泡菜微生物演替与风味物质变化的研究进展

泡菜的发酵是微生物不断演替变化的过程,微生物对泡菜风味的形成发挥着重要作用。随着发酵时间的延长,泡菜中微生物的种类和数量发生变化,不同生长阶段的优势微生物在泡菜发酵过程中所发挥的作用也会不同。本文综述了最近几年关于泡菜微生物演替及泡菜风味变化的研究进展,重点论述了泡菜微生物群落的组成与动态变化,外界因素对泡菜微生物演替的影响与作用,以及不同微生物在泡菜发酵过程中的动态变化对泡菜风味的影响,以期对泡菜的深入理论研究及产业应用提供参考。     

泡菜中亚硝酸盐消长规律及调控技术研究进展

泡菜是经盐水泡制新鲜蔬菜厌氧发酵而成,因其乳酸发酵、酒精发酵和醋酸发酵形成的风味物质,赋予了泡菜独特的风味,深受消费者喜爱。但是泡菜在发酵过程中产生亚硝酸盐,亚硝酸盐积累会对消费者健康不利。本文综合国内外相关研究文献,概述了泡菜发酵过程中亚硝酸盐形成与降解机理及变化规律研究进展,并对降低泡菜中亚硝酸盐含量的研究与应用进行综述。     

泡菜中微生物菌群的研究进展

泡菜是一种以蔬菜为主要原料,经微生物发酵而成的蔬菜加工制品,历史悠久,风味独特,深受人们喜爱。在泡菜的整个发酵过程中,微生物发挥着至关重要的作用,微生物的种类和数量不仅直接影响产品的风味和口感,同时也会造成产品的腐败。文章介绍了国内外泡菜微生物菌群的区别和泡菜发酵过程中微生物多样性的影响因素。同时,也指出泡菜中腐败微生物的污染及控制和功能微生物对风味的优化。通过对泡菜中微生物菌群的研究探讨,有助于泡菜生产企业利用微生物的特性,进行产品腐败的控制和风味的改善。     

发酵香肠中生物胺的研究进展

生物胺是一种低分子量的有机物,主要是通过氨基酸的脱羧作用生成.它广泛存在于发酵香肠、泡菜、干酪、酸奶等发酵食品中.本文综述了目前国内外关于发酵香肠中生物胺的研究情况,主要介绍了生物胺的产生原因、常见的生物胺种类、产生物胺的主要微生物、影响生物胺产生的理化因素以及对发酵香肠中生物胺含量积累的控制措施,旨在为今后对发酵香肠中生物胺的进一步研究提供帮助.     

中国泡菜发酵态相对稳定性的研究及应用

中国泡菜以四川泡菜为代表,发酵是其基本的状态(简称发酵态),而主导微生物是泡菜发酵的源动力。在系统研究的基础上,论文阐述了泡菜发酵原理、菌群结构的演变、主导微生物及其数量变化、发酵态的变化及其稳定系统(稳态)的形成、稳态的应用。揭示了我国传统泡菜发酵是动态和稳态的两个关键状态的演变过程,其中动态又包含启动态和非稳态。基于泡菜稳态的形成及其特征指标,首次正式提出“稳态发酵理论”。在该理论的指导下,实现了泡菜现代化发酵加工生产,并保持了传统泡菜风味,既传承了经典泡菜工艺,又创新引领了泡菜产业的发展。     

四川泡菜发酵过程中大肠杆菌消长规律的定量系统评价

目的探究四川泡菜发酵过程中大肠杆菌的消长规律。方法根据相关关键词在CNKI数据库中检索相关文献。对检索结果 13篇文献的50批次四川泡菜发酵过程中大肠杆菌消长数据进行定量系统评价。结果四川泡菜发酵过程中,大肠杆菌在数量上大体呈现为前升后降的动态变化模式;尽管乳酸菌生长及发酵产酸总体上对大肠杆菌产生抑制作用,但发酵过程中的多种参数和因素对大肠杆菌的消长具有显著影响。此外,泡菜发酵中,大肠杆菌数量的峰值与初始值之间有显著的正向相关关系;而发酵温度与泡菜发酵中大肠杆菌消失时间之间呈现反向相关关系。结论本研究可为进一步探讨四川泡菜发酵对大肠杆菌的抑制机制及风险评估提供参考。     

泡菜中乳酸菌的研究进展

乳酸菌在泡菜发酵过程中有重要意义,为了克服传统方法生产泡菜的不足,需进一步研究制作泡菜的乳酸菌发酵剂。该文对泡菜中乳酸菌的主要种类及发酵类型、影响乳酸菌发酵的主要因素、乳酸菌发酵剂的来源、在泡菜中的应用及基因组学等进行了综述,并展望了其发展趋势。     

泡菜的研究进展及生产中存在的问题

泡菜是一种乳酸发酵制品,含有大量的乳酸菌,而乳酸菌是参与人体肠道微生态平衡的主要菌系,它对人体具有各种保健功能。对泡菜发酵过程中微生物和各物质的变化规律、泡菜的工业化生产工艺、泡菜的功能、泡菜的安全性在国内外的研究进展作了综述,并对泡菜生产中存在的问题进行了分析。     

乳酸菌在泡菜发酵中的研究进展

泡菜工业是我国的一大产业，与人们日常饮食息息相关，而在泡菜制作过程中起主要作用的微生物则是乳酸菌，它们在发酵过程中主要起着发酵剂和风味改良剂的作用。近年来，随着食品研发技术的迭代，泡菜发酵技术也在不断发展增强，随之应用而生的产品种类也在不断增多。文章综述了近年来文献报道泡菜乳酸菌发酵方式（自然发酵、乳酸菌菌剂发酵）、发酵产品种类（四川泡菜、韩国泡菜）、菌群代谢（乳酸菌菌群、乳酸菌代谢）及其在泡菜中健康作用（安全性、感官属性、抗菌特性和营养物质）等方面应用的研究进展。以期为提升泡菜产品在消费者中的接受度和食用安全性，建立一个品质高、风味特征独特的泡菜产品工业化生产和发展体系，为消费者提供更好的选择。     

壳寡糖对泡菜品质、微生物多样及演替规律的影响

研究壳寡糖对泡菜品质、微生物多样及演替规律的影响,探究其在泡菜生产中的应用潜力。研究表明:壳寡糖能有效降低泡菜中亚硝酸盐含量,提高泡菜中总酸、氨基酸态氮含量,且随壳寡糖含量的增加呈现明显差异。当壳寡糖添加量为1%(质量分数)时,试验组的亚硝酸盐含量为(1.08±0.39)mg/kg(减少近50%)、总酸为(7.42±0.25)g/kg(提高87%)和氨基酸态氮为(56.67±7.5)g/kg(增加32%)。分析发现,壳寡糖显著影响泡菜发酵过程中微生物区系结构。壳寡糖泡菜样品与自然发酵样品中的优势微生物在门水平分析相类似,均为变形菌门和厚壁菌门,而在属水平出现较大差异,如自然发酵组共有17种属微生物参与泡菜的发酵过程,而壳寡糖泡菜仅9种属微生物。发酵中期(3 d),添加壳寡糖使得自然发酵过程中的优势菌微小杆菌属被乳球菌属所取代;发酵5 d后,自然发酵样品中泛菌属和明串球菌属共同主导着发酵的进程,而壳寡糖泡菜中优势菌属仍是乳球菌属,并延续至发酵末期。结论:添加壳寡糖有利于泡菜发酵过程中有益菌群的增长及泡菜品质的提升,壳寡糖在泡菜生产中的应用潜力大。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status