江南小窖宣酒酿造微生态系统中高产四甲基吡嗪功能微生物的筛选与鉴定

为挖掘、鉴定江南小窖宣酒酿造微生态系统中高产四甲基吡嗪的功能微生物,应用平板透明圈法、Voges-Proskauer(V-P)反应和目标产物定量分析从宣酒大曲中筛选高产四甲基吡嗪的功能菌株,菌株分子生物学鉴定,并应用于麸曲培养基发酵。结果表明,从曲中筛选出10株高产四甲基吡嗪的功能菌株,通过鉴定分别属于枯草芽孢杆菌属、解淀粉芽孢杆菌属和地衣芽孢杆菌属,其中解淀粉芽孢杆菌Bacillus amyloliquefaciens XJB-104固态发酵生产麸曲中TTMP的含量最高,为202.54 mg/kg。     

酱醪贝莱斯芽胞杆菌四甲基吡嗪高产菌的选育及其发酵优化

为获得四甲基吡嗪(TTMP)高产发酵菌株，以酱醪中筛选的贝莱斯芽胞杆菌CS1.11为出发菌株，进行紫外诱变，以酪素平板水解圈直径及乙偶姻显色反应为指标进行初筛，以蒸煮豆粕和焙炒小麦为原料固态发酵TTMP进行复筛，得到3株突变株。蛋白酶、淀粉酶活力及乙偶姻合成能力研究表明，其中2株突变株CS1.11-32、CS1.11-33更优，其TTMP的积累量较出发菌株分别提升了47.64%，78.89%，适用于酱油发酵体系。对影响TTMP积累的炒麦添加量、加水量、接种量、发酵温度及搅拌次数进行2株菌的对比发酵研究，CS1.11-33显示出更优的TTMP积累能力。响应面试验优化得出CS1.11-33固态发酵积累TTMP的最佳发酵条件为:炒麦添加量44%，加水量29%，发酵温度37 ℃，接种量8%，发酵过程中不进行搅拌，在此条件下TTMP积累量最大达到1 895.08 mg/kg干基，是其优化前的2.6倍。酱醪贝莱斯芽胞杆菌TTMP高产株的选育及其发酵研究将为提高酱油中TTMP浓度、快速增强酱香及促进TTMP的功能性应用奠定基础。     

汾酒大曲中高产四甲基吡嗪菌株的筛选与鉴定

从汾酒大曲中分离出15株可以产生TTMP的芽孢杆菌。通过观察菌落形态的基本特征和细胞的显微形态图对其进行纯种确认,采用气相色谱法筛选出3株高产TTMP的芽孢杆菌,并利用16SrDNA序列测定法进行菌种鉴定,得出3株高产TTMP的芽孢杆菌中2株为枯草芽孢杆菌、1株为弯曲芽孢杆菌,该结果增加了TTMP高产菌株的类型范围,为TTMP的生产实践应用提供了依据。     

高产乙偶姻酵母菌种的选育与提高白酒中四甲基吡嗪含量的研究

四甲基吡嗪是近年来在白酒中发现的一种健康因子,提高白酒中四甲基吡嗪的含量对于白酒产品风味与品质具有重要影响。总结了白酒中四甲基吡嗪的形成途径以及目前的研究进展,酿酒酵母细胞中的乙偶姻代谢与调控机制,并通过分子育种手段选育了一系列高产乙偶姻的酵母菌株。在清香型麸曲白酒中的应用结果表明,与出发菌株比较,高产乙偶姻菌株在固态厌氧发酵条件下的基本发酵性能没有发生变化,酒醅中乙偶姻的含量提高达320.38%,TTMP的含量提高了74.66%。     

2,3-丁二醇调控四甲基吡嗪及乙偶姻合成菌产物产量的研究

发酵初期在枯草芽孢杆菌发酵培养基中添加2,3-丁二醇(2,3-BD)可以调控发酵产物乙偶姻,四甲基吡嗪(tetramethylpyrazine,TTMP)的产量。随着2,3-BD添加量的增加,所产乙偶姻和TTMP的量随之增加,当2,3-BD的添加量≥4.0 g/L时,乙偶姻和TTMP的产量不再增加。同时,枯草芽孢杆菌的生物量、糖转化率也随之变化。该调控方法对枯草芽孢杆菌的分子改造菌株(Δbdh A)调控产乙偶姻和TTMP的产量影响不大。     

芽孢杆菌与酵母菌和根霉曲混合发酵提高四甲基吡嗪含量的研究

四甲基吡嗪(Tetramethylpyrazine,TTMP)是白酒中一种重要的香气成分,提高大曲中四甲基吡嗪的含量对提高白酒中四甲基吡嗪的含量具有重要意义.本研究通过芽孢杆菌纯种发酵(A);同时接种酵母菌和芽孢杆菌(B);先接种酵母菌,再接种芽孢杆菌(C);先接种酵母菌和根霉曲,再接种芽孢杆菌发酵(D),测定发酵结束...     

高温大曲中高产四甲基吡嗪芽孢杆菌的分离鉴定及发酵条件优化

该研究从高温大曲中分离筛选产四甲基吡嗪（TTMP）芽孢杆菌,采用细胞形态学观察、生理生化试验及分子生物学技术对高产四甲基吡嗪菌株进行鉴定,并优化四甲基吡嗪产量最高菌株的发酵条件。结果表明,经初筛从高温大曲中分离出20株产四甲基吡嗪芽孢杆菌（编号为WH1～WH20）,经过复筛得到四甲基吡嗪产量较高的菌株WH7、WH10和WH20。其中菌株WH7和WH20被鉴定为副淀粉芽孢杆菌（Bacillus paramycoides）,菌株WH10被鉴定贝莱斯芽孢杆菌（Bacillus velezensis）。菌株WH10的最佳发酵条件为：前发酵温度37℃、前发酵时间72 h,后发酵温度60℃,后发酵时间20 h,初始pH值6.5,铵盐添加量4 g/L。在此优化条件下,四甲基吡嗪产量为728.38 mg/L,比优化前提高了167%。     

常压室温等离子体诱变选育高产TTM P菌株

从新疆伊犁肖尔布拉克酒厂生产的酱香型高温大曲中筛选得1株能代谢四甲基吡嗪（TTMP）的枯草芽孢杆菌(Bacillus subtilis)R19,以该菌株为出发菌株,采用常压室温等离子体诱变系统（ARTP）进行诱变,根据脱脂奶粉平板初筛、摇瓶发酵复筛,连续传代培养后得到遗传稳定的TTMP产量较高的突变株T451,该菌株摇瓶发酵生产TTMP的产量为1.19 g/L,约为出发菌株产量的4.45倍。     

应用内源前体策略提高杆菌发酵制备TTMP的能力

基于前体乙偶姻和四甲基吡嗪(TTMP)分子结构的相关性,建立了一种适合于风味化合物TTMP筛选的内源前体筛选策略;并应用该策略,从酱香型高温大曲中获得1株TTMP产生菌XZ1124,该菌株能利用葡萄糖代谢产生大量前体乙偶姻,从而有效促进了TTMP的合成;根据菌落、细胞形态特征和生理生化特性以及16S rDNA序列分析,将该菌株鉴定为枯草杆菌(Bacillus subtilis).碳氮源以及培养条件的单因素优化结果表明,供氧条件和培养温度对TTMP合成的影响最为突出.在最优条件下,摇瓶发酵和发酵罐培养时前体乙偶姻的积累量＞ 20 g/L,TTMP的合成量＞ 4.08 g/L.上述结果有效证明了内源前体筛选策略用于筛选具有结构类似前体的风味功能菌;TTMP合成工艺具有生产强度高且能以廉价的农副产品(豆饼粉)作为底物,极具工业应用前景.     

响应面法优化枯草芽孢杆菌S0507产四甲基吡嗪的培养条件

通过响应面分析法对枯草芽孢杆菌S0507产四甲基吡嗪（tetramethylpyrazine,TTMP）培养工艺进行优化。经单因素试验后,以Box-Behnken法设计考察培养时间、培养温度、水分含量3 个因素对TTMP产量的交互影响,用Design-Expert v8.0.1.6软件对BBD试验数据进行分析处理。通过响应面试验得到的最佳培养条件为：低温培养时间33.84 h、培养温度41.75 ℃、水分含量59.63%,TTMP产量为332.70 mg/kg,理论值（335.49 mg/kg）与实验值的相对偏差为0.84%,证明应用响应曲面法优化枯草芽孢杆菌S0507产TTMP的培养条件是可行的。     

风味物质4-乙烯基愈创木酚的研究进展

4-乙烯基愈创木酚是一种挥发性酚类化合物,具有强烈香辛料、丁香和发酵香味,是决定白酒、啤酒、葡萄酒和酱油等产品的重要风味物质。该文综述了4-乙烯基愈创木酚的理化性质、生物合成及在发酵食品中的作用,介绍近年来4-乙烯基愈创木酚的研究状况,为提高发酵食品的质量奠定基础。     

Lactic acid fermentation as a tool for increasing the folate content of foods

Folate is an essential micronutrient involved in numerous vital biological reactions. The dietary consumption of naturally occurring vitamin B9 is often inadequate in many countries, and supplementation or fortification programs (using synthetic folic acid) are implemented to alleviate folate deficiency. Other food-based alternatives are possible, such as the use of lactic acid bacteria (LAB) to synthesize folate during fermentation. Many studies have been conducted on this topic, and promising results were reported for some fermented dairy products. However, in other studies, folate consumption by LAB or rather low folate production were observed, resulting in fermented foods that may not significantly contribute to the recommended B9 intake. In addition, the optimum conditions for folate biosynthesis by LAB are still not clear. The aim of this review was thus to (i) clarify the ability of LAB to produce folate in food products, (ii) check if the production of folate by LAB in various fermented foods is sufficient to meet human vitamin B9 requirements and (iii) suggest ways to optimize folate production by LAB in fermented food products.     

发酵食品微生物多样性分析方法研究进展

发酵食品含有丰富的微生物,微生物的构成对食品的功能、质构和风味有重要影响,也是筛选具有特殊功能微生物的重要源泉.对发酵食品微生物多样性分析方法进行综述,主要包括传统方法和分子生物学方法.比较各种方法的优缺点,以期对发酵食品的微生物多样性和菌群结构进行客观全面的分析,为发酵食品的发展提供基础.     

发酵食品工业中的生物安全性评价

发酵食品因其具有促进肠内营养吸收和消化道健康的有益生理功能而深受大众喜爱。然而发酵食品是经发酵菌株代谢而制成的,发酵菌株的安全性、有害代谢产物、杂菌污染等因素直接影响到发酵食品的安全性,发酵食品工业也因此面临着食品安全问题的挑战。本文对发酵食品工业中存在的安全性问题、生物安全性评价以及未来的展望等进行论述,旨在让人们了解发酵食品可能存在的安全风险以及如何进行安全性评价,这对于提高人们食品安全意识,保证发酵食品安全生产,消除安全隐患有重要意义。     

Tetramethylpyrazine in Chinese sesame flavour liquor and changes during the production process

Tetramethylpyrazine (TTMP) is a key bioactive alkaloid and flavour compound found in Chinese sesame flavour liquor. Changes in TTMP concentration during the production of sesame flavour liquor have received little attention. Here, TTMP was tracked from raw material, fermented grains and fresh liquor in storage using high‐performance liquid chromatographic–tandem mass spectrometry (HPLC‐MS/MS). The results showed that TTMP was formed during stack fermentation, solid‐state fermentation and distillation, while no TTMP was produced during the storage process of fresh liquor. Furthermore, a higher temperature fermentation and bacterial starter culture were beneficial to TTMP generation. Accordingly, technology strategies for increasing the concentration of TTMP in sesame flavour liquor include raising the temperature of stack fermentation and distillation, reducing the distillation speed and screening for high TTMP producing Bacillus species. © 2018 The Institute of Brewing & Distilling     

发酵食品中生物胺检测技术研究进展

生物胺作为一类具有生物活性的小分子含氮化合物,是发酵食品中常见的代谢物之一,过量摄入会引起呼吸困难、心悸等不良反应,而在食品发酵过程中,由于原料中蛋白质含量高,且发酵微生物能够产生蛋白酶和氨基酸脱羧酶等因素,导致生物胺的产生和积累。同时生物胺与食品腐败密切相关,其含量可作为衡量食品质量和新鲜度的指标,因此,发酵食品中生物胺的定性和定量检测技术非常重要。本文综述了国内外目前针对发酵食品中生物胺的检测技术,分析其优缺点,并探讨了生物胺检测技术的发展趋势,为发酵食品中生物胺的检测提供技术基础和方法依据。     

A review on selection of fermentative microorganisms for functional foods and beverages: the production and future perspectives

Fermentation has been employed as a traditional means of improving the shelf life and nutritional contents of foods, thus making fermented foods and beverages functional and therapeutic. Lactic acid bacteria (LAB) plays a major role in determining the health benefits of fermented milk and related products. This review takes into cognizance numerous investigations reporting certain microbial strains and mixes to contribute safety, quality, stability, health and organoleptic properties to fermented foods, due to increased consumers’ awareness of food products with health claims. A look was taken at selection criteria for the ideal fermentative microbial species and strains, their usefulness and prospective ‘OMICS‘-based approaches to elucidating fermentative complex communities in relation to their effects on fermented food products. Moreover, recommendations were given for improved fermentation of beverages and functional foods. It is projected that fermented foods and beverages will continually be a paramount in the global food and emerging functional food market.     

发酵豆制品酿造过程中组分和营养功能因子的变化及调控

发酵豆制品是发酵食品中的一大类,在亚洲国家人民饮食中占重要地位,并逐渐受到西方国家青睐。近年来,发酵豆制品酿造过程中产生的功能因子不断被报道,其抗氧化、降血压、降血糖、溶血栓、抗突变等功能性不断被揭示,引起世界广泛关注。发酵豆制品组分变化的调控对增强营养和富集功能因子意义重大,有利于进一步提升其食用价值,促进人类健康。本文综述发酵豆制品生产过程中与营养和功能相关的部分组分的变化及调控,并对该领域的科学问题进行展望。     

Fermentation for tailoring the technological and health related functionality of food products

Abstract

Fermented foods are experiencing a resurgence due to the consumers’ growing interest in foods that are natural and health promoting. Microbial fermentation is a biotechnological process which transforms food raw materials into palatable, nutritious and healthy food products. Fermentation imparts unique aroma, flavor and texture to food, improves digestibility, degrades anti-nutritional factors, toxins and allergens, converts phytochemicals such as polyphenols into more bioactive and bioavailable forms, and enriches the nutritional quality of food. Fermentation also modifies the physical functional properties of food materials, rendering them differentiated ingredients for use in formulated foods. The science of fermentation and the technological and health functionality of fermented foods is reviewed considering the growing interest worldwide in fermented foods and beverages and the huge potential of the technology for reducing food loss and improving nutritional food security.