Yeast strain affects 3‐isopropyl‐2‐methoxypyrazine concentration and sensory profile in Cabernet Sauvignon wine

Background and Aims: 3‐Isopropyl‐2‐methoxypyrazine (IPMP) is both a grape‐ and insect‐derived trace compound found in wine that can contribute green characters. There has been renewed interest in examining how wine IPMP concentrations can be modulated due to recent concerns regarding ladybug taint – an off‐flavour from IPMP extracted from Harmonia axyridis (Pallas) (multicoloured Asian lady beetle). This study sought to determine the influence of commercial Saccharomyces yeast strains on IPMP concentration in Cabernet Sauvignon wines and to describe their sensory impact. Methods and Results: Rehydrated juice from Cabernet Sauvignon concentrate was spiked with 30 ng/L IPMP and fermented in triplicate by yeast strains Lalvin BM45, Lalvin EC1118, Lalvin ICV‐D21 or Lalvin ICV‐D80. IPMP concentration was determined using headspace solid‐phase micro‐extraction coupled with gas chromatography mass spectrometry (HS‐SPME‐GC‐MS), and was unchanged from juice levels in wine fermented by EC1118, Lalvin D21 and Lalvin D80 but increased by 11 ng/L (29%) in wine fermented by Lalvin BM45. Yeast strains differed in their sensory impact on wine made from IPMP‐spiked juice for five aroma and four flavour attributes. Conclusions: HS‐SPME‐GC‐MS allows for sensitive measurement of IPMP that, for the first time, has demonstrated the capacity for wine yeast to affect IPMP concentration. Yeast strains demonstrate varying ability to mask green or ladybug taint characters in wine. Significance of the Study: This information should be useful in guiding selection of yeast strains for juices of high IPMP concentration, including those that are multicoloured Asian lady beetle‐affected, under‐ripe or from varieties with high methoxypyrazine loads such as Cabernet Sauvignon.     

不同酵母发酵的火龙果酒抗氧化活性及颜色变化

研究4种不同酵母发酵的火龙果酒在发酵过程中总酚、甜菜苷、抗氧化活性和颜色的变化规律。结果表明,在发酵过程中,4种酵母发酵火龙果酒的总酚、甜菜苷含量均呈下降趋势;L*值、a*值均升高,b*值降低。酵母RC212发酵的火龙果酒的多酚含量最高为272.5 μg/mL,其对DPPH自由基清除率IC50最低为22.98%;酵母R2发酵的火龙果酒的羟自由基清除率、总还原力IC50最低,分别为8.84%、28.52%,并且甜菜苷含量最高为581.4 mg/L。酵母RC212与酵母R2发酵的火龙果酒在抗氧化物质含量、抗氧化活性及红色素稳定性方面均优于酵母DV10与酵母D254发酵的火龙果酒。     

A comparison of the influence of eight commercial yeast strains on the chemical and sensory profiles of freshly distilled Chinese brandy

The current study examined eight commercial Saccharomyces cerevisiae strains [Lalvin ICV‐D80, Lalvin FC9 EDV, Lalvin QA23, Lalvin RHST, Uvaferm 43, Enoferm Burgundy (BGY), Lalvin EC1118 and Lalvin M69] for their influence on young brandies, with a special emphasis on chemical, volatile and sensory characteristics. Results of the chemical analysis of the fermented wines showed that all of the strains exhibited a similar performance for ethanol production, but titratable acidity was more variable, with the highest being found in the yeast BGY‐derived wine and the lowest in the yeast QA23‐derived wine. Spirits produced using yeast FC9 EDV showed a significantly higher content of volatile alcohols, esters and acids, and conveyed to the brandy typical fruity and rosy notes. Brandies derived using yeast Uvaferm 43 presented the highest content of total benzene compounds and this brandy was characterized by rosy and onion attributes. Higher levels of varietal compounds and a medium rosy and slightly acidic and rancid nuances were produced when yeast QA23 was used. When using principal component analysis to classify the samples, there were four groups: group 1 ( ICV‐D80, Uvaferm 43 and BGY), group 2 (FC9 EDV), group 3 (QA23, RHST and EC1118) and group 4 (M69). This work sheds some light on the flavour complexity owing to the use of different commercial yeasts and provides useful information for the brandy‐maker regarding the choice of yeast for the fermentation based on the volatile profile. Copyright © 2012 The Institute of Brewing & Distilling     

Antioxidant Properties of Sparkling Wines Produced with β-Glucanases and Commercial Yeast Preparations

The aim of this study was to evaluate the in vitro antioxidant potential of sparkling wines produced with β-glucanases, autolysated yeasts, yeast cell walls, and purified mannoproteins. Total antioxidant capacity (measured by 2,2-diphenyl-1-picrylhydrazyl [DPPH] radical-scavenging method and ferric reducing antioxidant power [FRAP] assay), and hydroxyl radical-scavenging activity (HRSA) were higher in the wine samples with coadjuvants (in relation to the control wine). The highest values of antioxidant activity were achieved with purified mannoproteins and, in lesser extent, with β-glucanases. Neutral polysaccharides and total proteins were highly and positively correlated with DPPH, FRAP, and HRSA assays. However, correlations between the levels of each different phenolic family and antioxidant and radical-scavenging activities were not found. β-Glucanase and commercial yeast preparations can be excellent coadjuvants to increase the antioxidant properties of sparkling wines. Practical Application: β-Glucanase and commercial yeast preparations can be excellent coadjuvants to increase the antioxidant properties of sparkling wines. The suggested improvement has significant implication for the production of high added value sparkling wines.     

酿酒酵母对樱桃酒挥发性组分及感官品质的影响

鉴于酿酒酵母（Saccharomyces cerevisiae）对樱桃酒挥发性香气及感官品质的重要贡献,测定了5种商业化酿酒酵母的产香性能,以期从中挑选适用于樱桃酒酿造的优质发酵剂。结果表明,5种酵母发酵的樱桃酒基本理化指标无差异（P＞0.05）,但是挥发性组分含量却存在显著差异（P＜0.05）。Lalvin 2323与Lalvin 71B能够增加丁酸乙酯、己酸乙酯、苯甲醛、β-大马酮等多种挥发性物质的合成量,赋予樱桃酒更浓郁的果香和花香特征,且Lalvin2323的整体香气比Lalvin 71B更浓郁;Laffort B0123可以提高里那醇、异戊醇、乙酸异戊酯的含量,感官品质也较好;Laffort X16酿造的樱桃酒果香味寡淡,生青气味浓郁,评分较低;Laffort Cervisiae（AC）酿造的樱桃酒整体香气略显不足,评分最低。总体来看,酵母Lalvin2323发酵樱桃酒的感官品质优于其他酵母。     

番木瓜果酒发酵及其抗氧化能力分析

以番木瓜为原料,经破碎、酶解、成分调整后接种葡萄酒活性干酵母,于（22±1） ℃发酵制备番木瓜果酒。研究发酵过程中总糖、还原糖、滴定酸含量与抗氧化能力的变化,明确番木瓜果酒的理化指标与感官品质。结果表明,番木瓜果酒发酵过程中总糖、还原糖含量逐渐降低,滴定酸含量增加,总酚含量、DPPH自由基清除率和亚铁还原能力（FRAP值）降低,pH值变化无规律性。番木瓜果酒酒精度10.7%vol,残糖量4.4 g/L,滴定酸4.5 g/L,总酚含量3.0 g/L,DPPH自由基清除率63.0%,FRAP值2.33 mmol/L,属半干型果酒,抗氧化能力较强,理化与感官品质均符合相关果酒标准要求。     

草莓酒发酵菌种的筛选及工艺优化

以草莓为原料,分别加入10种不同酵母进行草莓酒发酵,筛选出了发酵草莓酒感官得分相对较高的3种酵母：酵母F10、帝伯仕.果酒专用酵母(红)、Lalvin D254酵母。在此基础上,以果酒感官评分为评价指标,酵母种类、发酵温度、菌种添加量为影响因素进行3因素3水平的正交试验优化发酵工艺。试验结果表明：酵母种类对感官评分影响显著(P＜0.01),草莓酒发酵最佳条件为：酵母F10,添加量0.01%,发酵温度为20 ℃,此条件下果酒的感官评分达92.5分,酒精度是12.5%vol。     

Volatile aroma and sensory analysis of black raspberry wines fermented by different yeast strains

Robus coreanus Miquel is a small berry fruit used for Korean black raspberry (KBR) wine‐making. Twelve different yeast strains were investigated by laboratory‐scale fermentation to develop a wine with a high flavour quality. Volatile aroma compounds from the wines were analysed using headspace–solid phase microextraction–gas chromatography–mass spectrometry and sensory evaluation was performed to evaluate the flavour characteristics. The volatile aroma compounds that mostly contributed to the flavour of KBR wines were those related to fruity (esters) and floral (terpenes) aromas. Fifteen out of the 67 identified volatile compounds showed higher odour activity values than other compounds in the wines, and these compounds were considered as important contributors to the final aromas of the wine. Additionally, the KBR wine fermented by the M1 yeast strain had the highest sensory preference because of higher fruity and floral aroma characters compared with other wines. In addition to the M1 strain, the other yeast strains that produced favourable sensory characteristics included Enoferm CSM, Uvaferm VRB, Lalvin ICV GRE, Lalvin ICV Opale and LevureSeche Active. Of these strains, the M1 strain produced a particularly excellent black raspberry wine, and thus could be applied for further large‐scale production of black raspberry wines. It is also expected that this work will expedite research on the production of high‐quality black raspberry wines with beneficial physicochemical properties, functionality and good sensory characteristics. Copyright © 2015 The Institute of Brewing & Distilling     

不同酵母酿造霞多丽干白葡萄酒的发酵性能研究

选用5种商品酵母酿造霞多丽干白葡萄酒,对5种酵母的发酵性能进行比较,测定样品的理化指标和香气物质。结果表明,5种酵母酿造霞多丽干白葡萄酒的理化指标均符合国标,在发酵期的密度变化趋势基本一致,但发酵周期不同;结合固相微萃取和气质联用（GC-MS）检测技术,5种发酵的酒样中分别检出的香气物质33种、31种、36种、34种、29种,主要香气组分没有大的差别,只是在微量香气物质上有所区别。酵母CEC01对葡萄糖的利用率最高,其酿造霞多丽干白葡萄酒酒精度为12.9%vol,残糖含量为1.5 g/L,发酵周期短;检出的香气物质最多（36种）,并且酯类含量最高,占其香气物质总量的35.66%。     

香梨全果果浆与果汁发酵工艺及果酒香气成分分析

本研究以库尔勒香梨为试验原料,研究了EC118、KI、KD三种酵母在全果果浆与果汁发酵过程中发酵醪的基本理化指标,且对香梨果实与6种处理果酒的香气成分进行了分析。三种酵母在全果果浆与果汁发酵过程中各指标总体变化趋势没有表现出处理间差异,但各指标的变化水平存在一定的差异,6种果酒总酚含量为244.62～296.91 mg/L,全果果浆发酵果酒总酚含量高于果汁发酵果酒;EC118、KI、KD全果果浆与果汁发酵果酒香气种类分别为25、30、28、22、23、24,共有香气14种,主要包括醇类、酯类和酸类等,三种酵母中KI、KD酵母发酵产香气能力较优,所得果酒酸度适宜、酒精度高,色泽澄清透亮,全果发酵总酚含量、香气种类均高于果汁发酵,KI酵母香气成分最多,且KI全果果浆发酵果酒总酚含量最高,所以选择KI全果果浆为香梨果酒的最佳菌种及发酵原料。     

三白瓜酒发酵及其香气成分分析（网络首发、推荐阅读）

以山西产三白瓜为主要原料,使用实验室保藏酿酒酵母BH8（编号为B）和商业白葡萄酒酿酒酵母Enarts ES181（编号为E）发酵三白瓜汁并分析发酵酒中的香气成分。研究结果表明,两株酵母都表现出了较好的三白瓜酒发酵性能,发酵至第6天时达到发酵终点,产生的酒精浓度为5.96%（E）,5.50%（B）,残留葡萄糖含量为0.37 g/L（B）和0.30 g/L（E）,果糖含量为2.03 g/L（B）和1.05 g/L（E）,并伴随着总酸含量的增加。采用顶空固相微萃取气质联用法（HS-SPME-GC-MS）,在两种三白瓜发酵酒中共检出47种香气成分,主要为酯类和醇类,酵母B在产酯类风味物质方面相对优势更大。感官品评两种三白瓜发酵酒,酒体协调,具有浓郁的三白瓜果香。实验所选用的酵母可用于三白瓜酒的发酵,三白瓜可开发成三白瓜酒。     

三种甘薯发酵酒抗氧化特性研究

通过测定渝紫263、紫薯王以及豫薯王三种甘薯发酵酒中理化指标和酚类物质含量,以及对铁离子还原能力、DPPH自由基清除能力、羟基自由基清除能力,研究了3种甘薯发酵酒的抗氧化特性。结果显示,三种甘薯发酵酒总酚含量分别为247.5 mg/L、200.5 mg/L、63.5 mg/L,渝紫263发酵酒和紫薯王发酵酒的各项酚类物质含量及铁离子还原能力、DPPH自由基清除能力均明显高于豫薯王发酵酒,且三种甘薯发酵酒的羟基自由基清除均明显高于对照组VC。表明三种甘薯发酵酒均具有较强的抗氧化特性。     

不同酿酒酵母在菠萝果酒中的发酵特性

选取4株不同的酵母(CY3079、DV10、K1、QA23)为研究对象对菠萝皮渣进行发酵,通过对感官评分、色度、酒精度及发酵过程中抗氧化活性等指标进行比较,筛选出一株性能较优的酵母。结果表明:QA23酵母发酵酒的感官评分高达86分,其次是CY3079酵母发酵酒。CY3079、K1和QA23酵母发酵酒L*和b*均高于DV10酵母发酵酒。四种酒酒精度均达10% vol以上;发酵过程中黄酮含量变化相对平稳,多酚含量呈先升后降又上升的复杂变化趋势,抗氧化活性变化与多酚的趋势相近。酵母QA23发酵的菠萝果酒在第6 d时黄酮、多酚含量最高,分别为(0.29±0.021) mg/mL和(455.90±9.87) μg/mL,DPPH和ABTS自由基清除能力IC50值分别达到(4.40±0.29) mg/mL和(0.74±0.03) mg/mL,与CY3079、DV10和K1三种酵母发酵酒相比具有较高的抗氧化活性。QA23是最适合菠萝果酒发酵的酵母,为菠萝皮渣的加工利用提供理论依据。     

不同商品酵母对葡萄酒香气成分的影响

以5种不同商品酵母发酵的赤霞珠干红葡萄酒为原料,采用顶空固相微萃取（HS-SPME）和气质（GC-MS）联用技术对其香气成分进行分析,共检测出66种挥发性化合物,定量分析了各葡萄酒中共有的15种主要香气物质之间的差异。结果表明,不同商品酵母发酵葡萄酒中香气种类差别很小,但含量差别明显。酵母BDX具有较强的高级醇生成能力,其中苯乙醇的含量明显高于其他酵母;酵母BM4×4生成的酯类、高级醇和有机酸的含量均处于中间水平;酵母D254具有较强的酯类生成能力,其中辛酸乙酯和己酸乙酯的贡献最为突出;酵母L2323的乙酸异戊酯生成能力较强;酵母RC212的酯类和高级醇生成量最低。     

11种酵母菌对冬瓜酒品质及抗氧化性的影响

为筛选冬瓜酒专用商业酵母,促进冬瓜酒产业发展,以冬瓜为原料,采用11种酵母发酵冬瓜酒,通过对品质指标、抗氧化性能力及感官评分等指标进行比较,筛选出适合冬瓜酒发酵的最优酵母。结果表明:BV818酵母发酵的冬瓜酒酒精度(12.70% vol)、感官得分最高(90分),残糖最低(6.59 g/L),V_C含量、澄清度较高,酸度、色度适中,具有良好的·OH、O₂-·、DPPH·清除能力,其清除率分别为6.70%、43.25%、45.73%。所得产品口感良好、颜色淡黄、澄清透明,具有冬瓜的清香和酒的醇香。因此,BV818酵母是最适合冬瓜酒发酵的酵母,为冬瓜的加工利用提供了技术支撑。     

不同酵母菌种对发酵海红果酒品质的影响研究

本文研究了三种酵母菌(BV818、ICV254和CY3079)制备的海红果酒在发酵过程中发酵液的基本理化性质、多酚和黄酮的含量及抗氧化能力的动态变化,且对三种发酵酒的香气成分进行了定性分析。在三种酵母发酵海红果酒的过程中各指标总体变化趋势没有表现出酵母间差异,但各指标的变化水平存在一定的差异,三种酵母发酵酒中总酚含量为915.86±5.13~1066.85±16.44 mg/L,黄酮含量为31.60±1.32~42.64±0.45 mg/L,显著高于发酵原液(p0.05),表现出很高的清除DPPH·能力和还原能力;三种酵母发酵酒中共检出24种香气成分,主要包括醇类、酯类和酸类等,三种酵母发酵酒的特征香气均为3-甲基丁醇。在三种酵母中,酵母ICV254的降糖速率最快,发酵时间仅为8 d左右,所得发酵酒的酒精度高、残糖量低、酸度低、感官评分好,同时总酚和黄酮含量高、抗氧化能力最强,且香气成分多,所以选择酵母ICV254为海红果酒的最佳发酵菌种。     

Sweet Wine Production by Two Osmotolerant Saccharomyces cerevisiae Strains

The use of Saccharomyces cerevisiae to produce sweet wine is difficult because yeast is affected by a hyperosmotic stress due to the high sugar concentrations in the fermenting must. One possible alternative could be the coimmobilization of the osmotolerant yeast strains S. cerevisiae X4 and X5 on Penicillium chrysogenum strain H3 (GRAS) for the partial fermentation of raisin musts. This immobilized has been, namely, as yeast biocapsules. Traditional sweet wine (that is, without fermentation of the must) and must partially fermented by free yeast cells were also used for comparison. Partially fermented sweet wines showed higher concentration of the volatile compounds than traditionally produced wines. The wines obtained by immobilized yeast cells reached minor concentrations of major alcohols than wines by free cells. The consumption of specific nitrogen compounds was dependent on yeast strain and the cellular immobilization. A principal component analysis shows that the compounds related to the response to osmotic stress (glycerol, acetaldehyde, acetoin, and butanediol) clearly differentiate the wines obtained with free yeasts but not the wines obtained with immobilized yeasts.     

Influence of different yeasts on the growth of lactic acid bacteria in wine

The influence of various yeasts on the growth of lactic acid bacteria in wine was tested by inoculating Lactobacillus hilgardii, L. brevis and two strains of Leuconostoc mesenteroides into experimental wines made with twelve different yeasts of the genus Saccharomyces. Wines made from juice which had been infected with several spoilage yeasts and then fermented with a wine yeast were also tested in this way. It was found that the yeasts differed considerably in their effects on bacterial growth. In some of the experimental wines bacterial growth was delayed or failed altogether. Generally, the unfavourable influence of any yeast on bacterial growth was much reduced if the wines were left in contact with the yeast cells for some weeks after the fermentation. The significance of these results in relation to the occurrence of malo-lactic fermentation in commercial wineries is discussed.     

Post-harvest control of wine-grape mycobiota using electrolyzed water

Electrolyzed water (EW) has recently attracted much attention due to its efficacy against a broad spectrum of microorganisms. In this study, we investigated the impact of two EW treatments (40 and 400 mg/L free chlorine) on grape mycobiota using culture-dependent and -independent approaches. Moreover, the effect of yeast inoculation on treated and non-treated grapes was also considered. At the end of the fermentation, the wines produced were subjected to chemical and aroma analyses. The results revealed a decrease of about 0.5 log CFU/mL of the total yeast population on grapes surface independently of the dose of EW applied. Yeast inoculation and EW treatments shortened the time needed by Saccharomyces cerevisiae to dominate apiculate yeasts, particularly, 2 days for inoculated and 7 days for spontaneous fermentations. A decrease of acetic acid (about 55%) was also observed compared to untreated spontaneous fermentation. In addition, aroma analysis highlighted a positive contribution of inoculated yeast on the wine aromas, since they had approximately 50 % higher pleasant esters compared to spontaneous fermented wines.Industrial Relevance: Sulfur dioxide is widely used in crushed grapes prior to fermentation due to its antimicrobial and antioxidant activity. However, legislative rules, health risks and negative consumer perception related to its presence and use have resulted in a need to find new sanitizers able to reduce its use. The effectiveness of EW to reduce yeast species able to produce high levels of undesirable compounds was demonstrated. This research introduced an innovative antimicrobial agent, which could assist in the first step of wine production to reduce the use of SO₂.     

不同原料的米酒多酚及其抗氧化性能比较

为了更好地了解不同原料对米酒发酵过程中多酚及其抗氧化活性的影响,采用6种大米原料进行甜米酒的传统固态发酵工艺酿制.通过Folin-Ciocalteu法和高效液相色谱分别测定米酒的总多酚含量和主要酚类成分,根据ABTS自由基清除率和铁离子还原力(FRAP)检测米酒的抗氧化活性,并对米酒多酚含量与抗氧化性进行相关性分析,对...