几种下胶材料对干红葡萄酒澄清效果及品质的影响

研究不同下胶材料对酒的理化指标、澄清稳定效果及感官的影响,确定最佳下胶方案。选用皂土DC、复合皂土ACT、皂土NC、蛋清粉、土豆蛋白、豆类蛋白、有机澄清剂共计7种材料进行下胶,比较其对干红葡萄酒的澄清效果、热稳定性及品质的影响以及指标的显著性(P <0. 05)。结果显示,皂土DC和皂土NC的澄清效果显著,对干红葡萄酒的热稳定性提升最大,但对酒体质量的损失(理化指标、感官品评)相对其他材料较大;有机澄清剂、蛋清粉、土豆蛋白和豆类蛋白对酒体质量的损害最少,但酒的热稳定性差。综合比较,复合皂土ACT澄清稳定、热稳定效果较好,对酒体质量的影响较小,较符合实际生产的相应标准,可做下胶的首选材料。这一研究结果可为宁夏产区干红葡萄酒的澄清稳定工艺起到指导意义。     

蛋清粉对葡萄酒的澄清效果

了解蛋清粉对葡萄酒澄清效果的影响,为梅鹿辄干红葡萄酒下胶澄清提供一定理论依据;以产自焉耆盆地的梅鹿辄葡萄酿造的梅鹿辄干红葡萄酒作为试材,选取蛋清粉作为下胶澄清剂,研究蛋清粉的添加量和下胶澄清时间对葡萄酒澄清度的影响,并对原酒的色泽、色调、可溶性固形物、pH和总酸等进行检测分析;结果表明,所有处理组经过下胶澄清后,酒样的澄清效果显著提高(p0.05),色度值降低、色调值升高;以蛋清粉为梅鹿辄干红葡萄酒的澄清剂对酒体的可溶性固形物、p H和总酸影响不显著(p0.05)。最佳蛋清粉添加量为60 mg/L,下胶澄清时间为36 h。     

干红葡萄酒下胶澄清后两种分离方式的比较

结合实际生产需要,研究红葡萄酒下胶澄清后两种分离方式对酒的感官和理化指标的影响。试验证明两种分离方式对酒的感官和理化指标几乎没有差别,干红葡萄酒在下胶澄清后采用离心的方式分离悬浮颗粒比过滤方式更能提高容器的利用率,缩短生产周期和降低运行成本。     

桃红葡萄酒下胶材料的筛选

下胶工艺对桃红葡萄酒最终感官质量具有重要意义。通过对11种下胶材料加入桃红葡萄酒后的研究分析,结果表明,皂土3号、皂土4号和NaCalit皂土效果良好;对该3种下胶材料对桃红葡萄酒下胶澄清效果的进一步比较分析。结果表明,德国Erbsloeh公司的NaCalit皂土对桃红酒色度影响较小,澄清度好,酒脚含量小而且紧实,感官分析评价很好,热稳定性合格,是桃红葡萄酒最简易高效的下胶材料。     

两种葡萄酒澄清剂的效果及用量

葡萄酒是一种胶体溶液,含有各种胶体物质,如蛋白质、丹宁、重金属复合物、色素和果胶质等物质,虽然含量很低,但对葡萄酒澄清及稳定有很大影响。因此,在葡萄酒中添加明胶、皂土和蛋清等澄清材料,与葡萄酒中的胶体物质相互作用,除去葡萄酒中的各种胶体物质,以达到葡萄酒澄清的效果。通过小型实验,研究干红葡萄酒的下胶,主要是皂土和明胶对干红葡萄酒质量、感官的影响及澄清效果的影响,确定最佳下胶方案。结果表明,明胶比皂土的澄清效果好,最佳下胶方案为:明胶最佳用量为60 mg/L。     

下胶剂对起泡葡萄酒热稳定性及质量的影响

试验选用普通皂土、钠-钙复合皂土、起泡葡萄酒专用下胶剂三种不同的下胶剂,比较其对起泡葡萄酒的热稳定性及质量的影响。结果发现,普通皂土、钠-钙复合皂土、起泡葡萄酒专用下胶剂三种下胶剂的合适浓度范围分别为:0.8~1.0 g/L、0.6~0.8 g/L、02~0.4 g/L;起泡葡萄酒专用下胶剂的澄清效果最好,对气泡质量的提升效果最大,对酒体感官质量的损害最少,是起泡葡萄酒下胶的首选材料。     

不同澄清剂对葡萄酒澄清效果及葡萄酒品质的影响

本试验从澄清后葡萄酒的澄清效果及下胶处理后酒样的部分理化指标等方面比较研究了明胶和皂土（或明胶和皂土配合使用）、蛋清粉、明胶＋蛋清蛋白、植源胶、蛋清蛋白对葡萄酒的澄清效果,确定了不同澄清剂的最佳使用剂量。结果表明,明胶＋蛋清蛋白、植源胶在起到澄清作用的同时,葡萄酒综合理化指标及感官质量明显优于其它几种澄清剂法,最佳澄清剂量为明胶＋蛋清蛋白90mg／L,植源胶80mg／L。     

不同澄清剂对葡萄酒澄清效果及葡萄酒品质的影响

本试验从澄清后葡萄酒的澄清效果及下胶处理后酒样的部分理化指标等方面比较研究了明胶和皂土(或明胶和皂土配合使用)、蛋清粉,明胶+蛋清蛋白、植源胶、蛋清蛋白对葡萄酒的澄清效果,确定了不同澄清剂的最佳使用剂量.结果表明,明胶+蛋清蛋白、植源胶在起到澄清作用的同时,葡萄酒综合理化指标及感官质量明显优于其它几种澄清剂法,最佳澄清剂量为明胶+蛋清蛋白90mg/L,植源胶80mg/L.     

几种下胶材料对桃红葡萄酒热稳定性及质量的影响

选用明胶、蛋清粉、PVPP、皂土和单宁作为下胶材料,比较它们对桃红葡萄酒热稳定性及质量的影响,包括香气、口感和颜色。结果表明,皂土NC对提高桃红葡萄酒稳定性的效果最佳,且酒脚紧实、酒损少,处理后的桃红葡萄酒的质量(香气、口感、颜色)降低程度相对较小,是桃红葡萄酒下胶的最佳材料。     

不同澄清剂对起泡葡萄酒原酒的澄清作用及对香气品质的影响

以自然澄清的起泡葡萄酒原酒（霞多丽）为试材,研究大豆蛋白、皂土、酪蛋白、明胶和聚乙烯吡咯烷酮5?种不同类型下胶澄清剂对酒样澄清度、理化指标、风味成分和感官品质的影响。结果表明,下胶澄清处理可显著提高酒样透光率、降低酒样色度（P＜0.05）,酒样中乙醇体积分数无显著变化,总酸、挥发酸、总糖和总酚质量浓度分别降低0.18～0.30、0～0.09、0.25～1.20?g/L和0.05～0.21?g/L,其中除皂土和酪蛋白对总糖含量影响较大外,各处理间总酸、挥发酸和总酚含量无较大差异;下胶澄清后酒样中香气物质的种类及含量均有所下降,但大豆蛋白处理组中香气化合物含量显著高于其他处理组,主成分分析也印证了这一结果;200?mg/L大豆蛋白处理的酒样澄清透亮,香气浓郁丰富,感官评价最接近自然澄清的对照组,表明新型植物蛋白澄清剂大豆蛋白可用于起泡葡萄酒原酒的下胶澄清。     

Influence of Visual Masking Technique on the Assessment of 2 Red Wines by Trained and Consumer Assessors

ABSTRACT:  During sensory evaluation assessments, visual masking techniques are frequently employed to disguise color differences between samples and minimize perceptual bias. Particularly in wine, the impact of these masking techniques on panelist evaluations has not been well studied. The objective of this study was to study the influence of visual masking techniques on the aroma and flavor assessment of 2 red wines and observe the impact of these techniques on trained and consumer sensory panels. Specific masking techniques included (1) blue wine glass/white illumination; (2) clear glass/red illumination; and (3) clear glass/white illumination. Ten panelists were trained to recognize 7 aroma and flavor attributes, while consumer panelists ( n = 80) evaluated attributes and liking. For the trained panel, the visual masking technique affected only perceived spicy flavor of Syrah ( P ≤ 0.05), with the clear glass/red illumination resulting in more intense spicy flavor compared to the other 2 conditions. Principal components analysis showed that for the 2 red wines evaluated by the trained panel, red illumination resulted in higher spicy attributes and perceived astringency while wines served in blue wine glasses were higher in perceived astringency. For the consumer panel, red illumination resulted in wines higher in perceived astringency and blue wine glasses resulted in wines higher in perceived flavor liking. These results indicated that the visual masking techniques may influence both trained and consumer panel evaluation of aroma and flavor attributes of red wine. However, beyond red wine, this study makes the larger point that the choice of masking technique does impact sensory evaluations.     

甜橙果酒澄清技术研究

甜橙是柑橘属中一个较优良的加工品种,以其酿制的果酒营养丰富,但是果酒的澄清度会影响其品质。为了提高甜橙果酒的品质,通过添加蛋清、明胶、壳聚糖、果胶酶、皂土等不同的澄清剂处理果酒,以透光率作为澄清效果的评价指标,并对处理后的果酒进行酒精度测定和感官评价。结果表明,单一澄清剂对甜橙果酒有澄清作用,其中蛋清、明胶、壳聚糖、果胶酶、皂土最适添加量分别为0.08%、2.0%、0.08%、1.5%和9%,以皂土澄清效果最佳;将明胶及皂土组合得到复合澄清剂,透光率达96.20%,感官评价得分最高为89.6分,对酒精度影响最小。综上,以明胶-皂土的最佳配比明胶2.0%、皂土9%效果最为理想,经过澄清处理后的甜橙果酒呈金黄色,澄清透明,酒体丰满,具有良好的品质。     

杏酒澄清工艺的响应面法优化

以凯特杏为原料酿造杏酒,加入皂土进行澄清处理,在单因素试验基础上,以澄清温度、澄清时间、皂土添加量为变量,以透光率为响应值,用响应面分析法进行澄清工艺的优化,并对澄清后杏酒的稳定性、理化指标和感官特性进行测定。结果表明,杏酒的最佳澄清工艺为澄清温度24 ℃、皂土添加量0.5 g/L、澄清时间2.5 d。在此澄清工艺下,杏酒透光率可达97.60%,澄清后杏酒稳定性良好,还原糖由4.52 g/L降至3.75 g/L,总酸由5.25 g/L降至4.69 g/L,酒精度由14.7%vol降至13.2%vol,总酚含量由169.25 mg/L降至142.38 mg/L,蛋白质含量由1.18 g/L降至1.06 g/L。澄清后的杏酒澄清透明,有光泽,香气更加优雅,酒体更加平衡,感官评分由79分升至87分。     

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.     

Computer-aided Optimization of Wine Blending

An objective method was developed to blend wines for standardizing flavor quality. Aroma volatiles of varietal and white stock wines, and the target wine were analyzed by equilibrium gas headspace chromatography. Similarity of the aroma profiles of the varietal and stock wines to the target wine was calculated from GC peak areas. The simplex optimization program carried out computational bleeding to determine the ratios of the varietal and white stock wines that would be required to simulate the aroma of the target wine. For two blending experiments, the computer optimized blend could not be differentiated from target wine by a sensory taste panel.     

Freeze-dried grape skins by-products to enhance the quality of white wines from neutral grape varieties

Wastes generated by the wine industry (grape marc), mainly residues from white wine vinifications, are an important source of aroma and phenolic compounds. However, grape marcs are highly perishable and seasonal products, so they require an adequate conservation method. In this respect, freeze-drying, versus conventional drying methods, is a good alternative since this technique preserves the quality of the raw material. Specifically, freeze-drying hardly caused losses of characteristic grape variety volatiles, such as terpenes and C₆ compounds, neither increases in the concentration of furan compounds. Furthermore, freeze-dried grape skins obtained from residues did not presented changes in the amounts of phenolic compounds with respect to the fresh skins. On the other hand, skin-contact treatment with Muscat freeze-dried skins enhanced the aroma of white wines made from Airén grapes, a variety considered neutral, without affecting negatively their color. Skin-contact treatment preserved the wine fruity notes, although the only wine that conserved floral notes in its flavor profile was that macerated with freeze-dried skins. Also, these wines were better rated by the assessors than those macerated with Muscat fresh skins.     

Sensory attribute evolution in bottled young red wines from Rioja Alavesa

The evolution of 19 bottled young red wines from Rioja Alavesa was studied through 9 months. Twenty-four sensory attributes (including appearance, aroma, flavor, taste and mouth-feel) were evaluated at four times (at 1, 3, 5 and 9 months after bottling) by a ten-member panel. Fifteen physicochemical parameters were also analyzed at these four times. Effect of winemaking process (carbonic maceration vs. destemming), and grape variety (only Tempranillo vs. Tempranillo with a white variety) on wine evolution was considered too. Data were analyzed by analysis of variance. Nine sensory attributes changed significantly through the time: red berry aroma and flavor, body, balance, purple hue and color intensity increased, whereas alcoholic aroma and flavor, and astringency decreased. Almost all the physicochemical parameters changed significantly through the time. The winemaking process and the addition of white grapes did not influence sensory and physicochemical evolution.