Pigmented rice a potential source of bioactive compounds: a review

Rice (Oryza sativa L.) is one of the most important food crops in the world. In red rice, black, purple, brown, and brown red rice, major bioactive components are gallic, protocatechuic, hydroxybenzoic, p‐coumaric,ferulic, sinapic acid, cyanidin‐3‐O‐glucoside, peonidin‐3‐O‐glucoside,flavan‐3‐ol (+) catechin and (?) epicatechin,flavanols (flavan‐ 3‐ols), isoflavones, γ‐oryzanol contents, compositions of steryl, triterpene alcohol ferulates proportions, and tocopherols, etc. This review provides information of pigmented rice in the form of bioactive compounds, concentration, activities and its health's benefit. These bioactive compounds are having immense potential for many health benefit effects and can act as antitumour, anti‐atherosclerosis, anti‐diabetic, anti‐allergicagents, alleviating gallstones, anticancer activity, anti‐inflammatoryeffects, and others.     

Antioxidant phenolic compounds of pomegranate wines produced by different maceration methods

Various methods were evaluated in the production of ‘Hicaz’ pomegranate wine by microvinification. The chemical, phenolic and antioxidant characteristics of the wines were assessed by measurement of water‐soluble dry matter, acidity, density, alcohol content, volatile acidity, total monomeric anthocyanins, polarized colour intensity and individual phenolic compounds. Three different methods – classical maceration (N), seed‐supplemented maceration (S) and seed + enzyme supplemented maceration (E) – were applied. Total phenolic compounds of pomegranate must and wines (after 18 months of storage) were 1897 mg/L (must), 1663 mg/L (N), 1339 mg/L (E) and 1414 mg/L (S). Phenolic compounds in pomegranate must and wines included gallic acid, vanillic acid, caffeic acid, ferulic acid, p‐coumaric acid, hydroxycinnamic acid, epicatechin and catechin. Total antioxidant capacities (Trolox equivalents) of pomegranate must and wines (N, E and S) were 9.9 mm /L (must), 9.8 mm /L (N), 9.7 mm /L (E) and 9.5 mm /L (S). Copyright © 2017 The Institute of Brewing & Distilling     

Antioxidant and antimicrobial potentials of Serbian red wines produced from international Vitis vinifera grape varieties

BACKGROUND: Antioxidant and antimicrobial potentials of Serbian red wines produced from different international Vitis vinifera grape varieties and their correlation with contents of phenolic compounds were studied by spectrophotometric and chromatographic methods. The antioxidant activity of red wines was estimated through their ability to scavenge 2,2′‐diphenyl‐1‐picrylhydrazyl free radical (DPPH^?). The red wines, gallic acid, (+)‐catechin and quercetin were screened in vitro for antimicrobial activity against Gram‐positive and Gram‐negative strains using microdilution and disc diffusion techniques. RESULTS: Excellent correlations between the contents of quercetin‐3‐glucoside (R² = 0.9463) and quercetin (R² = 0.9337) and DPPH^?‐scavenging ability of the red wines were found. Serbian red wines exhibited significant activity against Staphylococcus aureus, Listeria inocua, Micrococcus flavus, Sarcina lutea, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Shigella sonnei strains, which was in correlation with their phenolic composition and antioxidant activity. The compounds gallic acid, quercetin and (+)‐catechin showed high activity against B. subtilis, S. aureus, S. lutea and M. flavus Gram‐positive and S. enteritidis and P. aeruginosa Gram‐negative strains. CONCLUSION: The results show that quercetin‐3‐glucoside and quercetin concentrations can be used as markers for the determination of antioxidant and antimicrobial potentials of red wines. Copyright © 2012 Society of Chemical Industry     

Effects of Vinification Techniques Combined with UV‐C Irradiation on Phenolic Contents of Red Wines

Red wines are typically high in phenolic and antioxidant capacity and both of which can be increased by vinification techniques. This study employed 3 vinification techniques to assess the increase in phenolic compounds and antioxidant capacity. Wines were obtained from Bo?azkere grape cultivar by techniques of classical maceration, cold maceration combined with ultraviolet light (UV) irradiation, and thermovinification combined with UV irradiation and changes in phenolic contents were examined. Total phenolic and anthocyanin contents and trolox equivalent antioxidant capacity of wines were measured spectrophotometrically and phenolic contents (+)‐catechin, (–)‐epicatechin, rutin, quercetin, trans‐resveratrol, and cis‐resveratrol were measured by High Pressure Liquid Chromatography with Diode Array Detection (HPLC‐DAD). As a result of the study, the highest phenolic content except for quercetin was measured in the wines obtained by thermovinification combined with UV irradiation. We demonstrated that the highest phenolic compounds with health effect, total phenolic compounds, total anthocyanin, and antioxidant activity were obtained from thermovinification with UV‐C treatment than classical wine making.     

Changes in phenolic composition of wines submitted to in vitro dissolution tests

Wine is an important source of dietary antioxidants, due to its content of phenolic compounds. These compounds may be degraded in the gastrointestinal tract before absorption. A hydroalcoholic standard solution containing 14 phenolic compounds and 25 wines (red, white and Sherry wines) were submitted to a dissolution test employing gastric and intestinal fluids according to The United States Pharmacopeia conditions. Concentration of each phenol was determined, before and after the treatments, by high-performance liquid chromatography with a photodiode array detector. In the standard solution, phenolic acids were rather stable in gastric and intestinal media. Flavonoids were affected most. When wines were submitted to this test, gallic acid, caffeic acid, catechin and quercetin increased in concentrations while resveratrol (trans-, cis- and their glucosides), caffeoyltartaric acid and ethyl gallate resisted gastric and intestinal media.     

Free radical scavenging capacity and inhibition of lipid oxidation of wines,grape juices and related polyphenolic constituents

The antioxidant activity of grape juices, wines made from the same lot as juices and their major polyphenolic constituents was measured by the inhibition of lipid oxidation (ferric-thiocyanate) and free radical scavenging (2,2-diphenyl-1-picrylhydrazyl) methods. dl-α-Tocopherol and 3-tertiary-butyl-4-hydroxyanisole (BHA) were used as references. The inhibition of lipid oxidation of the standards followed the order: rutin = ferulic acid > tannic acid = gallic acid = resveratrol > BHA = quercetin > dl-α-tocopherol > caffeic acid. Meanwhile, the free radical scavenging activity of gallic acid was the highest, tannic acid, caffeic acid, quercetin, BHA and rutin activities were intermediate and that for ferulic acid, dl-α-tocopherol and resveratrol were the lowest. Wines had higher activity than the corresponding grape juices and red wine showed the strongest activity among the grape products tested. The antioxidant activity of the samples seems to be based on their free radical scavenging capacity.     

Catechins and Derived Procyanidins in Red and White Sorghum: Their Contributions to Antioxidant Activity

Flavan‐3‐ol monomers and derived procyanidins were determined by NP‐ and RP‐HPLC‐ESI(?)‐MS/MS after extraction with a mixture of acetone/water/acetic acid (70:28:2, v/v). Logically, red sorghum was found to contain much higher amounts of monomers up to hexamers (S?(P1–P6) = 61.4–450.2 mg/kg, (?)epicatechin equivalents) than white sorghum (0.2 mg/kg, (?)epicatechin equivalents). (+)Catechin was identified as its major monomer and B1 turned out to be the main dimer. Thiolysis confirmed that (+)catechin is the major terminal unit (50–88%), while (?)epicatechin is more frequent as extension units (50–86%). The contribution of monomers ((+)catechin and (?)epicatechin) and dimers (B1 and B2) to the total antioxidant activity determined by RP‐HPLC‐online TEAC was revealed to be very weak.     

干红树葡萄酒与干红葡萄酒功能成分及其抗氧化活性对比

分别测定干红树葡萄酒与2种干红葡萄酒(法国干红葡萄酒、国产干红葡萄酒)中的总多酚、总黄酮、白藜芦醇、单宁、酚酸、维生素、花青素及矿物质等功能性成分,采用DPPH法、ABTS法、邻二氮菲法和FRAP法分析3种酒的抗氧化能力,并对其差异进行分析比较。结果表明:干红树葡萄酒与2种干红葡萄酒功能成分种类及含量各有特点和优势。干红树葡萄酒中没食子酸、VA、VC、Mn与Zn含量均极显著高于国产干红葡萄酒和法国干红葡萄酒;法国干红葡萄酒中总多酚、总黄酮、白藜芦醇、儿茶素、咖啡酸、香豆酸、阿魏酸、矢车菊色素及Fe含量均极显著高于国产干红葡萄酒和干红树葡萄酒;国产干红葡萄酒中单宁、VD、飞燕草色素、矮牵牛色素、天竺葵色素、芍药色素、锦葵色素、Ca和Mg含量均极显著高于法国干红葡萄酒和干红树葡萄酒。3种酒抗氧化活性亦各具特色,树葡萄红酒对DPPH·的清除能力最强,法国干红葡萄酒对·OH的清除能力最强,国产干红葡萄酒对ABTS~+的清除能力及对铁离子的还原能力最强。     

Determination of flavan-3-ols and trans-resveratrol in grapes and wine using HPLC with fluorescence detection

Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts.     

Phenolic profile of blackberry wine produced using Korean winemaking techniques in earthenware jars

This research evaluated the winemaking potential of ‘Natchez’ and ‘Triple Crown’ blackberries grown in Oklahoma and examined the phenolic composition of blackberry wines made using modified Korean traditional winemaking techniques. The winemaking variables were fermentation temperature (21.6 vs 26.6°C), and fermentation type (yeast inoculation vs wild fermentation). High‐performance liquid chromatography was used to examine the phenolic compounds in blackberry juice and wine. The phenolic compounds consisted of anthocyanins (kuromanin, keracyanidin, delphinidin) and phenolic acids (gallic acid, catechin, caffeic acid, epicatechin, p‐coumaric acid). The ‘Natchez’ berries had higher concentrations of anthocyanins (kuromanin) while ‘Triple Crown’ berries had higher levels of phenolic acids (p‐coumaric acid). For many compounds, a higher fermentation temperature generally corresponded to higher concentrations of the phenolic compound in the wine after three months aging, but this was not universally observed. Accordingly, fermentation temperature may best be matched with individual cultivars via experimentation in order to maximise extraction and retention of phenolic compounds in the finished wines. Overall, the Korean traditional winemaking technique may be a good technique to add value to wines made from blackberries suited for production in a mid‐continental climate such as the central USA. © 2018 The Institute of Brewing & Distilling     

Bioactive phenolic compounds of cowpeas (Vigna sinensis L). Modifications by fermentation with natural microflora and with Lactobacillus plantarum ATCC 14917

In this work we have determined the phenolic composition of raw cowpeas (Vigna sinensis L) of the variety Carilla by HPLC/PAD/MS and have studied the effect of fermentation, both spontaneous and with Lactobacillus plantarum ATCC 14917, on the phenolic compounds. This variety contains mainly ferulic and p‐coumaric acids esterified with aldaric acids, together with the cis and trans isomers of the corresponding free acids. Hydroxybenzoic acids such as gallic, vanillic, p‐hydroxybenzoic and protocatechuic were also found, along with flavonols such as a myricetin glucoside, mono‐ and diglycosides of quercetin and a quercetin diglycoside acylated with ferulic acid. Fermentation, both spontaneous and inoculated, modifies the content of phenolic compounds, but differently in each case. The antioxidant activity as free radical‐scavenging activity has also been evaluated. Fermentation followed by heating has been shown to be a very effective process to increase the functionality of this variety of V sinensis. For this reason, this cowpea variety could be used as an ingredient to obtain high value‐added flours. Copyright © 2004 Society of Chemical Industry     

Influence of variety and commercial yeast preparation on red wine made from autochthonous Hungarian and Canadian grapes. Part I: phenolic composition

Eight wines were made from two Canadian hybrid grape varieties (Maréchal Foch, Baco Noir) and two Hungarian Vitis vinifera varieties (Kadarka, Lemberger). One half was kept untreated; the other half received a commercial yeast preparation (OptiRed^®) before fermentation. Significant differences were found between varieties for basic measures of wine quality, including pH, titratable acidity, ethanol, colour density, hue and total phenolics. Quercetin was identified only in Maréchal Foch and Baco Noir wines, and quercetin-glucoside only in Baco Noir. Varietal differences were also found in the concentrations of the 11 other colourless phenolic monomers measured, especially gallic acid, protocatechuic acid, tyrosol, caftaric acid, catechin, caffeic acid, GRP, epicatechin, p-coumaric acid, ferulic acid and trans-resveratrol. The Canadian wines had higher concentrations of the four anthocyanins measured (malvidin, delphinidin, petunidin and peonidin), higher anti-oxidative capacity, and were characterised by lower ratios of monomeric/polymeric phenolics. Addition of OptiRed^® had little impact on the basic measures of wine quality. Concentrations of gallic acid, protocatechuic acid, caftaric acid and catechin were, on average, 6% higher in wines made from OptiRed^®-treated musts. A trend was observed for all varieties in OptiRed^®-treated wines of a greater proportion of the procyanidins being presented as polymeric rather than monomeric phenolics.     

Determination of Quercetin, Gallic Acid, Resveratrol, Catechin and Malvidin in Brazilian Wines Elaborated in the Vale do São Francisco Using Liquid–Liquid Extraction Assisted by Ultrasound and GC-MS

In this work, a fast and simple methodology has been applied for the determination of gallic acid, resveratrol, catechin and malvidin in Brazilian wines by gas chromatography–mass spectrometry. The procedure included a stage of ultrasound-assisted liquid–liquid extraction and subsequent derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and GC-MS analysis. The limit of detection varied from 0.41 to 1.18 mg?L^?1 in all the analytes. The relative standard deviations calculated for 8.0 and 20 mg?L^?1 were 1.90 and 0.82 % for gallic acid, 3.08 and 1.22 % for catechin, 1.30 and 0.44 % for malvidin, 1.50 and 0.53 % for resveratrol, and 1.41 and 0.61 % for quercetin. The developed methodology was applied for the analysis of red wine samples collected in the São Francisco region, Bahia state, Brazil. Quercetin concentration varied from 2.4 to 3.0 mg?L^?1, gallic acid 21.4–56.3 mg?L^?1, resveratrol 1.5–5.9 mg?L^?1, malvidin 15.3–32.2 mg?L^?1, and catechin 11.71–18.2 mg?L^?1. The obtained concentrations are in agreement with those reported in the literature.     

Textural Characteristic,Antioxidant Activity,Sugar, Organic Acid,and Phenolic Profiles of 10 Promising Jujube (Ziziphus jujuba Mill.) Selections

Abstract: Ten promising jujubes were analyzed for textural characteristic (hardness), antioxidant activity, sugar, organic acid, and phenolic profiles. Total phenolic content (TP) measured by Folin–Ciocalteu method ranged from 275.6 to 541.8 mg of gallic acid equivalents per 100 g fresh weight (mg GAE/100 g FW). Four sugars (rhamnose, fructose, sucrose, and glucose), 3 organic acids (malic, citric, and succinic acids), and 11 phenolic compounds (gallic acid, protocatechuic acid, cinnamic acid, chlorogenic acid, caffeic acid, ferulic acid, ellagic acid, catechin, epicatechin, rutin, and quercetin) were identified and quantified by high‐performance liquid chromatography in jujube fruits. The results showed that ascorbic acid and proanthocyanidins contents were positively correlated with hardness, and antioxidant activity was well correlated with TP content. Among 10 jujube cultivars, Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption containing high levels of total soluble solids, total sugars, fructose, and glucose, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants. Practical Application: Genotype is the main factor influencing the composition of bioactive compounds in jujubes. Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants for prevention of diseases caused by oxidative stress.     

Development of a reversed-phase high performance liquid chromatography (RP-HPLC) procedure for the simultaneous determination of phenolic compounds in peanut skin extracts

A reversed-phase high performance liquid chromatography (RP-HPLC) procedure was developed for simultaneous determination of five phenolic acids, two stilbenes and eight flavonoids in peanut skin extract. A C₁₈ column fitted with diode array detection at 250 and 320, 280 and 370, and 306 nm for phenolic acids, flavonoids and stilbenes, respectively, with mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in 100% acetonitrile. Phenolic compounds were eluted with good resolution (Rs > 1.5) within 95 min as follows: gallic, protocatechuic, epigallocatechin, catechin, β-resorcylic (internal standard), caffeic, procyanidin B₂, epicatechin, epigallocatechin gallate, p-coumaric, ferulic, piceid, epicatechin gallate, catechin gallate, resveratrol and quercetin. The variation in recovery and reproducibility in peak area was <11 and <2.5%, respectively. The correlation coefficients, r, of calibration curves of the 15 compounds were >0.999. The method was used to quantify phenolic compounds in peanut skin extracts from Runner, Virginia and Spanish peanuts.     

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.     

Addition of phenolic acids on the reduction of methanol content in wine

ABSTRACT:  Utilization of phenolic acids, including gallic acid, coumaric acid, caffic acid, cinnamic acid, and ferulic acid, for methanol reduction in wine was investigated. Enzyme activities of pectinesterase and pectin lyase decreased significantly when 0.1 mg/L of gallic acid, coumaric acid, caffic acid, cinnamic acid, or ferulic acid was added. However, no inhibition on polygalacturonase activity was observed when 0.5 mg/L of phenolic acid was added. Methanol content in commercial pectic enzyme (CPE) group increased from 11.53 ± 1.34 to 56.67 ± 3.75 ppm in the final products. Adding gallic acid or coumaric acid with CPE inhibited the increase of methanol production. In addition, when 0.2 mg/L of phenolic acid (gallic acid or coumaric acid) was added, the amount of total phenolic acid released from CPE + gallic acid or CPE + coumaric acid groups became higher than CPE group by approximately 466 and 539 mg/L, respectively. In conclusion, the values of lightness, red content, yellow content, total pigment, and total phenolic acid increased in the presence of gallic acid or coumaric acid with CPE, suggesting that adding gallic acid or coumaric acid into winemaking process is a potential method for reducing methanol content, improving wine quality, as well as increasing healthy compounds in wine production.     

Determination of phenolic composition and antioxidant capacity of native red wines by high performance liquid chromatography and spectrophotometric methods

A reversed-phase high performance chromatographic method for simultaneous determination of 14 phenolic compounds in native red wines was developed in this study. The identified compounds contained gallic acid, (+)-catechin, 3,4-dihydroxybenzoic acid, chlorogenic acid, (?)-epicatechin, 4-hydroxybenzoic acid, syringic acid, caffeic acid, p-coumaric acid, rutin, resveratrol, myricetin, quercetin and kaempferol. The method includes liquid–liquid extraction of acidic pH with ethylacetate. The analysis used a Zorbax Eclipse XDB-C18 column (5 μm, 4.6 mm × 250 mm). The chromatographic separation of these compounds performed in a single run by using the mobile phase gradient elution of methanol water mixture (% 0.2 formic acid) at room temperature, with flow rate at 1 mL/min. Detection was carried out by UV–vis and fluorescence detector. Each analysis required an equilibration period of 10 min and a run time of 14 min for completion. The optimized chromatographic method was carefully validated for precision and accuracy. Our findings indicated that the developed HPLC method was precise, accurate, specific and sensitive for simultaneous determination of phenolic compounds. Consequently, the described method was applied to the analysis of six wines from Malatya and Elaz??. Gallic acid was dominant phenolic acid in red wines. (+)-catechin, (?)-epicatechin and p-coumaric acid were the next most abundant phenolics. The highest level of trans-resveratrol among the red wines was found Buzba?? (Bogazkere–Öküzgözü). The red wines were analyzed for total polyphenol content (TP) by Folin–Ciocalteu (FC) method, using gallic acid as standard. Antioxidant activities (AA) of the red wines were measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. There was a very high correlation between AA and TP in all of the wines tested.     

The phenolic composition and antioxidant capacity of soluble and bound extracts in selected dietary spices and medicinal herbs

Phenolic compounds, commonly found in plant‐based foods, exist in free or bound form. Despite much research on the soluble phenolics in spices and herbs, their bound phenolics have not been intensively investigated. In this study, six common dietary spices and medicinal herbs (Padang cassia, oregano, clove, Chinese cassia, Japanese knotweed and peel of pomegranate) were selected to evaluate and compare their phenolic composition and antioxidant capacity in soluble extracts (SEs) and bound extracts (BEs). Generally, the samples had high total phenolic content and antioxidant capacity, with lower levels in the BEs. From the HPLC results, (+)‐catechin, (?)‐epicatechin, eugenol, cinnamaldehyde and carvacrol were the major phenolic compounds in the SEs, and gallic acid, p‐coumaric acid and ellagic acid in the BEs. Phenolic compounds are likely the major contributors to the antioxidant capacity of these plant samples. Overall, these dietary spices and medicinal herbs can be excellent sources of natural antioxidant phenolics.     

Antioxidant,free radical scavenging and type II diabetes‐related enzyme inhibition properties of traditionally processed Jequirity bean (Abrus precatorius L.)

The methanolic extract of raw Abrus precatorius (Jequirity bean, red‐ and black‐coloured seed coat) seeds contains a total phenolic content of 14.2 ± 0.39 g catechin equivalent/100 g extract. An analysis of phenolic profile revealed the presence of syringic acid, caffeic acid and (?)‐epicatechin in the methanolic extract of A. precatorius seeds. Encouraging levels of ferric reducing/antioxidant power (FRAP, 1247 mmol Fe[II]/mg extract), inhibition of β‐carotene bleaching (53.37%), 2,2‐Diphenyl‐1‐picryl‐hydrazyl (DPPH, 62.13%) and superoxide (64.47%) radical scavenging activities were exhibited by the extract of raw samples. Inhibition characteristics of 68.69%α‐amylase and 51.74%α‐glucosidase enzyme were also recorded under in vitro starch digestion bioassay. Sprouting + oil‐frying caused a significant increase in the total phenolic content and also substantially improved the antioxidant and free radical scavenging capacities, while soaking + cooking as well as open‐pan roasting treatments showed diminishing effects.