Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

ABSTRACT: The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching‐down, addition of grape seed tannins, addition of ellagic‐skin‐seed tannins, heating of must‐wine, cryo‐maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, β‐carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1‐y‐aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to β‐carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and β‐carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.     

Antioxidant capacity of methanolic and water extracts prepared from food‐processing by‐products

This study aims to evaluate the antioxidant capacity of mango peel, roselle seed, okara (by‐product of soya milk industry), cocoa shell and pink guava (by‐product of pink guava industry) in comparison to 6‐hydroxy‐2,5,7,8‐tetramethylchroman‐2‐carboxylic acid (Trolox). The β‐carotene bleaching, 1,1‐diphenyl‐2‐picrylhydrazyl and reducing power assays were used to determine the antioxidant capacity of selected by‐products by measuring the absorbance at 470, 520 and 700 nm, respectively. The results showed that methanolic extracts of pink guava and cocoa shell exhibited the highest antioxidant activity and free radical scavenging activity compared to other studied samples. Roselle seed water extract exhibited the highest antioxidant activity and free radical scavenging when extracted with water. Pink guava possessed the highest reducing power in methanolic extract at a concentration of 0.16 mg mL^?1. At the same concentration, mango peel exhibited the highest reducing power when extracted with water. The present study shows that pink guava, roselle seed and cocoa shell are potential sources of antioxidant components that can be exploited as food preservative agents or nutraceuticals. Copyright © 2006 Society of Chemical Industry     

Changes in Phenolic Content and Antioxidant Activity of Italian Extra‐Virgin Olive Oils during Storage

ABSTRACT: Phenolic composition and antioxidant activity of extra‐virgin olive oils extracted from several Italian varieties were studied at production and during storage. The antioxidant activity was measured according to the following tests: in the aqueous phase, by radical scavenging of the 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS) radical cation; and in the lipid phase, using the β‐carotene bleaching method. The phenolic content was not correlated to the oxidation indices (peroxide value and spectrophotometric constants). The phenolic contents and profiles of the various cultivars showed remarkable differences. The phenolic content was strongly correlated with the antioxidant activity measured according to the β‐carotene test and weakly correlated with the radical scavenging ability.     

Comparison of the total antioxidant status of Bohemian wines during the wine-making process

The total antioxidant status (TAS) of two white and two blue wine varieties from the ?ernoseky wine region (North Bohemia, Czech Republic) during the wine-making process was assessed by measurement with different radical scavenging assays: ABTS, DPPH and DMPD. Significant differences in the antioxidant activity between white and red wines were confirmed and changes of TAS during the wine production process were demonstrated. Moreover, differences were ascertained between individual varieties of red wine. No statistically significant relationship between the results provided by the ABTS and DPPH assays was found, obviously due to the fact that each phenolic substance in wine gives a different response to each specific radical used in the assay. The results obtained supported the assumption that variety plays a considerable role in TAS; the blue wine varieties showed a much higher TAS than did the white wines. The ABTS assay showed higher EQA (equivalents of ascorbic acid, mg/ml) values than the DPPH assay.     

Antioxidant properties of commercial alcoholic and nonalcoholic beverages

Recent interest in food phenolics has increased greatly, because of their antioxidant and free radical scavenging abilities. Popular beverages in the world include tea, coffee, cocoa, beer, wine and fruit/vegetable juices. All of these beverages contain phenolic compounds. In present study total polyphenol content and in vitro antioxidant properties were investigated in 16 red wines, 5 white wines, 5 lager beers, 3 dark beers, 17 fruit juices and 5 vegetable juices. High polyphenol content was measured in red wines (1720 +/- 546 mg x L(-1)) and in some fruit juices such as elderberry and prunes (5,680 and 1,807 mg x L(-1), respectively). The concentration of polyphenols was between 159 and 5,680 mg x L(-1) in fruit juices and between 255 and 696 mg x L(-1) in vegetable ones, while low level of phenolics was observed in dark and lager beers and white wines (473, 376 and 392 mg x L(-1), respectively). All samples exhibited significant antioxidant properties such as hydrogen-donating ability, reducing power, chelating ability and total antioxidant status (TAS) value. These antioxidant properties strongly correlated with the total polyphenol content of the beverages.     

Comparative analyses of total phenols,flavonoids, saponins and antioxidant activity in yellow soy beans and mung beans

Total phenol, flavonoid and saponin content of soy bean and mung bean were systemically compared in order to evaluate their contribution to overall antioxidant activity. Mung bean extract possessed significantly higher total phenol (2.03 GAE g^?1 vs. 1.13 GAE g^?1) and flavonoid contents (1.49 GAE g^?1 vs. 0.41 CAE g^?1) than soy bean extract, while the saponin content of the soy beans was 4.5 times greater than that of the mung beans. In several antioxidant assays including DPPH and ABTS radical scavenging, FRAP, SOD‐like activity, and a β‐carotene bleaching assay, mung bean extract consistently showed significantly greater antioxidant activity than soy bean extract. The specific antioxidant activity, which was evaluated at the same phenolic content suggested that the phenolic compounds present in the mung bean extract were not only of greater quantity but also had better quality to eliminate radicals. The radical scavenging activities of saponins were only marginal.     

Improvement of Antioxidant Activities in Red Cabbage Sprouts by Lactic Acid Bacterial Fermentation

In the present study, the influence of three types of lactic acid bacteria (Lactobacillus plantarum ATCC 8014, Lactobacillus acidophilus NCFM, Danisco, and Lactobacillus rhamnosus GG E522 (ATCC 53103)) on antioxidant activities of fermented red cabbage sprouts was determined and compared with those of their unfermented/control counterparts. The fermentation resulted in a significant increase (p < 0.05) of antioxidant functionalities as measured by four assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging, Trolox equivalent antioxidant capacity (TEAC), superoxide dismutase (SOD)-like, and β-carotene/linoleic bleaching. The most considerable shift in the antioxidant activities was observed after 24 h of fermentation. These increases were followed by a decrease in total phenolic compounds, anthocyanins, and L-ascorbic acid and by an increase in flavonoids, flavonols, and several phenolic acids (gallic, chlorogenic, caffeic, syringic, p-coumaric, trans-3-hydroxy-4-methoxycinnamic, and trans-o-hydroxycinnamic acid) content. The relationship between the antioxidant activities and the compositional changes in antioxidant compounds due to LAB fermentation was observed. Fermented red cabbage sprouts inoculated with L. plantarum had the highest antioxidant activities (DPPH scavenging: 70.92%; TEAC: 1.94 mM Trolox equivalent; SOD-like activity: 63.40%, and β-carotene/linoleic bleaching: 44.33%), which was almost two-fold higher than those of unfermented treatments. These results indicated that LAB fermentation could be applied as a method to improve the potent antioxidant activities of red cabbage sprouts.     

Beer and wine consumers' perceptions of the nutritional value of alcoholic and nonalcoholic beverages

ABSTRACT:  In general beer has not been portrayed as part of a balanced diet. However, red wine has been promoted as a beneficial part of a nutritious diet. The evidence is that beer is at least the equal of wine from a nutritional perspective and in countering ailments such as coronary heart disease. This study used surveys to compare beer and wine consumers' perceptions of alcoholic and nonalcoholic beverages. The consumers ranked 7 beverages based upon perceived healthfulness both before and after they were exposed to nutritional information about the beverages. The ranked data were analyzed using analysis of variance. The variance due to the 3-way interaction of place of recruitment, beverage, and ranking was found to be significant at P < 0.05. There was no significant difference between genders. Overall, consumers of alcoholic beverages perceived red wine to be more healthful than the other 6 beverages, including beer and white wine. The perceived healthfulness of a beverage does not appear to be the main factor driving the choice of beverage. Nutritional information does impact consumers' perceptions of the healthfulness of beverages. Consumers who are predominately beer drinkers were more heavily influenced by nutritional information than consumers who were predominately wine drinkers.     

苦荞红曲保健酒的抗氧化活性

为研究苦荞红曲保健酒的总黄酮和总酚的体外抗氧化活性,测定其对DPPH自由基、ABTS自由基的清除能力和铁离子还原/抗氧化能力（FRAP值）,并且与市售黄酒、VC、Trolox进行对比。结果表明,苦荞红曲保健酒有一定DPPH自由基清除率、ABTS自由基清除率和铁离子还原力。被测样品的抗氧化活性与总黄酮、总酚的含量有显著的相关性（P〈0.01）。     

In vitro studies on antioxidant activity of lignans isolated from sesame cake extract

The antioxidant activity of compounds isolated from a methanolic extract of commercial sesame cake was studied using a peroxidation model and a radical‐scavenging method. Pure compounds were isolated from the extract by preparative high‐performance liquid chromatography (HPLC) and identified and confirmed as sesamol, sesamin, sesamolin, sesaminol diglucoside and sesaminol triglucoside by HPLC, infrared, nuclear magnetic resonance and mass spectrometry. When the rate of inhibition of lipid peroxidation and the superoxide radical‐scavenging power of the individual compounds were evaluated, the compounds showed antioxidant activity to different extents. The antioxidant activity of compounds by the β‐carotene‐bleaching assay followed the order sesamol > sesamolin ≥ sesamin > butylated hydroxytoluene (BHT) > sesaminol triglucoside > sesaminol diglucoside. By the thiocyanate method the inhibition of linoleic acid peroxidation shown by sesamol, sesamin, sesamolin, sesaminol triglucoside, sesaminol diglucoside and BHT at 200 mg l^?1 was 77, 60, 69, 32, 25 and 49% respectively. A concentration–dependent superoxide–scavenging effect was also shown by these compounds. Sesamolin had an appreciable effect at 300 and 500 mg l^?1, while the other compounds were more effective at 100 mg l^?1. The study also established the occurrence of sesamol in the methanolic extract of defatted sesame cake for the first time. Copyright © 2005 Society of Chemical Industry     

Changes in Antioxidant Activity of Cyphomandra betacea (Cav.) Sendtn. Fruits During Maturation and Senescence

Antioxidants are extremely important substances that possess the ability to protect the body from damage caused by free radical induced oxidative stress. Antioxidants are derived from dietary sources, such as fruits, vegetables, and beverages. In this study, the antioxidant activity of different maturity stages of two varieties of Cyphomandra betacea fruits of Darjeeling was evaluated in vitro. The radical scavenging properties on 2,2-diphenyl-1-picrylhydrazyl, superoxide anion, hydroxyl radical, lipid peroxidation, nitric oxide, and reducing power as well as the flavonoids, phenolics, lycopene, and total carotene contents of methanolic extracts of the fruits were determined. All fruit extracts, mainly the mature red fruit of purple-red variety exhibited strong scavenging activity towards all radicals tested due to the presence of relatively high total phenol, flavonoids, and lycopene as well as total carotene contents. The findings suggest that purple red variety of C. betacea fruit is endowed with antioxidant phytochemicals, which could provide protection against oxidative stress induced diseases.     

Antioxidant Potential of Pea Beans (Phaseolus vulgaris L.)

ABSTRACT: Four bean varieties ( Phaseolus vulgaris L.) (white kidney, red pinto, Swedish brown, and black kidney) and their hull fractions were extracted with 80% acetone and evaluated for their phenolic contents and antiradical activities. Total phenolic content of bean hulls and whole seed extracts ranged from 6.7 to 270 and 4.9 to 93.6 mg/g extract as catechin equivalents, respectively. Trolox equivalent antioxidant capacity (TEAC) assay revealed that the antioxidant capacity of red, brown, and black whole seed extracts was in the same order of magnitude with little variation. TEAC values of red and brown whole seed extracts were superior to that of black whole seed extract. On the basis of the total phenolic content and TEAC values, it can be deduced that colored beans possess superior antioxidative activity compared with white beans. The hydrogen peroxide scavenging capacity of different bean extracts ranged from 58% to 67% at 50 ppm and 65% to 76% at 100 ppm. The corresponding superoxide radical scavenging capacity was 24% to 29% at 50 ppm and 53% to 60% at 100 ppm. The 2,2–diphenyl-1–picrylhydrazyl (DPPH) radical scavenging capacity of black bean whole seed extracts was 22% at 50 ppm, whereas the other extracts showed 100% scavenging of this radical at both 50 and 100 ppm levels. The hydroxyl radical scavenging capacities of the bean extracts at 50 and 100 ppm were 12% to 29% and 32% to 49%, respectively. All extracts used prevented human low-density lipoprotein (LDL) cholesterol oxidation by 61.4% to 99.9% at 2 to 50 ppm level as catechin equivalents.     

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.     

Antioxidant properties of commercial soft and hard winter wheats (Triticum aestivum L.) and their milling fractions

The total phenolic content (TPC), total antioxidant activity (TAA), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity, inhibition of coupled oxidation in a β‐carotene–linoleate model system, iron(II) chelation activity and inhibition of copper‐induced oxidation of human low‐density lipoprotein (hLDL) cholesterol of 80% ethanolic extracts of soft and hard winter wheat samples and their milling fractions, namely flour, germ, bran and shorts, were investigated. Soft wheat extracts examined demonstrated higher TPC and TAA compared to those of hard wheat extracts. The germ fraction possessed the highest TPC, followed by bran, shorts, whole grain and flour for both wheat types examined. The TAA of both wheat types showed similar results except that shorts performed better than bran in this assay. Free radical scavenging properties of whole grain and milling fractions of both soft and hard wheat samples were examined against DPPH radical. The germ and flour fractions demonstrated the highest and lowest DPPH radical scavenging activity, respectively, among wheat fractions. Wheat extracts were also efficient in preventing bleaching of β‐carotene, which is also known to be free radical mediated. In the iron(II) chelation assay the flour extracts demonstrated excellent activity, while the germ extracts showed a weak activity. The trends were similar in both soft and hard wheat for the iron(II) chelation assay. Wheat extracts also inhibited copper‐induced oxidation of hLDL. In LDL oxidation assay, wheat extracts performed better than the reference antioxidant, ferulic acid. Thus wheat phenolics may serve as effective antioxidative components as measured by in vitro techniques. Copyright © 2005 Society of Chemical Industry     

Antioxidant activity of Potentilla fruticosa

The molecular structures of the radical scavenging compounds present in extracts of Potentilla fruticosa blossoms were elucidated and the antioxidant activities of various extracts were determined. The activities of the different fractions were monitored by off‐line and on‐line RP‐HPLC DPPH^? and ABTS^?+ scavenging methods. Twelve compounds were isolated and identified, namely ellagic acid, catechin, quercetin‐3‐β‐glucopyranoside, quercetin‐3‐β‐galactopyranoside, quercetin‐3‐β‐rutinoside, quercetin‐3‐β‐glucuronopyranoside, quercetin‐3‐α‐arabinofuranoside, kaempferol‐3‐β‐rutinoside, kaempferol‐3‐O‐β‐(6″‐O‐(E)‐p‐coumaroyl)glucopyranoside, rhamnetin‐3‐β‐glucopyranoside and rhamnetin‐3‐β‐galactopyranoside. The radical scavenging activity of each isolated compound was measured using DPPH^? and ABTS^?+ assays and compared with the activity of rosmarinic acid. Catechin and ellagic acid were found to be the most active radical scavengers. The antioxidant properties of plant fractions were assessed in model systems by measuring superoxide anion and hydrogen peroxide scavenging, β‐carotene bleaching, hexanal production in edible oil, peroxide formation, and the increase in UV absorbance in the course of oxidation. Copyright © 2004 Society of Chemical Industry     

微型DPPH、ABTS和FRAP法动态监测从红酒中分离得到的不同种类多酚化合物的抗氧化活性

本文确定了微型1,1-二苯基-2-三硝基苯肼自由基清除能力测定法(2,2-Diphenyl-1-picrylhydrazyl,DPPH)、2,2-联氮基双(3-乙基-苯并噻唑啉-6-磺酸)二铵盐总抗氧化能力测定法(2,20-Azino-bis(3-ethylben zothiazoline-6-sulfonic acid)diammonium salt,ABTS)和铁离子还原/抗氧化力测定法(ferric reduction ability plasma assay,FRAP)测定从红酒中分离得到的不同种类多酚化合物抗氧化活性的最佳反应时间以及抗氧化活性的大小。以抗氧化剂Trolox和Vc为对照,动态监测红酒中不同种类多酚化合物在三种体系中的反应过程,计算不同浓度下红酒多酚类化合物的抗氧化活性。结果表明,三种反应体系的最佳反应时间分别是100 min、240 min和370 min。不同种类的红酒多酚类化合物与抗氧化剂一样,其样品浓度与抗氧化活性呈明显的量效关系。从相关性分析得出,表儿茶素、多聚体、低聚体、花色苷是影响葡萄酒抗氧化活性的主要成分,可以将其确定为葡萄酒质量控制的指标。本文建立的微型DPPH、ABTS和FRAP法操作简单,重复性好,样品消耗少。     

雪莲果体外抗氧化和自由基清除能力

抗氧化能力是衡量果蔬营养及保健价值的重要指标之一。雪莲果是一种药食两用植物,对多种慢性疾病有缓解作用。分别采用5 种方法(DPPH、ABTS、FRAP、SASR 和MCC)对雪莲果块根甲醇提取液的自由基清除能力及抗氧化活性进行体外评价。结果表明：DPPH 法测定的Trolox 当量抗氧化能力(TEAC)为410.263mg Trolox/g md,抗坏血酸当量抗氧化能力(AEAC)为230.485mg VC/g md,IC50 值为1.464mg/mL;ABTS 法测定的TEAC 为267.584mg Trolox/g md,AEAC为41.597mg VC/g md,IC50 值为1.269mg/mL;SRSA 法测定的TEAC 为652.816mg Trolox/g md,AEAC 为101.451mg VC/g md,IC50 值为7.720mg/mL。说明雪莲果块根提取物对DPPH 自由基、ABTS+·和O2·三种不同的自由基均有一定的清除活性。此外,雪莲果块根提取物还具有较高的总抗氧化(FRAP 值为131.723 mgFeSO4/g md)和较强的金属螯合能力(73.193%)。     

Antioxidant activity of chlorophylls and their derivatives

The antioxidant activity of six natural isolated chlorophyll derivatives and Cu-chlorophyllin was investigated by measuring their protective action against lipid oxidation. For this, the β-carotene bleaching method and the stable radical 2,2-diphenyl-1-picryldrazyl (DPPH) scavenging assay were employed. The results obtained by the β-carotene bleaching method showed that all chlorophyll derivatives presented a dose-dependent response. Pheophorbide b and pheophytin b were the strongest natural antioxidant compounds, whose activities were comparable to BHT. The high antioxidant activity found for pheophorbide b, in comparison to pheophorbide a, demonstrated the importance of the aldehyde group for functionality. On the other hand, by the DPPH assay, all natural pigments showed low antioxidant activity when compared to Trolox. Cu-chlorophyllin, tested by both methods, presented a higher antioxidant activity than that of natural chlorophylls, showing the importance of the nature of the chelated metal in the porphyrin ring. The mechanism of antioxidant activity displayed by the natural chlorophyll derivatives does not seem to be based on the ability to donate hydrogen but maybe, on the protection of linoleic acid against oxidation and/or preventing decomposition of hydroperoxides.     

Chemical,antioxidant and antibacterial study of Brazilian fruits

In this study, the antioxidant capability, total phenolic content and antimicrobial activity of ethanolic extracts of seven fruits from the Brazilian Atlantic Forest were evaluated. The conditions for the extraction of crude phenolics from the fruits were determined using an experimental factorial design. Total phenolic content, 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH^?) scavenging activity and β‐carotene‐linoleic acid couple oxidation assays were used to evaluate the antioxidant properties of the extracts. In addition, antimicrobial activity was screened using two Gram‐negative bacteria (Escherichia coli and Klebsiella pneumoniae) and one Gram‐positive bacterium (Staphylococcus aureus). All native fruits assayed in this study have high potential as natural antioxidant sources. Among the seven fruits evaluated, Jabuticaba and Uvaia had the highest antioxidant activity in the DPPH^? and of β‐carotene‐linoleic acid coupled oxidation assays. In the biological assay, K. pneumoniae was the most sensitive microorganism to the fruit extracts, and the Jabuticaba extract had a slight inhibitory effect against this Gram‐positive bacterium.