山苦茶的复合保鲜剂对冷却肉保鲜效果的研究

在测定山苦茶浸出物、茶多酚、木犀草素3种天然防腐剂对冷却肉中常见菌的抑菌效果基础上,根据栅栏技术,发挥协同效应,利用三因子二次正交旋转设计,确定最佳的保鲜液配比为木犀草素0.010%+茶多酚0.125%+山苦茶浸出物0.013%。结合真空包装,通过测定在冷藏过程中的细菌总数、TVB-N,表明保鲜液对冷却肉的保质期延长6 d。     

麻辣兔肉丁的综合保鲜技术研究

根据栅栏因子保鲜理论,采用多种栅栏因子科学合理的组合,并通过改进工艺,对麻辣兔肉丁进行了综合保鲜研究。结果表明,添加复合防腐剂(0.05% Nisin、0.05% 溶菌酶、2% 乳酸钠)组成的天然复合保鲜液,采用瞬间翻炸、水浴热处理(85～90℃、水浴杀菌30min、2 次,中间急速冷却)的综合保鲜技术可使麻辣兔肉丁在常温下(15～20℃)贮藏240d。     

茶多酚结合壳聚糖对冷却肉的保鲜效果

为了延长冷却肉的货架期,文中采用不同浓度茶多酚结合壳聚糖与可食性膜溶液混合制成涂膜保鲜剂,通过测定贮存过程中冷却肉的细菌总数、挥发性盐基氮(TVB-N值)、pH值、色差值、硫代巴比妥酸值(TBA值)等指标的变化,对冷却肉保鲜效果进行研究。结果表明:0.7%茶多酚、1.0%壳聚糖涂膜保鲜冷却肉效果较好,显著优于对照组和单纯使用壳聚糖涂膜保鲜组,在0～4℃条件下能将冷却肉保鲜期延长至16 d以上。     

低温羊肉火腿综合保鲜技术的研究

根据栅栏因子保鲜理论,采用多种栅栏因子科学合理的组合,对低温羊肉火腿进行了综合保鲜研究,结果表明:原料减菌化处理(醋酸2%、双乙酸钠3%、抗坏血酸2%、硫代硫酸钠2%、山梨酸钾1%) 保鲜剂(Nisin0.15%、山梨酸钾0.19%、双乙酸钠0.11%) 水浴热处理(85~90℃、30min杀菌2次,中间急速冷却)可使低温羊肉火腿在0~4℃贮存条件下,货架期达6个月之久;同等条件下,微波120s热处理(功率900W,中心温度90℃)的羊肉火腿货架期达到3~4个月。     

冷却肉卫生安全控制及保鲜技术研究进展

近年来,随着冷却肉消费的普及,延长冷却肉货架期成为了一项关键技术,多数方法是通过将几种传统方法相结合的途径来延长冷却肉的货架期.目前除了传统的保鲜方法外,也出现了一些新型的保鲜技术.本文重点介绍了几种常见的保鲜技术和冷却肉的卫生安全控制,期望能给研究者和生产商带来一些参考价值.     

茶多酚和大蒜素在冷却肉涂膜保鲜中的应用

采用茶多酚、大蒜素与天然可食性膜溶液研制成涂膜保鲜剂进行冷却肉的涂膜保鲜研究。以感官指标、pH 值、挥发性盐基氮(TVB-N)和细菌总数为考察指标,通过L9(34)正交试验筛选出最佳比例组合,提高冷却肉的保鲜度和延长冷却肉的保鲜期。结果表明：0.7% 茶多酚、0.4% 大蒜素和乙种膜溶液(3% 可溶性淀粉、0.6% 海藻酸钠、0.2% 单甘酯)组成的涂膜保鲜剂,对冷却肉的涂膜保鲜效果良好。用此涂膜保鲜剂处理冷却猪肉,在0～4℃条件下贮藏保鲜19d 以上。     

烧鸡综合保鲜技术研究

根据栅栏因子保鲜理论,采用多种栅栏因子科学合理的组合,对烧鸡进行了综合保鲜研究。结果表明:复合防腐剂(Nisin0.05%、溶菌酶0.05%、乳酸钠2%和双乙酸钠1%)+真空包装+水浴热处理(85～90℃水浴杀菌30min,流水冷却30min)的综合保鲜技术可使烧鸡在常温下(15～20℃)贮藏60d。     

荸荠皮提取物对冷却猪肉保鲜效果的影响

为考察荸荠皮提取物对冷却猪肉货架期品质变化的影响,将冷却猪肉分别用0.2%,0.4%,0.6%和0.8%的荸荠皮提取液浸渍处理,并置于4℃贮藏,分别进行感官评价、理化(p H、TVB-N值、TBA值)及微生物(菌落总数)指标测定。结果表明,荸荠皮提取物对冷却猪肉具有明显的保鲜作用,能保持猪肉良好的感官品质,延缓各项指标的上升。0.8%的处理液保鲜效果最明显,能使猪肉的冷藏货架期延长至15 d。     

辐照和保鲜剂对淡腌大黄鱼保鲜效果的研究

为探索伽马辐照和添加剂对淡腌大黄鱼的保鲜效果,以感官、微生物和化学变化为指标,探讨了低剂量辐照(1 kGy)和复合保鲜液(0.3%双乙酸钠和0.5%柠檬酸)对常温(25℃)贮藏下淡腌大黄鱼品质和货架期的影响。实验结果表明,2种处理方法均可延长淡腌大黄鱼的货架期,对照组货架期仅9 d,而实验组的货架期可分别延长至16 d和13 d;1 kGy的辐照处理要优于0.3%双乙酸钠和0.5%柠檬酸复合保鲜液的保鲜效果,为工厂化应用提供了技术依据。     

胡椒提取物在冷却肉保鲜中的应用

研究胡椒提取物作为复合保鲜剂的成分在延长冷却肉货架期方面的作用。采用常压回流方法获得胡椒提取物,再以胡椒提取物、壳聚糖和乙酸为试材,对冷却肉进行贮藏保鲜,最后采用二次通用旋转组合设计法,对复合保鲜液配方成分的比例进行优选。结果表明：复合保鲜剂能明显地抑制保藏过程中微生物的生长。胡椒提取物质量分数0.95%,壳聚糖质量分数0.99%,乙酸质量分数0.80%的保鲜剂配方较好,保鲜12d后细菌总数(lg(CFU/g))为5.2214。     

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.