基于电子鼻的葡萄酒感官评价模型的构建

利用PEN3电子鼻检测10种不同菌株酿造的葡萄酒及1瓶商业葡萄酒样的香气,并通过电子鼻WinMuster及SPSS 19.0软件进行模式识别分析,评价基于不同模式识别分析方法电子鼻对不同菌株葡萄酒的区分效果;建立葡萄酒感官评价的综合主成分评价模型,并用该模型对这11种葡萄酒进行感官评价,进一步通过传统的专业品尝员对葡萄酒感官评价方法检测所建综合主成分模型的评价效果。结果表明,基于主成分分析与线性判别分析,电子鼻可以更好地区分不同菌株酿造的葡萄酒样;另外所建模型对葡萄酒的感官评价结果与传统感官评价方法具有较好的一致性,为进行更客观的葡萄酒感官评价提供了新的途径及一定的参考。     

感官评价在葡萄酒研究中的应用

目前，葡萄酒质量的鉴别主要靠感官分析和理化指标分析的方法来确定。本文主要介绍了葡萄酒感官评价的定义及其在葡萄酒加工工艺、成分分析和评价结果统计分析等方面的研究进展。     

葡萄含糖量对蛇龙珠葡萄酒品质的影响

选取蛇龙珠葡萄为研究对象,对葡萄初始含糖量与蛇龙珠葡萄酒品质的关系进行研究.结果表明,随着初始含糖量的增加,葡萄酒中的总酚含量呈上升趋势,这有利于增加红葡萄酒的色泽及感官质量.初始含糖量增加,多数醇类和酯类成分的检出量也有所增加,主要包括2-甲基-1-丙醇、3-甲基-1-丁醇、2-甲基-1-丁醇、2,3-丁二醇、乙酸乙酯和丁二酸单乙酯.上述醇类和酯类均具有各自独特的感官特征,其含量的适量增加有利于提升葡萄酒的口感质量.葡萄原料糖分含量高时,葡萄酒口感圆润、醇厚,酒体丰满,结构感也比较强.综上所述,葡萄初始含糖量对葡萄酒品质具有极其重要的影响.酿造优质蛇龙珠干红葡萄酒时,应选择初始含糖量高的葡萄原料.     

Visualization of sensory profiling data for performance monitoring

Simple graphical techniques can be utilized to investigate the performance of individual assessors and to detect individual differences among assessors in a sensory panel. By visualizing different type of information in a set of various plots the panel leader can extract relevant information without the need of extensive knowledge in statistics. The joint information content gained from the plots can then be used as a basis for selective training in order to improve performance of single assessors and the panel as a whole.     

Sensory analysis of lipstick

Sensory analysis of lipstick product by trained panellists started with recruiting female panels who are lipstick users, in good health condition and willing to be a part of sensory members. This group of people was further scrutinized with duo-trio method using commercial lipstick samples that are commonly used among them. About 40% of the 15 panels recruited were unable to differentiate the lipstick samples they usually use better than chance. The balance of nine panels that were corrected at least with 65% across all trials in panels screening process was formed a working group to develop sensory languages as a means of describing product similarities and differences and a scoring system. Five sessions with each session took about 90 min were carried out using 10 types of lipsticks with different waxes mixture ratio in the formulation together with six commercial lipsticks that are the most common to the panels. First session was focus on listing out the panels' perception towards the characteristic of the lipstick samples after normal application on their lips. Second session was focus on the refining and categorizing the responses gathered from the first session and translated into sensory attributes with its definition. Third session was focus on the scoring system. Fourth and fifth sessions were repetition of the third session to ensure consistency. In a collective effort of the panels, sensory attributes developed for lipstick were Spreadability, Off flavour, Hardness, Smoothness, Moist, Not messy, Glossy and Greasy. Analysis of variance was able to provide ample evidence on gauging the panel performance. A proper panels selecting and training was able to produce a reliable and sensitive trained panel for evaluating the product based on the procedures being trained.     

Introduction of a quality index,based on Generalizability theory,as a measure of reliability for univariate- and multivariate sensory descriptive data

In the sensory industry there is a need to quantify the overall usability or reliability of the final results of a sensory study. The sensory field has developed various statistical methods and techniques resulting in graphs or plots aimed at identifying assessors that contribute high error variance. Most of these methods are focused on estimating levels of repeatability, discriminability and agreement. Yet not much attention has gone to estimating the general level of quality of the dataset as a whole. Quality indicators could be helpful to quickly determine which attributes still require panel training, when panel training has been done in a sufficient manner and to determine the usability of the final results.This contribution proposes to use a statistical method, Generalizability theory (G theory), to monitor reliability (or generalizability) (Cronbach, Rajaratnam, & Gleser, 1963; Gleser, Cronbach, & Rajaratnam, 1965; Rajaratnam, Cronbach, & Gleser, 1965) and to study the univariate and multivariate reliability of the dataset. Generalizability theory (G theory) can characterize, disentangle, and estimate all different sources of variation as defined by the investigator. This makes G theory a useful tool for characterizing products, when dealing with multiple different sources of variance in a set of product evaluations. Univariate generalizability coefficients (or univariate quality index) could serve as quality indicators to determine which attributes are sufficiently reliable and in which cases panel training is beneficial for the discriminative ability of the panel or when panel training is redundant. Multivariate generalizability coefficients (or multivariate quality index) could capture reliability of an entire study expressed in one easily interpretable measure and could answer questions related to the overall quality of the experimental design of the study.In this study, a demonstration will be given on how G theory is used to test attribute reliability and to assess panel performance.     

中国黄酒中若干重要风味物质嗅觉阈值的研究

首次应用国际公认标准递增必选三杯法(ASTM:E-679),分别由国家黄酒评委和青年消费者组成的品评小组对中国黄酒中的重要风味物质β-苯乙醇,4-乙烯基愈创木酚,香兰素及二甲基三硫进行嗅觉的觉察阈值与识别阈值的测定。获得β-苯乙醇,4-乙烯基愈创木酚,香兰素及二甲基三硫的觉察阈值和识别阈值。其中国家黄酒评委的觉察阈值分别为:871、77、26、0.08μg/L;识别阈值分别为3090、427、98、0.44μg/L。青年消费者的觉察阈值分别为:2042、229、79、0.10μg/L;识别阈值分别为8511、891、191、0.81μg/L。所获得的阈值与已报道的阈值明显不同,说明测定风味化合物在中国黄酒中的阈值的必要性。在此基础上,根据阈值对品评员进行了敏感性分析。结果表明,不同人群的敏感性与性别、生长地域、年龄及嗜好等都有关系。这为黄酒的风味研究提供了基础数据和科学依据,对企业针对不同人群的产品研发具有指导作用。     

Effect of sulphur dioxide and must extraction on colour,phenolic composition and sensory quality of red table wine

Red wines were made during 1992 from Vitis vinifera var Roriz grapes using a high and a low level of extraction and three levels of total sulphur dioxide (0, 75 and 150 mg SO₂ kg⁻¹). From this single experiment, the effects of total SO₂ and extraction on anthocyanin composition and colour were observed by HPLC, spectrophotometry and tristimulus colorimetry. High extraction produced a wine with more total pigments and total phenols than low extraction and increased the amount of organic acids extracted during fermentation. More anthocyanins were extracted with increasing SO₂ levels. On maturation, all wines lost colour and increased in brownness. Wines made without SO₂ browned more than the wines made with SO₂. The anthocyanins normally present in wines were all rapidly lost to trace levels at 24 months. Vitisin A, a more stable and highly coloured anthocyanin than malvidin 3-glucoside, showed a slower decrease in concentration than malvidin 3-glucoside and contributed significantly to the wine colour during aging. At the first analysis, the wines made without SO₂ had a higher percentage colour due to polymers than the wines made with SO₂. Polymerisation progressed during maturation, although the initial differences were maintained. Sensory analysis after 6 and 18 months storage by expert tasters revealed differences mainly related to the colour attributes, indicating that when wines are made using modern hygienic techniques, total SO₂ has a negligible effect on aroma and flavour attributes. © 1998 Society of Chemical Industry.     

武陵山区葡萄酒品质及感官分析研究

根据国家标准分析了酵母辅助发酵（甲）与自然发酵（乙）两种工艺的葡萄酒的理化指标（糖度、酸度、酒精度和固形物含量）,并进行了微牛物指标的检测,并对其营养元素（钾、钠、镁、钙、锌、铁、铜等）、蛋白质、氨基酸和感官进行了分析。结果表明：两种葡萄酒的各项理化指标均在国家标准规定范围之内,其中甲的固形物含量高出乙5．36％;两种葡萄酒的微,丰物指标均能达到国家标准要求;甲的各种矿物质含量均比乙高,蛋白质含量也高出35．90％,氨基酸含量甲（35．4g／100mL）比乙（33．2g／100mL）高,且铁铜含量均在国家标准规定范围之内;通过观察和品尝,甲的色泽较乙好,且酒香较浓郁。通过对武陵山区葡萄酒的品质和感官的分析研究,为以后的理论研究提供实验数据,同时也为武陵山区葡萄酒大规模的牛产奠定理论基础。     

Dairy Ingredients effects on sausage sensory properties studied by principal component analysis

The effects of dairy ingredients (1, 3, 5%)–ordinary and high-viscosity sodium caseinate, skim-milk powder, whey protein or demineralized whey powder–on sensory properties and instrumental texture and color of sausages, were investigated. Sausages were formulated with 2 or 4% potato starch and cooked to a core temperature of 76 or 82°C. Principal component analysis (PCA) revealed three dominating factors for sensory properties; the first related to dairy ingredients and starch concentrations, the two others to type of dairy ingredients. Results were verified by analysis of variance (ANOVA). Results of sensory analysis were further verified by textural and color analysis using PCA and ANOVA, respectively.     

Effect of using bentonite during fermentation on protein stabilisation and sensory properties of white wine

The bentonite use to remove proteins from white wine is a widespread practice that prevents protein haze formation after bottling. However, an excess of bentonite can have negative effects on both the aromatic profile of young white wines and the quality of the foam of sparkling wines. Therefore, the optimisation of bentonite amount to be used and the moment of its application during winemaking to minimise wine quality losses are of great interest for winemakers. This paper analyses how applying an equal bentonite dose at different stages (must clarification; beginning, middle and end of fermentation) on two scales (industrial and pilot) affects the protein content and stability, physical–chemical characteristics, aromatic profile and foam quality of the obtained wines. No important differences in the oenological parameters were observed between industrial and pilot scales, whereas the scale of the experimental treatments affected protein stability, aroma composition and foam quality of the wines.     

Reliability of the sensory analysis data of a panel of tasters

A method, the quantum measurement technique, is described which, by means of the conceptualisation of the information underlying a set of data which are considered as manifestations of a latent variable or theoretical construct, allows one to detect which are the data in sensorial analysis that, after obtaining a measure, do not fit the formulated conception. The theoretical foundation, based on Rasch probability and item response theory (IRT), detects and quantifies by means of the misfits the data that respond to unexpected scores. A detailed analysis of their residuals aids in finding the causes of these misfits. The technique is applied to the data of a tasting panel that form part of the sensory evaluation of virgin olive oil. © 2000 Society of Chemical Industry     

红枣酒发酵动力学研究

以陕西榆林地区黄河滩枣为原料,用酿酒酵母(Saccharomyces cerevisiae)EX1118低温浸渍发酵,进行了红枣酒发酵动力学研究。通过测定发酵过程中的生物量、酒精含量、总糖含量,并应用Logistic模型、Sgompertz模型、Boltzmann模型及DoseResp模型对其进行拟合,分别建立菌体生长模型、底物消耗模型、产物生成模型,模型反应了酿酒酵母发酵产生酒精的过程的动力学特征。通过分析模型发现,酵母在前96h内处于生长对数期,产酒精及糖消耗速度都较快;在96h之后酵母菌进入稳定期,糖消耗速度缓慢,132h后酒精生成量趋于稳定,在168h时酒精含量达到最大值11.7%vol。因此在生产上可以根据酿酒酵母生长趋势控制发酵工艺,提高酒精产量,缩短发酵时间等。     

Dependence of wine sensory attributes on vine water status

The dependence of wine sensory attributes on the water status of the source vines was determined following vineyard irrigation treatments which included early and late season water deficits and continually irrigated vines. In both seasons, the experimental wines made from the different irrigation treatments did not differ in the concentration of residual sugar or ethanol, titratable acidity, or pH. The concentrations of anthocyanins and total soluble phenolics in the wines were greater from water deficit treatments than from continually irrigated vines. For sensory evaluation, a novel protocol for paired comparisons was developed to test separately for differences in wine appearance, flavour, taste and aroma; differences were detected for each wine comparison. In both seasons, continually irrigated wine differed from early and late season water deficit wine, and early season water deficit wine differed from late season water deficit wine in appearance, flavour, taste and aroma. The sensory differences were not attributable to differences in vine yield or fruit maturity. When professional wine tasters were sampled using similar tests, a majority was able to detect visual but not flavour differences between a selected pair of wines. It is concluded that, where vine water status can be altered, irrigation offers a means to manipulate wine sensory characteristics in the vineyard.     

Proximate composition and sensory evaluation of anthocyanin‐rich purple sweet potato (Ipomoea batatas L.) wine

Purple sweet potato (PSP) is a special type of sweet potato having high anthocyanin pigment in the root. The starch contents of PSP (root/water homogenised in 1:1 ratio) were enzymatically saccharified [using commercial thermostable enzymes Termamyl^® (0.2%) and Dextrozyme^®GA (1%)] to fermentable sugars, and the filtrate was ameliorated with cane sugar to achieve 20° Brix, for subsequent fermentation into a red wine using 2% yeast (Saccharomyces cerevisiae) as starter culture. The wine had the following proximate compositions: total soluble sugar (TSS), 2.25° Brix; starch, 0.15 g per 100 mL; total sugar, 1.35 g per 100 mL; TA, 1.34 g tartaric acid per 100 mL; phenol, 0.36 g (caffeic acid equivalent) per 100 mL; anthocyanin, 55.09 mg per 100 mL; tannin, 0.64 mg per 100 mL; lactic acid, 1.14 mg per 100 mL; ethanol, 9.33%(v/v); and pH, 3.61. 2, 2‐Diphenyl‐1‐picrylhydrazyl (DPPH) scavenging activity of the wine was 58.95% at a dose of 250 μg mL^?1. Principal component analysis reduced the eleven original analytical and proximate variables (TSS, starch, total sugar, TA, phenol, anthocyanin, tannin, lactic acid, ethanol, pH, DPPH) to four independent components, which accounted for 76.65% variations. Sensory evaluation was carried out by sixteen trained panellists on various attributes such as clarity, colour, viscosity, odour, flavour, spritz and finish. Independent ‘t’ test confirmed that all the sensory attributes of the PSP wine scored closely (within 10% variation) to that of a commercial grape wine. The red wine produced contains essential antioxidants and acceptable sensory qualities.     

Effect of Colletotrichum acutatum ripe rot on the composition and sensory attributes of Cabernet Sauvignon grapes and wine

Background and Aim:  The impacts of the fungal bunch rot pathogen Colletotrichum acutatum (ripe rot) on grape growing are documented; however, little is known about how the disease affects the resulting wine. This work aimed to investigate how ripe rot affects wine composition and sensory properties.
Methods and Results:  Wine was made using Cabernet Sauvignon grapes grown in the Hastings Valley (NSW). Berries with ripe rot tended to shrivel and acquired a distinctive off flavour and bitterness, described as hessian sack and musty. Wine made from the infected fruit had a higher pH and a higher level of residual sugar, but lower titratable acidity. Volatile acidity in wine made from uninfected fruit was 0.57 g/L, but increased to 0.83 and 1.06 g/L with 1.5 and 3% infection, respectively. Wine made from infected fruit had higher levels of both glycerol and gluconic acid indicative of fungal contamination. Alcohol concentration was also higher in wine made from infected fruit. Sensory analysis indicated that wine made from as low as 3% infected fruit had a similar colour density to control fruit, but a distinctive off-flavour, and browner colour hue.
Conclusions:  As far as we are aware of, this is the first report of a correlation between the level of grape infection by C. acutatum and wine composition in Australia.
Significance of the Study:  These results underline the problems of red grapes infected with C. acutatum . It provides viticulturists and winemakers with information to be considered when assessing grape quality and winemaking process for red wines.     

Comparative assessment of talc slip using a sensory analysis technique

A technique was developed to evaluate the relative slip of ten test talcs and two control talcs (one with known good slip and one with known poor slip properties). The study was conducted under double-blind conditions with a naive panel of 19 subjects, who with minimal training ranked the 12 talcs. The rankings identified were in line with expectations. Such sensory analysis could be applied in this cost-effective manner to the evaluation and comparison of many properties of cosmetics and toiletries.     

枸杞酒发酵菌种的筛选及其香气分析

为筛选一株适合枸杞酒生产的酵母菌,考察活性干酵母K1、DSM、BY、DV10、EC118和安琪酵母的发酵能力,选择产酒精能力和产酒香乙酸异戊酯能力较强的安琪酵母、BY酵母和EC118酵母,进一步测定酒样中枸杞香气成分含量。采用气-质联用技术分析不同枸杞酒的香气成分,发现BY酵母的枸杞香气成分含量达到12.56mg/L,是安琪酵母和EC118酵母的1.44倍和1.91倍。综合考虑发酵能力和酒样的枸杞香气成分含量,选择BY酵母作为生产枸杞酒的菌种。