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1.
ABSTRACT: Amounts of total phenolics, anthocyanins, and ascorbic acid in 4 American cranberry varieties harvested at 4 stages of maturity were measured. The larger amount of phenolic compounds was found in berries of “Black Veil” cultivar (504 mg/100 g) at II stage of maturity. Significantly larger amounts of anthocyanins were determined in the overripe berries of the cultivars “Ben Lear” and “Black Veil.” The amount of ascorbic acid in berries increased during ripening from I to III stage, and slightly decreased in the overripe berries. The biggest quantities of ascorbic acid were found in the ripe berries of “Ben Lear” cultivar (15.8 mg/100 g). The distribution of anthocyanins pigments was determined by HPLC‐UV/MS in mature berries. The composition of individual anthocyanins in berries was quite similar in all the studied cranberry cultivars. While skins of cranberries are rich in anthocyanins and other phenolic compounds, the extracts of the by‐products of cranberries juice—berry cakes, were analyzed and obtained results were compared with the properties of extracts made from whole berries. The anthocyanins and total phenolics content, radical scavenging activity, antimicrobial activity of the whole berries, and their press cakes extracts were measured. All investigated extracts from berries and their press cakes showed good radical scavenging activity and revealed antimicrobial properties. It was found that Bacillus cereus (ATCC 10876) and Micrococcus luteus (ATCC 9341) were the most sensitive among 10 tested Gram‐negative and Gram‐positive bacteria.  相似文献   

2.
The effects of exogenous abscisic acid (ABA) on phenolic characteristics of grapes and wines were investigated in Vitis vinifera cvs. Merlot and Cabernet Sauvignon. Exogenous ABA treatment at veraison significantly improved phenolic contents, mainly anthocyanins and flavonols, and antioxidant properties of the grape skins, but had no effects on total phenolics and antioxidant activities in the seeds or on basic fruit qualities. The wines made from ABA-treated grapes were also consequently enhanced in total phenolics, anthocyanins, flavonols and antioxidant activities. The proportions of methylated anthocyanins in the skins and acylated anthocyanins and derived pigments in the wines were decreased to some degree by exogenous ABA treatment. No distinct relationships were observed between ABA concentrations and phenolic characteristics, and the effects were observed even with 200 mg/L ABA. The results revealed that exogenous ABA applied at veraison offered opportunities to improve phenolic contents and nutritional values of grape skins and wines.  相似文献   

3.
Pomegranate juice is consumed widely for its possible health benefits. The aril juice from 15 pomegranate cultivars grown in Georgia were analysed for juice yield based on fresh weight (FW) and physico-chemical properties, using blender and mechanical press extraction. Blender had a higher juice yield (42.04% FW) compared to mechanical press (38.05% FW). Total phenolics and antioxidant capacity was determined by Folin–Ciocalteau method and ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays, respectively. Total monomeric anthocyanins were determined by pH differential method and RP-HPLC. The major anthocyanin was delphinidin 3-glucoside. High negative and significant (p ? 0.05) correlations were found between pH and titratable acidity (TA). The total soluble solids content (TSS) averaged 15.59 in blender and 14.94 °Brix in mechanical press. Chemical analysis of juice showed significant differences among cultivars and extraction methods. Overall, blender was more efficient than mechanical press juice extraction.  相似文献   

4.
The influence of Ramsey, used as rootstock of the scion cvs Muscat Gordo Blanco (syn. Muscat of Alexandria), Shiraz (syn. Syrah), Riesling, Cabernet Sauvignon and Chardonnay, on the characteristics of the grape berries and of wine made from them was investigated, comparing ‘own-rooted’ and ‘grafted’, and comparing wine fermented as juice (without skins) and must (juice and skins). The study involved the partitioning of K+ within berries, changes in juice K+, malic and tartaric acid through fermentation, wine inorganic ion and organic acid composition, and wine spectral characteristics. K+ concentration was higher in berries from grafted than from own-rooted for all varieties except Chardonnay, and highest for grafted Shiraz. It was higher in skin than in pulp and seeds. In the pulp, it was highest for grafted Shiraz. K+ concentrations in all ferments using must (i.e. juice plus skins) increased during the initial two days after crushing, with the increase reflecting extraction from skins, being greatest for Shiraz and Muscat Gordo Blanco. Tartaric acid concentration in must also increased during the initial two days after crushing and then decreased. Malic acid concentration was higher in juice of Ramsey-grafted than own-rooted vines, especially for Shiraz; concentrations did not change markedly during the initial 12 days of fermentation, except where malo-lactic fermentation occurred. Wine made from grapes of grafted contained significantly less tartaric and more malic acid than that made from own-rooted for all varieties and for both fermentation types, with the exception of tartaric acid in wine of Muscat Gordo Blanco fermented as must. Wine made from juice had significantly higher tartaric acid and lower malic acid than that made from must for all varieties except for tartaric acid in wine from grafted Shiraz and malic acid in own-rooted Chardonnay. Wine had a smaller tartaric acid/malic acid ratio when made from must. Wine pH was positively correlated with K+ but negatively with tartaric acid and with the tartaric acid to malic acid ratio. Overall, Shiraz wine contained highest Cl?, Na+ and K+ concentrations. Red wines obtained from grafted had higher colour hue, especially those from Shiraz. Wines made from fruit borne on own-rooted Cabernet Sauvignon had the highest concentration of total anthocyanins, ionised anthocyanins and total phenolics.  相似文献   

5.
Grapes (Vitis vinifera L.) possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Juice and skin fractions of 4 varieties of table grapes: Red Globe, Crimson Seedless, Autumn Royal, and Ribier were prepared to determine and compare their total phenolics content, antioxidant capacity (DPPH, FRAP, and ORAC), anthocyanins, and specific phenolics (caffeic acid, gallic acid, resveratrol, and catechin) content, since a series of positive health benefits are expected from the intake of any of these fractions. Higher amounts of total phenolics and antioxidant capacity were observed in the skin fractions (P < 0.05). Blue grapes (Autumn Royal and Ribier) exhibited higher phenolics content and antioxidant capacity (P < 0.05) than red grapes. The most abundant phenolic compound observed was catechin (P < 0.05). Significant correlations between the antioxidant capacity and total phenolics were observed in grape juice and skin fractions. Autumn Royal juice provides a very high amount of phenolics, anthocyanins, and exhibits the highest antioxidant capacity, offering the best health promoting properties compared with the other grape varieties studied. PRACTICAL APPLICATION: Grapes possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Grape juice made with blue grapes (Autumn Royal, Ribier) exhibit higher phenolics content and antioxidant capacity than juice elaborated with red grapes (Red Globe, Crimson Seedless). The skin is a good source of phenolics and has a high antioxidant capacity. Specific health-promoting phenolics are more abundant in blue grapes, mainly in their skin fraction, which should not be discarded.  相似文献   

6.
The total phenolics, anthocyanins, flavan 3‐ols, carotenoids and antioxidant capacity of mashua (Tropaeolum tuberosum Ruiz & Pavón) tubers from 10 yellow and purple cultivars were determined at different maturity stages (5–7.5 months after planting) and sunning post‐harvest storage periods (7–35 days). Both the antioxidant capacity (ORAC and ABTS assays) and the content of the bioactive compounds tested varied markedly between cultivars. Purple varieties reached the highest antioxidant capacity during tuber development (271–446 µmol Trolox equiv g?1 DM, ORAC assay). The kinetics of accumulation or disappearance of the bioactive compounds tested during maturation was dependent both on the cultivar and on the compound considered. For anthocyanins, there was a marked increase during maturation in all the purple cultivars. During the sunning post‐harvest storage, the changes in antioxidant capacity (ABTS assay) and content of the bioactive compounds tested also varied between cultivars. A marked decrease in anthocyanins was observed for the anthocyanin‐containing cultivars. In general, the correlation between antioxidant capacity and the content of bioactive compounds varied markedly between cultivars. Antioxidant capacity in purple varieties correlated with total phenolics or flavan 3‐ols while only in some yellow varieties antioxidant capacity correlated with total phenolics. Copyright © 2007 Society of Chemical Industry  相似文献   

7.
The composition of polyphenols in the skin, seed and pulp extracts of the grapes of Vranec and Smederevka varieties, and Merlot and Chardonnay as well, was analyzed by liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS) and MS/MS techniques. Thirty-one phenolic compounds, including anthocyanins, flavonols and flavan-3-ols, as well as phenolic acids derivatives, have been identified in the extracts prepared from the grapes at physiological maturity, by mass spectrometry applying electrospray ionization operated in alternating ion mode and by performing tandem MS experiments in the ion trap mass analyzer. Grapes were analyzed at three different phases: (i) veraison, (ii) physiological ripeness and (iii) late harvest, in order to follow the evolution of polyphenolic content during berry development, applying spectrophotometric methods. Vranec had a higher polyphenolic content compared to Merlot due to the higher levels of total phenolics and flavonoids in the skins and seeds as well as a higher content of flavan-3-ols and anthocyanins in the skins, allowing discriminating the varieties. HPLC-DAD-MS analysis presented significantly higher relative amounts of anthocyanin monoglucosides and p-coumaroylglucosides in Vranec grapes. Smederevka seeds had a higher amount of flavan-3-ols than Chardonnay, while a higher content of total phenolics and flavonoids was found in the skins of the Chardonnay variety. Anthocyanin content in both red varieties increased during the berry ripening, while flavan-3-ols in seeds were mainly accumulated in the veraison phase followed by decrease of the content with ripening.  相似文献   

8.
Phenolic extraction in hybrid and interspecific wine grape cultivars is poorly understood, especially in terms of the impact of fermentation and enological conditions on condensed tannins and anthocyanins. Following fractionation via solid‐phase extraction and high‐performance liquid chromatography, phenolic profiles of must and wine from red hybrid grape cultivars Maréchal Foch, Corot noir, and Marquette were examined to assess the impact of enzyme and tannin addition, cold soak, and hot press during vinification. Across cultivars, hot press treatments resulted in the greatest extraction of condensed tannin, anthocyanin, and other monomeric phenolic compounds in musts, and treatments that increased skin contact time or cellular degradation during fermentation produced higher concentrations of tannins, anthocyanins, and flavonols. However, these increases were transient, evincing incomplete carryover into finished wines. Depending on initial must extraction, diglucoside forms of anthocyanins were either selectively extracted or selectively retained throughout fermentation when compared to their monoglucoside counterparts. Typical of hybrid grapes, tannin concentrations across cultivars were low, even under hot press conditions. For condensed tannins and anthocyanins, a cultivar‐specific, stable‐state concentration and phenolic profile emerged regardless of fermentation conditions. Due to the high levels of diglucoside anthocyanins and low levels of condensed tannins, it is expected that the color development and profile in these wines produced from hybrid grape cultivars will be dictated by the monomeric anthocyanins and their potential role in copigmentation processes involving other monomeric phenolic species, as opposed to the formation of polymeric color pigments.  相似文献   

9.
以天津蓟州区栽培的"美乐"和"赤霞珠"葡萄为试验品种,分别在其始熟期的初、中和末期3个阶段利用外源脱落酸(200 mg/L)处理果实,采用分光光度法测定葡萄和葡萄酒中酚类总含量和抗氧化活性,利用液质联用技术分析花色苷的含量和组成.研究结果表明:始熟期的外源脱落酸处理对成熟果实的质量、可溶性固形物、可滴定酸和pH值,以及葡萄籽的酚类含量和抗氧化活性没有显著影响,但对葡萄皮和葡萄酒的酚类物质含量和活性具有显著影响.在始熟期中期(30% ~50%果实转色)以前,对果实喷施外源脱落酸可以显著提高葡萄皮和葡萄酒的酚类总含量、花色苷总含量和抗氧化活性.始熟期外源脱落酸处理使"美乐"和"赤霞珠"果实的酚类总含量分别提高了14% ~39%和73% ~172%,花色苷总含量和抗氧化活性分别提高了18% ~143%和88% ~178%;外源脱落酸处理使葡萄酒的3个指标(酚类总含量、花色苷总含量和抗氧化活性)分别提高了17% ~69%、18% ~36%和21% ~46%,而这些影响可以有效改善葡萄酒的感官品质和营养价值.外源脱落酸处理时期的精准控制可以提高酿酒葡萄及葡萄酒中酚类物质含量及抗氧化作用,进而提高葡萄酒品质和营养价值.  相似文献   

10.
The vinification technique called pre-fermentative cold maceration is used to enhance the anthocyans diffusion from the skins to the must, increasing the pigments extraction. For using this technique the application of low temperatures is needed. In this study, two different refrigerating methods (dry ice and cooling of grapes) have been assessed regarding the colour and the phenolic composition of the Syrah wines elaborated by applying pre-fermentative cold maceration. Results showed more intense and stable colours when grapes were previously refrigerated in cold-storage rooms, which showed higher values of chroma and more red-bluish hues. As regards phenolic composition, the cold maceration technique used yields to significant differences among the levels of phenolics, having higher levels of anthocyanins and some non-coloured phenols as flavonols in PR wines. Regarding the colour-composition relationships, it has been highlighted the importance of the co-pigments such as flavonols and cinnamic acids for classify the two groups of samples.  相似文献   

11.
Total phenolics and chlorogenic acid in different plum cultivars ranged from 262 to 922 μ/g and 33 to 103, μg/g, respectively. Stanley plums had the highest polyphenol oxidase (PPO) activity and chlorogenic acid to total phenolics ratio as compared to all other cultivars. Degradation of anthocyanins in the juice made from Stanley plums was directly related to the level of PPO in the juice. Among PPO inhibitors, L-cysteine and sodium metabisulfite (at 0.5 and 1.0 mM) were effective in minimizing degradation of anthocyanins. Anthocyanins in the juice samples were heat stable and pasteurized juice showed acceptable microbial quality.  相似文献   

12.
ABSTRACT: The effectiveness of temperature, SO2, citric acid, and industrial juice-processing enzymes ( n = 9) for producing extracts of blueberries ( Vaccinium corymbosum , cv. Rubel) and blueberry skins that are rich in anthocyanins and polyphenolics were evaluated individually and/or in combination. Enzyme treatment had little effect on total monomeric anthocyanins and on total phenolics recovery. Various combinations of heat, SO2, and citric acid yielded extracts with higher concentrations of ACY and TP than the control. The distribution of anthocyanins and polyphenolics in 'Rubel' was also investigated. Anthocyanins existed almost exclusively in the skins, and polyphenolics were mostly in the skins with lesser amounts in flesh and seeds. Skins were also highest in antioxidant activity. All portions contained the same individual anthocyanins but in varying amounts. Cinnamic acid derivatives and flavonol-glycosides were found in the skins and seeds, whereas the flesh contained only cinnamic acids.  相似文献   

13.
The objective of this study was to evaluate the effect of exogenous abscisic acid (ABA) on the antioxidant capacity and phenolic content of muscadine grape skins (cvs. Noble and Alachua). ABA was applied on grapes during and after veraison. Average berry weight, total soluble solids (0Brix) and pH of the juice from both cultivars were not affected by the ABA treatment. Antioxidant capacity was enhanced by 38% and 18% in treated Noble at the first and second sampling, respectively. High performance liquid chromatography analysis revealed a significant increase in individual anthocyanins in treated Noble grapes at both sampling times. However, increase in the content of ellagic acid, myricetin, quercetin and kaempferol was observed at first sampling only. No effects of ABA treatment were seen in Alachua grapes. Our results indicate that exogenous application of ABA enhances the antioxidant capacity, anthocyanins and phenolic content of muscadine grapes but these effects may vary depending upon the cultivar.  相似文献   

14.
In this work, the chemical compositions and texture characteristics of three native Romanian wine grape varieties (Feteasc? regal?, Feteasc? alba, and Feteasc? neagr?) were studied. We assessed the distinct characteristics directly linked to their phenolic compositions, volatile profiles, and mechanical properties and compared these characteristics with those of Pinot noir grapes. The effect of the growing zone was also evaluated. Various spectrophotometric indices directly related to the phenolic compositions of berry skins and seeds were determined. The detailed phenolic compositions (anthocyanins, hydroxycinnamoyl tartaric acids, and stilbenes) of the skins were determined using high-performance liquid chromatography methods. Free and bound volatile compounds in the berries were quantified by gas chromatography/mass spectrometry. The textural properties of the skins and seeds were measured by instrumental texture analysis. The results showed high diversity among the varieties and zones that affected the enological potential. Among the white varieties, Feteasc? alb? grapes could be less susceptible to browning as a consequence of their lower trans-caffeoyltartaric acid concentration, whereas Feteasc? regal? grapes from Cluj had the highest concentrations of total free and bound volatile compounds, particularly terpenes and norisoprenoids. Among the red varieties, Feteasc? neagr? was identified as a promising variety to be exploited in the future for its particular phenolic characteristics, particularly those grapes grown in Mica. Nevertheless, Feteasc? neagr? grapes grown in Cluj had the highest total glycosidically bound terpene concentrations. Finally, differences in the mechanical and/or acoustic properties of the skins and seeds could strongly influence the kinetics and completeness of phenolic compound extractions.  相似文献   

15.
不同品种甘薯汁抗氧化活性的研究   总被引:1,自引:0,他引:1  
研究了9个品种甘薯汁的酚类物质及其抗氧化活性,旨在为甘薯汁的开发利用提供参考依据。分别采用Folin-酚法、亚硝酸钠法、pH示差法测定了甘薯汁的总酚、总黄酮、总花色苷含量。结果表明,甘薯汁中含有丰富的酚类物质,不同品种甘薯汁的总酚、总黄酮和总花色苷含量存在差异。通过4个体外抗氧化体系(FRAP法、DPPH自由基法、ABTS+自由基法、OH自由基法)评价了甘薯汁的抗氧化能力。结果显示,不同品种甘薯汁所呈现的抗氧化能力不同,酚类物质含量较高的甘薯汁其抗氧化能力较强。从抗氧化能力方面考虑,杭引薯1号、杭引薯3号、浙紫薯1、13号这4个抗氧化能力较强的品种较适合用于果汁加工以及功能性饮品的开发。   相似文献   

16.
Juices from grape samples subjected to two storage methods (fresh and frozen) and two post-homogenisation treatments (21oC and 71oC) were examined for extraction of grape berry components and compared to a microvinified wine made from the same lot of fresh grapes. Cabernet Franc ( Vitis vinifera ) and Cynthiana ( Vitis aestivalis ) grapes were evaluated in 2003. Cabernet Franc, Cabernet Sauvignon ( Vitis vinifera ), Chambourcin (interspecific hybrid) and Cynthiana grapes were evaluated in 2004. Fresh grapes from each variety were sampled, analysed and prepared for microvinification. Frozen grapes of all varieties were thawed and analysed at the same time. For all varieties in both years, heating the must of fresh or frozen grapes increased the titratable acidity (11–58%), tartaric acid levels (12–110%), potassium content (15–62%), darkness (31–97%), red colour (54–1517%) and total red pigment values (36–1171%) of juice as compared to the juice from unheated must. For all varieties in 2004, heating the must from fresh or frozen grapes increased total phenolics (43–619%) of juice as compared to the juice from unheated must. Compared to fresh grape processing, freezing the grapes and then processing at 21oC or 71oC had varying results (increases and decreases) regarding the extraction of components in all varieties and both years but usually provided juice with composition most similar to that of the red wine produced by microvinification. Although the degree of extraction of individual components in the juice is influenced by selection of grape storage and must processing procedures, consistency of handling and procedure provided consistent results with low variability.  相似文献   

17.
Large decreases in colour density during the making of red wines, whether by the traditional fermentation on skins or by thermovinification, have not previously been explained in terms of juice and wine composition. The major colour loss is actually due to the extreme instability of deeply coloured pigment structures initially present in the juice extract to ethanol, whereas decrease in anthocyanin content is a minor contributing factor. The consequent decline in colour density during fermentation can be as much as five-fold under conditions of high pH. Both red and blue chromophoric forms of the anthocyanins, in self-association and co-pigmentation with related flavonoid phenolics, are proposed as being present in the juice pigments. The stability of such complexes is ascribed to intermolecular hydrogen bonding forces. The existence of two nearly distinct phases in the accounting of total phenolics during ‘evolution ’of a red wine is emphasised.  相似文献   

18.
Blueberry fruits from five commercial cultivars and 13 breeding selections grown at the same locations over two growing seasons were analysed for total phenolics (TPH), total anthocyanins (ACY), total hydroxycinnamic acids (HCA), total flavonols (FLA), fruit weight and oxygen radical‐absorbing capacity (ORAC). Variation in ORAC, TPH, ACY, HCA, FLA and fruit weight among genotypes was much greater than that observed between growing seasons, indicating that genetics plays a more important role than growing season in influencing ORAC and phenolic content in blueberries. Significant main effects for growing season and genotype × growing season observed for ORAC, ACY, HCA and fruit weight demonstrate that environmental growing conditions can impact levels of phenolics and ORAC in blueberries and that certain genotypes vary in their capacity to synthesise phenolics under different growing conditions. In general, genotypes with smaller berries had higher ORAC values and levels of TPH, ACY, HCA and FLA than large‐berried genotypes. Over both growing seasons, ORAC correlated highly with TPH, ACY, HCA and FLA, while fruit weight correlated inversely with all phenolics measured. Our results indicate that blueberry genotypes should be screened over multiple growing seasons in order to identify antioxidant‐ and phenolic‐rich germplasm. Copyright © 2003 Society of Chemical Industry  相似文献   

19.
ABSTRACT: Water, an inexpensive and environmentally friendly solvent is an ideal solvent for industrial extraction of phenolics, but its use is limited due to poor extraction efficiency at low temperatures. In this study, subcritical water (SW) and subcritical sulfured water (SSW) (containing 1400 μg/mL sodium metabisulfite) extractions of grape skin phenolics were conducted over the temperature range of 100 to 160°C in 10°C increments for a short time (40 s), and compared with conventional hot water or aqueous 60% (v/v) methanol extractions (50°C, 1 h). The composition and contents of anthocyanins, flavonols, hydroxycinnamates, phenolic acids, and antioxidant capacities (Oxygen Radical Absorbing Capacity [ORAC]) in the extracts were determined. Increasing SW extraction temperature from 100 to 160°C resulted in a linear increase in ORAC values, but extraction temperatures > 110°C resulted in decreased contents of individual and total anthocyanins. Subcritical sulfured water extracts had higher levels of total anthocyanins and total phenolics than SW extracts. The SW and SSW extracts had comparable or higher levels of anthocyanins and ORAC values than extracts obtained using conventional hot water or 60% methanol. Subcritical water at 100 to 110°C appears to be an excellent alternative to organic solvents to extract anthocyanins and other phenolics from dried red grape skin and possibly other grape processing byproducts.  相似文献   

20.
Consumption of berries has become popular among health-conscious consumers due to the high levels of valuable antioxidants, such as anthocyanins, and phenolic compounds in berries. Four Rabbiteye blueberry cultivars (i.e., Powderblue, Climax, Tifblue, and Woodward) grown organically and conventionally were compared regarding their chemical profiles and antioxidant capacity in terms of total phenolic content (TPC), total anthocyanin content (TAC) and ORAC activity. Regardless of the high TPC, TAC and ORAC in both organically and conventionally grown blueberries, not all the organic berries showed significantly higher TPC, TAC and ORAC than the conventional berries. The chemical profiles (i.e., the free phenolic compounds and anthocyanins) were determined with aid of HPLC-MS, by which 13 individual anthocyanins and seven free phenolics were identified. This study demonstrated the subtle differences of bioactive phytochemicals between the organically and conventionally grown berries.  相似文献   

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