高温大曲和中温大曲生产中常见病害及防治

根据大曲培养过程中控制曲块的最高品温不同,一般可以把大曲分为高温大曲、中温大曲和偏高温大曲。高温大曲主要用于生产茅香型（俗称酱香型）大曲酒;中温大曲主要用于生产汾香型（俗称清香型）大曲酒和沪香型（俗称浓香型）大曲酒。由于大曲生产是生料制曲、自然接种,这其中就有有益微生物和有害微生物,而且优劣共存。虽然在工艺上严格控制温度、湿度、水分,使之达到适于有益微生物的繁殖,而有害微生物的生长亦属难免。有时工艺条件掌握上也存在问题,这就给大曲生产带来木利--常出现病害。下面分别介绍高温大曲和中温大曲生产中常见…     

不同季节生产浓香型中高温包包曲的分析与探讨

以不同季节生产的浓香型中高温包包曲为研究对象,探讨大曲发酵过程中理化指标、微生物动态变化及酿造过程中大曲量化使用模型,结果表明：各季节大曲理化指标和微生物含量变化趋势大体一致,但春秋季节大曲理化指标明显高于夏季,夏季大曲微生物多样性明显高于春秋季节,通过分析糟醅发酵状况,合理搭配各季节大曲,能起到改良酿酒工艺,降低消耗,推进酿酒业发展的作用。     

浓香型大曲与生产环境微生物群落间的溯源性分析

为揭示浓香型大曲微生物群落的来源,以同企业的新老制曲基地及生产的大曲为对象,应用高通量测序技术对大曲与生产环境的微生物群落进行了溯源性研究。生产环境在大曲的制造过程中起关键作用,SourceTracker结果显示,老厂曲坯中微生物主要来源于原料和制曲工具,新厂曲坯微生物主要来源于原料。老厂环境对曲坯和成曲（刚转房的大曲）细菌群落组成的贡献度都更高,但真菌群落相对稳定,受环境微生物的影响较小。由于撒陈曲（存放3 个月以上）粉强化,新厂曲坯和成曲的微生物还来源于陈曲。通过适当强化方式改善和营造了适合大曲生产的环境,对维持大曲品质稳定性具有重要意义。研究结果揭示了浓香型大曲微生物群落的来源,为解析大曲群落定向驯化和驱动作用奠定了基础。     

有益功能微生物在强化大曲生产中的应用

以传统中高温大曲作为研究对象,对其微生物体系进行分析,通过分离筛选获得一些具有提高大曲性能的有益功能微生物。将有益功能微生物应用于传统大曲生产中,制备强化大曲。通过指标测定及生产应用,取得了良好的效果,对提高大曲品质,以及推进大曲机械化生产具有重要意义。     

青稞大曲微生物菌群的多样性及其核心菌群的判定

采用高通量测序方法分析青稞大曲制作过程中微生物群落结构及其演替规律,并应用多元统计分析方法揭示了影响制曲过程的微生物群落变化的关键因子,分析了不同配料大曲微生物群落之间的差异,初步确定青稞大曲中的优势微生物属为:Pantoea、Staphylococcus、Pichia和Saccharomycopsis。通过微生物与代谢产物网络可视化分析,初步判定在大曲发酵过程中与重要的代谢产物相关的微生物有Lactobacillus、Leuconostoc、Pediococcus、Saccharomycopsis、Pediococcus、Wickerhamomyces和Aureobasidium。通过冗余分析发现,与主要环境因子相关的微生物有Wickerhamomyces、Rhizopus、Ralstonia、Lactobacillus、Saccharomyconsis和Acinetobacter,它们很可能是青稞大曲制作过程中的核心微生物。蒙特卡洛置换检验结果表明,在大曲制备过程中游离氨态氮对微生物群落分布具有极显著相关性,随着原料中小麦含量的增加,氨态氮含量变化会驱动大曲中微生物群落衍变。     

浓香型大曲生产过程中微生物及温度变化规律的研究分析

在浓香型大曲生产过程中，细菌、酵母菌、霉菌的生长和消亡与温度、水分有密切联系，本文主要探讨微生物消长规律与曲温、品温和室温的关系，以及水分、糖化力在大曲生产过程中的变化规律，以期为生产实践中翻曲和排潮提供参考。     

“无稻草，不翻仓，控温控湿”曲房创新对高温大曲微生物组成的影响研究

为了探究使用稻草的传统曲房和不用稻草的控温控湿曲房所生产的酱香型高温大曲的微生物组成差异,本文采用Illumina平台对传统曲房大曲、控温控湿曲房大曲及生产用稻草的微生物群落组成进行了研究。结果表明,传统曲房大曲与控温控湿曲房大曲共同拥有着多种优势微生物。两种大曲优势细菌均为Virgibacillus、Kroppenstedtia和Scopulibacillus属的细菌(该三属的细菌在传统曲房和控温控温曲房大曲中分别占88.04%和87.28%),但比例有所差异,Pearson相关系数为0.5725;该两种大曲优势真菌均为Thermoascus、Thermomyces和Rasamsonia属的真菌(该三属的真菌在传统曲房和控温控温曲房大曲中分别占98.56%和98.57%),且比例也较相似,Pearson相关系数为0.9505。另外,生产用稻草微生物组成非常丰富,细菌以Bacillus、Pantoea、Saccharopolyspora、Methylobacterium、Staphylococcus为主,真菌以Aspergillus、Mycosphaerella、Saitozyma、Wallemia、Papiliotrema为主。通过两种大曲及稻草微生物的组成对比发现,稻草在高温大曲发酵过程也具有接种的作用,但并非起决定性的影响,酱香型大曲发酵微生物主要还是来自曲母、原料和制曲条件及环境。     

酱香型白酒大曲微生物研究进展

酱香型白酒是中国白酒的重要香型,具有“酱香突出,幽雅细腻,酒体醇厚,回味悠长,空杯留香持久”的风格特点,其所具有的独特风味越来越受到消费者的喜欢。大曲在白酒的发酵中有着重要作用,作为白酒的糖化发酵剂,大曲发酵过程中产生丰富的微生物和酶等物质,形成了酱香大曲特有的风味。该文系统综述了酱香型白酒大曲微生物的多样性分析、产香成分分析、酶活研究,以及大曲微生物在酱香型白酒生产中应用的最新研究进展,并对酱香型白酒酿酒微生物的未来的研究提出了思考与展望。     

基于26S rRNA D1/D2区序列对不同时期大曲中酵母菌的分离与鉴定

利用大曲作为糖化发酵剂是中国传统白酒主要的工艺特点之一。大曲中的微生物组成十分丰富包括各种种类的霉菌、酵母以及细菌,这些复杂的微生物体系为白酒的发酵提供了必要的微生物、酶以及风味物质。酵母菌作为所有酒类发酵生产中必不可少的微生物,在大曲的生产过程中也起到了很重要的作用。为了探究大曲中功能微生物,本文对不同时期大曲中分离的酵母菌采用26S rRNA D1/D2区序列进行分析比对,共分离鉴定了260株酵母菌,分属于22个种。主要为Wickerhamomyces anomalus,Candida orthopsilosis,Meyerozyma guilliermondii,Pichia caribbica,Saccharomycopsis fibμLigera,Cryptococcus neoformans var.grubii,Clavispora lusitaniae,Saccharomyces cerevisiae等。对序列比对的结果进行了单链构像多样性(Single Strand Conformation Polymorphism,SSCP)分析,确定了它们的种间差异,并构建了M-L系统树。根据这些分离鉴定的结果初步探究出大曲生产过程中不同时期酵母菌的组成和变化规律。这些结果为进一步研究中国传统白酒的酿造微生物奠定了一定的基础。     

浓香型习酒架式大曲微生态研究

将分子生物学技术与传统微生物培养技术等研究方法有效结合,从制曲发酵过程中微生物量化分析、大曲优势微生物菌群的鉴定,以及酒曲微生物菌群多样性3个方面对浓香型习酒架式大曲微生态进行了系统全面的比较学研究,探讨了大曲生产体系微生物区系的形成和演变规律,为揭示黔派浓香型习酒酿酒微生态学特征奠定了基础。     

Deposition of glomalin-related soil protein and sequestered toxic metals into watersheds

We hypothesized that glomalin-related soil proteins (GRSP) are eroded in sufficient quantities to influence metal loading into watersheds. We tested correlations among GRSP, Glomeromycota fungi, and metals (cadmium, iron, lead, and manganese) in proteins extracted from embankment soils at seven locations along an urban/coastal watershed. Immunoreactive (IRSP) and easily extractable (EE-IRSP) glomalin ranged from 0.007 to 2.9 mg g(-1) and from 0.006 to 0.63 mg g(-1) of soils, respectively. Glomalin-bound metals (microg mg(-1) protein) were Cd = 0.00-0.338; Fe = 0.5-227.7; Pb = 0.11-188.95; Mn = 2.23-784.42). Glomeromycota fungi were detected in 24% of all samples tested with PCR targeting the 18S and 28S ribosomal DNA extracted from soils. Specific assay for G. intraradices showed 3.08 x 10(7) copies g(-1) and 1.96 x 10(3) copies g(-1) of soil at two sites. Estimated annual glomalin loading into the watershed ranged from 5.48 x 10(2) to 7.22 x 10(4) kg of IRSP and from 2.57 x 102 to 2.86 x 10(4) kg of EE-IRSP; including 2.7 kg (Cd), 6.3 x 10(3) kg (Fe), 5.06 x 10(2) kg (Pb), and 1.80 x 10(3) kg (Mn). These data provide insights into the sources and ecological fate of a ubiquitous soil protein and its metals content.     

几种不同来源的酵母抽提物性质的比较研究

为了了解目前国内酵母抽提物产品的性状,比较了国内、外8种不同来源的酵母抽提物的物理性状,溶解性,干湿比,1%水溶液的pH,总氮含量和氨基氮含量,分别将其配成YEPD培养基培养啤酒酵母,测定菌株在不同来源的酵母抽提物培养基中的生物量。经比较发现,部分国内生产的酵母抽提物颗粒的细致程度和水溶液的澄清程度有待提高,部分国内生产的酵母抽提物1%水溶液的pH呈弱酸性,干湿比、总氮含量和氨基氮含量与国外生产的酵母抽提物无明显差别,培养啤酒酵母得到的生物量略优于国外生产的酵母抽提物。故国内生产的酵母抽提物在大部分的生物试验和食品与发酵生产中,可以代替国外生产的酵母抽提物,而且价格仅为进口酵母抽提物的30%~50%。     

枸杞酒发酵菌种的筛选及其香气分析

为筛选一株适合枸杞酒生产的酵母菌,考察活性干酵母K1、DSM、BY、DV10、EC118和安琪酵母的发酵能力,选择产酒精能力和产酒香乙酸异戊酯能力较强的安琪酵母、BY酵母和EC118酵母,进一步测定酒样中枸杞香气成分含量。采用气-质联用技术分析不同枸杞酒的香气成分,发现BY酵母的枸杞香气成分含量达到12.56mg/L,是安琪酵母和EC118酵母的1.44倍和1.91倍。综合考虑发酵能力和酒样的枸杞香气成分含量,选择BY酵母作为生产枸杞酒的菌种。     

DETERMINATION OF SOME LIPID CONSTITUENTS OF BAKER'S YEAST

Lipid was extracted from whole yeast cells with difficulty because of the limited porosity of the cell wall and its sensitivity to dehydrating solvents. Extraction from mechanically broken cells was rapid and complete. Metabolic alteration of lipid when cells were disintegrated was minimized by first heating a yeast suspension briefly at 90°C. Details are given for the routine analysis of yeast phospholipids by quantitative paper chromatography and of neutral lipids by column chromatography. Lysophosphatides were found in some types of yeast after drying, but not in pressed commercial yeast or in yeast grown on synthetic media. They were formed when yeast was suspended in methanol-water, as yeast phospholipase A was activated and split palmitoleic acid from lecithin and phosphatidyl ethanolamine. Phosphatidyl inositol in baker's yeast contained a higher proportion of saturated fatty acids than other phospholipids. Sterols were present free and as esters with palmitoleic and oleic acids. Phospholipid content was affected by growth conditions. A high level of inositol in the growth medium reduced the formation of neutral lipid but did not affect the content of yeast phospholipid.     

利用固定化酵母进行黄酒主发酵的初步研究

该文以海藻酸钙凝胶为固定化载体,从酵母浓度、海藻酸钠浓度、氯化钙浓度3方面来探究黄酒主发酵阶段的最佳固定化条件,确定了酵母浓度为109个/mL,海藻酸钠浓度为2.0%,氯化钙浓度为4%。同时将其与传统游离酵母的发酵曲线进行对比,并且在实验室条件下连续进行了12次固定化酵母发酵,结果显示主发酵结束时酒样的酒精度在7.4%vol左右(与游离发酵结果类似),稳定性较为理想。     

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.     

THE SENSITIVITY OF DIFFERENT BREWING YEAST STRAINS TO CARBON DIOXIDE INHIBITION: FERMENTATION AND PRODUCTION OF FLAVOUR-ACTIVE VOLATILE COMPOUNDS

The sensitivity of brewing yeast strains, with different oxygen demands, to carbon dioxide inhibition was investigated. Laboratory fermentations were performed with, and without, protein-based “yeast foods” to lower dissolved CO₂ during fermentation. Differences were observed in yeast fermentative performance in the presence and absence of “yeast foods” for all yeast strains tested. Fermentation performance was improved with the addition of “yeast foods”. There was improved carbohydrate utilisation and amino acid uptake, while acetaldehyde levels at the end of fermentation were decreased. There was an increase in fusel oil production and acetate ester levels at the end of fermentation. Sulphur dioxide levels at the end of fermentation were unaffected by “yeast food” addition. Different yeast strains displayed differing sensitivity to CO₂ inhibition for all parameters tested. Sensitivity to CO₂ was not found to be related to oxygen demand of the yeast strains.     

酵母抽提物风味成分研究进展

该文对酵母抽提物的呈味机理进行了研究,分析了主要呈鲜成分在酵母抽提物中的作用及影响方式,发现酵母抽提物的呈 鲜主要依靠谷氨酸和核苷酸,而风味则依靠其中的肽或美拉德产物;对酵母抽提物的生产原料来源、生产技术及用途进行了简要分 析。 发现培育高产蛋白和核苷酸的酵母菌种,并采用自溶法、酶法处理酵母细胞为主流技术方向。 同时,新的酵母抽提物产品向风味 酵母抽提物及根据特殊产品定向开发的方向发展。     

两种酵母提取物对调理鲈鱼品质影响研究

目的 研究两种酵母提取物浸渍液对调理鲈鱼品质影响。方法 以鲈鱼片为研究对象,通过安琪和一品鲜酵母提取物(记为YE1和YE2)分别与姜汁组成浸渍液,实验确定最佳组合,并研究不同组合浸渍液对鲈鱼片气味成分的影响以及在贮藏过程中气味、白度、菌落总数、感官评分、质构的变化。结果 浸渍液结果表明, YE1和YE2酵母浸渍液最佳组合分别为:YE1酵母浸渍液中含有0.10%的YE1酵母提取物和5.00%姜汁、料液比(m:V)为1:2、酵母浸渍液与姜汁浸渍液比为1:1、浸泡时间为30 min; YE2酵母浸渍液中含有0.15%的YE2酵母提取物和5.50%姜汁、料液比(m:V)为1:2、酵母浸渍液与姜汁浸渍液比为5:1、浸泡时间为30 min。贮藏结果表明,经酵母提取物处理后的鱼肉气味差异较大,在白度上的变化较平缓;贮藏20d后,酵母处理组菌落总数低于酵母未处理组;样品感官评分随贮藏时间延长而下降,但与对照组相比,贮藏后酵母处理组的感官评分更高;贮藏后期, YE2酵母提取物组合浸渍后的鲈鱼片硬度和咀嚼度高于对照组, YE1酵母处理组低于对照组。结论 经酵母提取物组合处理后,能有效减缓鲈鱼肉在贮藏过程中...     

Sorption of wine volatile phenols by yeast lees

The capacity of Saccharomyces cerevisiae yeast lees to sorb 4-ethylguaiacol and 4-ethylphenol was investigated in a synthetic medium and in wine. Active dried yeast was more effective when volatile phenols were diluted in red wine. Partition coefficients between wine model solution and wine yeast lees were determined and compared with those measured for dried active yeast. They showed a larger affinity of volatile phenols for wine yeast lees than for dried active yeast. The effect of yeast lees on volatile phenol sorption was sensitive to yeast autolysis level and to physicochemical parameters, such as ethanol content, temperature and pH. These results could be applied in the technology of reduction of organoleptic defects in wine due to phenols.