红枣果汁果渣与果酒果渣膳食纤维功能特性的比较研究

为了探究红枣果汁果渣与果酒果渣膳食纤维功能特性的差异,以红枣果汁果渣和果酒果渣为原料制备膳食纤维,通过测定膳食纤维的持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力,评价红枣果汁果渣与果酒果渣膳食纤维的功能特性。结果表明:红枣果酒果渣膳食纤维的持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力均显著高于果汁果渣膳食纤维(P<0.05),且随发酵天数延长,红枣果渣膳食纤维的功能特性均逐渐增加。发酵8 d时,果酒果渣膳食纤维持水力、膨胀力、溶解性、持油力、阳离子交换能力以及吸附胆固醇、胆酸钠、葡萄糖能力较果汁果渣膳食纤维分别提高了1.10、1.11、1.75、1.39、2.03、1.49、1.10和1.83倍,表明发酵有助于提高红枣果渣膳食纤维的功能特性。     

皂土、硫酸处理对苹果汁发酵过程中果胶甲酯酶活性以及苹果蒸馏酒甲醇含量的影响

新鲜苹果汁分别采用皂土、硫酸处理后,经酿酒酵母（Saccharomyces cerevisiae）发酵获得苹果基酒,经二次蒸馏制备苹果蒸馏酒。研究苹果汁发酵过程中果胶甲酯酶（PME）活性及甲醇含量的变化,探究皂土、硫酸处理对苹果蒸馏酒中甲醇含量、风味物质及感官品质的影响。结果表明,皂土和硫酸处理苹果汁PME活性在发酵4 d后分别降低90.48%、91.75%,均未检出甲醇。与对照相比,皂土和硫酸处理的苹果基酒PME活性分别降低33.18%与24.71%,甲醇含量分别降低37.76%与30.88%;皂土和硫酸处理的苹果蒸馏酒甲醇含量分别降低47.46 mg/L、34.86 mg/L;酯类物质总含量分别提高145.73 mg/L、38.51 mg/L;醇类物质总含量分别提高144.04 mg/L、降低530.79 mg/L;总挥发酸含量分别降低50.18 mg/L、61.90 mg/L。皂土处理蒸馏酒感官评分最佳（91.3分）。综上,2种处理均可有效降低苹果蒸馏酒甲醇含量,皂土处理可以显著提高苹果蒸馏酒的品质。     

杏汁发酵与杏皮渣发酵对杏酒香气质量的影响

为优化杏酒的发酵工艺,提高杏果的综合利用价值,减少资源浪费和环境污染,以杏汁和杏皮渣为原料,分别加入两种酵母进行发酵,比较发酵工艺对杏酒基本理化指标、香气物质和感官特性的影响。采用4 种发酵工艺,工艺1为杏汁＋酵母BV818,工艺2为杏汁＋酵母CECA,工艺3为杏皮渣＋酵母BV818,工艺4为杏皮渣＋酵母CECA。用气相色谱-质谱测定杏酒中的香气物质,并对杏酒进行感官评价。在杏酒中共检测出41 种香气物质,包括酯类29 种、醇类5 种、醛类2 种和萜烯类5 种,其中酯类物质种类最多,且含量最高,占香气总量的72.7%。在工艺1～4的酒样中,香气总量分别为14 765.27、15 034.37、12 580.27 μg/L和7 347.61 μg/L,用杏汁发酵的杏酒中香气总量显著高于用杏皮渣发酵的杏酒。在4 种工艺酒样中均能检出且气味活性值大于1的香气物质为杏酒的特征香气物质,共有6 个,分别为辛酸乙酯、己酸乙酯、乙酸异戊酯、芳樟醇、癸酸乙酯和丁酸乙酯。主成分分析结果显示,工艺2的酒样与乙酸异戊酯、丁酸乙酯、己酸乙酯、辛酸乙酯和芳樟醇5 种特征香气物质处于同一象限,说明该酒样具有杏酒的典型香气特征。感官评价结果显示,杏酒具有杏、桃、柑橘、苹果、梨等果香和槐花、金银花等花香,采用工艺2酿造的杏酒,感官评分最高。结论：用杏汁发酵的杏酒,香气物质含量较高,以果香和花香为主,酒体轻盈,口感清爽,而用杏皮渣发酵的杏酒,总酚含量较高,香气复杂,酵母味明显,酒体饱满。本研究为杏酒发酵工艺的优化提供技术支持,也为进一步研究杏酒香气物质的合成提供理论依据。     

Comparison of fining red wines with purified grape pomace versus commercial fining agents: effect on wine chromatic characteristics and phenolic content

The large quantity of grape pomace (seeds, skin, and peduncle) produced during the winemaking process can be a problem and the search for procedures which could permit their valorisation is considered an important issue. This study investigates the use of purified grape pomace as a fining agent for reducing the level of some wine phenolic compounds, especially tannins. For this, purified grape pomace was applied to three young red wines of different phenolic composition and the results were compared with the effect of some common commercial fining agents. The results demonstrated that grape pomace can be used to decrease the wine tannin content with similar results to those obtained with casein, while also reducing anthocyanin content although to a similar extent to when bentonite is used. The effect of purified Monastrell grapes pomace is similar in the three different studied wines although it affected the most to wines with high monomeric anthocyanin content.     

Fining of Red Wines with Pomace Cell Wall Material: Effect on Wine Phenolic Composition

Fining is a winemaking technique used to remove unwanted wine components that affect clarification, astringency, color, bitterness, and aroma. One of the objectives of fining is often to reduce the wine tannin content due to its effect on wine astringency. Proteinaceous agents are commonly used with this objective, but problems related with their possible allergenic properties or the excessive enrichment of wine with proteins, which may cause stability and turbidity problems, have led to the search for new fining agents. In this way, the cell wall material from processed grape pomace could be a good alternative since it has a high affinity for tannins. In this work, the effect of cell wall material from processed pomace from Monastrell and Cabernet Sauvignon grapes on the reduction of the phenolic content of red wines is studied and the results are compared with those obtained with commercial fining products. Also, the varietal effect due to the different composition of the cell wall material from these two varieties has been evaluated. The concentration and composition of wine anthocyanins and tannins, before and after the fining process, were analyzed by HPLC and their molecular mass distribution by SEC. The results showed that, at laboratory scale, pomace cell walls have a fining effect that exceeds that of most the protein-based fining agents, even when used at their highest recommended doses. The cell wall material significantly reduced the wine phenolic content, the reduction ranging from 48 to 68% for anthocyanins and from 44 to 64% for tannins, although varietal differences exist regarding the cell wall-binding capacity. Monastrell cell walls exhibited the highest capacity and could be used at much lower doses than those used in this study, reducing the formation of lees and the wine adsorbed on them. The results indicate that this material could be an appropriate alternative for protein-based fining agents in red wine and their use would avoid allergen-related effects.     

壳聚糖和酵母甘露聚糖对蓝莓酒单宁特性及品质的影响

为探究壳聚糖和酵母甘露聚糖对蓝莓酒单宁特性、理化指标、香气成分及感官品质的影响。通过比色法测定单宁的含量及平均聚合度,并运用高效液相色谱法（HPLC）和气相色谱-质谱（GC-MS）技术分析蓝莓酒中的有机酸和挥发性香气成分。结果表明,添加多糖后蓝莓酒中单宁的含量和平均聚合度较未添加多糖显著增加（P＜0.05）。酵母甘露聚糖组蓝莓酒中乳酸的含量最高,为1.15 g/L。香气成分GC-MS分析表明,酵母甘露聚糖组的香气成分种类（35种）和质量浓度（205.65 mg/L）均最高,主要是乙酸乙酯、月桂酸乙酯、香茅醇、α-松油醇、苯乙酸、β-大马士酮等物质。感官评价结果表明,酵母甘露聚糖组的涩感最弱,圆润度和香气浓郁度最高。综上可知,添加酵母甘露聚糖比添加壳聚糖更适合蓝莓酒的酿造。     

香梨酒中甲醇产生的原因及控制方法研究

采用库尔勒香梨清汁、带肉果汁、果渣在相同条件下发酵,分离得香梨酒,测定甲醇含量高低依次为果渣、带肉果汁、清汁,结合原料中的果胶含量测定,得出原料中果胶是甲醇产生的主要原因。为控制香梨酒中的甲醇含量,选取果胶酶处理、氯化钙处理、发酵温度、发酵时间4个因素进行正交试验,得出香梨清汁中添加0.3%果胶酶和0.2%的氯化钙除去果胶,20℃发酵21d,所得香梨蒸酒的甲醇含量最低。     

蓝莓酒发酵过程中主要成分变化规律研究

研究了蓝莓酒主发酵过程中总糖、总酸、挥发酸、花色苷、单宁、乙醇、甲醇、高级醇和酯等主要物质含量的变化。结果表明,蓝莓通过加糖9.6%发酵,原酒酒精度可达到11.8%(体积分数),总酸7.53g/L,pH2.95;花色苷含量逐渐减少,发酵结束后达0.615g/100g;单宁含量变化较小;挥发酸含量随着发酵时间的延长而逐渐上升,主发酵期间上升较快,但最终可控制在国标(≤1.2g/L)允许范围以内;甲醇在刚开始发酵时就存在,发酵前期略有上升,后略有下降,含量相对稳定;高级醇中的异丁醇和苯乙醇是蓝莓酒的主要香气成分,约占香气成分的60%以上,苯甲酸乙酯、乙酸乙酯、己酸乙酯、癸酸乙酯是蓝莓酒香气的主要成分,在发酵过程中高级醇和酯都不断增加,发酵过程中还检测到一些未知成分。     

皂土处理对葡萄酒发酵及质量的影响

以霞多丽和玫瑰香为原料,通过优化和添加两种皂土处理方式,研究皂土对酒精发酵和葡萄酒质量的影响。结果表明:添加处理可增加葡萄汁中不溶性固形物含量,对最大发酵速率和总发酵时间及葡萄酒组分无明显影响;优化处理可提高葡萄汁的澄清度,降低发酵速率,延长总发酵时间,使葡萄酒的残糖含量较高。无论是添加处理还是优化处理均对葡萄汁的氨基氮含量无明显影响,因此在优化葡萄汁中添加氮素营养不能扭转发酵缓慢现象。     

Detection of pectinmethylesterase activity in presence of methanol during grape pomace storage

Methanol is an unwanted component in the production of spirit beverages. Its presence in grape pomace stored until distillation greatly affects the composition of the final product, which requires redistillation, modifying the aromatic characteristics of the distillate. Consequently, reduction of methanol, by controlling its formation during pomace storage, can increase the quality of grappa. The aim of this work was to monitor pectinmethylesterase activity during grape pomace storage, in order to identify its presence related to methanol release. The enzyme activity was detected during various storage times by spectrophotometric and electrophoretic methods. Results show that yeasts do not contribute to PME production. Moreover, by using paranitrophenyl acetate, a specific substrate for esterase, also as PME substrate, we demonstrate the presence of several enzymes hydrolysing ester bonds.     

Yeast and bacterial modulation of wine aroma and flavour

Wine is a highly complex mixture of compounds which largely define its appearance, aroma, flavour and mouth‐feel properties. The compounds responsible for those attributes have been derived in turn from three major sources, viz. grapes, microbes and, when used, wood (most commonly, oak). The grape‐derived compounds provide varietal distinction in addition to giving wine its basic structure. Thus, the floral monoterpenes largely define Muscat‐related wines and the fruity volatile thiols define Sauvignon‐related wines; the grape acids and tannins, together with alcohol, contribute the palate and mouth‐feel properties. Yeast fermentation of sugars not only produces ethanol and carbon dioxide but a range of minor but sensorially important volatile metabolites which gives wine its vinous character. These volatile metabolites, which comprise esters, higher alcohols, carbonyls, volatile fatty acids and sulfur compounds, are derived from sugar and amino acid metabolism. The malolactic fermentation, when needed, not only provides deacidification, but can enhance the flavour profile. The aroma and flavour profile of wine is the result of an almost infinite number of variations in production, whether in the vineyard or the winery. In addition to the obvious, such as the grapes selected, the winemaker employs a variety of techniques and tools to produce wines with specific flavour profiles. One of these tools is the choice of microorganism to conduct fermentation. During alcoholic fermentation, the wine yeast Saccharomyces cerevisiae brings forth the major changes between grape must and wine: modifying aroma, flavour, mouth‐feel, colour and chemical complexity. The wine bacterium Oenococcus oeni adds its contribution to wines that undergo malolactic fermentation. Thus flavour‐active yeasts and bacterial strains can produce desirable sensory results by helping to extract compounds from the solids in grape must, by modifying grape‐derived molecules and by producing flavour‐active metabolites. This article reviews some of the most important flavour compounds found in wine, and their microbiological origin.     

Flavonoids and C13-norisoprenoids in Vitis vinifera L. cv. Shiraz: relationships between grape and wine composition,wine colour and wine sensory properties

Background and Aims: This study investigated flavonoid composition and C₁₃-norisoprenoids (β-damascenone and β-ionone) in Shiraz grapes and wines, their relationships and links to wine sensory properties. Methods and Results: Differences in the grape berry flavonoid profile were created by exposing bunches to varying levels of sunlight intensity through canopy manipulation. Grapes were harvested at similar maturity and three replicate wines were made for each treatment in both vintages. Grapes produced under shaded canopy conditions had reduced anthocyanins and skin tannins, but little effect on seed tannins was observed. Pigmented polymers and tannins in wines were related to berry flavonoid composition (anthocyanins, skin and seed tannins, and their ratios). In grapes and wines, no significant effects were observed in response to canopy manipulation for two hydrolytically released C₁₃-norisoprenoids, β-damascenone and β-ionone. Relationships were established for wine flavonoid composition, wine colour density, sensory perception of the astringency-related mouth-feel attributes and a quality scale. A positive relationship between wine quality score and hydrolytically released β-damascenone in both berries and wines was found, but not for free β-damascenone or any quantified forms of β-ionone. Conclusion: Higher concentrations of anthocyanins and skin tannins in berries, coupled with a lower concentration of seed tannins were associated with higher wine quality. The ratio anthocyanins*skin tannins/seed tannins is proposed as an indicator of wine flavonoid composition, wine colour and wine quality. Excessive canopy shade was detrimental to berry and wine composition and intensified sensory detection of ‘straw’ and ‘herbaceous’ characters in the wines. Significance of the Study: This study increases the understanding of the balance and composition of flavonoid compounds and C₁₃-norisoprenoids in berries and their relationship with wine composition and wine sensory properties, but also highlights the importance of a canopy microclimate assessment.     

甘露糖蛋白对‘赤霞珠’葡萄酒中糖酸和香气的影响

为进一步探究甘露糖蛋白对葡萄酒感官品质的影响,以'赤霞珠'葡萄为原料酿造葡萄酒,分别在其酒精发酵前和酒精发酵后添加不同量的甘露糖蛋白,在酒精发酵结束后放置12个月检测葡萄酒常规理化指标和单体糖、有机酸、香气物质含量并进行感官品评。结果表明,酒精发酵前添加甘露糖蛋白对于葡萄酒感官品质无促进作用,而酒精发酵后添加0.3 g/L甘露糖蛋白可使葡萄酒中果糖含量降低20.7%,苹果酸和酒石酸分别降低4.4%和8.4%,同时成倍提高了香气组分中酯类、醇类的含量,从而提高葡萄酒的感官品质。因此,甘露糖蛋白的添加可作为提高葡萄酒感官品质的处理措施,推荐在酒精发酵后以0.3 g/L的剂量添加。     

Addition of phenolic acids on the reduction of methanol content in wine

ABSTRACT:  Utilization of phenolic acids, including gallic acid, coumaric acid, caffic acid, cinnamic acid, and ferulic acid, for methanol reduction in wine was investigated. Enzyme activities of pectinesterase and pectin lyase decreased significantly when 0.1 mg/L of gallic acid, coumaric acid, caffic acid, cinnamic acid, or ferulic acid was added. However, no inhibition on polygalacturonase activity was observed when 0.5 mg/L of phenolic acid was added. Methanol content in commercial pectic enzyme (CPE) group increased from 11.53 ± 1.34 to 56.67 ± 3.75 ppm in the final products. Adding gallic acid or coumaric acid with CPE inhibited the increase of methanol production. In addition, when 0.2 mg/L of phenolic acid (gallic acid or coumaric acid) was added, the amount of total phenolic acid released from CPE + gallic acid or CPE + coumaric acid groups became higher than CPE group by approximately 466 and 539 mg/L, respectively. In conclusion, the values of lightness, red content, yellow content, total pigment, and total phenolic acid increased in the presence of gallic acid or coumaric acid with CPE, suggesting that adding gallic acid or coumaric acid into winemaking process is a potential method for reducing methanol content, improving wine quality, as well as increasing healthy compounds in wine production.     

百合酒酿造工艺研究

该试验以百合鳞茎为原料制备百合酒,研究初始糖度、酵母菌接种量和发酵温度对百合酒酒精度及感官品质的影响,通过单因素试验和正交试验优化百合酒发酵工艺条件。结果表明,百合酒最佳发酵工艺为初始糖度28 °Bx,酵母菌接种量4%,发酵温度26 ℃,在此最佳发酵条件下,所得百合酒酒精度为10.0%vol,感官评分为85分。澄清试验结果表明,在百合酒中添加1.6 g/L的皂土澄清效果最佳,透光率为99.6%。     

酿酒酵母F15和CC17共接种发酵对赤霞珠葡萄酒品质及感官特性的影响

为解决使用单一商业酵母菌株发酵引起的葡萄酒“同质化”问题,本研究以河北昌黎产赤霞珠葡萄为原料,以商业酿酒酵母（Saccharomyces cerevisiae）F15和本土优良酿酒酵母CC17为发酵剂进行单菌株和双菌株共接种（F15:CC17=1:1）发酵,同时监测酒精发酵过程中比重、温度、残糖、乙醇、总酸、pH、花青素、单宁、总酚、色度和色调的变化。发酵结束（192 h）后,分别对酒的香气成分和感官特性进行了测评。结果表明:与F15单菌株发酵相比,双菌株共接种发酵能够提高赤霞珠葡萄酒中花青素、单宁和总酚含量,增加酒的色度并使色调更趋向于红色;与CC17单发酵相比,共发酵组残糖、总酸含量较低;共发酵调谐主要香气成分,并增加饱和脂肪酸乙酯的含量。此外,感官评价结果表明共发酵葡萄酒色、香、味均优于F15单独发酵。因此,在酒精发酵过程中采用商业酵母与本土菌株共发酵是改善葡萄酒品质和感官特性有效方法。     

果汁发酵和带渣发酵蓝靛果酒香气成分分析

采用顶空固相微萃取和气相色谱-质谱联用技术,分析果汁发酵和带渣发酵两种工艺条件下蓝靛果酒香气成分的不同,为蓝靛果酒加工利用和评价提供理论依据。结果表明:2种不同工艺蓝靛果发酵酒共鉴定出62种香气成分,果汁发酵和带渣发酵各检出39种和50种香气成分,27种是两者共有的。2种蓝靛果发酵酒的主要香气成分都为苯乙醇和辛酸乙酯,其中,果汁发酵酒相对含量分别为23.11%和12.97%,带渣发酵酒相对含量分别为30.27%和16.83%。此外,根据感官评价,带渣发酵的果酒优于果汁发酵,带渣发酵的果酒酒色清澈透明,色泽稳定,口感圆润柔和,香气持久迷人,更具蓝靛果典型性风味。     

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。     

Production of white wine by Saccharomyces cerevisiae immobilized on grape pomace

White wine was produced with Saccharomyces cerevisiae cells immobilized on grape pomace, by natural adsorption. The support, the main solid waste from the wine industry, consisted of the skins, seeds and stems. Immobilization was tested using different media, namely complex culture medium, raw grape must and diluted grape must. Grape pomace was revealed to be an appropriate support for yeast cell immobilization. Moreover, grape must was shown to be the most suitable medium as immobilized cells became adapted to the conditions in the subsequent alcoholic fermentation in the wine‐making process. The wines produced, either with immobilized cells or with free cells, were subjected to chemical analysis by HPLC (ethanol, glycerol, sugars and organic acids) and by gas chromatography (major and minor volatile compounds); additionally, colour (CIELab) and sensory analysis were performed. The use of immobilized systems to conduct alcoholic fermentation in white wine production proved to be a more rapid and a more efficient process, especially when large amounts of SO₂ were present in the must. Furthermore, the final wines obtained with immobilized cells demonstrated improved sensory properties related to the larger amounts of ethanol and volatile compounds produced. The more intense colour of these wines could be a drawback, which could be hindered by the reutilization of the biocatalyst in successive fermentations. Copyright © 2012 The Institute of Brewing & Distilling