现制饮料中腐败微生物及其检测与防控技术研究进展

我国现制饮料种类丰富,产业发展快速且前景广阔。然而,近年来现制饮料中由腐败微生物引起的食品安全问题频发,受到了人们的高度重视。因此,本文归纳并总结了现制饮料中存在的主要腐败微生物种类、污染源及其产生的不良影响。介绍了传统检测法和快速检测法在腐败微生物检测中的应用,其中近红外光谱技术和高光谱成像技术等快速检测法具有样本量少、检测结果快、识别准确率较高等优点。阐述了物理杀菌法和食品防腐剂法等在腐败微生物防控中的应用,具有高效抗菌性、成本低、对现制饮料的感官品质和活性成分影响较小等优点。现制饮料行业的可持续发展离不开对腐败微生物的有效防控。本文为现制饮料腐败微生物控制和产业的可持续发展提供了理论依据和技术支撑。     

发酵类食品中微生物鉴定方法及功能研究进展

发酵类食品是主要通过直接接种微生物而产生特殊风味或者将食物浸入含有微生物的臭卤水中,从而获得特殊食品风味的中国传统食品。其中,采用含有微生物的卤水进行发酵是常见的发酵方式。因此,微生物在该类食品中一直扮演着一种非常重要的角色,具有较高的研究价值。本文阐述了发酵类型的食品所需要的卤水中微生物的鉴定常用方法,以及卤水微生物与风味成分的产生之间的关系,同时论述了卤水中微生物在各种发酵食品制作过程中所起到的功能特性,包括提高豆制品的营养价值、延长保质期、去除有害成分等问题,并提出了较为可行的新型发酵类食品卤水改进方向,为进一步开发理想的食品微生物发酵剂,控制有害物质的残留、拓展相关有益微生物资源的研究提供较为明确的指导方向。     

Early detection of food pathogens and food spoilage microorganisms: Application of metabolomics

BackgroundFood safety is a major issue, with a large number of people around the world suffering from illness due to the consumption of contaminated and unsafe food products. An early detection of food pathogens and spoilage microorganisms is an important step that can help to control a foodborne outbreak, thus avoiding the loss of a massive amount of food products.Scope and approachMetabolomics is generally a hypothesis generating tool that makes use of different analytical instruments to analyse as many metabolites as possible in a given biological sample. Metabolomics has already been successfully applied to different areas of food science. Here, I present metabolomics as a valuable tool for studying the metabolism of food pathogens and spoilage microorganisms.Key findings and conclusionsThe scientific area of metabolomics has improved tremendously over last decade. Due to the rapid development of instrumental platforms, it is now possible to analyse a wide range of metabolites present in food and produced by microorganisms. This approach has a high potential to determine biomarkers which can later be used for the development of early detection tools for food pathogens and spoilage microorganisms, thus ensuring a better management of food safety.     

肉类微生物学(九) 肉类微生物的控制

肉类的腐败变质主要是由微生物引起的,本文主要介绍了肉类微生物控制的三个基本策略,即防止微生物的生长、杀死微生物、促进有益微生物的生长,使其抑制有害微生物的生长,并重点介绍了各种不同的控制措施。     

非热加工技术诱导微生物亚致死损伤及控制方法研究进展

近年来,非热加工技术在食品杀菌保鲜领域的应用受到广泛关注。然而,大量研究表明,非热加工技术能够诱导微生物发生亚致死损伤。亚致死损伤是指微生物介于存活和死亡之间的一种损伤状态,可造成潜在的食品安全风险。本文综述了脉冲电场、高压二氧化碳、冷等离子体、高静水压等非热加工技术诱导微生物亚致死损伤的最新研究进展,探讨了亚致死损伤微生物的检测和控制方法,并展望了今后的研究方向,以期为研究亚致死损伤微生物及其控制技术提供理论参考。     

自然发酵腐与人工接种发酵腐乳的微生物比对研究

目的分析自然发酵腐乳与人工接种发酵腐乳两者微生物种类及可能产生的安全隐患,并对腐乳的生产环节中易产生的杂菌提出改进方案。方法利用传统的微生物分离鉴定方法,依据SB/T 10170-2007行业标准及食品安全国家标准食品微生物学检验等方法对影响腐乳中微生物的几个安全性指标和致病菌进行检测。结果通过2种方式培育的毛霉腐乳,其微生物含量和种类对比性很强,自然发酵腐乳的方式其细菌含量高,致病菌中金黄色葡萄球菌和沙门氏菌也均有检出,其他致病菌也存在很大的风险。选用人工接种发酵的腐乳其可培养出的微生物种类少,致病菌也未检出。结论选用人工接种发酵的腐乳较自然发酵的腐乳安全性高,更符合市场需求。     

壳聚糖复合生物防腐剂的抑菌效果研究

本实验研究了以壳聚糖及其金属锌螯合物为主复配的五个生物防腐剂配方以及配方中的主要组分在不同pH条件下的抑菌效果。研究选定的五种指示菌是大肠杆菌(Escherichia coli)8099、金黄色葡萄球菌(Staphylococcus aureus)ATCC6538、枯草杆菌黑色变种(Bacillus subtilis)ATCC9372、白色念珠菌(Candida albicans)ATCC10231和黑曲霉(Aspergillus niger ATCC16404),采用平板培养计数法检测了从加入不同种类的菌悬液至含抑菌剂和培养基的试管中培养0、4、24、48、72和96h的活菌残留数,以活菌残留数的对数值随时间变化的趋势表示抑菌效果。结果表明:配方A、B、D、E在p H6.0以下可以抑制五种指示菌。配方A～E和单组份壳聚糖金属锌螯合物对大肠杆菌、金黄色葡萄球菌和枯草芽胞杆菌的抑制效果好,而对羟基苯甲酸乙酯主要对枯草芽胞杆菌和黑曲霉的抑制较好,对其余三种菌的抑制效果较差,所有配方对白色念珠菌的抑菌效果较其它四种指示菌的抑制效果差,这是由于实验的起始菌悬液浓度较高造成的,同一配方在起始菌悬液浓度和作用pH值均低的情况下抑菌效果好。     

Effects of low-shear modeled microgravity on a microbial community filtered through a 0.2-μm filter and its potential application in screening for novel microorganisms

The effects of low-shear modeled microgravity (LSMMG) on a microbial community filtered through a 0.2-μm filter were investigated, and the potential application of LSMMG in the screening of microorganisms was evaluated. Pond water was passed through a 0.2-μm filter and the filtrate inoculated into two kinds of media (Schneider's insect medium, and ten-times-diluted Schneider's insect [0.1-Sch] medium). The cultures were incubated under LSMMG and normal-gravity and the microbial cell growth rates compared. Cell growth rates, final cell concentrations, and substrate consumption rates were higher in the LSMMG culture than in the normal-gravity culture. The microbial communities obtained under the various culture conditions were subjected to denaturing gradient gel electrophoresis (DGGE), revealing three different groups of microorganisms: (i) microorganisms whose growth rates were increased by LSMMG; (ii) microorganisms whose growth rates were suppressed or inhibited by LSMMG; and (iii) microorganisms whose growth rates were not affected by LSMMG. Sequence analysis of the microorganisms whose growth rates were increased by LSMMG showed that some had high similarity with unculturable microorganisms. When these microorganisms that displayed similarity with unculturable microorganisms were cultivated on agar plates, some of the DGGE bands present in the LSMMG culture were also present. We show that it is possible to isolate and cultivate uncultured microorganisms by using combinations of LSMMG, normal-gravity, and agar plate culturing techniques.     

拮抗微生物对枣果实采后病害生物防治的研究进展

枣果实采后极易发生真菌侵染性病害而造成重大损失,利用拮抗微生物防治枣果实采后病害是替代化学合成杀菌剂的一种绿色、环保、安全的防治方法.目前应用于防治枣果实采后病害的拮抗微生物主要为梅奇酵母属(Metschnikowia sp.)、假丝酵母属(Candida sp.)、隐球酵母属(Cryptococcus sp.)以及芽...     

微波辐射技术在食品微生物中的应用

微波辐射作为一种新型的物理处理手段，因其具有清洁、高效、无污染、节能省时、操作简便等优点，广泛应用于食品热加工、食品杀菌及微生物育种等研究领域。理论和实践表明微波辐射对食品微生物具有良好的适用性，利用微波辐射的热效应进行有害微生物与物质提取，利用微波辐射的非热效应进行微生物育种与发酵均可以达到优良的处理效果。微波辐射效应中的热效应与非热效应可以改变微生物的生理性状及代谢能力，达到一定强度还可灭活微生物，在微波辐射作用下物质提取较常规方法也更加高效。故本文针对微波辐射在食品微生物诱变育种、控制有害微生物、强化发酵及药食同源微生物功能性物质提取分离方面的应用研究与作用机理进行了相关综述，以期推进微波辐射在食品微生物领域的相关应用研究。     

利用洛伐他汀选育高产β-胡萝卜素的三孢布拉霉菌株

β-胡萝卜素为类萜化合物，是重要的VA的前体，并具有较强的抗氧化作用，在食品、保健品、化妆品以及医药领域具有重要用途。利用三孢布拉霉（Blakeslea trispora）发酵生产天然β-胡萝卜素最有应用前景。我们利用含有洛伐他汀（lovastatin）和OP乳化剂或脱氧胆酸钠（SDC）的平板实现了对高产菌株的选育，方法简单，效果明显。     

MICROBIOLOGICAL HAZARDS DURING PROCESSING OF CROQUETTES

Croquette is a prepared food made with meat or fish as its basic ingredients. Since it is a perishable, heavily handled product, microbiological hazards are associated with the process. Microbiological analyses were performed throughout the commercial processing of chicken croquettes to evaluate the microbial hazards. Moderately high levels of microorganisms were observed in raw materials, but the highest plate counts were noted following extrusion of the croquettes. Pathogenic bacteria, such as Clostridium perfringens, were detected during the process. The increase in the levels of microorganisms observed after extrusion and the presence of C. perfringens were associated with the semi-solid paste called bechamel. Rapid cooling of the bechamel was critical to avoid microbial proliferation and represented an effective critical control point for the implementation of a HACCP program in the processing of croquettes.     

原料乳中腐败微生物对液态乳品质的影响及防控

乳因其营养丰富备受关注,被称为人体的“白色血液”,同时乳也是微生物良好的培养基,因此原料乳品质和液态乳加工过程都会受到严格把控,但目前液态乳在储藏期、流水线或货架期内发生腐败变质现象仍屡屡发生,引起行业对乳及乳制品安全的高度重视。原料乳作为液态乳生产的原料,是其品质保障的基础,原料乳中腐败微生物随着储藏时间的延长而大量繁殖,经过热处理后未被完全杀死的腐败菌及其产生的耐热酶仍会继续影响液态乳品质,此外生物膜的形成也为腐败菌在管道内残留提供了机会,加大了腐败微生物防控的难度。因此本文将从原料乳中腐败微生物多样性进行阐述并探究腐败微生物对于液态乳的不良影响,挖掘腐败微生物破坏液态乳可能存在的作用机制,总结现阶段国内外对腐败微生物的防控手段并探讨其商业应用价值,旨在为今后液态乳质量安全保障及延长货架期提供理论指导。     

Proteolytic activity of conditionally pathogenic microorganisms causing food poisoning

A study was made of proteolytic activity of the microorganisms Proteus and Bac. cereus, as well as of infected extract from raw meat. Subject to study were also the effects of the temperature, storage and microbial association on the production of exoproteases. The results indicate an increase in the proteolytic activity in the course of storage at room and decreased temperatures and a lowering of the soluble protein amount in the samples, which attests to an active process of spoiling. Association of the bacteria in question appears to be a factor with a certain effect of protease repression. It is necessary to exercise control over the amount of the microorganisms in foods with a high content of protein, and to revise the times of meat storage in refrigerators.     

贝莱斯芽孢杆菌对浓香型白酒酒醅微生物群落结构及挥发性风味物质的影响

分析贝莱斯芽孢杆菌（Bacillus velezensis）存在条件下浓香型白酒酒醅微生物群落结构和挥发性风味物质合成的改变,以探究大曲微生物对酒醅微生物及其代谢的影响。通过接种1 株从中高温大曲中筛选得到的贝莱斯芽孢杆菌至酒醅中进行发酵实验,采用顶空固相微萃取气相色谱-质谱联用技术对对照组和实验组酒醅的挥发性风味物质进行检测分析,使用扩增子测序研究对照组和实验组酒醅的微生物群落结构,利用偏最小二乘-判别分析探究对照组和实验组酒醅间的差异挥发性风味物质,采用Spearman相关性分析研究酒醅优势微生物群落与差异挥发性风味物质的相关性。结果表明,与对照组相比实验组酒醅中微生物的丰富度和均匀度并没有发生显著改变,且微生物群落结构在整个发酵过程中也没有显著差异。实验组酒醅中酸类、酯类、醇类挥发性风味物质与对照组酒醅相比都出现了明显增加。对照组和实验组酒醅共有15 种差异显著的挥发性风味物质。实验组酒醅中己酸和己酸乙酯的含量显著增加,己酸与乳杆菌属有显著正相关;己酸乙酯与毕赤酵母属和威克汉姆酵母属呈正相关,与热子囊菌属、芽孢杆菌和魏斯氏菌属呈负相关。研究结果揭示了接种贝莱斯芽孢杆菌对浓香型酒醅微生物群落结构和挥发性风味物质的影响,有助于了解大曲微生物对酒醅微生物的扰动及代谢物的改变情况。     

代县黄酒风味劣变与微生物之间的关系研究

黄酒储存过程中微生物污染会引起黄酒腐败,对黄酒风味产生了极大的影响,解析黄酒主要腐败微生物与风味的关系对黄酒品质控制具有重要意义。该研究首先利用高通量测序技术分析了腐败黄酒中细菌菌群结构,然后通过固相微萃取结合气相色谱质谱联用（HS-SPME-GC-MS）仪对正常黄酒及腐败黄酒的风味化合物进行了对比分析,并对微生物和风味化合物进行了相关性分析,最后通过感官分析对比正常黄酒和腐败黄酒的香气特征。结果表明,乳酸菌是导致黄酒腐败的主要微生物,L（-）-乳酸乙酯在腐败黄酒中含量较大,是导致黄酒风味不协调的主要风味化合物。腐败的黄酒酸味、腐臭味和霉味明显。该研究结果揭示了黄酒风味劣变与微生物之间潜在相关性,为黄酒腐败控制提供了依据。     

A review of microbial injury and recovery methods in food

The existence of injured microorganisms in food and their recovery during culturing procedures is critical. Microbial injury is characterized by the capability of a microorganism to return to normalcy during a resuscitation process in which the damaged essential components are repaired. Injury of microorganisms can be induced by sublethal heat, freezing, freeze-drying, drying, irradiation, high hydrostatic pressure, aerosolization, dyes, sodium azide, salts, heavy metals, antibiotics, essential oils, sanitizing compounds, and other chemicals or natural antimicrobial compounds. Injured microorganisms present a potential threat in food safety since they may repair themselves under suitable conditions. Detection of injured microorganisms can be important to practical interpretations of data in food microbiology. This review provides an overview of microbial injury in food and discusses the development of recovery methods for detecting injured foodborne microorganisms.     

高压对牛乳理化性质和成分的影响

高压食品加工是一种非热杀菌技术,是指在室温或低温下用100-800MPa高压处理食品。与传统的热杀菌比较,它具有很多优点,不仅能杀死微生物钝化酶类,而对食品的营养成分和感官品质改变较小。本文综述了高压处理对牛奶物理化学性质和成分的影响。     

微生物源菊粉酶的研究进展

菊粉作为新资源食品和食品原料,近年来以菊粉为目标,开展微生物源菊粉酶生产高果糖浆、低聚果糖和酒精研究成为热点。本文综述了近几年来国内外微生物源菊粉酶的研究现状,主要论述了产酶微生物菌株的筛选、产酶条件、工程菌株的构建及应用等研究的进展。     

HACCP在控制非发酵性豆制品生产中微生物的应用

非发酵性豆制品生产存在工业化程度较低、卫生质量差、标准化程度较低、品质不稳定等问题, 而且其营养丰富、水分含量高, 极易滋生微生物而导致产品变质。本文采用HACCP原理对非发酵性豆制品生产的各个环节进行危害分析, 确定生产过程中可能遭受的微生物的种类及危害程度, 便于通过操作性前提方案(operational prerequisite program, OPRP)、卫生标准程序(sanitation standard operation procedures, SSOP)和关键控制点(critical control point, CCP)来实现对微生物的控制, 从而增进产品的质量, 降低成本, 显著提高企业的经济效益。