酵母发酵法去除木糖母液中葡萄糖的研究

以木糖母液为原料,采用酵母发酵法去除母液中的葡萄糖。通过单因素分析,对影响去除效果的主要因素进行了研究。利用正交试验筛选出最佳工艺参数。结果表明:母液浓度为12%,调pH值4.5,酵母添加量2%,30℃下发酵6h,葡萄糖的去除率可达96%以上。     

传统黄酒淋饭酒母制作过程微生物的变化和作用

搭窝糖化期：乳酸球菌以肠球菌属、明串珠菌属、片球菌属、乳球菌属、酒球菌属等属的菌株为主，且有极少量乳酸杆菌。静止期：升酸幅度较大，酵母增殖迅速。搅拌期：酵母快速产酒精，乳酸球菌数迅速下降，乳酸杆菌数大量增加达到高峰期，醪液pH值又降至最低；是酵母、乳酸菌(乳酸球菌、乳酸杆菌)变化最剧烈的时期；此期间拟内孢霉酵母的作用已小。淋饭酒母制作过程中乳酸球菌、乳酸杆菌起到非常重要的作用，把酒药、曲、熟地上接入的酵母和乳酸杆菌顺利培养成酒母。乳酸球菌、乳酸杆菌是保障淋饭酒母制作正常进行、顺利完成的关键菌。影响淋饭酒母制作的主要因素：气温、曲、操作手法、水。淋饭酒母中主要微生物来源于酒药、曲和生产场地。淋饭酒母的作用：接种、作掺醅、冲缸、淋饭酒、家酿酒、分离酵母菌和乳酸杆菌等。(孙悟)     

玉米原料超高浓度酒精发酵

以全磨玉米为原料,研究了超高浓度条件下传统工艺与生料工艺的黏度变化。采用传统工艺,在超高浓度条件下,物料的糊化、液化会变得非常困难。而采用生料工艺,黏度始终维持在合理的水平。对高浓度传统工艺和生料工艺发酵的结果进行对比,证明生料工艺可以产出更多的酒精;对超高底物浓度(35%绝对干物)生料发酵时采用温度梯度控制,使用市售酒精干酵母,在98 h内发酵醪液酒精浓度可达20%以上。     

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.     

客家糯米酒药曲开发的工艺技术研究

在客家米酒民间制曲工艺基础上,利用筛选得到的根霉和拟内孢霉属酵母为生产菌株,研究了温湿度、接种量及接种比例、添加中草药等工艺条件对药曲生产的影响,确定了药曲生产工艺条件为添加中药材6％,根霉菌种和酵母液重量比3∶2,接种量1％,保持品温30℃～32℃,相对湿度85％～95％,培养60h烘干即成药曲;按0.5％～1.0％比例加曲进行糯米酒6批次发酵试验,酒精度平均达到13.5％vol较对照组提高17％.     

生物转化法生产木糖醇的细胞增殖培养基优化

以木糖为底物利用酵母细胞转化生产木糖醇,研究细胞增殖培养基中不同种类的碳源、氮源和微量元素及其添加量对酵母细胞生长和木糖转化率的影响。结果表明,当碳源为木糖和葡萄糖添加量分别为1%时,木糖醇浓度为49.6g/L;当无机氮源为蛋白胨且浓度为2%时,木糖转化时间为60h,木糖醇浓度达到58g/L;微量元素为磷酸二氢钾浓度为0.1%时,木糖的转化时间为48h,此时木糖醇浓度达到59g/L。     

中国酿酒酵母菌的研究--不同酒类酵母筛选与应用纪实(下)

总结了我国50多年来对不同酒类酵母筛选也应用的研究成果，并通过大量翔实的数据详尽地阐释了酒类酵母不同的特性与作用，推出优良菌种，以达到优质高产、节约粮食之目的。酒类酵母分为酒精酵母、生香酵母、威士忌酵母。酒精酵母又分为小曲酒酵母、大曲酒酵母、小麦酒精酵母、甘蔗酒精酵母。四川小曲酒酵母以纳溪109号酵母较优良，黄酒126号酵母次之；大曲酒酵母以1308号较优，AS2．399次之；小麦酒精酵母以1308号酒精酵母较优；甘蔗酒精酵母则以川102号较优。（陶然）     

Effect of Yeast Extracts Containing Propionic Acid on Bread Dough Fermentation and Bread Properties

ABSTRACT: Three commercial yeast extracts (Oxoid, Champlain, Lallemand) fermented with immobilized cells of Propionibacterium freudenreichii were added in broths and bread formulations, and their effect on growth and gas production by bakers yeast was determined. Appearance and preservation of the breads were examined. There was significantly more gas produced by the yeast when fermented yeast extracts were added to the dough. In broths, the initial growth rate was slower with media containing fermented yeast extract when compared to their unfermented equivalents. Loaves formulated with propionic acid of the fermented yeast extract contained less ethanol. Paired t-tests showed that breads formulated with fermented yeast extract were protected for a longer period against mold than those that contained non-fermented yeast extract.     

富钒酵母中钒含量的初步研究

利用啤酒酵母对钒的富集作用制备钒酵母,并对钒酵母中钒的含量进行分析。结果表明,钒酵母中有机钒含量可达到474.9μg/g,紫外扫描光谱分析,钒酵母在311nm处有一特征吸收峰,红外光谱分析,钒酵母有多处特征吸收峰的变化。用氨基酸自动分析仪对钒酵母中的15种氨基酸含量进行分析表明,钒对啤酒酵母氨基酸的合成有一定的影响。     

啤酒废酵母超声破壁提取食源性β-1,3-D-葡聚糖

以啤酒废酵母为原料,采用Box-Behnken正交析因素试验优化超声破壁工艺,得出破壁参数理想条件为酵母质量浓度200 g/L,超声功率800 W,超声时间80 min,超声温度50℃;制得的酵母β-1,3-D-葡聚糖不含甘露聚糖,纯度达90.63%,得率达10.31%。