast, uric acid and ascorbic acid showed low activity in some assays. Most of the assays determine the antioxidant activity in the micromolar range needing minutes to hours. Only one assay (PCL) is able to analyse the antioxidant activity in the nanomolar range. Black currant juice showed highest antioxidant activity in all tests compared to tea, apple juice and tomato juice. Despite these differences, results of these in vitro assays give an idea of the protective efficacy of secondary plant products. It is strongly recommended to use at least two methods due to the differences between the test systems investigated.
Article
Peanut skin is a by-product of the peanut industry that has low economic value despite its high content of antioxidants such as phenolics. The effects of three skin removal methods (direct peeling, blanching, and roasting) and extraction solvents (water, ethanol, and methanol) on total phenolics and total antioxidant activities (TAA) of peanut skin extracts were studied, and the composition of extracts were determined by HPLC. Results show that both skin removal methods and extraction solvents had significant effects on total extractable phenolics and TAA, with the combination of roasting and ethanol extraction being the most efficient recovery method. One gram dry peanut skin contained 90–125 mg total phenolics. TAAs of water and ethanol extracts of peanut skin were 3.39 and 4.10 mM Trolox Equivalent/mM of total phenolics compared with 1.91 and 2.46, respectively, for green tea. Three classes of phenolics (phenolic acids, flavonoids, and stilbene) were found in peanut skin extracts.
Article
Representative condensed and hydrolyzable tannins and related simple phenolics were evaluated as biological antioxidants using cyclic voltammetry, the metmyoglobin assay, and the deoxyribose assay. The redox potentials of the tannins were similar to those of structurally related simple phenolics. However, the tannins were 15−30 times more effective at quenching peroxyl radicals than simple phenolics or Trolox. One of the tannins, polygalloyl glucose, reacted an order of magnitude more quickly with hydroxyl radical than mannitol. These results suggest that tannins, which are found in many plant-based foods and beverages, are potentially very important biological antioxidants. Keywords: Tannins; plant phenolics; antioxidant; total antioxidant activity; oxidative damage; dietary antioxidant
Article
Phenolic acids were extracted from the nutmeats and/or testae of pine nut, almond, filbert, American Chestnut, a hybrid American chestnut, Chinese chestnut, black walnut, butternut and shagbark hickory and analyzed as their methyl esters/trimethylsilyl derivatives by GLC-MS. Both qualitative and quantitative differences were observed among samples in the acids present with gallic acid being predominant except in pine nut, almond and filbert. Caffeic was the predominant acid in pine nut; protocatechuic acid was predominant in almond and filbert. Phenolic acids isolated and identified were p-hydroxybenzoic, p-hydroxyphenylacetic, vanillic, protocatechuic, syringic, gallic, caffeic and ferulic acids.
Article
Phenolic compounds were extracted from defatted almond seeds using 80% aqueous acetone. Crude extract was applied onto a Sephadex LH-20 column. Fraction I consisting of low-molecular-weight phenolics was eluted from the column by ethanol. Fraction II consisting of tannins was obtained using water-acetone (1:1, v/v) as the mobile phases. Phenolic compounds present in the crude extract and its fractions showed antioxidant and antiradical properties as revealed following studies using a β-carotene-linoleate model system, total antioxidant activity (TAA) method, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power evaluation. Results of these assays showed highest values when tannins (fraction II) were tested. For example, TAA of tannin fraction was 3.93 mmol Trolox/g, whereas the crude extract and fraction I showed values of only 0.24 and 0.09 μmol Trolox/mg, respectively. The content of total phenolics in fraction II was the highest (80.4 mg/g). The content of tannins in this fraction determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g was 2436. The high-performance liquid chromatography (HPLC) analysis of almond seed crude extract showed the presence of phenolic compounds, namely vanillic, caffeic, p-coumaric, ferulic acids (after basic hydrolysis), quercetin, kaempferol and isorhamnetin (after acidic hydrolysis), delphinidin and cyanidin (after n-butanol-HCl hydrolysis) and procyanidin B2 and B3.
Article
Many analytical methods are used to measure the antioxidative activity of substances yet little is known about the comparability of the test results between laboratories. After an initial evaluation of a broad range of methods conducted by one laboratory, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the trolox equivalent antioxidant capacity (TEAC) assay, the lipid assay (or 2,2′-azobis(2-aminepropane) (ABAP) assay) and the thiobarbituric acid (TBA) assay were selected to be evaluated in the interlaboratory study. The antioxidative potentials of trolox, tocopherol, lipochroman-6, ascorbic acid, 4-methyl-brenzcatechin, and/or 3,5-di-tert-butyl-4-hydroxytoluene (BHT) were assessed using each of the methods. These methods were then evaluated in respect of their reproducibility and classification properties. Based on the results of this study, the DPPH assay followed by the TEAC assay yielded the best results based on reproducibility and sensitivity both within one laboratory and between laboratories. The results of the interlaboratory study were then compared with the single center results obtained from the commercially available photochemolumiescence (PCL) kit. To assess the transferability of chemical data to biological systems, they were also compared with the single center results obtained using the cell-based Dichlorodihydrofluoresceine (DCFH)q3 assay. © 2006 Society of Cosmetic Scientists and the Socièété Française de Cosmétologie.
Article
Hazelnuts were investigated for the presence of antioxidant compounds other than tocopherol. Hazelnuts from 2 regions were extracted with methanol:water (2:1; v/v). Extracts were subjected to either acid or alkaline hydrolysis but neither improved the separation quality during high pressure liquid chromatography (HPLC) analysis. Nonhydrolyzed extracts of hazelnut had greater antioxidant activity in comparison to hydrolyzed extracts. The 1st 10 minute eluent in the HPLC had greater antioxidant activity relative to the later eluting fractions. Gallic acid, p-hydroxyl benzoic acid, caffeic acid and/or epicatechin, sinapic acid, and quercetin were tentatively identified using HPLC.
Article
Response surface methodology was applied to predict the optimum conditions for extraction of phenolic compounds in hazelnut shell. The phenolic content in the shell extract was determined spectrophotometrically according to the Folin‐Ciocalteu method and expressed as gallic acid equivalent (mg GAE g−1). Two central composite designs were used to investigate the effects of two independent variables, namely solvent composition (%) and extraction time (min), on phenolic extraction. In a first series of repeated batch extractions, the solvent consisted of different methanol percentages in distilled water at pH 4, while in a second series methanol was substituted by ethanol. The highest phenolic content (6.67 mg GAE g−1 of shell) was predicted at the extraction conditions of 55.7% ethanol and 108.7 min. These best conditions, obtained and applied to 13 different cultivars, showed values varying from 9.18 mg GAE g−1 of shell for Barcelona to 3.00 mg GAE g−1 of shell for Tonda di Giffoni. Copyright © 2007 Society of Chemical Industry
Article
A comparative study of the antioxidant activity of wine phenolics has been performed. Standards of phenolic compounds, including benzoic and cinnamic acids, flavanols, flavonols and resveratrol, as well as some of their metabolites have been analysed for their antioxidant activity. Antioxidant assays included the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging methods and the Oxygen Radical Absorbance Capacity method (ORAC).We compared the reactivity of standard phenolic compounds under selected tests and obtained a ranking order for each one. Both ABTS and DPPH methods were well correlated. Several new structure–activity relationships were observed. As the number of phenoxyl groups increases, the antioxidant capacity, determined by DPPH and ABTS tests, improves. In the case of the ORAC assay, the ortho-position of phenoxyl groups clearly determines the activity. The metabolites of phenolic compounds present antioxidant activity and their values are similar to those of the phenolic compounds themselves.The choice of solvent, the effect of concentration and the information provided by the three tests under study are considered.
Article
The growing interest in the substitution of synthetic food antioxidants by natural ones has fostered research on vegetable sources and the screening of raw materials for identifying new antioxidants. Oxidation reactions are not an exclusive concern for the food industry, and antioxidants are widely needed to prevent deterioration of other oxidisable goods, such as cosmetics, pharmaceuticals and plastics. Polyphenols are the major plant compounds with antioxidant activity, although they are not the only ones. In addition, other biological properties such as anticarcinogenicity, antimutagenicity, antiallergenicity and antiaging activity have been reported for natural and synthetic antioxidants. Special attention is focussed on their extraction from inexpensive or residual sources from agricultural industries. The aim of this review, after presenting general aspects about natural antioxidants, is to focus on the extraction of antioxidant compounds (mainly polyphenols) from agricultural and industrial wastes, as well as to summarize available data on the factors affecting their antioxidant activity and stability, and, in some cases, the reported major active compounds identified.
Article
The kinetics of peroxide accumulation during oxidation of sunflower oil at 100 °C in the presence of different concentrations of hexane, ethyl acetate and ethanol extracts of Melissa officinalis L., Mentha piperita L., Mentha spicata L., Ocimum basilicum L., Origanum vulgare L. and Saturejae hortensis L. have been studied. It has been established that the extracts from Ocimum basilicum L. and Origanum vulgare L. do not improve the oxidation stability of sunflower oil. The ethanol extracts from the other four spices have proved to be the most active in retarding the autoxidation process. The strongest action has been exhibited by the ethanol extracts from Saturejae hortensis L., followed by the ethanol extracts from Mentha piperita L. and Melissa officinalis L. The stabilization factor F for the ethanol extracts (0.1–0.5%) from Saturejae hortensis L. is 1.8–2.3. It is higher than F for 0.02% butylated hydroxytoluene BHT (F = 1.2). From a practical point of view (yield and stabilization factor), the direct ethanol extract from Saturejae hortensis L. should be recommended as the most suitable antioxidant for the stabilization of sunflower oil.
Article
The antiradical activities of various antioxidants were determined using the free radical, 2,2-Diphenyl-1-picrylhydrazyl (DPPH*). In its radical form. DPPH* has an absorption band at 515 nm which dissappears upon reduction by an antiradical compound. Twenty compounds were reacted with the DPPH* and shown to follow one of three possible reaction kinetic types. Ascorbic acid, isoascorbic acid and isoeugenol reacted quickly with the DPPH* reaching a steady state immediately. Rosmarinic acid and δ-tocopherol reacted a little slower and reached a steady state within 30 min. The remaining compounds reacted more progressively with the DPPH* reaching a steady state from 1 to 6 h. Caffeic acid, gentisic acid and gallic acid showed the highest antiradical activities with a stoichiometry of 4 to 6 reduced DPPH* molecules per molecule of antioxidant. Vanillin, phenol, γ-resorcylic acid and vanillic acid were found to be poor antiradical compounds. The stoichiometry for the other 13 phenolic compounds varied from one to three reduced DPPH* molecules per molecule of antioxidant. Possible mechanisms are proposed to explain the experimental results.
Article
Catechins are flavanols present in a variety of foods such as wine, tea, fruits and chocolate. Catechin, epicatechin and gallates of epicatechin are major catechins with dietary importance for human health. In recent years, catechins have been used as natural antioxidant in oils and fats against lipid oxidation, supplement for animal feeds both to improve animal health and to protect animal products, an antimicrobial agent in foodstuffs and a health functional ingredient in various foods and dietary supplements. This review outlines the novel uses of catechins in foods.
Article
The two most widely used chromogen compounds to measure the antioxidant activity of biological material are the ABTS+· and the DPPH· radicals. Both present excellent stability in certain assay conditions but also show several important differences in their response to antioxidants and in their manipulation. In this study, we present the interferences, at different wavelengths, caused by plant-derived materials (citrus juices and wines) using the two above chromogens to measure their antioxidant activity.
Article
The free radical scavenging activity of ethanolic extracts of cashew nut (Anacardium occidentale, L.) skin powder (CSP) was evaluated by employing various in vitro antioxidant assay systems. The yield of the extract as well as the total phenolic content was also determined. The yield of ethanolic extract of the skin powder was quite high (0.45 g/g powder) with a total phenolic content of 243 mg/g extract. The cashew nut skin extract (CSE) demonstrated promising antioxidant activity with EC50 of 1.30 ± 0.02 μg/ml in 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, 10.69 ± 1.13 μg/ml in superoxide scavenging assay, 17.70 ± 0.05 μg/ml in deoxyribose oxidation assay, 24.66 ± 0.32 μg/ml in lipid peroxidation (LPO) assay and 6.00 mg/ml in iron chelation assay. To identify the compounds in the CSE responsible for the antioxidant activity, thin layer chromatography (TLC) was performed with the extract. The spot showing protection towards β-carotene bleaching was extracted and analyzed by high performance liquid chromatography (HPLC); epicatechin was found to be the major polyphenol present. The results of the present study suggest that cashew nut skin, a byproduct of cashew processing industry, can be used as an economical source of natural antioxidants.
Article
The objective of this work was to extract antioxidant components from peanut skins using different solvents and to determine antioxidant activity of the extracts. Methanolic, ethanolic, acetonic and aqueous extracts were prepared from defatted and non defatted peanut skins. Total dry matter content and total phenolic content, radical-scavenging activity and antioxidant activity in sunflower oil were determined from the extracts. The peanut skins used in this work had the following proximate composition: 16.60% oil, 12.32% protein, 2.83% ash and 69.8% other components. High content of total dry matter was found in methanolic (17.11%), ethanolic (17.70%) and acetonic (18.54%) extracts from non defatted peanut skins. The acetonic extract from defatted peanut skins had lower dry matter extraction than the non defatted peanut skin extract. High content of total phenolics was detected in methanolic (158.6 mg/g) and ethanolic (144.1 mg/g) extracts from deffated peanut skins. These last two extracts in concentration of 1 μg/mL, the radical-scavenging activities were 32.59% in methanolic extract and 31.5% in ethanolic extract. All extracts (0.05% w/w) in sunflower oil showed antioxidant activity. This antioxidant activity from the extracts was lower than that activity from BHT.
Article
The antioxidative activity of a total of 92 phenolic extracts from edible and nonedible plant materials (berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible plant materials, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.
Article
This paper presents a simple, convenient method for determining the efficiency of antioxidants in aqueous systems. Production of conjugated diene hydroperoxide by oxidation of linoleic acid in an aqueous dispersion is monitored at 234 nm. 2, 2'-Azobis(2-amidinopropane) dihydrochloride is used as a free radical initiator. Among 12 antioxidants tested, phenolic compounds proved to be the most efficient, both kinetically and in terms of the inhibition time (T(inh)). Applied to wort, malt, and hops, the method confirmed a significant antioxidant activity in such products, especially hops. This assay can be used to follow oxidative changes throughout the brewing process and to understand the contribution of each raw material.
Article
The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.
Article
Consumption of plant foods, particularly fruits, vegetables and cereal grains is encouraged because they render beneficial health effects. Phenolics and polyphenolics are among the most desirable food bioactives because of their antioxidant activity, brought about by a number of pathways, or due to other mechanisms. The analysis of phenolics and polyphenolics requires their extraction possible purification and structure elucidation. This overview provides a cursory account of the source, extraction and analysis of phenolics in fruits, vegetables and cereals.
Article
Phenolic compounds in the aqueous systems were extracted, from hazelnut kernel (HK) and hazelnut green leafy cover (HGLC), with 80% (v/v) ethanol (HKe and HGLCe) or 80% (v/v) acetone (HKa and HGLCa). The extracts were examined for their phenolic and condensed tannin contents and phenolic acid profiles (free and esterified fractions) as well as antioxidant and antiradical activities by total antioxidant activity (TAA), antioxidant activity in a beta-carotene-linoleate model system, scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, and reducing power. Significant differences (p < 0.05) in the contents of total phenolics, condensed tannins, and TAA existed among the extracts that were examined. HGLCa extract had the highest content of total phenolics (201 mg of catechin equivalents/g of extract), condensed tannins (542 mg of catechin equivalents/g of extract), and TAA (1.29 mmol of Trolox equivalents/g of extract) followed by HGLCe, HKa, and HKe extracts, respectively. Five phenolic acids (gallic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid) were tentatively identified and quantified, among which gallic acid was the most abundant in both free and esterified forms. The order of antioxidant activity in a beta-carotene-linoleate model system, the scavenging effect on DPPH radical, and the reducing power in all extracts were in the following order: HGLCa > HGLCe > HKa > HKe. These results suggest that both 80% ethanol and acetone are capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction process. HGLC exhibited stronger antioxidant and antiradical activities than HK itself in both extracts and could potentially be considered as an inexpensive source of natural antioxidants.
Article
Antioxidant efficacies of ethanol extracts of defatted raw hazelnut kernel and hazelnut byproducts (skin, hard shell, green leafy cover, and tree leaf) were evaluated by monitoring total antioxidant activity (TAA) and free-radical scavenging activity tests [hydrogen peroxide, superoxide radical, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical], together with antioxidant activity in a beta-carotene-linoleate model system, inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol, and inhibition of strand breaking of supercoiled deoxyribonucleic acid (DNA). In addition, yield, content of phenolics, and phenolic acid profiles (free and esterified fractions) were also examined. Generally, extracts of hazelnut byproducts (skin, hard shell, green leafy cover, and tree leaf) exhibited stronger activities than hazelnut kernel at all concentrations tested. Hazelnut extracts examined showed different antioxidative efficacies, expected to be related to the presence of phenolic compounds. Among samples, extracts of hazelnut skin, in general, showed superior antioxidative efficacy and higher phenolic content as compared to other extracts. Five phenolic acids (gallic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid) were tentatively identified and quantified (both free and esterified forms). Extracts contained different levels of phenolic acids. These results suggest that hazelnut byproducts could potentially be considered as an excellent and readily available source of natural antioxidants.
Kernel quality and com-position of hazelnut (Corylus avellana L.) cultivars. Acta Horticultu-rae
  • C Bignami
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