一种青稞格瓦斯的制备及挥发性风味成分分析

采用单因素及正交试验对以青稞原料的格瓦斯发酵工艺进行优化,并利用顶空固相微萃取-气相色谱-质谱联用技术(SPME-GC-MS)分析青稞格瓦斯挥发性风味成分。结果表明:原料经灭酶处理所得青稞汁中β-葡聚糖含量比未灭酶处理提高了36.08%;最佳发酵条件为青稞汁含量(以白利度计)14%,菌种添加量1.4 g/L,面包酵母菌与乳酸菌的添加比例为1∶1,温度30℃,时间10 h;经10 h熟化后,获得的青稞格瓦斯总酸度为1.76g/L、酒精度为2.13%vol、β-葡聚糖含量为15.75 mg/L、氨基氮含量为12.26 mg/100 m L;其主要挥发性风味成分为乙醇(53.46%)、异戊醇(13.08%)、苯乙醇(6.09%)、乙酸异戊酯(3.17%)等;色泽金黄透亮、酸甜苦味均衡、有成熟水果香与酒香。     

固、液态发酵生产微生物脂肪酶

目前脂肪酶生产主要有固、液态两种发酵方法。该文对两种发酵方法进行详细对比,概述固、液态发酵生产脂肪酶菌种及发酵底物,并对分批、补料分批、连续发酵等技术进行对比;介绍数学模型在脂肪酶生产中应用,并展望利用酶工程技术和数学模型改良脂肪酶生产。     

家庭自制格瓦斯饮料

介绍格瓦斯饮料的特点,以及以一些常见食品为原料制作家庭格瓦斯饮料的方法,重点介绍面包格瓦斯、玉米面格瓦斯和豆奶格瓦斯的制作方法。     

微生物发酵法生产食品风味物质

微生物发酵法已经成为生产食品风味物质的一种重要手段.主要对食品中的常见的芳香风味物质(主要包括醛类、酮类、酯类、萜类等)和味感风味物质的微生物发酵进行了概述,并介绍了几种用于生产风味物质的发酵方式.     

微生物发酵竹香鸡加工技术

研究了利用微生物发酵技术,添加益生菌生长促进剂加工竹香鸡的加工工艺和技术要点。     

量热法监控生物发酵过程的研究

量热法是生物热化学的重要方法之一,适合于生物体系各个层次的研究。在生物反应器的发酵过程中,量热法作为一种新的技术,简单适用,有着很大的市场前景。本文主要通过对生物发酵过程中罐体热流变化的研究,得出热量控制对生物发酵的影响,从而为大规模生产发酵过程的在线控制提供一定指导意义。     

茁霉多糖的微生物发酵及在食品工业中的应用

茁霉多糖具有很好的成膜性 ,形成的薄膜透明、防油、不透气 ,可作包衣和包装材料及纸的上光剂 ,代替淀粉制成低热量食品等 ,具有广阔的工业化应用前景。本文就茁霉多糖的生物学性质、影响微生物发酵的重要因素进行了综述 ,并简要叙述了茁霉多糖在食品工业中的应用     

沙蟹汁发酵过程中微生物与理化成分动态变化分析

该实验探究了沙蟹汁发酵过程中微生物及理化指标的变化规律。结果表明,沙蟹汁发酵前期（0～3 d）微生物主要是马胃葡萄球菌（Staphylococcus equorum）及阿尔莱特葡萄球菌（Staphylococcus arlettae）,后期（第6天）出现腐生葡萄球菌（Staphylococcus saprophyticus）、解淀粉盐水球菌（Salinicoccus amylolyticus）及蜡样芽孢杆菌（Bacillus cereus）,马胃葡萄球菌为发酵过程中的优势菌。沙蟹汁发酵过程中氨基酸态氮含量先迅速增加,后期增加缓慢,最终达到0.43 g/100 mL,总氮和游离氨基酸含量先增加后降低,分别达到为0.72 g/100 mL、2.99 g/100 mL,在沙蟹汁的发酵后期（12～15 d）,挥发性盐基氮含量迅速增加,达到105 mg/100 mL。沙蟹汁发酵过程中各理化指标的变化与微生物有一定的联系,其发酵主要是沙蟹体内内源酶和微生物共同作用的结果。     

馒头面团发酵过程中的微生物变化

探讨馒头面团长时间发酵过程中的酵母菌、醋酸茵、乳酸菌、大肠杆菌等微生物的变化。结果表明,发酵初期酵母菌数量增长较快,随着发酵的进行又逐步下降,最终酵母活力降至零;乳酸菌可以与酵母共生,并相互有利,它的变化与酵母密切相关;醋酸菌主要利用酵母的发酵产物,它的变化趋势基本上和酵母的趋势保持一致。大肠杆菌36h不超标。     

朗姆酒发酵过程中微生物群落结构及其动态演替

采用高通量测序技术对朗姆酒发酵过程中的微生物群落结构及其动态演替进行研究,共检出53个细菌属和25个真菌属。结果表明,朗姆酒发酵液中细菌群落多样性始终大于真菌,且细菌群落多样性在第3天添加丹多液后达到最大,此阶段中主要优势细菌为未分类的蓝细菌属（unclassified Cyanobacteria）,第5天的细菌群落多样性最小,此阶段主要优势细菌为厚壁菌门的乳酸杆菌属（Lactobacillus）;真菌群落多样性在第2天最大,酵母菌在整个发酵过程中始终属于优势真菌;采用Mantel text分析样品中微生物群落与环境因子间的相关性,结果显示,在OUT水平上,影响细菌群落和真菌群落多样性的主要是pH值,且真菌群落多样性与pH之间具有显著正相关（P＜0.05）。     

臭豆腐卤水微生物群落及其接种发酵

对样品臭豆腐卤水中微生物分离,应用传统微生物鉴定、细菌16S rRNA鉴定,探索不同微生物种属组成结构对臭豆腐品质作用以及风味的影响。分离鉴定了臭豆腐卤水中的主要细菌为漫游球菌（Vagococcus carniphilus）、嗜冷杆菌属（Psychrobacter sp.）、沙克乳杆菌（Lactobacillus sakei）、地衣芽孢杆菌（Enterococcus avium）、鸟肠球菌（Enterococcus devriesei）,并在无菌条件下采用纯菌种以及混合菌种直接进行豆腐发酵。单一菌种发酵比混合菌种发酵的臭卤所制得的臭豆腐总体感官评价结果偏低。除空白发酵结果以外,菌株St2（嗜冷杆菌）发酵的臭豆腐样品总体评价最差。菌株St5（鸟肠球菌）发酵所得的臭豆腐样品色泽较好,香气成分也较浓郁。     

中国传统食醋微生物污染及控制措施研究进展

食醋微生物污染是导致食醋腐败变质的最主要原因,有效地检测和控制污染微生物是保证食醋安全以及进一步发展的基础。该文对食醋污染微生物的原因、危害以及种类进行了综述,开放式发酵环境及容器管道的不洁是食醋污染微生物的主要原因,致使胀气、产膜、发黏及浑浊等现象发生,最终造成企业经济损失并对消费者健康造成隐患。总结了目前的检测方法和控制措施,现有的传统微生物培养检测方法弊端很多,非培养技术更能满足快速准确的检测要求。除加热和添加防腐剂等常用控制措施外,紫外线消毒、膜过滤等技术也逐渐应用。针对现有研究的不足,展望了食醋污染微生物未来的研究方向,以期为食醋污染微生物的深入研究及有效控制提供参考和理论依据。     

生姜猕猴桃自然酒精发酵醪微生物多样性研究

为了探讨和评估生姜猕猴桃自然酒精发酵醪酵母菌系多样性及其产品的安全性,采用微生物可培养方法对生姜猕猴桃自然酒精发酵中的酵母菌进行分离,并利用5.8S rDNA ITS序列信息分析不同时期生姜猕猴桃自然酒精发酵醪的酵母菌株α多样性和β多样性。结果表明,生姜猕猴桃自然酒精发酵中酵母菌有8属11种,包括假丝酵母、孢汉逊酵母、德巴利酵母、毕赤酵母、伊萨酵母、柯达酵母、梅奇酵母、Meyerozyma。毕赤酵母是生姜猕猴桃自然酒精发酵醪初期和后期的优势酵母菌群,Myerozyma是生姜猕猴桃自然酒精发酵醪初期和中期的优势酵母菌群。α多样性、β多样性分析结果显示,生姜猕猴桃自然酒精发酵中期物种多样性最高,发酵后期酵母菌数与独有酵母菌数最多,物种丰富度最高。     

Microbial and chemical changes in 'Sobrasada' during ripening

‘Sobrasada’ is a raw-cured product typical of Mallorca (Balearic Islands). Throughout its ripening process the product, like other raw-cured sausages, undergoes a series of chemical and microbial changes which lead to the formation of its desirable final characteristics.In the ‘sobrasada’ studied, the breeds, feeding and casings used in the Balearic Islands were employed. The evolution of different groups of microorganisms was followed: mesophylic aerobic microorganisms, lactic acid bacteria, Enterobacteriaceae, yeasts and moulds, group D Streptococcus, proteolytic microorganisms and lipolytic microorganisms. It was found that the predominant flora, from the beginning to the end, was made up of lactic acid bacteria. Conversely, Enterobacteriaceae disappeared as ripening went on, and the rest of the microbial groups studied underwent little variation along the process.An important characteristics of the product is the fast fall of pH, from values near 6·0 to values around 5·3, in the first week.     

Microbial community structure of pit mud in a Chinese strong aromatic liquor fermentation pit

Pits are necessary solid bioreactors for the production of Chinese strong aromatic liquor, and the microbial community in these pits significantly affects the quality and yield of the liquor. In this study, the microbial community structures of different aged pit muds were evaluated by phospholipid fatty acid analysis. The results indicated that the microbial community was composed of bacteria, actinomycetes and fungi, with Gram‐positive (G⁺) bacteria and anaerobic bacteria being dominant. The biomass of the pit mud increased and the microbial community shifted to G⁺ bacteria as the pit age increased. Principal component analysis showed that PC1 consisted mainly of fatty acids of saturated (15:0, 16:0 and 18:0), methyl‐branched (a15:0, i16:0, a16:0, i17:0 and 8Me18:0), polyunsaturated (16:1ω7c, 16:1ω9) and cyclopropane (cy17:0 and cy19:0), and PC2 mainly of 18:1ω9, 18:1ω10 and a14:0, The characteristics of the microbial community structure in the pit mud resulted from the stress effects of low oxygen concentration, low pH and a high alcohol concentration. Copyright © 2013 The Institute of Brewing & Distilling     

桑椹酒人工发酵过程中化学成分变化的研究

研究了桑椹酒人工发酵过程中一些主要成分如总糖、总酸、挥发酸、单宁、乙醇、甲醇、高级醇和酯等物质含量的变化。结果表明,桑椹通过加糖发酵原酒酒度可达到12.0%vol,总酸6.83g/L,pH3.12;单宁含量基本上无变化;挥发酸含量随着发酵时间的延长而逐渐上升,但最终可控制在1.0g/L(国标≤1.2g/L);甲醇在刚开始发酵时就存在,且含量维持在相对稳定的水平;高级醇主要包括正丙醇、异丁醇和异戊醇3种,占香气成分的50%,且在发酵过程中不断增加;发酵过程中还检测到乙醛、乙酸乙酯、己酸乙酯、戊酸乙酯、乳酸乙酯和一些未知成分。     

格瓦斯对大鼠肠道微生物代谢功能的影响

为探究格瓦斯对大鼠肠道轴向微生物代谢功能的影响,通过给大鼠灌胃青霉素钠建立肠道微生物失调大鼠模型,探讨格瓦斯饮料对大鼠体质量变化、排便时间、8 h内排便量、胃动素（MTL）、环磷酸鸟苷（cGMP）和肠道微生物相关指标的影响。结果表明,与模型组比较,格瓦斯给药组大鼠体质量有显著性差异（P＜0.05）,格瓦斯高剂量组大鼠的排便量与排便时间有显著性差异（P＜0.05）,且显著增加大鼠血清中MTL的含量（P＜0.05）,显著降低cGMP水平（P＜0.05）,格瓦斯可以显著增加双歧杆菌、乳杆菌数（P＜0.05）,显著降低肠杆菌、肠球菌、产气荚膜梭菌、拟杆菌数（P＜0.05）。格瓦斯对于肠道菌群失调导致的微生物代谢功能损伤有一定的拮抗作用,调节肠道微生态。     

Microbial community dynamics during the Scamorza Altamurana cheese natural fermentation

The growth dynamics of the natural microbial community responsible for the fermentation of Scamorza Altamurana, a typical Southern Italian cheese made using backslopping, was investigated applying a polyphasic approach combining 1) microbial enumeration with culture media, 2) randomly amplified polymorphic DNA (RAPD) fingerprinting of microbial communities, 3) sequencing of partial 16S ribosomal DNA (rDNA) genes, and 4) physiological tests. Viable cell counts on different culture media showed that the cocci community prevailed during the 18 h of curd fermentation and the 6 d of cheese ripening. RAPD fingerprinting made it possible to isolate 25 different strains identified by 16S rDNA sequencing as belonging to five species of Lactobacillus, three species of Streptococcus, one species of Weissella, and one species of Enterococcus. The physiological analyses of all lactic acid bacteria strains revealed that the isolates belonging to Streptococcus genus were the most acidifying, whereas lactobacilli were most proteolytic. Streptococcus thermophilus C48W and Lactobacillus delbrueckii subsp. bulgaricus B15Z dominated all through the fermentation process. Furthermore, they seemed to be stable in a subsequent whey sample analyzed after 7 mo. The recovery of strains endowed with interesting technological features, such as acidifying and proteolytic activities, and surviving in natural whey could allow the upscaling of cheese processing safeguarding the organoleptic characteristics of Scamorza Altamurana and could possibly improve other fermented dairy products.     

Use of lipase from Rhizomucor miehei in dry fermented sausages elaboration: Microbial, chemical and sensory analysis

Three different amounts of lipase (0.075, 0.100 and 0.150 LU/g) from Rhizomucor miehei (Palatase M 200L Novo Nordisk) were used to determine the correct amount to use in dry fermented sausages. Determination of acidity values through fourteen days of ripening showed that 0.100 LU/g was the most appropriate. Two types of fermented sausages were manufactured, addition of the enzyme being the only difference between them. Addition of Palatase did not affect product stability (pH and A(w)), and the growth of micro-organisms. In spite of the increase in acidity value, no rancidity developed as determined by both chemical and sensory analysis. Increases in the liberation of palmitic, palmitoleic, stearic, oleic and linoleic acids were found when lipase was used. Juiciness and taste were slightly better in the sausages with Palatase than in those without, but these differences were not reflected in the overall acceptability.