Prediction of perceived astringency induced by phenolic compounds

A method which can be used to estimate perceived astringency due to polyphenolic compounds is presented here. Thirty subjects were selected on the basis of them having similar salivary flows and they were trained to rate the perceived astringency of tannic acid and grape seed extract solutions. A scale of phenolic compound concentrations ranging from 0 to 3.2 g/L was selected in order to obtain an experimental curve describing the perceived intensity of the sensation. The same astringent solutions were added to a mucin solution in conditions resembling those present in the oral cavity. The formation of polyphenol–protein complexes was measured on the basis of the increasing turbidity of the reaction mixture and was expressed in terms of nephelometric turbidity units (NTU). Experimental curves describing NTU vs polyphenol concentration were obtained. Predictive models of astringency intensity vs NTU were produced. The predictive capacity of the models was checked by comparing the measured and predicted intensities of a set of samples prepared at phenolic compound concentration level varying from 0.94 to 2.13 g/L.     

强化葡萄籽超微粉蛋糕的感官品质及其抗氧化研究

葡萄籽含有丰富的多酚类物质,具有很强的抗氧化活性和抵抗多种疾病的能力。本研究建立了适宜的焙烤工艺,将葡萄籽超微粉以5%、10%、15%三种不同浓度添加到蛋糕中,最终通过感官品评和抗氧化活性确定了最佳的葡萄籽超微粉添加量。结果表明:霞多丽葡萄籽超微粉有一定的清除ABTS+·能力和Fe3+还原能力,其值分别为12.83、10.80 mmol TE/g脱脂干重;强化葡萄籽超微粉蛋糕也表现出较强的抗氧化能力,且随着葡萄籽超微粉添加量的增加,强化蛋糕的ABTS+·清除能力和Fe3+还原力显著（p<0.05）增强;葡萄籽超微粉的添加对于储藏期内蛋糕油脂的氧化酸败同样有较强的抑制作用。三个浓度的葡萄籽超微粉添加量对于蛋糕的感官品质和整体接受度无显著影响,但结合抗氧化结果,以10%和15%的添加量最为适宜。      

葡萄籽粉对太谷饼风味的影响

将葡萄籽粉碎添加到太谷饼中,采用气相色谱-离子迁移谱(Gas Chromatography-Ion Mobility Spectroscopy,GC-IMS)联用技术结合感官评价,重点研究添加葡萄籽粉对太谷饼风味的影响。结果表明:三种太谷饼中共检测出已定性的挥发性有机物18种,其中醛类6种,酮类3种,醇类5种,酯类3种,呋喃类1种;添加葡萄籽粉的太谷饼中风味物质种类未改变,但各种风味物质含量发生变化,葡萄籽粉添加10%时,太谷饼中乙酸乙酯和2-甲基丁醇的相对含量由对照组的1.67%和0.65%增加到8.62%和7.25%,但3-甲基丁醛和己醛降低了1.65%和5.03%;结合感官评价结果,虽然对照组得分最高,但三种太谷饼无显著性差异(P>0.05),说明葡萄籽粉添加量小于10%时,消费者均可以接受。本研究为太谷饼风味物质的研究提供一定科学依据,为葡萄籽的开发利用提供一些思路。

     

功能性葡萄籽太谷饼配方工艺的研究

将葡萄籽进行处理后添加到传统食品太谷饼中,研制功能性葡萄籽太谷饼,以太谷饼感官评价结果为考核指标,分析不同葡萄籽添加方式对太谷饼品质的影响,采用正交试验优化生产工艺.结果表明:葡萄籽的最佳添加方式为普通粉碎葡萄籽粉,过60目筛;最佳配方工艺为:葡萄籽粉添加量50 g,蔗糖添加量100 g,亚麻油添加量150 g,烘焙条...     

Red Wine and Model Wine Astringency as Affected by Malic and Lactic Acid

Red wines and model solutions containing grape seed phenols were assessed for perceived astringency, bitterness and sourness by a panel of trained assessors using time-intensity (T–I) methodology. The effect of lactic and malic acid on perception of these attributes was evaluated at two pH values, by adding different amounts of acids. Maximum intensity (I_max) and total duration (T_tot) of astringency increased with decreasing pH in model solutions and red wine, but no differences were found between malic and lactic acid on perception of astringency. The pH and the acid type did not affect any of the bitterness T-I parameters. However, sourness showed an increase in 1_max and T_tot with decreasing pH.     

几种油溶性天然抗氧化剂在核桃油、葡萄籽油中的应用研究

对茶多酚棕榈酸酯、抗坏血酸棕榈酸酯、迷迭香提取物、维生素E在核桃油和葡萄籽油中的抗氧化能力和4种油溶性天然抗氧化剂相互之间的增效作用进行了研究。采用响应面方法 D-最优设计进行试验,测定添加了各种抗氧化剂的核桃油和葡萄籽油的氧化稳定性,并进行感官评价。对试验数据进行方差分析并构建回归模型,将添加了抗氧化剂的核桃油和葡萄籽油的感官评价结果控制在可接受范围内,优化出抗氧化效果最佳的复配配方。该配方在核桃油和葡萄籽油中分别为:茶多酚棕榈酸酯0.40 g/kg,抗坏血酸棕榈酸酯0.02 g/kg,迷迭香提取物0.15 g/kg;茶多酚棕榈酸酯0.39 g/kg,抗坏血酸棕榈酸酯0.04 g/kg,迷迭香提取物0.11 g/kg。     

Preliminary studies on acidity-astringency interactions in model solutions and wines

Intensity of astringency in model solutions and wines varying in total acid and total phenols was evaluated by paired comparisons by 10 trained judges. Model solutions consisted of tannic (500, 1000, 2000 mg litre^?1) and tartaric (0, 2, 4, 6 g litre^?1) acids dissolved in aqueous solutions of ethanol (120 ml litre^?1) and sucrose (5 g litre^?1). Wine solutions were prepared by addition of citric acid (0, 0.5, 1, 2, 3 g litre^?1 as tartaric acid) to a high phenol-red wine (2645 mg litre^?1 GAE) and a moderate phenol-white wine (800 mg litre^?1 GAE). At all three levels of tannic acid, astringency of model solutions increased significantly (P<0.001) with tartaric acid concentration. Astringency of white wine also increased significantly (P<0.05) with citric acid concentration. A negative linear relation was found between relative astringency and pH at a given tannin level for both model solutions and white wine. As pH was reduced, more phenolic molecules were in the phenol form thereby increasing the likelihood of hydrogen bonding between hydroxyl groups of wine tannins and ketoimide groups of mouth proteins. The preliminary hypothesis that hydrogen bonding is the main reaction involved in the formation of protein-tannin complexes resulting in the sensation of astringency was reinforced.     

添加葡萄籽单宁对橡木桶陈酿‘赤霞珠’和‘马瑟兰’干红葡萄酒香气的影响

采用气相色谱-质谱联用法和感官分析排序法,研究橡木桶陈酿前添加葡萄籽单宁（200 mg/L）对陈酿12 个月后‘赤霞珠’和‘马瑟兰’干红葡萄酒香气组分和感官特征的影响。结果表明：添加葡萄籽单宁对2 个品种葡萄酒香气的影响各异。葡萄籽单宁添加促进了橡木桶陈酿期间‘赤霞珠’葡萄酒中香草酸、香草醛、香草酸乙酯、糠醛、乙酰呋喃和糠醇等橡木来源香气物质的浸出,而抑制‘马瑟兰’干红葡萄酒中糠醛、乙酰呋喃、糠醇、5-甲基糠醛和5-羟甲基糠醛等橡木来源香气物质的浸出。添加葡萄籽单宁后,‘赤霞珠’葡萄酒的生青味和浆果香降低,烘烤味增强,‘马瑟兰’葡萄酒的生青味和花香略有增强,对陈酿型干红葡萄酒的生产具有重要指导作用。     

葡萄籽油毒性评价的研究

目的检测葡萄籽油的生物安全性。方法对葡萄籽油样品进行小鼠急性毒性试验和小鼠遗传毒性试验。结果小鼠急性和遗传毒性测试均为阴性。对大鼠喂养30天的试验表明，在试验期内个试验组动物生长发育良好，动物体重、食物利用率、血常规、血生化、脏器系数等各项指标均在正常值范围内，与对照组之间差异无显著性（P〉0．05）。病理组织学检查无异常。结论表明该物质对大鼠各项观察指标未产生明显毒性作用。     

Differential interaction of seed polyphenols from grapes collected at different maturity stages with the protein fraction of saliva

Grape seed and skin proanthocyanidins undergo significant changes during grape maturation. Those changes have been associated with a decreased astringency of grapes collected at later maturation stages. We have now compared the ability of proanthocyanidin‐rich extracts from Carménère grape seeds collected at two stages of berry development (veraison vs. harvest) both to interact with salivary proteins and to produce astringency. Interaction of proanthocyanidins with the salivary protein was assessed by analysing the concentration‐dependent effect of seed extracts both on inducing salivary protein precipitation and on restricting diffusion of the salivary protein on cellulose membranes. Seed extracts from grapes collected at veraison compared with those of grapes collected at harvest displayed a higher ability both to interact with the salivary protein fraction and to produce astringency. As a whole, our observations show that astringency is closely dependent on the magnitude of the interactions between proanthocyanidins and the salivary protein fraction.     

葡萄籽原花色素对马铃薯馒头感官品质的影响

向马铃薯馒头中添加不同比例的葡萄籽原花色素(Grape seed proanthocyanidins,GSP),研究GSP对马铃薯馒头的外观、组成、质构、比容、孔隙度和感官品质的影响。结果表明:GSP不会改变马铃薯馒头的成分组成。但是,GSP会使马铃薯馒头的亮度降低,红度升高,黄度降低,并且会显著增加馒头的硬度,降低馒头的弹性、内聚性和回复性。随着GSP添加量的增加,马铃薯馒头的气孔数量和平均大小显著降低,马铃薯馒头的比容显著降低,内部结构变得紧致,这导致了馒头感官品质的降低。模糊感官评价表明,当GSP添加量大于2%时,马铃薯馒头的感官品质急剧下降。在马铃薯馒头中,GSP的添加量应小于2%。     

酿酒后葡萄籽综合利用的研究进展

酿制葡萄酒时,会产生大量的废弃物,其中包括葡萄籽。该文对酿酒后的副产品-葡萄籽的综合利用进行了综述,介绍了葡萄籽中葡萄籽油、多酚物质和蛋白质的提取及其应用技术。将葡萄籽进行合理开发利用,不仅可以避免环境污染,而且将增加葡萄酒的附加值。     

葡萄叶在面条中的应用

以高筋面粉和葡萄叶粉为原料,采用单因素试验,测试葡萄叶面条的断条率和吸水率,同时进行感官评分,分析葡萄叶粉、水、盐、谷朊粉添加量对葡萄叶面条品质的影响。通过正交试验得出制作葡萄叶面条的最佳工艺参数。结果表明,葡萄叶面条最佳配方为:葡萄叶粉添加量4%、高筋粉添加量96%、水用量52%、盐添加量2%、谷朊粉添加量2%,在此工艺条件下葡萄叶面条断条率低,吸水率高,感官品质良好。     

低温处理葡萄对爱格丽干白葡萄酒香气成分的影响

目的：以不同温度处理爱格丽葡萄原料,寻找增加爱格丽干白葡萄酒香气的最适温度。方法：以白色酿酒葡萄品种爱格丽为原料,16 ℃处理为对照,分别在4、－8、－20、－32 ℃条件下进行低温处理,采用小容器酿酒规范酿制葡萄酒并测定葡萄酒的理化指标,搅拌棒吸附萃取（stir bar sorptive extraction,SBSE）提取葡萄酒中的香气成分,再通过热脱附-气相色谱-质谱联用仪来定性和定量分析葡萄酒的香气成分,用SPSS 19.0软件进行香气成分的主成分分析（principal component analysis,PCA）,8 名经过培训的感官品尝小组成员对酒样进行感官评价。结果：低温处理能促使葡萄酒中香气成分种类的增加和含量的提高。结论：－8、－20 ℃低温处理葡萄可以显著提高爱格丽干白葡萄酒的香气质量,可在一定程度上使葡萄酒的香气更加浓郁。     

葡萄籽的开发与利用

葡萄籽含有14%～17%的油脂,还含有3.9%的原花青素.为了合理利用葡萄籽资源,采用仁壳分离的方法,仁用于提取葡萄籽油,壳用于提取原花青素.同时,还对葡萄籽的国内外研究利用情况,市场应用情况和前景作了客观的分析论述,以期促进葡萄籽资源的合理利用.     

7种酵母酿造摩尔多瓦葡萄酒的发酵特性比较

在常用的商业酵母中筛选一株酵母,应用于摩尔多瓦葡萄酒酿造,从而实现鲜食摩尔多瓦葡萄的增值。以摩尔多瓦葡萄为材料,选用VL1、F15、NS-D、P、HXD29、LE28、LD1015 7种酵母进行葡萄酒酿造试验,以自然发酵作为对照,对不同酵母发酵酒的总酸、总酚等理化性质进行检测和感官评价,比较不同酵母对摩尔多瓦葡萄酒理化性质及品质的影响。结果表明,酵母LD1015发酵的摩尔多瓦酒干浸物含量最高,为17.96 g/L;总糖含量为3.54 g/L,总酚含量为1.17 g/L,略低于酵母VL1、HXD29、LE28,感官评分最高,为91分。综合判定酵母LD1015具有较强的糖转化和干物质浸提的能力,有利于产出口感醇厚、香气馥郁的葡萄酒,是7种酵母中最适合鲜食葡萄摩尔多瓦酿酒的酵母菌种。