Yeast viability during fermentation and sur lie ageing of a defined medium and subsequent growth of Oenococcus oeni

Interactions between the yeast strain used for primary oenological fermentation and the bacterium used to conduct subsequent malolactic fermentation were studied under model winemaking conditions. A commercial Saccharomyces cerevisiae wine yeast (strains, EC 1118, AWRI 835 and CY-3079) was grown in a defined medium whose composition approximated grape juice. Fermentations by all strains reached dryness, and retained a cell viability of greater than 90% upon completion of fermentation. Highest total viable cell number and percentage of viable cells were recorded for EC 1118. A sur lie ageing of the fermented medium over a 12 week period revealed a bi-phasic decay of culture viability for all strains. Thus 99% of cells had died within 2 weeks post-fermentation. Viabilities were then stable for the subsequent 4–6 week period before a second decline phase ensued and ended in either a minimal ( ca 100 CFU/mL, EC 1118) or no viable cells being detected at 12 weeks of ageing. The growth response of an Oenococcus oeni inoculum to yeast culture supernatants, previously aged for up to 12 weeks in the presence or absence of yeast lees, was evaluated in a bio-assay. In this way, yeast strains could be designated as being either inhibitory, neutral or stimulatory to the growth of O. oeni (strain Lc5p). Inhibition by supernatants of strain EC 1118 was evident, but found to be reduced by ageing the supernatant (with or without lees). Conversely, longer ageing on yeast lees increased the magnitude of the stimulatory response in O. oeni (strain Lc5p) to the supernatant from the wine yeast (strain CY-3079).     

旋转闪蒸干燥器干燥酒糟过程的实验研究

为获得旋转闪蒸干燥器干燥啤酒糟过程的最佳操作工况,对不同操作条件下的啤酒糟含水质量分数进行了测试,依据实验数据关联出了啤酒糟含水质量分数的计算公式。在此基础上对干燥过程进行寻优计算,得出干燥器所能达到的最低含水质量分数为3.92%,与实际对比误差为2.08%。满足要求含水质量分数(小于8%),处理量为75 kg时能量消耗最低的操作参数为进风温度94.9℃、轴向风速4.46 m/s,175 kg时进风温度155.9℃、轴向风速3.29 m/s,与实际对比误差小于1.65%。     

6款市售红谷黄酒的营养及安全性评价

目的 对目前市售的红谷黄酒类产品(无其他辅料添加)的营养价值及安全性进行分析评价。方法 采用比色法对产品的总蛋白、总多糖、总多酚、总黄酮、总皂苷、尿素含量及自由基清除能力进行测定,利用高效液相色谱法对γ-氨基丁酸(γ-aminobutyric acid, GABA)、苯甲酸及生物胺(biogenic amine, BA)含量进行测定,比较市售红谷黄酒产品的组间差异以及与其他类型黄酒产品的异同。结果 市售红谷黄酒产品拥有较高的营养价值,其中SC品牌黄酒具有较高的GABA与总皂苷含量,GC品牌黄酒具有较高的总多酚与总黄酮含量,同时具有最佳的体外抗氧化能力。从安全性角度分析,除SC品牌黄酒中总BA含量较高外,其余市售红谷黄酒产品的BA含量以及所有产品的尿素含量均处于较低水平,苯甲酸均未检出。结论 市售红谷黄酒产品相较于其他原料酿造的产品,具有更高的营养价值与较强的抗氧化性能,且产品的总体饮用安全性较高。本研究明确了红谷黄酒的产品优势,为红谷黄酒的推广提供数据支撑。     

桑椹果酒酒糟中原花青素提取工艺研究

选用溶剂浸提法从桑椹果酒酒糟中提取花青素.通过单因素和响应面(BBD)试验优化提取工艺.结果表明,影响花青素提取量因素的优先次序为提取温度＞固液比＞提取时间,较优的提取工艺条件为提取温度80℃、提取时间150.3min、料液比1∶20.在该条件下,花色素提取量的理论预测值为1.92264mg/g,实际验证为1.894mg/g,提取得率达到理论预测值的98.5％.     

ACA微囊化酵母细胞利用酒糟水解液发酵木糖醇的初步研究

通过ACA(Chitosan-alginate)微胶囊技术包埋的热带假丝酵母(Candidatropicalis)细胞能有效地发酵酒糟(文中均指丢糟)半纤维素水解液生产木糖醇。在摇瓶条件下,适宜的工艺条件为:初始木糖质量浓度100g/L,发酵液初始pH值6.0,限制性供氧,分段改变摇床转速(0～24h为180r/min,24～48h为120r/min)使菌株在培养早期获得较高水平的通气率,而后降低菌株的呼吸率。每升氮源含酵母膏1.8g,蛋白胨3.0g,微囊化胶珠与水解液体积比为1∶4。此方法有望大幅降低原料预处理的成本,发酵结果良好,显示了良好的应用潜力。     

Advances in Wine Aging Technologies for Enhancing Wine Quality and Accelerating Wine Aging Process

Wine aging is an important process to produce high-quality wines. Traditionally, wines are aged in oak barrel aging systems. However, due to the disadvantages of the traditional aging technology, such as lengthy time needed, high cost, etc., innovative aging technologies have been developed. These technologies involve aging wines using wood fragments, application of micro-oxygenation, aging on lees, or application of some physical methods. Moreover, wine bottling can be regarded as the second phase of wine aging and is essential for most wines. Each technology can benefit the aging process from different aspects. Traditional oak barrel aging technology is the oldest and widely accepted technology. The application of wood fragments and physical methods are promising in accelerating aging process artificially, while application of micro-oxygenation and lees is reliable to improve wine quality. This paper reviews recent developments of the wine aging technologies. The impacts of operational parameters of each technology on wine quality during aging are analyzed, and comparisons among these aging technologies are made. In addition, several strategies to produce high-quality wines in a short aging period are also proposed.     

中国浓香型白酒窖池糟醅中微生物群落演替分析

为探索中国浓香型白酒发酵糟醅中微生物群落演替规律,利用克隆分析,从时间和空间两个层面对糟醅微生物区系的消长变化进行较为全面的调查。根据有效克隆子分布数据计算的群落多样性参数表明:窖池糟醅微生物群落多样性在时间和空间上存在差异。应用CANOCO 4.5软件对物种和生态因子进行典范对应分析(CCA),应用CANODRAW 4.0作种类、样方分布与生态因子关系的二维排序图,排序图上清楚地反映了窖池糟醅微生物种类、群落分布与生态因子的关系。结果表明:酸度、乙醇含量、水分含量是影响微生物群落结构组成的主要微生态因子;大部分微生物适宜在低酸度条件下生长,少数耐酸微生物能在高酸度条件下生长;随着发酵的进行,生态因子发生变化,微生物群落也进行相应的演替,向耐高酒精含量、高酸度的群落发展。     

燕麦黄酒发酵过程中微生物群落结构变化及对高级醇的影响

燕麦作为一种营养独特的作物,用于酿造黄酒是黄酒酿造研究的一项新的尝试。为进一步探究燕麦黄酒中的高级醇指标、微生物群落结构及其相关性,研究燕麦黄酒特性,本研究应用顶空固相微萃取、气相色谱-质谱联用技术对燕麦黄酒发酵过程中的高级醇变化进行了定量分析,并通过高通量测序检测了燕麦黄酒发酵过程中的微生物群落结构变化。利用统计学原理对高级醇变化与微生物代谢之间的相关性进行预测。燕麦黄酒中共检测到β-苯乙醇、异戊醇等18种高级醇。门水平上,相对丰度最高的细菌和真菌分别是厚壁菌门和子囊菌门;属水平上,相对丰度最高的细菌和真菌分别是乳球菌属和酵母属。高级醇与微生物间共建立869项关联,有297属微生物可能参与高级醇的代谢。本研究表明,以燕麦为原料酿造黄酒不仅可以增加黄酒的品类及原料来源,还可能改善黄酒营养价值;另外,高级醇与微生物之间的关联分析可以预测燕麦黄酒品质特性的生物学机制。     

Influence of Lees Contact on Evolution of Amines in Chardonnay Wine

ABSTRACT:  Some white wines of Chardonnay variety are aged on their lees in oak barrels over several months. Over this period, autolysis takes place and different compounds are freed in the wine, among them, nitrogen compounds. The aim of this work was to study the evolution of amines in Chardonnay wine during 180 d of maturation on lees, with and without weekly stirring. The process was carried out in new French oak barrels with 225 L capacity. From the results obtained it was found that weekly stirring mainly had an influence on histamine and tyramine concentration. The concentration of these amines at the end of the aging period was higher in the wine with weekly stirring. This treatment showed no effect on the amine concentration at the beginning of the wine aging on lees. The aging time also had an influence on the concentration of amines in the Chardonnay wine.     

红曲米添加量对红曲酒多酚成分及其抗氧化活性的影响

红曲酒是我国华中、华东和南方地区流行的一种黄酒,酚类物质含量较高,具有较高的营养价值。 该实验研究了红曲米添加 量对红曲酒中5种酚酸、2种黄酮成分的影响及其总抗氧化能力、DPPH自由基、ABTS+自由基清除能力和还原力的差异。 结果表明,随 着红曲米添加量的增加,红曲酒总酚含量与单体多酚成分增加趋势一致,红曲米添加量为10.0%时总酚含量达到470.07 mg/L,没食子 酸、绿原酸、对羟基苯甲酸、芦丁、芥子酸、阿魏酸以及槲皮素的含量分别达到5.54 mg/L、11.33 mg/L、3.18 mg/L、9.14 mg/L、12.42 mg/L、 4.46 mg/L和2.12 mg/L。 红曲酒的总抗氧化能力、DPPH自由基及ABTS+自由基清除率和FRAP值也随着红曲米添加量的增大而增大。 红曲酒中3种酚类物质（芥子酸、阿魏酸、芦丁）与其总抗氧化能力、DPPH自由基和ABTS+自由基清除能力以及还原力具有较高的相 关性（R＞0.890,P＜0.05）。