膨大处理对红地球葡萄酚类物质及抗氧化活性的影响

以红地球葡萄为研究对象,对葡萄进行膨大处理后,定期采样,测定处理组和对照组的总酚、总黄酮、总黄烷醇以及铜离子还原力、铁氰化钾还原力、DPPH自由基清除率、金属螯合力、羟自由基(·OH)清除率,用DPS软件对处理组和对照组之间的差异及酚类物质与抗氧化活性之间的相关性进行分析。结果表明：膨大处理可增加红地球葡萄酚类物质含量并增强其抗氧化活性;膨大处理对红地球葡萄总酚、总黄酮、总黄烷醇、铜离子还原力、铁氰化钾还原力的影响较大,对DPPH自由基清除率、金属螯合力、·OH清除率的影响较小。铜离子还原力、铁氰化钾还原力与酚类物质(总酚、总黄酮、总黄烷醇)含量均呈极显著正相关;金属螯合力、DPPH自由基清除率与酚类物质含量均无显著相关性,·OH清除率与酚类物质含量呈极显著负相关。铜离子还原力与铁氰化钾还原力呈极显著正相关;与DPPH自由基清除率呈显著正相关。铜离子还原力与·OH清除率、铁氰化钾还原力与·OH清除率呈极显著负相关。     

菠菜提取物抗氧化性研究

本文研究了菠菜的抗氧化性,采用不同极性溶剂对菠菜中的抗氧化性物质进行提取,测定不同极性提取物中的总酚、总黄酮含量及DPPH自由基清除率,发现95%乙醇本本效果最好本95%乙醇本本率为4.96%;本本含量为39.60μg/mg样品;本黄酮含量为17.53μg/mg样品;终浓度0.5mg/mL时本DPPH自由基本清除率为62.09%。     

产地与品种对葡萄酒中酚类物质含量的影响

选取同一产地(天水)3 个葡萄品种：“西拉(Shiraz)”、“蛇龙珠 (Carbernet Gernischet)”、“赤霞珠(Cabernet Sauvignon)”所酿制的新鲜干红葡萄酒以及5 个不同产地(天水、和硕、玛纳斯、延庆和怀来)赤霞珠葡萄酒,采用高效液相色谱(HPLC)法分析葡萄酒中11 种酚酸、5 种黄烷-3- 醇、10 种黄酮醇和2 种黄酮的含量。结果表明：同一产地不同品种和同一品种不同产地间的葡萄酒中酚类物质的含量都存在显著差异。其中,赤霞珠葡萄酒是3 个葡萄品种中酚类物质含量最高的品种;在5 个不同产地中,延庆赤霞珠葡萄酒中酚酸含量最高,黄烷-3- 醇含量最高的为和硕赤霞珠葡萄酒,而怀来赤霞珠葡萄酒中所含黄酮醇含量最高。     

葡萄多酚的抗氧化活性

本文对葡萄多酚抗氧化活性进行研究。结果表明，葡萄多酚对DPPH、超氧阴离子自由基、羟基自由基清除活性IC50值分别为：1．96μg／ml、7．50mg／ml、1．91mg／ml，同时，在实验条件下它可将油脂的酸败时间推迟1d。     

酚类物质对红葡萄酒颜色影响的研究进展

颜色作为红葡萄酒的重要感官指标,提供了葡萄酒的品质、类型以及储存期的稳定性,也成为了消费者选购葡萄酒的重要因素。酚类物质作为红葡萄酒的"骨架结构",对葡萄酒的风味、口感以及颜色等都起着决定性的作用。因此,系统的对影响红葡萄酒颜色的酚类物质进行总结归纳,以及对其对红葡萄酒的颜色影响进行研究具有重要的参考意义。     

镇江香醋抗氧化活性成分来源分析

文中研究了镇江香醋生产过程中抗氧化性成分酚类、黄酮类化合物含量及DPPH自由基清除活性的变化,并分析了总酚、总黄酮与DPPH自由基清除活性的相关性。研究表明,在醋酸发酵阶段,镇江香醋总酚含量及总黄酮含量开始明显增加。露底封醅阶段和煎煮过程对镇江香醋DPPH自由基清除作用有较明显的影响。总酚含量与总黄酮含量与DPPH自由基清除活性有较高的相关性,相关系数分别为0 9334和0 935 3。     

26种市售食醋抗氧化性的比较

测定了不同品种食醋中酚类、黄酮类化合物含量及DPPH自由基清除活性,并分析了总酚、总黄酮含量与DPPH自由基清除活性的相关性。结果显示,不同品种食醋的自由基清除作用和它们含有的酚类及黄酮类成分相关,相关系数分别为0.952 3和0.869 1。总酚含量、总黄酮含量可作为评价食醋抗氧化性的指标,总酚含量、总黄酮含量、DPPH自由基清除率可作为鉴别不同品种食醋的指标。     

Assessment of the Antioxidant Properties During Storage of a Dessert Made from Grape, Cherry, and Berries

A 1‐y storage trial was designed involving different temperatures (8, 21, and 30 °C) to assess the antioxidant properties of a dessert formulated with concentrated juices of grape, blackberry, blackcurrant, raspberry, and cherry. The total antioxidant activity (TAA) of the dessert was measured as the scavenging capacity of the 2,2′‐azino‐di‐[3‐ethylbenzothiazoline‐6‐sulphonate] radical cation (ABTS) and as its iron‐reducing ability (FRAP). Color was spectrophotometrically measured, and vitamin C and phenolics were analyzed by HPLC. The color parameters and the concentrations of different antioxidant compounds were affected by storage conditions, especially in samples stored at 30 °C, although the TAA remained practically invariable during storage.     

应用HS-SPME技术分析葡萄果皮与果肉挥发性香气物质

采用顶空固相微萃取(HS-SPME)和气质联用法(GC-MS)快速测定葡萄中的挥发性香气成分,定量分析了蛇龙珠、品丽珠、赤霞珠和梅鹿辄4种葡萄果皮与果肉中的香气成分。在4种葡萄中,果皮中的化合物总量高于果肉,含有较多的酯类、芳香族化合物、挥发性有机酸和挥发酚,这些化合物在果皮中的含量是果肉中的1.58～20.54倍。不同的风味化合物在葡萄果皮与果肉中含量差别较大,其中有19种化合物在果皮中含量较多,茴香脑、(S)-3-乙基-4-甲基戊醇、萘在4种葡萄皮中含量远高于果肉。不同品种葡萄果皮中,高含量化合物是不同的,主要风味成分浓度也是不一样的。     

葡萄皮渣中花旗松素提取工艺优化及其抗氧化能力测定

采用乙醇加热法提取葡萄花旗松素,利用响应面分析法优化葡萄花旗松素的提取工艺并测定其最优组的抗氧化性能.结果表明:葡萄花旗松素的最佳提取工艺为静置处理时间为30 min、乙醇含量58％、提取温度56℃、液料比23∶1 mL/g、提取时间2.0 h,最佳提取量为3.936 mg/g.以VC 为参照测定提取液对ABTS 自由...     

Influence of must composition on phenolic oxidation kinetics

White grape musts with added sulphur dioxide, ascorbic acid, glutathione, copper or flavanols were prepared and oxidised using known amounts of oxygen. Sulphur dioxide and ascorbic acid delayed caffeoyltartaric acid oxidation, 2-S-glutathionyl caffeoyltartaric acid (GRP) formation and browning development. The glutathione content determined the quantity of GRP formed; browning was prevented when all the caffeoyltartaric acid quinones generated by enzymic oxidation could be trapped as GRP. Cupric ions, which lower the concentration of available glutathione, enhanced must browning. Coupled oxidation of flavanols by the caffeoyltartaric acid quinones also led to increased discoloration.     

葡萄籽多酚化合物抗氧化能力与抗癌细胞增殖活性的评价

目的:探讨葡萄鲜果及酿酒皮渣中葡萄籽提取物中的酚类化合物含量,抗氧化特性及对癌细胞增殖的抑制作用。方法:乙醇法提取葡萄籽中多酚化合物,分光光度计法测定三大酚类化合物参数(总酚、类黄酮类、黄烷-3-醇类)及3种抗氧化性能参数(DPPH及ABTS自由基清除能力,FRAP分析)。体外培养肝癌细胞HepG2,建立细胞模型,不同浓度的提取物作用于癌细胞后,采用四甲基偶氮唑盐比色法(MTT法)检测多酚提取物对癌细胞增殖的抑制作用。结果:不同样品葡萄籽所含酚类化合物、抗氧化性能、抗癌细胞增殖能力均不同,酿酒皮渣的葡萄籽中仍含有大量的多酚化合物,其中欧亚种赤霞珠鲜果及酿酒皮渣中葡萄籽所含酚类化合物、抗氧化能力及抗癌细胞增殖活性高于圆叶葡萄Noble鲜果及酿酒皮渣。结论:葡萄鲜果与酿酒皮渣中的葡萄籽多酚化合物具有抗氧化能力及抗癌细胞增殖活性。     

Evaluation and Improvement of Antioxidant Activity of Water-soluble Lignin Products from Steam Explosion Processing of Corn Stalk

In this study, corn stalk was pretreated by steam explosion under various processing conditions, and the antioxidant activity of hydrolysates in the post-proces...     

Antioxidant activities and phenolic compounds of pigmented rice bran extracts

This study was carried out to investigate the antioxidant activities and phenolic compounds of pigmented rice (black, red, and green rice) and brown rice brans. Antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, 2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulfonic acid) (ABTS) radical cation assay, reducing power, and chelating ability. Phenolic compounds were measured by using HPLC. Pigmented rice brans were extracted by using aqueous mixtures of acetone, ethanol, and methanol to determine the most effective extraction solvent. Of all solvents examined, extract from 40:60 acetone-water mixtures (v/v) provided the highest DPPH radical assay as well as the highest total phenolic and flavonoid content. We finally selected 40% acetone as an extraction solvent for antioxidant study of pigmented rice bran. Antioxidant activities of 40% acetone extracts of pigmented rice bran, measured in the range of 0 to 1500 μg/mL. At 500 μg/mL concentration, red rice bran, which had the highest total phenolic (259.5 μg/mg) and total flavonoid (187.4 μg/mg) contents, showed the highest antioxidant activity: 83.6%, 71.5%, 1.2%, and 16.4% for DPPH radical assay, ABTS radical cation assay, reducing power, and chelating ability, respectively. Red rice bran showed a lower EC(50) value (112.6 μg/mL) than that of butylated hydroxytoluene (144.5 μg/mL) from the DPPH radical assay. The major phenolic acids of red rice bran were ferulic, vanillic and p-coumaric acids. The results indicated pigmented rice bran might be used as a natural antioxidant. PRACTICAL APPLICATION: The present study revealed black and red rice bran shows high antioxidant activities and they contain high amount of phenolic compounds. Indeed, black and red rice bran could be better raw materials for manufacturing the food with high antioxidant activity.     

超声波提取葡萄籽油的工艺优化及其抗氧化性研究

通过单因素试验选择温度、提取时间、功率为影响超声波提取葡萄籽油效率的3个主要因素,运用响应曲面法进行超声波提取葡萄籽油的最佳工艺研究,分析各因素对提取效果的影响,并采用DPPH自由基实验以对其抗氧化性进行评价。结果表明：最佳工艺条件为温度54℃、提取时间37min、超声波功率456W,在此条件下进行验证实验,每5g葡萄籽的葡萄籽油提取量为0.63314g,提取率13.31%;葡萄籽油质量浓度为1～25mg/mL时,其质量浓度变化与自由基清除率呈正相关,在25mg/mL时,清除率达到80.7%,继续增大葡萄籽油质量浓度,对自由基清除率影响不大。     

蒸汽爆破预处理对籽粒苋籽实抗氧化能力的影响

实验选取汽爆压力0.3、0.6、0.9、1.2、1.5 MPa,汽爆时间10、20、30、60、120 s,对籽粒苋籽实进行预处理。分别测定汽爆前后各组样品的总酚、总黄酮含量,并通过测定其对DPPH、ABTS⁺自由基的清除率、铁离子还原能力来衡量各组样品的抗氧化能力,旨在探讨蒸汽爆破对籽粒苋籽实总酚、总黄酮和抗氧化能力的影响。结果表明:经过汽爆处理,籽粒苋籽实总酚、总黄酮含量和抗氧化能力显著提高(p<0.5)。0.6 MPa、60 s是最佳处理条件,此时总酚、总黄酮含量分别为未汽爆组的5.3倍和7.3倍,DPPH、ABTS⁺自由基清除率、铁离子还原能力分别是未汽爆组的4.6、3.8和11.6倍。蒸汽爆破是一种高效、无污染的前处理方式,为籽粒苋籽实的后续开发奠定基础。     

浓缩葡萄汁在红花籽油贮藏中的抗氧化效果

通过测定木纳格、无核白、美国红提、玫瑰香四种浓缩葡萄汁的清除DPPH·能力,评价了四种葡萄汁的抗氧化能力。同时研究了四种浓缩葡萄汁在红花籽油贮藏中的抗氧化效果。结果表明:四种浓缩葡萄汁的抗氧化能力强弱顺序为:美国红提>玫瑰香>无核白>木纳格。四种浓缩葡萄汁对红花籽油在贮藏中具有明显的抗氧化作用,当其添加量分别为0.05%,0.10%,0.05%,0.10%时达到最强的抗氧化效果。     

红葡萄酒、啤酒和白酒抗氧化作用研究

采用二苯苦味酰肼(2,2-Diphenyl-1-picryl-hydrazyl radical,DPPH)法、ABTS(3-ethyl benzot hiazoline-6-sulfonic acid)法、邻苯三酚自氧化法及羟自由基抑制法对红葡萄酒、啤酒和白酒的清除自由基活性进行比较.结果表明,红葡萄酒对DPPH自由基、ABTS·+自由基、超氧阴离子自由基的清除率分别为73.05%、64.37%和50.08%.啤酒对上述3种自由基的清除率分别为2.31%、1.40%和4.03%.白酒对这3种自由基的清除率分别为0.19%、0.04%和0.11%.红葡萄酒、啤酒和白酒对羟自由基的抑制率分别是43.39%、4.99%和1.24%.结果显示,葡萄酒对DPPH自由基、ABTSS·+自由基、超氧阴离子自由基、羟自由基的清除作用最强,啤酒其次,白酒最弱.     

Optimization of Extraction of Bioactive Compounds from Different Types of Grape Pomace Produced at Wineries and Distilleries

Natural extracts obtained from grape pomace are particularly interesting, due to the substantial variety of valuable compounds present with health benefits, specifically phenolic compounds such as anthocyanins, trans‐resveratrol, quercetin, and proanthocyanidins. The production of such extracts has been recognized as a profitable way to valorize grape byproducts, which are low‐value and most abundant. First, the effect of the solvent on the extraction of bioactive compounds from grape pomace is studied. The selected solvents are water and ethanol, biocompatible and available in wineries and distilleries. Then, different types of grape pomace obtained along the various stages of current industrial winemaking and distillation processes are analyzed. As a result, the best stage of the winemaking and distillation processes for pomace valorization is identified, corresponding to the grape byproduct with the highest potential as source of bioactive compounds. These studies were performed with Vitis vinifera variety of Tempranillo grapes (same year, same vineyard).     

柠檬形克勒克酵母对葡萄酒风味的影响

Klockera apiculata 1466纯种发酵和与Saccharomyces cerevisiae按不同时间、不同比例接种进行混菌发酵试验研究.结果表明,与S.cerevisiae纯种发酵酒相比,K.apiculata纯种发酵酒中酯类和酸类物质的含量提高了104.73%和119.8%,K.apiculata是一类产酸菌;当添加该酵母和酿酒酵母混合发酵时,酒样中高级醇和甘油含量显著增多,酸类和酯类的含量减少,说明混合发酵有益于高级醇和甘油的生成.