Selection of the Solvent and Extraction Conditions for Maximum Recovery of Antioxidant Phenolic Compounds from Coffee Silverskin

The extraction of antioxidant phenolic compounds from coffee silverskin (CS) was studied. Firstly, the effect of different solvents (methanol, ethanol, acetone, and distilled water) on the production of antioxidant extracts was evaluated. All the extracts showed antioxidant activity (FRAP and DPPH assays), but those obtained with methanol and ethanol had significantly higher (p?<?0.05) DPPH inhibition than the remaining ones. Due to the lower toxicity, ethanol was selected as extraction solvent, and further experiments were performed in order to define the solvent concentration, solvent/solid ratio, and time to maximize the extraction results. The best condition to produce an extract with high content of phenolic compounds (13 mg gallic acid equivalents/g CS) and antioxidant activity [DPPH?=?18.24 μmol Trolox equivalents/g CS and FRAP?=?0.83 mmol Fe(II)/g CS] was achieved when using 60 % ethanol in a ratio of 35 ml/g CS, during 30 min at 60–65 °C.     

Major Polyphenolics in Pineapple Peels and their Antioxidant Interactions

Major polyphenolic compounds in pineapple peels were identified and quantified. The antioxidant capacities of pineapple peel extracts and these polyphenolic compounds were determined using DPPH? scavenging capacity and phosphomolybdenum method. Effects of these polyphenolics’ interactions on their antioxidant capacity were also evaluated. Gallic acid (31.76 mg/100 g dry extracts), catechin (58.51 mg/100 g), epicatechin (50.00 mg/100 g), and ferulic acid (19.50 mg/100 g) were found to be the main polyphenolics in pineapple peels. The IC₅₀ for DPPH? scavenging assay of the extracts was 1.13 mg/ml and total antioxidant capacity was 0.037 g ascorbic acid equivalents/g. The order of DPPH? scavenging capacity of per mole of these polyphenolic compounds present in pineapple peels was gallic acid > epicatechin = catechin > ferulic acid, but it was different when using phosphomolybdenum method the order of which was epicatechin. > catechin > gallic acid = ferulic acid. Results of polyphenolics’ interactions indicated no synergistic effects. In the combinations of ferulic acid-epicatechin and ferulic acid-gallic acid, additive effects were found using both antioxidant activity assays.     

Influence of thermal treatment on phenolic compounds and antioxidant properties of oak acorns from Serbia

The aim of the present work was to investigate and compare phenolic compounds and antioxidant activity of methanol extracts of Quercus robur and Quercus cerris acorn kernels obtained before and after thermal treatment. Content of total phenolics, tannins, non-tannin phenolics and flavonoids was determined spectrophotometrically and content of gallic acid with HPLC. Antioxidant activity of the samples was assayed through FRAP (Ferric Reducing Antioxidant Power), DPPH scavenging test and inhibition of Fe²⁺/ascorbate induced lipid peroxidation. Extracts of native and thermally treated kernels showed high antioxidant activity, with extracts of thermally treated kernels being more active than extracts of native ones. Hydrolysable tannins and gallic acid were identified in all samples. Non-tannin phenolics, including gallic acid, were present in significantly higher quantities in thermally treated samples, whilst tannin content decreased. This indicates that during thermal treatment hydrolysable tannins were degraded. As the result of this degradation and consequent increase of non-tannin phenolics content, and amongst them especially gallic acid, thermally treated samples possess higher antioxidant activity than do the native ones. The obtained results have provided further grounds for establishing Q. robur and Q. cerris acorn kernels as a source for functional food preparation.     

茶叶提取物体外抗氧化活性与其功能性成分含量的相关性研究

分别选取信阳毛尖、红碎茶、普洱熟茶为典型不发酵、全发酵及后发酵茶种,测定其醇提物及水提物中的主要成分,并以氧自由基的吸收能力(ORAC)和DPPH自由基的清除能力为指标,比较各样品体外抗氧化活性,采用功能化合物重组模型,探究茶叶提取物抗氧化活性的主要贡献物质。结果表明:茶叶醇提物中茶多酚、咖啡因及醇溶蛋白的含量较高,其ORAC值及DPPH自由基清除能力均较对应水提物强;茶叶水提物功能性组分以茶多酚、茶多糖及氨基酸为主,都具有一定的抗氧化活性。其中茶多酚含量,尤其是酯型儿茶素(ECG和EGCG)含量是影响茶叶提取物抗氧化活性的主要因素。重组试验结果表明,儿茶素和没食子酸是不发酵茶(信阳毛尖)提取物的主要抗氧化组分,但并不是红碎茶、普洱熟茶等发酵茶中的主要抗氧化成分。     

Chemical Composition and Antimicrobial and Antioxidant Activities of Essential Oils and Various Extracts of Juniperus phoenicea L. (Cupressacees)

ABSTRACT:  GC-FID and GC-MS analysis of essential oils of  Juniperus phoenicea  resulted in the identification of 30 compounds, representing more than 98% of the total composition. α-pinene (55.7% and 80.7%), δ-3-carene (10.7% and 4.5%), and γ-cadinene (2.9% and 5.1%) were the main components, respectively, in leaves and berries essential oil. Extracts of  J. phoenicea  were obtained by different extraction solvents: methanol, ethanol, ethyl acetate, and dichloromethane and evaluated composition for polyphenols (gallic acid equivalent 52 to 217 g/kg), tannins (catechin equivalent 6.5 to 60.2 g/kg), antocyanins (cyanidin equivalent 84 to 373 mg/kg), and flavonoids (quercetin equivalent 6.4 to 29.3 g/kg). The samples (essential oils and extracts) were subjected to a screening for their antioxidant activity by using DPPH and ABTS assays; antimicrobial activity was tested with 6 bacteria (3 Gram-positive and 3 Gram-negative), 1 yeast, and 2 fungi. The strongest antioxidant activity was obtained by the methanolic extract ( IC ₅₀= 6.5 ± 0.3 mg/L). Flavonoids are likely to contribute to the antifungal activity against  Saccharomyces cerevisiae.  Correlations were studied between chemical composition and antioxidant and antimicrobial activities.     

Fatty acids,tocopherols, phenolic and antioxidant properties of six citrus fruit species: a comparative study

Citrus fruit is a rich source of bioactive phytochemicals. Information on the fatty acid and tocopherol composition of locally grown citrus fruits in Korea is elusive. This work was aimed to study fatty acid, tocopherols, ascorbic acid, antioxidant potential, and selected phenolics from peel and pulp of six citrus species. The most dominant fatty acid was linoleic acid (15–45%), followed by linolenic, palmitic, and oleic acid. Stearic acid was highly abundant in yuzu peel (14.45%) and pulp (15.88%) compared to the other fruits. Unsaturated fatty acids (54–74%) contributed higher composition than saturated fatty acids (25–46%). Peel exhibited better antioxidant potential and contained higher phytochemicals than pulp. The concentrations of α-tocopherol and γ-tocopherol were ranged from 22.96 (yuzu) to 86.93 (cheonhyeyang) and 38.59 (yuzu) ~83.03 (tangerine) μg/g DW, respectively. J-Redhyeyang peel exhibited highest total flavonoids (4.17?±?0.10 mgQE/g DW) and DPPH radical scavenging activity (6.17?±?0.03 mgTE/g DW). FRAP values were highest (20.05?±?0.64 mgTE/g DW) in yuzu peel, while peel of cheonhyeyang was superior in total phenolic contents. Tangerine (3.02?±?0.05 mg/g DW) and yuzu (7.49?±?0.38 mg/g DW) had higher hesperidin concentrations in pulp and peel, respectively. Naringin was found in an appreciable amount in yuzu pulp (2.04?±?0.09 mg/g DW) and peel (6.30?±?0.19 mg/g DW) but not detected in all other fruit species. Our results indicate that citrus fruit peel is the rich source of antioxidant compounds, which can be used to prepare antioxidant rich food product.     

Lipophilic phenols partially explain differences in the antioxidant activity of subfractions from methanol extract of camellia oil

The crude methanol extract (ME) from camellia oil was fractionated by serial benzene, ether, EtOAc and n-BuOH, divided into five subfractions designated as SF1–5. The obtained fractions as well as ME were evaluated for their antioxidant activities using DPPH assay, and their phenolic constituents were isolated using silica gel column chromatography and analysed by TLC, RP-HPLC–PDA, UPLC-ESI–MS and GC–MS. Results showed that the content of total phenolics (TPs) of ME, determined by the Folin–Ciocalteu method, was estimated to be 79.5?±?10.2?mg of p-hydroxybenzoic acid equivalent/kg oil, while that of the total flavonoids was 8.98?±?0.54?mg of rutin equivalent/kg oil. ME exhibited pronounced radical-scavenging activity against the stable DPPH radical (with an antioxidant capacity IC₅₀ value of 52.37?μg/mL), and three subfractions (SF1–3) separated from ME contributed the most significant activity with IC₅₀ of 28.41, 17.42 and 43.17?μg/mL, respectively. Consistent with the different capacity of scavenging DPPH radicals, the subfractions from ME showed different composition and contents of phenolic compounds as detected by TLC, RP-HPLC–PDA, UPLC-ESI–MS and GC–MS. Kaempferol, as well as a number of volatile phenolic compounds, was first identified from camellia oil. Results showed that the presence of phenolic compounds and flavonoids in each extracts may be responsible for its individual antioxidant activity, and the lipophilic phenolic fractions would likely account for a great part of the antioxidant properties of the oil.     

Antioxidant properties of pomegranate (Punica granatum L.) bagasses obtained as co-product in the juice extraction

The aim of this work was to determine the total phenol (TPC), the total flavonoid (TFC), the tannins contents (TC), organic acids and sugar contents and the antioxidant activity of pomegranate juice extraction bagasses, which were obtained in two different ways: (i) Direct extraction that involved arils and peel (WFB) and (ii) only from arils (AB). Four different test systems were used, namely the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, the ferric reducing antioxidant power (FRAP); determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and the ferrous ion-chelating ability (FIC). WFB presented higher total phenolic, flavonoid and tannins contents (10.05 mg gallic acid equivalent/g sample; 7.19 mg rutin equivalent/g sample and 8.18 mg catechin/g sample) than AB. The organic acid detected were oxalic acid, citric acid, malic acid and succinic acid while the sugar identified were fructose and glucose. As regards antioxidant activity, at all concentrations and with all methods, the WFB samples showed a higher antioxidant activity than AB samples. BHT, used as control positive, present higher antioxidant activity than WFB and AB in all antioxidant methods used except in the FRAP assay.The results of this study indicate that pomegranate bagasse obtained as co-product in the process to obtain juice may be considered a good source of natural compounds with significant antioxidant activity which could be suitable for applications on the food industry as potential ingredient for food products.     

Antioxidant power,bacteriostatic activity,and characterization of white grape pomace extracts by HPLC–ESI–MS

Polyphenolic fractions obtained from white grape pomace by aqueous extraction were analyzed to determine their antioxidant power (DPPH and TBARS methods), bacteriostatic activity, the effect of particle size on total extractable polyphenols (expressed as gallic acid equivalents (GAE)), and to characterize by HPLC–ESI–MS. The extraction of polyphenols from Albariño variety grape pomace was performed both on lab-scale and on pilot-plant scale using particles sizes of <1 mm, 3–5 mm and entire particle. Lab-scale assays showed that the lower the particle size the higher the raw extract (RE) percentage (%w/w), which values were 21.3 ± 0.37% (SD), 12.6 ± 0.38%, and 6.6 ± 0.44%, respectively. Several fractions were obtained from RE, either as result of applying liquid–liquid partition or gel permeation chromatography. The antiradical activities of the fractions were lower than that of gallic acid (17.8 ± 0.1 mg GAE/mol DPPH) but similar to that of catechin or procyanidin B₂ (46.0 ± 2.3 mg GAE/mol DPPH and 52.3 ± 6.3 mg GAE/mol DPPH). Several fractions showed bacteriostatic activity both at 50 and at 100 mg/L. Total aerobic bacterial enumeration (TABE, log UFC/cm²) of treated samples revealed a significant lower TABE than that for control. HPLC–ESI–MS studies demonstrated that fractions V and VI included monomers, dimers, and trimers of procyanidins, few of them galloylated. Fraction VII contained several oligomers and galloylated procyanidins.     

A comprehensive study of polyphenols contents and antioxidant potential of 39 widely used spices and food condiments

Spices and condiments are rich sources of potent antioxidants. In the present investigation, total equivalent antioxidant capacities (TEAC) of 39 spices were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging, and cupric reducing antioxidant capacity (CUPRAC) assays. Their total phenolic contents (TPC) and total flavonoid contents (TFC) were also determined. TEAC, TPC, and TFC varied significantly (P?<?0.05) among these spices. ABTS, DPPH, and CUPRAC assay values of studied spices ranged from 1.42 to 112.94 mg ascorbic acid equivalents (AAE)/g, 1.14 to 91.09 mg Trolox equivalents (TE)/g, and 0.52 to 54.47 mg TE/g, respectively (dry weight basis; DW). Based on Folin–Ciocalteu assay, TPC ranged from 2.93 to 160.55 mg of gallic acid equivalents (GAE)/g DW. Strong correlations between TPC and TEAC values (R?=?0.966, 0.825, and 0.954 for ABTS, DPPH, and CUPRAC, respectively) were found. This indicates that phenolic compounds are potent antioxidants in these spices. Principal component analysis (PCA) indicated that cloves (flower buds of Syzygium aromaticum) had the most distinct and potent antioxidant capacity, followed by allspice (fruits of Pimenta dioica) and cinnamon (bark of Cinnamomum verum). Results of the present study provide adequate evidence that polyphenols are responsible for their compelling antioxidant capacities of studied spices. Thus, consumption of antioxidant-rich spices such as cloves, allspice, and cinnamon can significantly prevent oxidative stress in the human body.     

Evaluation of antioxidant activity of ten compounds in different tea samples by means of an on-line HPLC–DPPH assay

Tea (Camellia sinensis), a well-known traditional beverage in China, has drawn growing attention due to its various benefits to health. In this study, an on-line assay of coupling high performance liquid chromatography separation with 1,1-diphenyl-2-picrylhydrazyl free radical reaction system (HPLC–DPPH) was applied to evaluate the antioxidant activity of different teas. Twelve main chromatographic peaks were detected in tea, and they were identified as gallic acid, 3-galloyl-quinic acid, theobromine, (−)-gallocatechin, (−)-epigallocatechin, caffeine, procyanidin dimer, (−)-epicatechin, (−)-epigallocatechin gallate, (−)-gallocatechin gallate, 1,2,6-tri-galloyl-glucose and (−)-epicatechin gallate by comparing their retention times and DAD spectra with standard compounds respectively or with reference to our previous study. DPPH assay showed that ten out of twelve investigated compounds have free radical scavenging activity, and their contents were determined or estimated. Trolox equivalent antioxidant capacities (TEACs) of the ten active components were also determined. EGCG was the most potent antioxidant with a TEAC value of 5.822. Catechin components were the major contributors to the antioxidant activity of tea; they decreased during tea fermentation and led to the reduction of antioxidant activity. Different tea samples were scientifically classified and their antioxidant activities were comprehensively evaluated by on-line HPLC–DPPH assays coupled with principal component analysis and hierarchical clustering analysis. The results indicated that the combination of the on-line HPLC–DPPH assay, principal component analysis and hierarchical clustering analysis could be suitable for the bioactivity assessment and variety characterization of tea and its derived products. Additionally, a simple and rapid method for simultaneous capture of chemical quantitative analysis and bioactivity evaluation by determining contents of the bioactive compounds was firstly established. This method could provide a comprehensive evaluation of tea.     

Oregano: chemical analysis and evaluation of its antimalarial, antioxidant, and cytotoxic activities

Abstract: GC‐FID and GC‐MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p‐cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC₅₀= 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC₅₀= 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC₅₀ of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic.     

Optimization of Microwave-Assisted Extraction of Phenolic Antioxidants from Grape Seeds (Vitis vinifera)

Grape seeds (Vitis vinifera) are rich in phytochemicals that have antioxidant properties. The influence of independent variables such as microwave power (100, 150, and 200 W), extraction time (2, 4, and 6 min), and solvent concentration (30%, 45%, and 60% ethanol) and their interactions on total phenols and the antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP)) were determined; and the microwave-assisted extraction (MAE) process was optimized using a central composite design. The total phenols that were expressed as gallic acid equivalents (GAE), catechin equivalents (CAT), and tannic acid equivalents (TAE) were significantly influenced by the solvent concentration and the time of extraction. A numerical optimization was carried out to obtain the overall conditions for MAE of phenolic antioxidants from grape seed. The response variables were maximized for 6 min of MAE of grape seed (GS) with 32.6% ethanol at 121 W with a desirability function of 0.947. The predicted extraction yields were 13?±?0.89, 21.6?±?1.59, and 15.9?±?1.32 mg GAE, CAT, and TAE, respectively per gram of GS. The predicted antioxidant activity per gram of dry weight GS was 80.9% for the inhibition of DPPH and 135 μM ascorbic acid equivalents for FRAP test. The predicted response values were significantly correlated with the observed ones as follows: GAE r?=?0.995, CAT r?=?0.990, TAE r?=?0.996, DPPH r?=?0.996, and FRAP r?=?0.996.     

Identification of ultraviolet radiation induced gallic acid and caffeic acid formation in palm juice (Borassus flabellifer) by HPLC & mass spectra technique

Palm juice, a common-cheap-antioxidants rich natural plant juice has been investigated for optimizing the effect of UV-radiation on the antioxidant activity using a DPPH free radical scavenging activity method. In this study separate set of samples of raw palm juice has been treated with 365 and 254 nm UV-lights (UVL) respectively for different exposure time. When exposed for 15 min with 365 nm UVL induces concentration factor of caffeic acid, whereas, 254 nm UVL induces gallic acid accumulation, but overall antioxidant activity was higher for 365 nm UV-radiation. Caffeic acid and other polyphenol compounds are increased by 5.5 ± 0.5 % than normal palm juice, observed after irradiation with 365 nm UVL. Even after the exposure of UV irradiation for 15 min, did not affect on peptide bond modification of protein molecules present in palm juice, therefore a green effect of UVL is explored for the effective increase of antioxidant activity.     

Comparative analysis of antioxidant and antimelanogenesis properties of three local guava (Psidium guajava L.) varieties of Thailand, via different extraction solvents

The antioxidant and antimelanogenesis potentials of three local varieties of guava (Psidium guajava L.) from Thailand namely: Pansithong, Thai original and Kimju were studied. The extracts were made with water, 40 % ethanol and simulated gastrointestinal digestion (SGD). Antioxidant properties were determined by total polyphenolic compounds, DPPH assay, superoxide anion assay and hydroxyl radical assay. Antimelanogenesis properties were determined by anti-tyrosinase assay, total phenolic acid and total vitamin C contents. The results for antioxidant analysis revealed that Pansithong, when extracted by 40 % ethanol and SGD showed the presence of highest polyphenol compounds, and DPPH antioxidant activity respectively. Kimju exhibited the highest hydroxyl radical antioxidant activity among all extracts and highest superoxide anion antioxidant activity, when extracted by 40 % ethanol. The results for antimelanogenesis determination presented that Kimju showed highest tyrosinase inhibition, total phenolic acid and total vitamin C contents. It was concluded that Pansithong showed highest antioxidant potential while the highest antimelanogenesis potential was found in Kimju. Over all water has been found as the best solvent for antioxidant extraction followed by 40 % ethanol and SGD.     

Chemical and Phytochemical Properties and Antioxidant Activities of Three Pomegranate Cultivars Grown in South Africa

A comparative study of chemical contents and antioxidant activities of three pomegranate cultivars (‘Arakta’, ‘Bhagwa’ and ‘Ruby’) grown in South Africa was conducted. Fresh pomegranate juice (PJ) of each cultivar were assessed for soluble solid contents (SSCs), pH and titratable acidity (TA), while extracted juice samples were evaluated for total phenolic (TP), including total tannins (TT), proanthocyanidins (Pcy), total flavonoids, anthocyanins and gallic acids (GA) using spectrophotometric methods. The antioxidant properties of the juice samples were evaluated against stable 2, 2–diphenyl–1–picryl hydrazyl, as well as in ferric reducing ability of plasma (FRAP) and QuantiChrom? (TAC) antioxidant assays. There were significant differences in the chemical properties of the cultivars. SSC, TA and pH varied between the range of 14.07–15.10 °Brix, 0.22–0.28 g/100 ml and 3.32–3.64, respectively. ‘Bhagwa’ had the highest TP (449.9 mg/100 ml), 1.3-fold and 1.6-fold higher than ‘Arakta’ and ‘Ruby’, respectively. The strongest total antioxidant activity was exhibited by ‘Bhagwa’ with an antioxidant index of 95.7%, followed by ‘Arakta’ (93.2%) and ‘Ruby’ (79.9%). PJ phytochemical properties (TP, TT, Pcy, GA) and antioxidant activity (FRAP and TAC) were significantly correlated (r ²?=?0.509–0.885) with each other.     

Antioxidant activity and phenolic composition of sumac (Rhus coriaria L.) extracts

Antioxidant activity and phenolic compounds of sumac extracts were investigated. Sumac was extracted in methanol and subjected to solvent–solvent partitioning to yield two fractions as ethyl acetate and aqueous. Methanol extract was further fractioned over Sephadex LH-20 column. Antioxidant activity of extracts and fractions were screened using ferric thiocyanate and DPPH radical scavenging methods. Phenolic composition of active fraction(s) was determined by HPLC–MS systems. Those fractions which exhibited strong antioxidant activity were rich in anthocyanins and hydrolysable tannins. While gallic acid was the main phenolic acid in the extracts, anthocyanin fraction contained cyanidin, peonidin, pelargonidin, petunidin, and delphinidin glucosides and coumarates. Pentagalloyl glucose was abundant in the hydrolysable tannin fraction. Effective scavenging concentration (EC₅₀) on DPPH radical was 0.70 μg/mL both in ethyl acetate and tannin fractions, and 5.33 μg/mL in anthocyanin rich fraction. Same extracts and fractions showed moderate lipid peroxidation inhibition effect compared with the synthetic antioxidants. The findings demonstrate that sumac can be used as a natural antioxidant.     

Bioactive composition and sensory evaluation of blended jambolan (Syzygium cumini) and sugarcane alcoholic fermented beverages

The consumption of wine has increased considerably in recent years, which has aroused consumer interest in the consumption of alternative wines produced from various fruits. This study evaluates polyphenolic composition, identifies bioactive compounds and assays the total antioxidant capacity of four different formulations of jambolan (Syzygium cumini) and sugarcane fermented beverages (100:0, 70:30, 50:50 and 30:70), as well as their physical and chemical characteristics and also the sensory profile of the beverages. Significant levels of different phenolic compounds were found in the fermented alcoholic beverages. Beverages with higher jambolan content had the greatest content of phenolic compounds. The product produced with 100% jambolan presented 2.99 g gallic acid equivalents per litre of phenolic compounds, 0.67 g Cy3Glu L^?1 of anthocyanins, 0.92 g tannic acid equivalents per litre of tannins and a DPPH free radical scavenging capacity of 85.24%. The phenolic compounds found in higher amounts in the beverages were caffeic, chlorogenic and gallic acid. Treatments elaborated with 100, 70 and 50% of jambolan pulp received the best overall feedback from consumers. The results suggest that jambolan fruit (currently not consumed fresh or used in other ways) could serve as a source of bioactive compounds and therefore be of interest to the food industry. Copyright © 2016 The Institute of Brewing & Distilling     

Characterization of Valuable Compounds from Winter Melon (<Emphasis Type="Italic">Benincasa hispida</Emphasis> (Thunb.) Cogn.) Seeds Using Supercritical Carbon Dioxide Extraction Combined with Pressure Swing Technique

In this study, we describe the extraction of different valuable compounds from winter melon seeds using supercritical carbon dioxide extraction combined with pressure swing technique (SCE-PST). The effects of the extraction variables, namely pressure, holding time (HT), and continuous extraction time (CT), were optimized by response surface methodology (RSM) to maximize the crude extraction yield (CEY). The optimal conditions were at pressure of 181.35 bar, HT of 9.93 min, and CT of 50.14 min. Under these conditions, the experimental CEY was 235.70?±?0.11 mg g^?1 with a relatively strong antioxidant activity (64.42?±?0.21 % inhibition of DPPH^· radicals, 67.36?±?0.34 % inhibition of ABTS^·+ radicals) and considerable amount of phenolic compounds (42.77?±?0.40 mg gallic acid equivalent/g extract). The high-performance liquid chromatography (HPLC) analysis revealed that the bioactive phenolic compounds increased significantly using PST (p?<?0.05), where gallic acid had the highest concentration (0.688?±?0.34 mg g^?1). The extract obtained using optimal SCE-PST conditions contained more than 83.65 % total unsaturated fatty acids (UFAs) and linoleic acid accounted for 67.33?±?0.22 % in the total extract. From the results, the SCE efficiency in terms of extract quantity and quality has been enhanced significantly applying PST. Finally, the results were compared with previous published findings using supercritical carbon dioxide, ultrasound-assisted, and Soxhlet extraction. It was found that higher CEY could be achieved using Soxhlet extraction even through the quality of SCE-PST extracts in terms of antioxidant activity and phenolic compounds was better.     

Evaluation of antioxidant activities of Iranian sumac (R. coriaria L.) fruit and spice extracts with different solvents

The antioxidant capacity and phenolic content of three sumac (Rhus coriaria L.) samples, including brown sumac fruit, brown sumac powder and red sumac powder were investigated in the present study. Methanol, ethanol, distilled water, and a mixture of methanol and ethanol (1:1) were used as solvent systems. Antioxidant activities of extracts were screened using 1,1-diphenyl-2-picrylhydrazyl DPPH radical scavenging method. Phenolic content was determined through Folin–Ciocaltaeu procedure. The efficiency of the solvents used to extract phenols from the samples varied considerably. The phenolic content of brown sumac powder ranged from 2.906 to 2.997 gallic acid equivalents/100 g (GAE/100 g), while that of the brown sumac fruit was 2.438–2.529 GAE/100 g, and that of the red sumac powder was 2.172–2.263 GAE/100 g. Findings indicated that water extracts of sumac have effective antioxidant and radical scavenging activities as compared to other extracts.