壳聚糖/明胶/纤维素纳米晶体复合壁材制备香精微胶囊

本研究以柠檬香精为芯材,壳聚糖(CS)、明胶(GE)和纤维素纳米晶体(CNC)为复合壁材,采用复凝聚法制备柠檬香精微胶囊。研究了壁材质量分数、CNC质量分数、芯壁比和乳化速率对微胶囊粒径和包埋率的影响,确定了最佳制备工艺条件为:壁材质量分数0.2%,CNC质量分数0.3%,芯壁比3:1,乳化速率900 r/min。在此最佳条件下制得的香精微胶囊包埋率为74.35%。傅里叶变换红外光谱(FT-IR)表明,CS、GE与CNC之间发生了静电吸引。扫描电子显微镜(SEM)表明,香精微胶囊呈球形,粒径在1.8～5.2μm之间,分散性良好。热重分析表明,CS/GE/CNC壁材体系能很好地保护柠檬香精在200℃以下的缓慢释放。     

锐孔-凝固浴法制备大蒜油微胶囊的工艺

文章主要研究了锐孔-凝固浴法制备大蒜油微胶囊的工艺过程和方法。试验以大蒜油为芯材,以海藻酸钠为壁材,氯化钙为固化液,探讨了海藻酸钠浓度、芯材与壁材比例、乳化剂浓度、氯化钙浓度及乳化温度等影响成型的主要因素。通过三元二次回归正交实验确定了制备大蒜油微胶囊的最佳工艺条件,并对最佳工艺条件下制备的微胶囊进行包埋率的测定。结果表明:锐孔法制作大蒜油微胶囊的最佳工艺条件为壁材海藻酸钠的浓度为1.4%,芯材大蒜油与壁材的配比为3.8:1,乳化剂的浓度为0.3%,乳化温度为65℃,凝固浴氯化钙的浓度为2%;包埋率可以达到77.21%。     

响应面法优化葱油香精微胶囊制备工艺的研究

文章以明胶、阿拉伯胶为壁材,采用复合凝聚法对葱油香精进行包埋,以微胶囊包埋率为评价指标,采用响应面分析法优化了影响包埋率的主要因素:壁材浓度、芯壁比和pH值。研究发现,复凝聚法制备葱油香精微胶囊的最佳工艺参数为:壁材浓度为1.82%、芯壁比1∶1.87、pH 4.16。在此基础上,采用喷雾干燥法可以制备出葱油香精微胶囊白色粉状产品,微胶囊粒径大小较为均一,体积平均粒径为65.54μm。     

响应面法优化薄荷香精微胶囊制备工艺的研究

以壳聚糖、海藻酸钠作为壁材,用复凝聚相法对薄荷香精进行包埋,通过海藻酸钠的单因素实验确定壳聚糖和海藻酸钠比例为1∶1,运用响应面分析法优化影响微胶囊包埋的主要因素:壁材浓度、芯材/壁材比、pH和搅拌速度,采用多元二次回归方程拟合上述四个因素与包埋率的函数关系,确定了复凝聚相法制备微胶囊的最佳条件为芯材/壁材比1∶1.5,搅拌速度2500r/min,壁材浓度0.5%和pH4.4,在此条件下包埋率为82.4%。     

内源乳化法制备溶菌酶微胶囊的研究

研究了壳聚糖-海藻酸钠内源乳化法制备溶菌酶微胶囊的工艺条件。海藻酸钠浓度2.0%,溶菌酶浓度1.5%,壳聚糖浓度为0.3%,Span80的添加量为油相体积的1.0%时,正交实验得出最佳制备条件为：碳酸钙与海藻酸钠质量比为7：40,水相与油相体积比为30：70,冰醋酸与碳酸钙质量比为1.4：1。然后,研究了溶菌酶微胶囊的粒径分布以及在模拟胃肠液中的控制释放效果和包埋后的溶菌酶在模拟胃液中的稳定性。结果表明,微胶囊粒径大小为483.7μm,粒径分布指数为0.6;优化得到的微胶囊在模拟胃液中2h释放率为35.5%,在模拟肠液4h后总释放率达88.9%;模拟胃液处理后溶菌酶保留活性达90.0%。     

复凝聚法制备白术挥发油微胶囊及表征

以白术挥发油为芯材,壳聚糖和海藻酸钠为壁材,采用复凝聚法制备微胶囊,通过单因素实验研究工艺参数对挥发油包埋率的影响,采用激光粒度分析仪、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、热重分析仪(TG-DTA)对微胶囊的粒径分布、表面形貌、化学结构、芯材含量进行表征。结果表明:在芯壁比为1∶2,乳化剂用量为5%,复凝聚温度为40℃,壳聚糖质量分数为1%,海藻酸钠质量分数为2%,pH 1.5,乳化转速6 000 r/min条件下制备的微胶囊包埋效果最好。微胶囊颗粒大致呈球状,表面结构致密,无明显的裂缝和洞孔,包埋率高,热稳定性能好,研究结果可为白术挥发油微胶囊的制备、鉴定、质量控制和制剂学性质的研究提供依据。     

β-环糊精制备葱油香精微胶囊的工艺研究

文章研究了以β-环糊精为壁材制备葱油香精微胶囊的工艺,考察了制备工艺中芯壁比、β-环糊精浓度、包埋温度、包埋时间对β-环糊精制备葱油香精微胶囊包埋效果的影响,通过实验得到了葱油香精微胶囊的最佳工艺条件,芯壁比1∶10,β-环糊精浓度为15%,包埋温度为50℃,包埋时间为120 min,同时对微胶囊产品进行了初步的质量评定。     

不同壁材对水酶法提取油茶籽油乳化相微胶囊的影响

以水酶法提取油茶籽油所制得的乳化相为芯材,分别以明胶-阿拉伯胶、明胶-海藻酸钠、乳清蛋白-阿拉伯胶、乳清蛋白-海藻酸钠为壁材,制备4种油茶籽油乳化相微胶囊,并分析4种微胶囊的性质。结果表明：在4种微胶囊中,以明胶-海藻酸钠为壁材制备的油茶籽油乳化相微胶囊包埋效果最好,包埋率高达93.96%;以明胶-阿拉伯胶为壁材制备的油茶籽油乳化相微胶囊具有最小的平均粒径,更好的溶解性和热稳定性,可以制备出具有更好性能的油茶籽油乳化相微胶囊产品。     

锐孔法制备大粒径薄荷油微胶囊

以薄荷油为芯材,海藻酸钠为壁材,2%氯化钙溶液为固化液,研究了锐孔法制备大粒径薄荷油微胶囊的工艺过程,探讨了不同的海藻酸钠浓度对微胶囊感官品质及包埋率的影响。结果表明,薄荷油微胶囊的感官质量随海藻酸钠浓度的增加而提高。海藻酸钠浓度为1.5%,2%和2.5%时,包埋率分别为32.44%,36.51%和40.59%。综合感官评价和包埋率,以海藻酸钠浓度为2.5%时制备的微胶囊为佳。     

响应面法优化保加利亚乳杆菌微胶囊制备工艺

为增强保加利亚乳杆菌（Lactobacillus bulgaricus）的抗逆性,提高其在产品中的存活率,该研究采用内源乳化法制备保加利亚 乳杆菌微胶囊,并通过单因素试验和响应面试验对其制备工艺进行优化。结果表明,最佳微胶囊制备工艺参数为海藻酸钠质量分数2%, 复合壁材海藻酸钠与果胶质量比1∶1,水相油相体积比1∶2.5,交联剂碳酸钙与海藻酸钠质量比1:2,乳化剂Span-80体积分数1.5%,搅拌 速率400 r/min。在此优化条件下,利亚乳杆菌微胶囊包埋率达到91.8%。     

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.