连翘精油抑菌及抗氧化作用研究

利用超临界CO2萃取法提取连翘精油,研究测定了连翘精油对各种供试菌种的抑菌圈直径,加热处理及pH值对连翘精油抑菌效果的影响,同时研究了连翘精油的抗氧化效果.结果表明:连翘精油对各供试菌种的抑菌圈直径在12.5～26.0 mm之间,对G 和G-细菌、霉菌和酵母均有很强的抑制作用;连翘精油的抑菌效果随pH值的降低而增强;121℃加热处理15 min对连翘精油的抑菌效果无明显影响;连翘精油还具有一定的抗氧化性能.     

牛至精油抑菌及抗氧化性能研究

利用超临界CO2萃取法从牛至中提取精油,研究测定了牛至精油对各种供试菌种的抑菌圈直径,加热处理及pH值对牛至精油抑菌效果的影响,同时研究了牛至精油的抗氧化效果。结果表明,牛至精油对各供试菌种的抑菌圈直径在14.7~25.3 mm之间,表明牛至精油对G+和G-细菌、霉菌和酵母菌均有很强的抑制作用;牛至精油的抑菌效果随pH值的降低而增强;121℃,15min加热处理对牛至精油的抑菌效果无明显影响;牛至精油还具有一定的抗氧化性能。     

肉桂精油抑菌及抗氧化作用的研究

采用超临界CO2萃取法提取内桂精油,研究测定内桂精油对各种供试菌种的抑菌圈直径.加热处理及pH值对精油抑菌效果的影响,同时研究肉桂精油的抗氧化效果.结果表明:内桂精油对各供试菌种的抑菌圈直径在20.6mm～49.6 mm之间,对细菌、霉菌和酵母均有很强的抑制作用;肉桂精油的抑菌效果随pH值的降低而增强;121℃/15 min加热处理对内桂精油的抑菌效果无明显影响;内桂精油还具有一定的抗氧化性能.     

五种香辛料精油抑菌及抗氧化性能研究

选取牛至、丁香、连翘、山苍子及肉桂为原料,利用超临界CO2萃取法提取精油,研究测定了五种精油对供试菌种的抑菌圈直径、加热处理及pH值对精油抑菌效果的影响,同时研究了五种精油的抗氧化效果.结果表明:五种精油对细菌、霉菌和酵母均有较强的抑制作用,其综合抑菌能力是肉桂＞丁香＞牛至、连翘和山苍子,五种精油均表现出对霉菌抑制最强的特点;五种精油的抑菌效果均随pH值的降低而增强;121℃15min加热处理对五种精油的抑菌效果均无明显影响;五种精油均具有一定的抗氧化能力.     

植物复合精油对5种稻谷霉变优势菌株抑菌作用研究

为了研究天然植物精油(百里香、丁香、肉桂)对霉变稻谷的抑菌效果,以5种稻谷霉变优势菌株为受试菌,以霉菌抑菌圈直径大小和最低抑菌浓度（MIC）为指标,通过混料设计方法建立复合精油抑菌模型,结合方差分析得到抑菌效果最佳的植物精油配比。研究结果表明,单一精油抑菌活性对亮白曲霉（A. candidus）,杂色曲霉（A. versicolor）和聚多曲霉（A. sydowii）为肉桂精油>丁香精油>百里香精油;对稻黑孢霉（N. oryzae）为肉桂精油=丁香精油>百里精香油;对布罗克青霉菌（P. brocae）为丁香精油=百里香精油<肉桂精油。当肉桂精油:丁香精油:百里香精油的体积比为55.2%︰26.9%︰17.9%时,3种植物精油对5种菌株抑制效果最佳,复合抑制值大于90.9%。     

植物精油对水产品中常见微生物的抑制效应

研究植物精油对水产品中常见腐败致病微生物的抑制效果。采用滤纸片法测定植物精油的抑菌圈直径,筛选出3种效果较佳的精油;然后运用试管梯度稀释法测定精油对供试菌的最低抑菌浓度(MIC);采用棋盘稀释法对3种精油的联合抑菌活性进行了研究,并以FICI值对效果进行评价。通过抑菌圈的测定,筛选出肉桂精油、紫苏精油、丁香精油,各精油对供试菌的MIC值范围分别为:0.313~0.625,0.625~2.50,0.625~2.50μL/mL。棋盘稀释法结果表明复配精油对6种供试菌都显示出了协同或相加作用,不存在无关作用和拮抗作用。     

不同壁材丁香精油微胶囊保鲜剂性能研究

采用饱和水溶液法,以β-环糊精和壳聚糖为壁材,丁香精油为芯材与壁芯比为4∶1制备3种丁香精油微胶囊保鲜剂,并对三种组合壁材微胶囊保鲜剂的表面形态、光照稳定性、包埋率、缓释效果以及抑菌效果进行测定,结果表明β-环糊精丁香精油微胶囊的包埋率最高,为67%;β-环糊精-壳聚糖丁香精油微胶囊1的光照稳定性最好,丁香精油损失率仅为32.67%;β-环糊精-壳聚糖丁香精油微胶囊1的缓释效果最好;β-环糊精-壳聚糖丁香精油微胶囊1的抑菌圈直径最大(38.5±0.40 mm)。综合考量得β-环糊精-壳聚糖1为壁材制得的丁香精油微胶囊性能最好。     

水蒸气蒸馏提取丁香精油及其抑菌性研究

丁香精油具有抑菌性、杀虫活性和抗氧化作用,可作为食品天然防腐剂和保鲜剂.文章研究了水蒸气蒸馏法提取丁香精油的条件和抑菌特性,正交实验结果表明:料剂比为1∶15,粉碎度为60～80目,提取时间为1.5 h的条件下提取率最高;应用平板法考察丁香精油对酵母菌,枯草杆菌和大肠杆菌的抗菌作用,通过测定出现的抑菌圈的大小表明:丁香精油对酵母菌的抑制性最强,其次是枯草杆菌和大肠杆菌.     

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。     

肉桂精油抑茵活性研究

利用滤纸片液相和气相扩散法进行体外抑菌试验,测定肉桂精油对6种供试菌的抑菌圈直径和最小抑菌浓度,以及加热处理和pH值对精油抑菌效果的影响.结果表明:肉桂精油对各供试茵的抑茵圈直径在19.6～43.5mm,对细菌、霉菌和酵母均有很强的抑制作用,对霉菌的抑菌作用高于酵母菌和细菌;气相也具有较强的抑茵作用;120℃加热处理20min对内桂精油的抑菌效果无明显影响;在pH值偏酸或偏碱时内桂精油的抑菌效果增强.     

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.