啤酒酵母菌种的石蜡保藏法

啤酒酵母菌种是啤酒生产的灵魂,因而得到一支好的菌种,人们无不十分珍惜,在将它应用于生产的同时,总是千方百计把它很好保藏起来,以利长久应用。啤酒酵母菌种保存的方法很多,诸如固体斜面保藏法、液体试管保藏法、真空冷冻干燥保藏法、液体石蜡保藏法等,这些方法各...     

葡萄酒酿酒菌种的保藏方法

本文介绍了酿酒菌种常用的保藏方法,酵母菌的短期保藏可采用橡皮塞代替棉塞的斜面试管或液体试管保藏法,长期保藏可采用液体石蜡保藏法,乳酸菌的短期保藏可用液体试管和穿刺培养保藏法,长期保藏可用旋塞试管保藏法,但长期有效的保藏菌种还是以真空冷冻干燥保藏法最行。     

黄姚豆豉中产纤溶酶菌种保藏方法的效果比较

黄姚豆豉属于特色性农产品,对于区域经济发展具有重要的推动作用。但受到环境、人为等多种因素的影响,在黄姚豆豉的菌种保藏上存在一定问题,为了提高黄姚豆豉的菌种性能,必须要探究科学合理的保藏方式。为了保持从黄姚豆豉中筛选的产纤溶酶的菌种-枯草芽孢杆菌的优良性状,不降低其生产性能,本研究三个月内分别用斜面低温保藏法、甘油冷冻保藏法、超低温磁珠保藏法三种方法保藏的菌种活性、形态学和生化特性效果进行比较,得出超低温磁珠保藏法的保藏效果最佳。     

影响啤酒酵母液氮保藏因素的探讨

啤酒酵母保藏过程中,如果保藏方法不适当,很容易引起酵母的变异、退化,严重影响啤酒质量和风味稳定性.在-196℃温度条件下,酵母几乎完全处于休眠状态,这就使液氯保藏法成为酵母菌种最有效的保藏方法之一.本文通过试验总结了液氮保藏过程中保护剂浓度和降温方式的不同对保藏后酵母菌种死亡率的影响.     

啤酒酵母菌种的石蜡保藏技术

啤酒酵母菌种是啤酒生产的灵魂，因而得到一支好的菌种，人们无不十分珍惜,在将它应用于生产的同时，总是千方百计把它很好保藏起来，以利长久应用。啤酒酵母菌种保存的方法很多，诸如固体斜面保藏法、液体试管保藏法、真空冷冻干燥保藏法、液体石蜡保藏法等，这些方法各有千秋，选择应用无有不可。但据笔者实践，上述诸种方法中，液体石蜡保藏法具有设备简单、操作方便、存活率高、变异少、优良种性能保持较长时间的优点，故实用价值较高，值得推广。笔者曾用此法保存啤酒酵母菌种十数载，取得了“年年用好种，岁岁没买种”的好结果。现将…     

双歧杆菌培养及保藏方法比选研究

对双歧杆菌进行了不同培养方法和保藏方法的比选研究。双歧杆菌在厌氧条件下,液体培养比斜面培养的生长状况好。双歧杆菌的保藏,短期适宜用液体保藏法,中长期适宜用液体石蜡保藏法、冷冻保藏法或冷冻干燥保藏法。     

无菌蒸馏水长期保藏酵母菌种的研究

采用蒸馏水长期保藏酵母菌种进行了3年的研究。结果表明，经蒸馏水保藏3年的酵母菌种其发酵特性无明显改变。证明该方法是一种长期保藏酵母菌种行之有效的的方法。     

甘蔗糖蜜酒精酵母菌的筛选与应用

熊先生自１９４７年开始搜集和保藏酒精酵母菌种。建国后，从中筛选了川１０２、川３４５两株酒粗酵母菌应用于甘蔗、糖蜜酒精的生产，不仅解决了蒸馏酒精过程中的过醪问题，同时提高了出酒率，降低了生产成本。迄今，这两株菌种仍在四川、广东、云南等地推广使用，为我国酿酒行业作出了贡献。文中介绍了这两株菌种的特性、应具备的条件及应用方法。     

双歧杆菌微生态制剂保藏技术研究现状

基于双歧杆菌的生理特性并结合目前国内外最新研究成果 ,论述了冷藏、冷冻保藏、真空冷冻干燥法和和固定化细胞微胶囊等技术在延长双歧杆菌活菌保藏期中的研究进展 ,对双歧杆菌活菌保藏期技术的未来作了展望。     

鲜肉制品低温冷却与冷冻保藏

介绍了鲜肉制品低温冷却与冷冻保藏的重要性.主要论述了鲜肉制品的低温冷却和冷冻保藏的生产加工流程,并简要的介绍鲜肉制品保藏的几种方法.     

高浓度糖蜜快速热澄清发酵酒精技术的研究

酒精高浓度发酵能够提高发酵醪液含酒分,可以节省酒精蒸馏蒸汽消耗量,减少酒精废醪液排放量,提高设备利用率,日益受到酒精生产企业的重视。目前糖蜜酒精生产发酵含酒分普遍偏低,糖蜜高浓度发酵面临很大困难,笔者认为主要原因是糖蜜中的灰分和胶体等杂质含量不断增高,会抑制酵母的繁殖和发酵,影响糖蜜高浓度发酵酒精。对糖蜜进行澄清处理是实现糖蜜酒精浓醪发酵的快捷途径,通过对糖蜜快速热澄清处理,得到糖蜜高浓度发酵酒精,与传统糖蜜酸化后发酵酒精相比,发酵含酒分明显提高,发酵成熟醪锤度降低。     

Intracellular concentration of exogenous glycerol inSaccharomyces cerevisiaeprovides for improved leavening of frozen sweet doughs

Addition of glycerol to baker's yeast coupled with an incubation period under conditions of refrigeration to allow equilibration of the polyol across the yeast membrane, resulted in improved frozen sweet (10% sugar) dough leavening and keeping, relative to doughs made with yeast containing no added glycerol. Glycerol-loaded yeast showed smaller proof time increases after initial freezing and thawing. Also, glycerol treatment led to slower deterioration of the frozen sweet doughs during storage at −21°C for up to 8 weeks (proof time increases were significantly lower in stored frozen doughs made with glycerol-added yeast). Benefits of glycerol loading of yeast for the purpose of production of frozen plain (unsugared) doughs were less significant. The glycerol treatment effects became more significant as the yeast was stored refrigerated prior to mixing and freezing of doughs, i.e. shelf-life of yeast for use in frozen dough manufacture was improved by addition of glycerol. The improvements were dependent on glycerol concentration.     

Isolation and Characterisation of Sri Lankan Yeast Germplasm and Its Evaluation for Alcohol Production

Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two strains, SL‐SRI‐C‐102 and 111, showed an appreciable fermentation efficiency of about 90%. The latter strain produced the highest level of ethanol, 11% (v/v) within a 48 h fermentation and exhibited improved alcohol tolerance when compared with the baker's yeast strains currently used in Sri Lankan alcohol distilleries. This study highlights the benefits of exploiting indigenous yeasts for industrial fermentation processes.     

甘蔗糖蜜酒精无酸发酵应用现状与展望

无酸发酵工艺克服了添加硫酸对设备、环境的危害,十多年来在糖蜜酒精行业多家酒精厂成功应用。随着糖蜜纯度变低,无酸发酵遭遇到细菌感染无法控制等问题,甘蔗糖蜜酒精厂陆续放弃无酸发酵工艺。糖蜜中含量不断增多的灰分、胶体等物质抑制酵母生长繁殖,酵母对细菌无法取得生长优势,导致无酸发酵工艺无法继续应用。在无酸或微酸条件下,尽可能多地排除糖蜜中灰分和胶体,才能从根本上解决无酸发酵染菌问题。     

冷冻面团中酵母抗冻保护剂的优选

为改善冷冻面团品质,减少低温对酵母的损害,对常见的几种酵母抗冻保护剂进行配方优化。单因素试验测定冷冻7 d后酵母存活率和面团发酵力,筛选出保护剂及其添加量水平,再运用二次回归正交旋转组合设计进行优选试验,在对存活率影响试验中,因素主次顺序为：海藻糖＞甘油＞脯氨酸;在对发酵力影响试验中,因素主次顺序为：海藻糖＞脯氨酸＞甘油。验证得到最优试验条件为：海藻糖、甘油和脯氨酸添加量分别为2.23%、3.43%和1.55%。在此条件下,酵母存活率和面团发酵力分别为85.86%和322 mL。     

高压静电场对酿酒酵母菌的作用研究

利用高压静电场对甘蔗糖蜜工业生产用酿酒酵母菌进行处理,把酵母菌糖蜜进行酒精发酵,再利用气相色谱仪对产生的乙醇含量进行分析。结果表明,高压静电场对酿酒酵母菌具有明显的生物刺激作用。并找到乙醇含量具有较大变化的高压静电作用变异菌株,将高压静电作用变异菌株的乙醇脱氢酶同工酶的比较,证实高压静电场对酿酒酵母菌具有诱变作用。     

玉米醇溶蛋白阻湿性及抗氧化性应用的研究

对玉米醇溶蛋白在食品保鲜中的应用进行了研究。实验证明玉米醇溶蛋白具有良好的保湿性抗氧化性。采用玉米醇溶蛋白液作硬糖,可以延缓硬糖吸水溶化,防止硬糖发烊、返砂,以便长久地保持硬糖的质量,在玉米醇溶蛋白溶液中添加增塑剂能更有效地增强其保湿性。用玉米醇溶蛋白浸涂杏仁及核桃仁能延缓其氧化酸败速度,而添加增塑剂能使膜更好地粘着于食品表面,从而增强了膜的阻氧性。杏仁及核桃仁的最佳涂膜液配比为：在10ml10%玉米醇溶蛋白中加入0.8ml甘油、0.5ml虫胶.     

ISOLATION AND SELECTION OF ETHANOL-RESISTANT AND OSMOTOLERANT YEASTS FROM REGIONAL AGRICULTURAL SOURCES IN MEXICO

In Mexican alcohol distilleries using sugarcane molasses, one reason for low alcoholic fermentation efficiency is the use of inferior yeast cultures. The objective of the present study was to isolate and select yeast strains from alcoholic fermentations of natural sources (sugarcane molasses, grape juice, cane juice and pineapple) from Veracruz city market and Mexican distilleries, and to evaluate their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Ethanol production, glucose composition, growth rate, "Killer" activity, ethanol and glucose tolerance of the most promising strains were monitored on synthetic and molasses media. A total of 112 yeast strains were isolated by their capacity to produce ethanol, and from these, only 58 were selected on the basis of best ethanol theoretical yields (88–96%). These strains were exposed several times to high concentrations of glucose and ethanol in order to select ethanol- and glucose-tolerant yeast; 10 were obtained that adapted best to these conditions and that showed "Killer" activity. Of these strains, U3-11, M11, JC10 and U2-10 (obtained from grape juice, sugarcane molasses and cane juice) demonstrated the highest adaptation to both ethanol (5–7% w/v) and glucose (20% w/v). The maximum yield obtained was 0.46 g/g (90% theoretical yield) in a 20-L bioreactor with cane molasses under nonsterile conditions.

PRACTICAL APPLICATIONS

The selected yeasts could be introduced into industrial processes in Mexican distilleries using sugarcane molasses in order to improve productivity and diminish contamination problems.     

原糖蜜对酵母质量影响和研究

原糖蜜的储存时间对酵母生产影响较大,事实证明,原糖蜜储存时间越长,对酵母质量带来的不利影响就越小.原糖蜜对酵母质量的影响与储存过程中原糖蜜的代谢及挥发性作用有关.     

耐高温絮凝酵母HK-3糖蜜原料发酵生产酒精特性

在机械搅拌罐内，以糖蜜为原料，对原生质作融合法构建的耐高温絮凝酵母HK－3的发酵特性进行了研究。利用正交实验法，考察了通气、搅拌和初糖浓度对发酵的影响。在38℃，100r／min，0.3vvm通气量，19％初糖浓度的最优工艺条件下间歇发酵，酵母数、酒精浓度、综合生产能力、原料利用率、乙醇收率分别可达2．8亿／ml、10．56％、3．7g乙醇／L／h、86．67％、98％，很有工业推广价值。与亲本KF－7的连续发酵结果表明，该融合子的发酵稳定性需进一步改善。