植物精油及其活性成分的抗菌机理

芳香植物精油普遍具有良好的抗菌能力,是潜在的天然抗菌剂。本文概述山苍子、肉桂、丁香、辣木、百里香、鼠尾草、孜然、八角茴香、牛至、花椒、大蒜等24种精油的主要化学成分、抗菌作用对象和抗菌机理,并对香芹酚、肉桂醛、百里香酚、丁香酚、柠檬醛、柠檬烯等6种精油单体成分对不同微生物的抗菌作用进行分析。     

丁香和肉桂挥发油的提取、主要成分测定及其抗菌活性研究

本文采用水蒸汽蒸馏法提取丁香和肉桂的挥发油,并对所得挥发油主要成分进行气相测定,通过体外抗菌试验,比较了这两种挥发油及其主要成分和目前常用化学防腐剂苯甲酸钠和山梨酸钾对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌和志贺氏菌等5株食品中常见污染菌的抗菌作用。结果表明丁香油中丁香酚含量为78.1%,肉桂油中肉桂醛含量为86.8%;这两种挥发油及其主要成分丁香酚和肉桂醛的抗菌作用均强于两种化学防腐剂,其中肉桂油与其主要成分肉桂醛表现出的抗菌活性最强,最小抑菌浓度(MIC)为200～1600mg/L;仅为苯甲酸钠和山梨酸钾MIC(6400～25600mg/L)的1/64～1/16;丁香油及其主要成分丁香酚的抗菌活性次之,MIC为800～1600mg/L,相当于苯甲酸钠和山梨酸钾MIC的1/16～1/8。     

植物精油对食品中常见有害微生物的抑菌活性研究

通过测定抑菌圈、气相熏蒸法等体外抑菌试验研究了罗勒精油、茶树油、百里香精油、丁香精油、小茴香精油、依兰油、甘牛至精油、肉桂精油、桉叶油、芫荽籽精油、香茅油、鼠尾草油、甘松精油十三种植物精油对六种食品常见有害微生物抗菌作用。结果表明:十三种植物精油均对细菌、霉菌和酵母具有一定的抑杀能力。百里香精油和肉桂精油抗菌活性最强,均表现程度不等的抗菌活性。六种供试菌种对百里香精油、肉桂精油极敏感,抑菌圈直径均大于20 mm;当两种精油空间体积浓度达到300μL/L时,两种精油对多数供试菌表现出强抑菌效果。肉桂精油与百里香精油复配后对供试菌没有表现出强的协同增效效果,部分出现相加作用和无关作用。复配精油中肉桂精油占80%时,对供试菌效果最好。     

抗果蔬致腐真菌中草药的筛选及有效成分的分析

研究了陈皮、肉桂、丁香、五倍子、艾叶、辛夷、姜黄、川芎、虎仗和蜂胶10种中草药提取物对果蔬致腐真菌扩展青霉和黑曲霉的抑制作用。结果表明：中草药丁香提取物具有较强的抗菌活性，对扩展青霉和黑曲霉的MIC分别为25％和50％；通过GC-MS从丁香挥发油中分离分析出14种化合物，其中丁香酚的相对含量最高，达68％；抑菌试验表明，丁香挥发油MIC中丁香酚的浓度高于丁香酚的MIC。     

10种中草药提取物对常见果蔬致腐真菌的抑制作用及有效成分分析

研究了陈皮、肉桂、丁香、五倍子、艾叶、辛夷、姜黄、川芎、虎仗和蜂胶10种中草药提取物对果蔬致腐真菌扩展青霉和黑曲霉的抑制作用,结果表明:中草药丁香提取物具有较强的抗菌活性,对扩展青霉和黑曲霉的MIC分别为25%和50%;通过GC-MS从丁香挥发油中分离分析出14种化合物,其中丁香酚的相对含量最高,达68%;抑菌试验还表明,丁香挥发油中含有削弱丁香酚抗菌性能的成分。     

香料调味品防腐作用的试验

有些香料调味品添加到熟食品中,不仅产生芳香,增强风味,而且有较强的抗菌活性、如肉桂、丁香、肉寇、干姜、大蒜、洋葱。胡椒等均能抑制某些食品微生物的生长,象金黄色葡萄球菌、鼠伤寒沙门氏菌,埃希氏大肠杆菌,副溶血孤菌和黄曲霉菌均可受到抑制。但是     

丁香和肉桂精油气相抑菌活性研究

采用超临界CO2萃取法提取丁香和肉桂精油,并通过滤纸片法、固相扩散法、气相扩散法等体外抗菌试验,比较了丁香、肉桂精油及混合精油和常用化学防腐剂山梨酸钾对11株食品中常见污染菌的抑菌作用。结果表明:丁香、肉桂精油及混合精油对供试细菌、霉菌和酵母菌均有较强的抑制作用,抑菌效果显著优于山梨酸钾;对霉菌的抑菌作用显著高于酵母菌和细菌,且气态抑制作用比固相抑菌作用强;混合精油对细菌的抑菌作用有拮抗作用,在气相中的拮抗作用更强;对酵母菌的抑菌作用没有影响;对黄曲霉和黑曲霉有相加作用;对桔青霉有协同作用。     

香辛料提取物对副溶血弧菌生物膜的抑制作用

对大蒜、肉桂等6种天然的香辛料分别采用水和80%乙醇进行提取并筛选出对副溶血弧菌抑菌能力较强的提取物,探究这些香辛料提取物对副溶血弧菌生物膜的抑制作用。研究结果表明大蒜、肉桂、丁香具有较强的抗菌作用,而花椒、小茴香、迷迭香则相对较弱。肉桂和大蒜的乙醇提取物对副溶血弧菌的最低抑菌浓度(Minimum inhibitory concentration,MIC)皆为6.25 mg/m L。亚抑菌浓度的提取物除了能够抑制副溶血弧菌生物膜的形成,还能抑制生物膜内细菌的代谢活性,减少细菌胞外多糖的分泌。激光共聚焦扫描显微镜(Confocal Laser Scanning Microscope,CLSM)观察发现,处理后死细胞的数量明显增多,且生物膜内多糖的含量明显变少。     

多种中药挥发油的抑菌活性的研究进展

本文通过查阅国内外相关文献的研究信息,归纳总结出鱼腥草、艾叶、肉桂、香茅、大蒜等挥发油的常用提取方法和抑菌作用研究,并对其主要抑菌成分和作用机制进行相关阐述,以期更好地利用这五味中药和为研发低毒高效的中药抑菌剂提供一定的实验参考。     

天然防腐剂的筛选及其抗菌性研究

通过用滤纸片法比较大蒜、生姜、辣椒、八角、丁香、肉桂、花椒等植物材料提取液的抗菌效力,发现大蒜、丁香、八角的抗菌效力较强。进而用平板法对这几种材料提取液的抗菌性进行了探讨和比较,结果表明:辣椒的抗菌性优于其他几种材料。它对于多数细菌的最低抑菌浓度为3.125mg/ml;对于酵母菌的最低抑菌浓度为12.5mg/ml;活性pH 范围为4.4～8.3;经121℃湿热条件下处理15min 仍有较强的抗菌活性;与低浓度的糖或盐协同作用后其抗菌效力增强,最低抑菌浓度由3.125mg/ml 降低到1.563mg/ml。这些数据说明用辣椒提取液作为天然防腐剂代替化学防腐剂保藏食品是可行的。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.