酵母味素在低温圆火腿中的应用研究

研究了LB00型酵母味素、猪肉型酵母味素添加量对低温圆火腿品质的影响,获得LB00型酵母味素与猪肉型酵母味素的添加量范围及最佳添加量:LB00添加范围0.2%～1.2%、最佳用量0.7%;猪肉型添加范围0.2%～0.8%、最佳用量0.6%。酵母味素还可以替代部分调味、调香料(如:香精、味精、I+G等),既降低了成本又提高了品质,是一种新型的肉类制品调味料与品质改良剂。     

酵母味素在低温圆火腿中的应用研究

本课题研究了LB00型酵母味素、猪肉型酵母味素添加量对低温圆火腿品质的影响，获得LB00型酵母味与猪肉型酵母味素的添加量范围及最佳添加量－－LB00添加范围0．2％－1．2％，最佳用量0．7％；猪肉型添加范围0．2％－0．8％，最佳用量0．6％；酵母味素还可以替代部分调味调香料（如：香精、味精、I＋G等），既降低了成本又提高了品质，是一种新型的肉类制品调味料与品质改良剂。     

国内啤酒废酵母生产酵母味素的困惑及思考

国内对酵母味素的研究和开发始于20世纪80年代，随国产食用酵母行业的发展，酵母味素的生产得以发展，又酵母味素的市场也得到发展，但受啤酒酵母味素行业不景气的影响。困扰国内啤酒酵母味素生产的因素有：脱苦、脱色困难；原材料得不到保征；啤酒酵母味素风味欠佳；酵母味素抽提单低；生产操作难度大。投资啤酒酵母味素必须考虑啤酒行业的格局变化；生产技术、生产工艺有待进一步完善和提高；啤酒酵母味素的生产线最好建在啤酒企业内部；啤酒废酵母的综合开发都是行业内存在的问题。(孙悟)     

酵母味素用于面包烘焙的探讨

介绍了酵母味素用于面包制作的工艺,探讨了酵母味素、糖、盐不同 含量时对其风味的影响。     

基于主成分和聚类分析酵母品种对预醒发冷冻披萨面胚食用品质的影响

为探究不同酵母品种对预醒发冷冻披萨面胚食用品质的影响,以5种不同酵母品种制作的冷冻披萨面胚为试验材料,对烘焙成品的感官、质构、色差及理化指标进行主成分和聚类分析。结果表明:由聚类分析可知5种酵母聚为4类,第一类为法国金燕子酵母(耐高糖)和法国红燕子酵母(耐低糖),第二类为安琪半干酵母,第三类为安琪高活酵母(耐高糖),第四类为安琪高活酵母;由主成分分析可知安琪高活酵母和安琪半干酵母的综合品质较为接近,可分为一类;法国金燕子酵母(耐高糖)和法国红燕子酵母(耐低糖)的综合品质相近,可分为一类,安琪高活酵母(耐高糖)的综合得分最低,单独为一类;其中安琪半酵母加工的披萨饼胚食用品质最好,综合评分达到0.62,安琪高活酵母(耐高糖)效果最差,综合得分仅为-0.87。     

啤酒废酵母综合破壁法提取酵母味素技术

研究了高压均质、酶法溶胞、温差破壁3种细胞壁破碎法对啤酒废酵母抽提物(酵母味素)的得率、蛋白质的转化率及氨基氮溶出率的影响.结果表明,在适宜的自溶条件下,利用综合破壁法可使酵母抽提物中酵母味素得率、蛋白质的转化率及氨基氮溶出率显著提高.     

啤酒废酵母回收与利用的研究

研究了以啤酒废酵母和啤酒糟为主要原料分别制取酵姆味素和发酵饲料的工艺流程,并对啤酒废酵母在制取酵母味素过程中,酵母自溶时间,自溶剂用量,自溶温度等工艺参数的确定,作了进一步讨论,最后确定制取酵母味素的工艺方案。     

酵母味素在蚝油生产中的应用

介绍了蚝油的生产工艺及原辅料对蚝油品质的影响；通过试验表明酵母味素能明显改善蚝油风味，提高产品品质。     

啤酒废酵母生产酵母味素的研究

研究利用啤酒废酵母生产酵母味素的方法和条件。啤酒废酵母经洗涤、自溶,浓缩制得的酵母味素,基酸含量２．３１ｇ／１００ｍｌ,总氮含量４．６４ｇ／１００ｍｌ,食盐含量１４．１ｇ／１００ｍｌ,水分含量４９．５％。产品有较强的鲜味和醇厚味,有有肉香味。每１ｋｇ含水量７６％左右的啤酒废酵母可制成该质量的酵母味素约０．５５ｋｇ。     

鸡精专用酵母抽提物的研制与应用

酵母抽提物(又称酵母味素、酵母精,英文名称为Yeast extract)是以蛋白质含量丰富的食用酵母为原料,采用生物技术,将酵母细胞内的蛋白质、核酸等进行降解后精制而成的天然调味料.     

糖化酵母在干啤酒生产中应用的研究（Ⅰ）──具有糖化酶活性和去除POF1基因的糖化酵母的选育

比较了多株单、双倍体糖化酵母，选出糖化酶活性及发酵度较高的糖化酵母单倍体──Ｓｏｃ．ｄｉａｓｔａｔｉｃｕｓ２６０６７－４４。同时发现糖化酵母单倍体菌株的酶活性高于二倍体菌株。含有ＰＯＦ１基因的糖化酵母（ｐｏｆ＋表型）可脱羧肉桂酸形成苯乙烯，ｐｏｆ－菌株无此能力。通过气相色谱检测肉桂酸－酒花麦汁发酵液中的苯乙烯含量，可以鉴别出去除ＰＯＦｌ基因的菌株。本文利用酵母菌的群体杂交法，通过Ｓ．ｄｉａｓｔａｔｉｃｕｓ２６０６７－４４与酿酒酵母单倍体杂交，获得１株糖化酶活性及发酵度较高，并且去除了ＰＯＦ１基因的单倍体菌株Ｈ－３（２）－２（ａ，ＳＴＡ，ｐｏｆ－）·     

Scarcity of ars sequences isolated in a morphogenesis mutant of the yeast Yarrowia lipolytica

Previous attempts is isolate autonomously replicating sequences (ars) from the dimorphic yeast Yarrowia lipolytica have been unsuccessful. We isolated a Fil- mutant unable to produce hyphae and growing only in a yeast form to facilitate ars isolation. This mutant was transformed with a Y. lipolytica DNA bank and several unstable clones were obtained. Extrachromosomal plasmids were evidenced in yeast, recovered in Escherichia coli and characterized by restriction mapping. They were able to retransform Fil- and Fil+ yeast strains at high frequency and transformants displayed a slightly unstable phenotype. The detailed analysis of the plasmids showed that only two different ars sequences had been isolated, each of them corresponding to a unique sequence in the Y. lipolytica genome. We concluded that functional ars sequences that can be cloned on plasmids are rare in this yeast.     

Determination of Antifungal Effect of Edible Coatings Containing Williopsis saturnus var. saturnus Against Yeast and Mold Growth on Kashar Cheese

One of the most important problems of Kashar cheese producers is mold and yeast spoilage during storage. Williopsis saturnus var. saturnus killer yeast has been reported to have an antagonistic effect on mold and yeast reproduction. In this study, the antifungal effect of a whey protein concentrate (WPC) coating containing W. saturnus was investigated in Kashar cheese. WPC with or without W. saturnus (7 log CFU/g) or W. saturnus without coating was applied on the surface of Kashar cheese samples and stored at 4 °C for 56 days. Microbiological, chemical, physical and sensory properties of cheese samples were assessed. After 56 days of storage, the numbers of lactic acid bacteria were not affected by WPC containing W. saturnus; however, the population of W. saturnus increased by 1 log CFU/g. Application of W. saturnus reduced the growth of other yeasts and molds (P < 0.05). Chemical, physical and sensory properties of all coated cheeses remained unchanged. In a conclusion, use of WPC coatings containing W. saturnus can potentially minimize mold and yeast spoilage of cheese during storage.     

胆固醇氧化酶的发酵条件及酶学性质研究

Brevibacterium sp．可以发酵生产胆固醇氧化酶,实验中对该菌种进行了底物诱导及发酵条件的优化, 确定其最适培养基为(%)：蔗糖0．3,酵母膏0．2,蛋白胨0．3,牛内膏0．3,K_2PO_4 0．1,MgSO_4 0．05,pH6．8。最适培养条件为：接种量5%,24℃培养20h,通气量为50mL 培养基/250mL 三角瓶,200r/min。在最适培养基及最适条件下,胆固醇氧化酶的酶活力可达到24．01U/mg,比未优化前1．71U/mg 提高了14倍。该酶具有较强的酸碱稳定性和热稳定性,最适 pH 为6．5,最适温度为54℃。在最适 pH 和温度条件下测得该酶 km 值为7．1 ×10~(-5)mol/L。     

乳酸菌混合菌株基础培养基及增殖因子的筛选

研究了嗜热链球菌和保加利亚乳杆菌混合菌株培养时,其基础培养基的选择和增殖因子的筛选.实验结果表明：经蛋白水解酶处理后的脱脂奶培养基适宜乳酸菌混合菌株的生长;在此基础上,通过对促进生长物质的研究,得出了增殖因子的配比：蛋白胨0.8%、酵母粉0.8%、吐温0.1%、乳糖0.5%.     

2种酵母对蓝靛果果酒理化特性的影响

该文以蓝靛果为原料,以选择适宜的酿造蓝靛果果酒酵母为研究目的,比较LA酵母和安琪酵母对蓝靛果果酒中总糖、总酸、酒精度和多酚等理化指标的影响,并对蓝靛果果酒进行了感官评定.综合分析的结果是LA酵母比安琪酵母更适合蓝靛果果酒的发酵.     

A simple method for determining the metabolic activity of brewer's yeast during the brewing process

Metabolic activity of three strains of brewer's yeast during beer fermentation and during storage in tanks between individual fermentations was determined by measuring their acidification power. Under appropriate experimental conditions changes in acidification power during fermentation closely resemble changes in the Q_CO2^Ar quotient measured by Warburg manometry. The method gives immediate and reproducible results, requires only standard equipment (bench-top centrifuge, pH meter) and is suitable for assessing the course of fermentation. When the same batch of yeast is used for repeated fementations interspersed with resting intervals in storage tanks, it can be used for estimating the decline in the metabolic activity of such a yeast batch.     

啤酒酵母石蜡保藏方法

啤酒酵母菌种的质量好坏,对啤酒的酿造质量是至关重要的。选择妥当的原菌种保藏方法是稳定酵母纯种的性能、防止变异和衰退、保持优质菌种的前提条件。     

Molecular cloning and application of a gene complementing pantothenic acid auxotrophy of sake yeast Kyokai no. 7

Kyokai no. 7 is the most widely used yeast in sake brewing. This yeast is a pantothenic acid auxotroph at 35 degrees C, and this phenotype has been used to distinguish Kyokai no. 7 from other sake yeasts. We cloned a DNA fragment complementing the pantothenic acid auxotrophy from a genomic library of a Saccharomyces cerevisiae laboratory strain. DNA sequence analysis revealed that the DNA fragment encodes ECM31, the deletion of which had previously been identified as a calcofluor white-sensitive mutation. The ECM31 product is similar to the Escherichia coli ketopantoate hydroxymethyltransferase. Disruption of ECM31 in a laboratory S. cerevisiae strain resulted in pantothenic acid auxotrophy, indicating that ECM31 is also involved in pantothenic acid synthesis in yeast. A hybrid of a Kyokai no. 7 haploid and the ecm31 disruptant required pantothenic acid at 35 degrees C for its growth, suggesting that Kyokai no. 7 possesses a temperature-sensitive allele of ECM31. Thus, the ECM31 gene can be used as a selective marker in the transformation of Kyokai no. 7.     

A simplified procedure to analyse mitochondrial DNA from industrial yeasts.

A rapid method based on mtDNA restriction analysis is described for yeast strain identification. The method is an adaptation of that devised by Querol et a]. [Syst. Appl. Microbiol. 15 (1992) 439] for Saccharomyces cerevisiae wine strains, and consists of the standard miniprep isolation of yeast total DNA, and the use of restriction endonucleases that recognise a large number of sites in yeast nuclear DNA, but few sites in the mitochondrial DNA. In the adapted method, the propagation of yeast cells and restriction analysis were the steps mainly affected: cell growth was reduced to 36 h by using microfuge tubes, and the restriction analysis was carried out in just 33 min using a microwave oven for DNA digestion, and minigels for restriction fragment separation. The DNA extraction procedure was performed in the same way as in the original protocol. but slightly reducing the duration of each step and scaling down the volumes of the different solutions. enzymes and reagents used. As result, a large time reduction (52.5 h) was obtained compared to the original method. The DNA obtained can be directly digested with endonucleases displaying clear restriction patterns useful for S. cerevisiae yeast strain differentiation. In addition, strains belonging to other foodborne yeast species, including spoilage yeast species, can also be identified.