Study on Brewing Properties of Three Strong Ale Beer Yeasts

The brewing characteristics of three kinds of beer yeasts commonly used in the market were compared and studied.The results showed that the three kinds of yeasts had different characteristics and slightly different fermentation degrees,but the fermentation speeds all were higher and the diacetyl reduction ability was excellent.The finished beers were golden yellow in appearance,rich and delicate in foam,pleasant in aroma,mellow in body and similar in physicochemical indexes,all in line with domestic beer standards.

Effects of Emulsifier on Fermentation Performance of Active Dry Wine Yeast

[Objectives]To explore the influence of emulsifier on the fermentation performance of wine active dry yeast.[Methods]Angel active dry yeast RV002 was selected as the test strain,and the simulated grape juice was used as the fermentation medium to investigate the fermentation rate,the yeast cell number and morphology,and the physicochemical indexes of the produced wine.[Results]It was found that the viable cell rate of the active dry yeast without the emulsifier was significantly reduced,and the fermentation rate was significantly slowed down.However,the emulsifier had no significant effect on the morphology of yeast cells,the fermentation cycle,the final number of viable cells,and the quality of the produced wine.[Conclusions]The active dry wine yeast without emulsifier can reduce the formation of grape juice foam and reduce the risk of grape juice spillover.

Composition Analysis of Grape Wine from Different Brewing Technology and Its Nutrition Constituent

[Objective] The aim was to to enhance the technology to brew better the traditional grape wine, which provided theoretical basis for the development of Wuling Mountain grape wine. [Method] Taking grapes in Wuling Mountain as the row materials, Saccharomyces cerevisiae of different wines was chosen and brewed. The quality of grape wine was studied and the sensory evaluation was analyzed by dint of GC-MS. [Result] Result illustrated that the ethanol concentration of the wine brewed by exploration craft A was 68.5 g/L and that brewed by exploration craft B was 59.5 g/L; the higher alcohol content of craft A was 37.86% while that of craft B is 35.99%; craft A's percentage content of esters was 28.82% while that of B was 27.10%; craft A's percentage content of acids was 2.20% while that of B was 1.24%; the gamma-aminobutyric acid content of craft A was 33.2 g/100 ml while that of craft B was 35.4 g/100 ml. the essential amino-acid content of craft A was 11.8 g/100 ml while that of craft B was 13.9 g/100 ml .The result indicates that the wine brewed by craft A was aromatic and had special flavor. [Conclusion] In this case, the grape wine has particular flavor and has good property, which can be exploited.

Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review

Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research.

The setereoselective preparation ofβ-keto esters using baker's yeast in the presence of rice wine koji

By the addition of rice wine koji, enhancement of the reactivity was observed for the baker＇s yeast reduction of β-keto esters into （S）-β-hydroxy esters with high enantiomeric purity （73-98%）.

Microbiota for production of wine with enhanced functional components

Microbial communities during winemaking are diverse and change throughout the fermentation process. Microorganisms not only drive alcohol fermentation, flavor and aroma, but also enhance wine functional components such as extraction of polyphenols from the berries, production of γ-aminobutyric acid, hydroxytyrosol and melatonin. Polyphenols such as resveratrol, catechin and quercetin determine the functional quality of the wine. Moderate wine consumption, particularly red wine has been associated with functional benefits to human health, which includes anti-inflammation, promoting healthy aging, prevention of cardiovascular diseases, cancers, type 2 diabetes and metabolic syndrome. Indeed, the management of microbiota allows the production of wine with distinct features and functional components that benefits human health. This review scrutinizes the possible contributions of wine microbiota to the production of wine with enhanced functional components and highlights the contributions of Saccharomyces and non-Saccharomyces yeasts and bacteria to enhance wine functional components during winemaking. Thus, contributing to the dissemination of the benefits of light to moderate wine intake to human health.

Isolation and Characterization of Hydrocarbon Utilizing Yeast (HUY) Isolates from Palm Wine

Several studies have reported on the capabilities of different yeasts to utilize hydrocarbons hence the need to ascertain the petroleum hydrocarbon biodegradation potential of yeast isolated from palm wine. The study aimed at isolation, characterization and testing of yeasts from palm wine for biodegradation of petroleum hydrocarbons. Hydrocarbon utilizing yeasts (HUY) were isolated from palm wine, a rich sugar substrate from a non-oil impacted environment using Bacto Bushnell Haas broth. The medium composed of 0.2 g MgSO4, 0.02 g CaCl2, 1 g KH2PO4, 1 g K2HPO4, 0.05 g FeCl2, 1 g/L NH4NO3, pH (7.2 ± 0.2) and mineral salt broth comprising of 4.4 g KH2PO4, 8 g (NH4)2SO4, 2 g Na2HPO4·H2O, MgSO4ܭH2O, 0.1 g FeSO4, 0.01 g/L CaCl2, pH (4.5 ± 0.2) supplemented with palm wine (0.5%) and crude oil (1%). Yeasts isolated from an enriched medium and palm wine showed similarities. Yeast isolates were further screened for hydrocarbon degrading potentials using the Bacto Bushnell Haas broth containing 2, 6-dichlorophenol indophenols as the indicator agent. The isolates were identified using microscopic, macroscopic, fermentation and molecular characteristics as Candida adriatica (ZIM 2468) and Candida taoyuanica (MYA-4700).

Physico-Chemical and Microbiological Profile of Wine Lees of Red Wines from Local Grapes Varieties

In the Republic of Moldova, the viticulture industry is a sector with a high economic impact, and the utilization of secondary products from winemaking represents a growing concern regarding environmental sustainability. Wine lees, one of the types of wine waste, is less studied in order to valorize it. Currently it is used in the production of ethyl alcohol, as aggregates in the soil and others. The aim of this study was to characterize from a physico-chemical and microbiological point of view the lees sediments obtained after the primary fermentation of three types of individualized red wines made from autochthonous grapes varieties. It was found that residual yeasts represent a valuable raw material containing carbohydrates (from 14.35% ± 0.19% to 25.11% ± 1.51% SU), lipids (from 4.61% ± 0.21% to 9.41% ± 2.04% SU), proteins (from 42.62% ± 1.57% to 77.62% ± 9.14% SU), anthocyanins (from 9.18 ± 0.15 to 22.78 ± 1.60 mg cianid) and beta-glucans (from 12.84% ± 0.01% to 17.42% ± 0.02%). The pH value of wine lees ranges from 3.49 ± 0.0 to 3.083 ± 0.01, the dry matter from 9.62% ± 0.22% to 25.06% ± 0.42% and the ash from 0.03% ± 0.42% to 0.035% ± 0.21%. The microbiological study confirmed the presence of live yeasts of the genus Saccharomyces cerevisiae, which remain active due to the presence of residual sugars and oxygen. The results of the research are promising and encourage the obtaining of new products with special purpose and added value.

不同酵母菌对酿造‘北冰红’干红葡萄酒品质影响研究

为探究不同酵母菌对酿造‘北冰红’干红葡萄酒品质影响,分别选用7种酵母菌CEC01、BV818、ViC、ADT、RV171、MST和‘左山二’酵母菌株发酵制备北冰红干红葡萄酒,并对7种干酒中总糖、总酸、花色苷和挥发性香气物质含量进行测试分析,以此判定不同酵母菌种对‘北冰红’干酒品质影响。结果表明:‘左山二’酵母菌株酿造干酒总糖最低,其次是ADT、RV171和MST;安琪酵母CEC01酿造干酒总酸最低,其次是‘左山二’酵母菌株、安琪酵母RV171、VIC;安琪酵母VIC酿造干酒花色苷含量最高,其次是RV171、BV818和MST;通过GC-IMS法在7种干酒中均检测到54种挥发性香气成分,香气成分含量差异较大。安琪酵母ADT酿造干酒酯类最高,甲醇、乙酸最低,RV171酿造干酒乙醇最高,酯类含量略低于ADT酿造的干酒。综合数据分析:以‘左山二’酵母菌株酿造的‘北冰红’干酒酒质最佳,其次为安琪酵母RV171> CEC01> ADT> BV818> MST,依此作为‘北冰红’干酒酿造优势菌株选择的依据。

黄精黑糯米酒酿造工艺优化及其品质分析

以黑糯米为主要原料,黄精提取液为辅料制备黄精黑糯米酒。以感官评分为评价指标,通过单因素试验和正交试验优化液态法发酵黄精黑糯米酒酿造工艺条件,并对其理化指标及活性成分进行测定。结果表明,最佳酿造工艺条件为酒曲与酵母质量比1:1、发酵时间6 d、黄精提取液添加量28%、料液比(糯米与水)1.0:7.0(g:mL)。在此优化条件下,黄精黑糯米酒的酒体澄清透亮、呈紫红色、酒香醇厚、具有黄精风味,感官评分为87分,酒精度达12.0%vol,总糖、还原糖、总酸、氨基酸态氮、花色苷和总黄酮含量分别为4.13 g/100 mL、3.74 g/100 mL、6.32 g/L、0.22 g/L、37.9 mg/L、0.023 g/100 mL。

耐低温酵母的分离鉴定及对低温酿造米酒品质的影响

为筛选适合低温酿造米酒的酵母菌株,本研究从米曲中分离纯化、筛选出低温下产香舒适、发酵能力优良、产酒精能力和产酯能力强的酵母,通过形态观察及分子生物学方法对其进行菌种鉴定,分析其生长情况和耐受性,并将其应用于低温酿造米酒。结果表明,分离、筛选得到一株耐低温酵母菌株XQ2-8,经鉴定为酿酒酵母(Saccharomyces cerevisiae)。与对照菌株相比,菌株XQ2-8在15℃下生长曲线的延滞期变短、达到稳定期时的生物量更高,具有较好的耐低温特性。菌株XQ2-8对生长环境具有一定的耐受性,可在乙醇体积分数8%vol、葡萄糖含量60%、pH3.0、低温10℃条件下正常生长。利用菌株XQ2-8酿造米酒,与常温酿造相比,低温米酒的总酯含量(60.08 mg/L)和甘油含量(2.59 g/L)分别提高了15.6%、22.7%;总酸含量(1.91 g/L)和总高级醇含量(578.20 mg/L)分别降低了18.0%、17.7%;感官得分(89.47)提高了11.7%。说明利用筛选得到的菌株XQ2-8低温酿造可以改善米酒中酯类含量低、高级醇含量偏高的问题,提高米酒品质。

富含谷胱甘肽酵母制品在葡萄酒酿造中的应用进展

葡萄酒酿造过程中由于存在较高浓度乙醇、大量酚类物质和溶解氧等因素,易出现发酵缓慢、葡萄酒氧化褐变、香气损失等问题。富含谷胱甘肽酵母制品(glutathione-enriched inactive dry yeast derivatives,g-IDYs)是一种以活性酵母为原料制得的非活性酵母制剂,其能够在葡萄酒中释放大量谷胱甘肽,具有改善发酵迟缓、提高葡萄酒抗氧化能力、增加葡萄酒风味、减少SO_(2)使用量等功能。目前,市场上g-IDYs产品多样,其有效成分差异较大,且在葡萄酒酿造中作用机制不明晰,增加了其有效解决生产问题的应用难度。该文对g-IDYs产品的主要功能成分、在葡萄酒酿造中的应用,以及各物质成分在葡萄酒酿造中作用机制及抗氧化性和测定方法进行了简要综述,为g-IDYs在葡萄酒酿造中的合理使用提供理论参考。

降解氨基甲酸乙酯酿酒酵母的筛选及其应用

以宁夏5个产区的酿酒葡萄为原料筛选可以降解氨基甲酸乙酯(Ethyl carbamate,EC)且具有优良酿酒特性的红葡萄酒和白葡萄酒酿酒酵母。初筛试验获得了10株酵母,复筛试验以EC作为唯一氮源筛选出6株EC降解能力较好的酵母菌株,最后通过产气试验和耐受性试验筛选出了2株发酵性能较好的菌株。经过18S rDNA分子生物学鉴定后确定这2个菌株为酿酒酵母。使用筛选出的2个菌株发酵红葡萄酒和白葡萄酒,并以商业酵母作为对照,测定其理化指标及EC含量;再通过GC-MS分析其香气物质并结合感官评价最终筛选出具有优良酿酒特性和降解EC功效的红葡萄酒酿酒酵母(Saccharomyces cerevisiae)NXSC2和白葡萄酒酿酒酵母(Saccharomyces cerevisiae)NXSC1。

不同酵母多糖添加条件下早酥梨-美乐低醇复合果酒品质研究

为提高早酥梨-美乐低醇复合果酒的品质,以体积比50∶50复配的早酥梨和美乐葡萄汁为试材,在酒精发酵前分别添加0.25 g/L的酵母细胞壁、水溶性β-葡聚糖和甘露糖蛋白,接种酿酒酵母和非酿酒酵母进行混菌发酵,采用顶空固相微萃取结合气相色谱质谱联用技术(HS-SPME-GC-MS)测定发酵酒样的挥发性香气化合物,结合模糊数学感官评价法分析探讨其对酒体品质的影响。结果表明,3种酵母多糖均对早酥梨-美乐低醇复合果酒酒精发酵动力学和理化指标有一定影响,尤其是添加酵母甘露糖蛋白的复合果酒与空白对照组酒样的CIELab颜色参数差异显著。此外,添加酵母甘露糖蛋白可以提高酒样中萜烯类、酯类、高级醇类物质,尤其是2-甲基丁酸乙酯、丁酸乙酯、乙酸苯乙酯、癸酸乙酯、香茅醇和香叶醇等化合物含量,呈现较为突出的花香、果香属性;模糊数学综合感官评价达到7.400分。综上,外源添加酵母甘露糖蛋白能够有效稳定早酥梨-美乐低醇果酒颜色,改善香气品质。

混菌发酵对红心猕猴桃果酒品质及其抗氧化性的影响

该研究以红心猕猴桃为原料,以酵母菌AU、MA、BV、FR为发酵菌株,分别接种两种酵母菌(BV-FR、BV-MA、BV-AU、FR-MA、FR-AU、MA-AU)(1∶1)混合发酵得到红心猕猴桃果酒,对果酒酒精度、颜色参数、滋味、气味指标及抗氧化活性进行检测,并基于品质指标进行主成分分析(PCA)及聚类分析(CA)。结果表明,BV-AU发酵果酒酒精度(13.9%vol)、a*值、鲜味的回味响应值、芳香类物质含量最高,缺陷性气味含量最低;其DPPH自由基清除率为94.18%,具有较好的抗氧化活性。PCA及CA结果表明,基于品质指标可有效区分不同混合酵母菌发酵酒样。综上,BV-AU可优先作为发酵红心猕猴桃果酒的混合菌种。

酿酒酵母的筛选及其发酵性能应用研究

以葡萄、草莓、苹果、桃子为研究材料筛选、分离和纯化出4株酵母菌,并和实验室前期筛选出的未知酵母菌进行共同培养研究。通过形态学观察和生理生化反应鉴定,识别出酿酒酵母,并对其进行生长曲线测定和耐受性分析。结果表明:试验成功分离筛选出5株酵母菌,其中J-1和J-3菌株经鉴定为酿酒酵母,J-2和J-5为克鲁维酵母,J-4菌株为季也蒙毕赤酵母。在相同生长时间下,分离筛选出的酿酒酵母J-1相较J-3生长速率更快;J-1菌株耐受性方面综合性能优于J-3菌株。相较于未添加酵母菌的米酒,当酵母菌添加量达108 CFU/mL时,J-1菌株在感官评分、乙醇体积分数方面整体稍优于J-3菌株;但在出汁量和活菌落数方面J-1菌株和J-3菌落没有明显差异。

孔石莼多糖无花果果酒酿造工艺优化及其抗氧化活性研究

为提高海藻生物活性物质的利用率,增加果酒品种多样性,以山东威海青皮无花果为原料,添加孔石莼多糖制备孔石莼(Ulva pertusa)多糖无花果果酒。采用单因素和响应面法优化果酒发酵条件,探究初始糖度、酵母菌接种量、孔石莼多糖添加量、发酵温度、发酵时间对孔石莼多糖无花果果酒感官评分和酒精度的影响。结果表明,孔石莼多糖无花果果酒的最佳发酵条件为初始糖度22°Bx,酵母接种量0.04%,孔石莼多糖添加量0.3%,发酵温度26℃,发酵时间8 d。在此最优条件下,孔石莼多糖无花果果酒呈澄清透亮的褐色,酒香突出,绵柔协调,无花果风味独特,酒精度为11.8%vol,感官评分为93.8分,各项指标均符合国家相关标准,对1,1-二苯基-2-三硝基苯肼(DPPH)和2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基的清除率分别为94.4%、95.8%,具有较强的抗氧化性。

葡萄酒中挥发性酚及其预防措施的研究进展

葡萄酒中挥发性酚会对其香气产生负面影响,使其具有马腥味、谷仓味、烟熏味和药味。挥发性酚主要来源于酒香酵母属(Brettanomyces)酵母菌的感染。Brettanomyces酵母菌广泛存在于酿酒设备或储存环境中,因此保持酿酒过程的卫生状况非常重要。本文综述了葡萄酒挥发性酚的形成、酿酒过程中的预防措施和成品酒的补救措施,并对以后的研究重点进行了展望。

蓝莓酒酿造工艺研究进展

蓝莓富含生物活性成分,经发酵制成的蓝莓酒风味独特、营养丰富,越来越受消费者青睐。本文就蓝莓酒的营养价值及酿造工艺研究进行了综述,并简要概括了目前蓝莓酒酿造中存在的问题,以期对未来蓝莓酒的深入研究提供理论参考。

发酵石榴酒中非酿酒酵母菌的筛选及风味分析

石榴果酒是石榴精深加工的一种产品,兼具石榴果实的清甜及酒的醇香,营养丰富,发展前景广阔。参与发酵石榴果酒的酵母菌株与果酒风味物质的产生密切相关,良好的发酵菌株有助于石榴果酒形成稳定的色泽,丰富的风味层次。本研究以发酵石榴果酒为研究对象,采用培养基培养并富集目的菌株;通过GC-MS对发酵风味物质进行测定分析,并通过产物检测筛选出一株具有优良发酵风味的法尔皮有孢汉生酵母(Hanseniaspora valbyensis),可用于石榴果酒的酿造生产,通过与商业酿酒酵母组合发酵生产的石榴果酒风味对比分析,前者风味物质含量明显增多,香气的复杂性和多样性更为显著。