香辛料精油用于猪肉保鲜的研究

利用超临界CO2萃取获得丁香、肉桂、山苍子和牛至四种香辛料精油,配比成不同浓度的四种复合保鲜剂,对鲜猪肉进行处理,结合真空包装,于0～4℃贮藏,测定肉样的理化、微生物及感官指标对肉样新鲜度进行综合评价,研究其保鲜效果。结果表明:9%牛至精油+9%丁香精油+9%山苍子精油+9%肉桂精油的复合保鲜剂,结合真空包装技术,在延长冷藏猪肉保鲜期方面效果良好。     

几种常用香辛料精油对冷藏调理鸡肉串的保鲜效果

文中研究了桂皮精油、八角精油、花椒精油、大蒜精油、生姜精油、丁香精油6种精油对冷藏调理鸡肉串的保鲜效果,并通过单因素实验和正交试验筛选出最佳复合香辛料精油保鲜剂。结果表明:6种香辛料精油的保鲜效果差异显著(P0.05),通过抑菌与感官风味的综合评价,其保鲜效果顺序为,桂皮精油八角精油与花椒精油丁香精油与姜油大蒜精油。香辛料精油的最佳复合保鲜剂组合是:0.1%八角精油、0.08%花椒精油、0.04%桂皮精油,该复合保鲜剂能使调理鸡肉串在4℃下保鲜达20 d,25℃下保鲜16~18 h,同时能使鸡肉串产品保持复合香味浓郁、略带麻辣香味,风味协调宜人。     

复合香辛料精油对冷却猪肉中单核增生性李斯特菌的抑制作用

利用超临界CO2萃取丁香、肉桂及黑胡椒精油,研究三种精油对单核细胞增生性李斯特菌的抑制作用,并将复合精油应用于冷却猪肉保鲜。结果表明:三种精油对单增李斯特菌都有较强的抑制作用,黑胡椒精油的抑菌能力最强,最低抑菌浓度为48 mg/L,肉桂和丁香分别为72 mg/L和96 mg/L;通过正交实验确定最优复合精油菌比例,即丁香精油∶肉桂精油∶黑胡椒精油为3∶2∶2;复合精油MIC值为16 mg/L,精油复配产生相加作用,使复合精油的抑菌效果增强;复合精油对冷却肉中的单增李斯特菌具有抑制作用,可以延长冷却猪肉的保鲜期。     

丁香精油微胶囊工艺优化及其对冰温猪肉保鲜效果的影响

为克服丁香精油在保鲜应用中易挥发、难溶于水的缺点,采用复凝聚法制备丁香精油微胶囊,以包埋率为评价指标,采用Box-Behnken中心组合试验和响应面分析法优化包埋工艺,并将丁香精油微胶囊应用于冰温猪肉的保鲜。结果表明,所得回归模型具有高度显著性(p<0.0001),方程对试验拟合较好,在CaCl₂浓度12 g/L,壁芯比7:1 (m/m),复合壁材比(海藻酸钠-壳聚糖)0.8:1 (m/m),包埋时间47 min的条件下,制得的丁香精油微胶囊包埋率最高为84.20%,与预测包埋率相对误差小于5%;用该条件制备的丁香精油微胶囊处理冷却猪肉,冰温下对照组猪肉可保鲜9 d,空芯组可保鲜21 d,精油组可保鲜27 d,表明丁香精油微胶囊可显著延长冰温猪肉的保鲜期(p<0.05)。     

壳聚糖-丁香精油微乳液复合膜的制备及其对猪肉的保鲜作用

目的 探究壳聚糖-丁香精油(clove essential oil, CEO)微乳液复合膜对猪肉的保鲜效果。方法 首先将丁香精油运载到微乳液中, 然后制备壳聚糖-丁香精油微乳液复合膜, 并探索复合膜的理化特征及其对猪肉的保鲜作用。结果 丁香精油微乳液对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度(minimum inhibitory concentration, MIC)均为62.5 μL/L ppm, 而纯丁香精油对这两种菌的MICs分别为500和125 μL/L, 说明微乳液技术提高了丁香精油的抑菌效果。随着添加到壳聚糖薄膜中的微乳液浓度增加(0, 0.5%, 1.0%, 3.0%), 复合膜的厚度、不透明度和色差均不断增加, 而水分活度却逐渐降低。其中, 复合膜的水分活度(0.486~0.536)低于允许微生物生长的最低水分活度(0.610), 说明其适合作为抑菌包装材料。此外, 猪肉保鲜试验结果显示, 壳聚糖-丁香精油微乳液复合膜可以有效抑制猪肉冷藏期间总菌数的增长, 同时较好的延缓猪肉的脂质氧化。结论 本研究制备的复合膜理化特征较好, 可用于猪肉的防腐保鲜, 为丁香精油在肉制品保鲜领域的应用奠定了基础。     

柑橘皮精油对鲜切马铃薯褐变及冷却猪肉保鲜的影响

以柑橘皮为原料,采用水蒸气蒸馏法制备柑橘皮精油。通过对鲜切马铃薯PPO和POD活性两个指标的测定研究柑橘皮精油对马铃薯褐变的影响。结果表明,与抑制剂柠檬酸、CaCl2和Na2SO3相比,浓度为1.2%精油的抑制褐变效果较好。通过对猪肉进行H2S实验、挥发性盐基氮和菌落总数等指标的测定研究橘皮精油对冷却猪肉保鲜的影响,得出精油浓度为2.4%时,可在保存期内保持肉样的一级新鲜度,且精油与其他保鲜剂混合使用时,对肉样保鲜效果具有协同增效的作用。     

花椒精油用于猪肉保鲜的研究

利用超临界CO2萃取获得花椒精油,配比成不同浓度的保鲜剂,对鲜猪肉进行处理,结合真空包装,于0～4℃贮藏,测定肉样的微生物指标对肉样新鲜度进行评价,研究其保鲜效果.结果表明:花椒精油最佳萃取条件为CO2流量为20 kg/h、萃取压力29 MPa、萃取时间140 mmin、萃取温度37℃,此条件下花椒精油的得率为9.52％;花椒精油能有效抑制肉类腐败微生物的生长,从而延长冷却猪肉的保鲜期,且保鲜效果随花椒精油浓度的增大而加强.     

丁香精油纳米脂质体的制备及其在不同豆制品中的应用

丁香精油是一种天然、安全、无毒副作用的广谱抗菌剂,在天然食品添加剂的开发中拥有较好的应用前景。但因强烈的气味、挥发性和水不溶性限制了其在食品中的应用。纳米脂质体是一种人工细胞膜,将精油包裹在纳米脂质体里面,能显著提高精油的稳定性和水溶性,及在食品应用中的控释保鲜效果。本文通过薄膜-超声分散法制得丁香精油纳米脂质体,当丁香精油浓度为0.5%时,纳米脂质体的稳定性最佳,平均粒径为149.2 nm,PDI为0.196,Zeta电位为-24.5 mV,包封率为20.4%。利用FIM观测到丁香精油纳米脂质体呈光滑囊泡状、颗粒分散均匀、无明显聚集现象。丁香精油纳米脂质体在不同豆制品中对金黄色葡萄球菌显示了长效抗菌保鲜效果。作用5d后,其在豆干、豆腐、百叶和素鸡中的杀菌率分别已达到99.995%,99.994%,99.996%和99.996%。     

孜然精油对冷却猪肉保鲜效果的影响

为了延长冷却猪肉的货架期,将质量浓度为0、25、50、75mg/mL的孜然精油对冷却猪肉进行涂膜处理,并采用PE有氧包装形式,以pH、挥发性盐基氮(TVB-N值)、硫代巴比妥酸(TBA)、色差值和细菌总数为考察指标,评价孜然精油对冷却猪肉的保鲜效果.结果表明,质量浓度为50mg/mL的孜然精油保鲜效果最佳,显著优于对照组,在(4±1)℃条件下能将冷却猪肉保鲜期延长至14d.     

四种保鲜处理对龙安柚的品质和生理变化的研究

研究四种保鲜方法对地理标志农产品龙安柚贮藏品质及生理变化的影响。选用适宜浓度的壳聚糖、乳酸钙、丁香精油和肉桂精油对龙安柚进行保鲜处理,并置于阴凉通风、常温(25±1)℃的条件下贮藏,定期测定贮藏过程中的品质和生理指标。结果表明:与对照组相比,四种处理方法均不同程度减缓了龙安柚的贮藏品质的下降,且有效控制了生理变化速度。其中1.5%壳聚糖对保持龙安柚的贮藏品质和控制生理变化效果最好,较其他处理组具有显著性差异(p0.05),1.5%乳酸钙可有效抑制贮藏期间的软化衰老。0.04%丁香精油和0.04%肉桂精油虽然有一定的保鲜作用,但效果不及乳酸钙和壳聚糖的好。     

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