魔芋葡甘聚糖及其与大豆蛋白复合成膜的研究

对单一魔芋葡甘聚糖膜及其与大豆分离蛋白(SPI)复合膜的制备条件优化进行了研究。发现高 pH(>10)对阻隔性能不利,反应温度的提高和增塑剂的加入会分别导致膜的阻氧和阻湿性能下降,而与大豆分离蛋白的复合,则会明显地提高其阻隔特性。pH10、温度45℃、甘油含量1.5%、魔芋与大豆分离蛋白比值1∶1时制备的复合膜具有较好的阻隔性能。     

魔芋葡甘聚糖复合膜对迷你黄瓜的保鲜性研究

对魔芋葡甘聚糖及其与大豆分离蛋白、分子蒸馏单甘酯、硬脂酸复配成膜的工艺条件和对迷你黄瓜的保鲜性能进行了研究.实验确定的最佳配比及工艺条件为w(魔芋葡甘聚糖)=2.0%,w(单甘酯)=0.5%,w(硬脂酸)=0.5%,m(魔芋葡甘聚糖):m(大豆蛋白粉)=1:1,pH=9,溶胀温度为35℃.该复配膜对减少迷你黄瓜的失重率、抑制呼吸强度效果理想.     

脱乙酰改性对魔芋葡甘聚糖/黑米膳食纤维复合膜特性的影响

目的 对比脱乙酰魔芋葡甘聚糖/黑米膳食纤维复合膜与魔芋葡甘聚糖/黑米膳食纤维复合膜, 探究脱乙酰对魔芋葡甘聚糖复合膜的影响。方法 以魔芋葡甘聚糖为原料, 对魔芋葡甘聚糖进行脱乙酰改性, 再与黑米膳食纤维、甘油、蛭石共混, 采用流延法制备两种复合膜, 以复合膜拉伸强度、断裂伸长率、水蒸气透过率、溶水率为考察因素, 确定最优配方, 并通过傅里叶变换红外光谱和扫描电镜进行表征。结果 。脱乙酰改性使复合膜抗拉强度提高12%、断裂伸长率降低17%、溶水率降低12%、水蒸气透过系数降低41%, 红外光谱与扫描电镜结果表明脱乙酰魔芋葡甘聚糖黑米膳食纤维复合膜具有更高的稳定性。结论 脱乙酰改性处理改善了复合膜微观结构, 提高了复合膜的物理性能。脱乙酰魔芋葡甘聚糖/黑米膳食纤维复合膜制备以期为新型复合膜的开发提供理论参考, 并为魔芋葡甘聚糖与黑米膳食纤维的开发利用提供参考。     

魔芋葡甘聚糖-壳聚糖-羧甲基纤维素钠复合可食性保鲜膜研究

将魔芋葡甘聚糖(KGM)、壳聚糖(CTS)和羧甲基纤维素钠(CMC-Na)作为成膜基质,以盐酸调节pH,添加甘油作为增塑剂,研究了各种成分的添加比例、甘油添加量及烘干温度对成膜性能的影响,制备出可食性复合保鲜膜.通过对膜的阻湿性、阻氧性、抗拉强度、断裂伸长率等指标进行测定,研究了膜的性能.结果表明:当三种主要成膜材料的配比(KGM:CTS:CMC-Na)为1:2:1、甘油含量为1.5%、烘干温度为40℃时,复合膜形成一种新的结晶体,具有最大的阻隔性能、较强的抗拉强度和中等强度的断裂伸长率,并能在短时间内迅速溶解,此时膜性能最优.     

魔芋葡甘聚糖基抗菌活性包装膜的研究进展

魔芋葡甘聚糖是一种天然高分子,具有成膜性、生物相容性、可降解和可再生等特性,来源广泛,价格低廉。在众多以魔芋葡甘聚糖为基质的复合材料研究中,魔芋葡甘聚糖基抗菌活性包装膜的研究受到广泛关注,在食品包装领域表现出广阔的应用前景。本文主要从魔芋葡甘聚糖的结构、性能与复合膜的制备方法,以及不同种类魔芋葡甘聚糖基抗菌膜的制备、功能特性、抗菌效果等方面综述了魔芋葡甘聚糖基抗菌活性包装膜的研究进展。     

魔芋葡甘聚糖—卡拉胶共混膜制备及其性能研究初探

本文以魔芋葡甘聚糖（KGM）和卡拉胶制作魔芋葡甘聚糖-卡拉胶共混制成复合膜，研究了不同比例对膜的透明度、厚度、洗刷性能等性能的影响。结果表明，魔芋葡甘聚糖与卡拉胶用量比为6：4时，共混膜的能达到较好的效果。     

化学改性魔芋葡甘聚糖成膜性能的研究进展

魔芋葡甘聚糖(KonjacGlucomannan,简称KGM),是从魔芋块茎中分离、提取的一种天然复合多糖,具有亲水性、凝胶性、成膜性、抗菌性、可食用性等多种特征,在食品、医药、化工及生物领域应用广泛.简要论述魔芋葡甘聚糖的结构和理化特性,并综合介绍魔芋葡甘聚糖的化学改性研究进展,分析概括化学改性对魔芋葡甘聚糖成膜性能的改善作用.以期为魔芋葡甘聚糖膜的进一步研究提供理论基础,扩大它的应用范围,从而促进魔芋资源的开发.     

纳米TiO2对魔芋葡甘聚糖/玉米醇溶蛋白复合膜结构和性能的影响

本文以魔芋葡甘聚糖、玉米醇溶蛋白为成膜基质,添加不同含量（1%、2%、3%）的纳米TiO₂,以流延方式制备纳米TiO₂/魔芋葡甘聚糖/玉米醇溶蛋白复合膜,并对复合膜的微观结构、热性能、力学性能、疏水性、水蒸气透过率和抑菌性能进行了分析。结果表明,纳米TiO₂与魔芋葡甘聚糖、玉米醇溶蛋白间发生相互作用,有良好的相容性;添加纳米TiO₂使复合膜表面粗糙度增加,复合膜热稳定性和疏水性增强,力学性能降低;纳米TiO₂添加量为1% wt时,复合膜的水蒸气透过率（5.7×10?13 g·cm/（cm2·s·Pa））和溶胀率（16.4%）最小,水接触角值（99.6 °）最大;复合膜对金黄色葡萄球菌和大肠杆菌有明显的抑制作用,对枯草芽孢杆菌的抑制作用不明显。本研究为纳米TiO₂/魔芋葡甘聚糖/玉米醇溶蛋白复合膜作为包装材料的开发与应用提供一定参考依据。     

羧甲基葡甘聚糖/大豆分离蛋白复合膜的制备及表征

以溶液共混法制备羧甲基葡甘聚糖/大豆分离蛋白复合物.正交实验确定了羧甲基葡甘聚糖与大豆分离蛋白质量比为1.5∶1、pH10、6 mL/100g干粉质量的三氯氧磷作用下,40℃水浴反应3 h,羧甲基葡甘聚糖与大豆分离蛋白有良好的相互作用,复合膜的力学性能、抗潮性能及阻气性能均有明显提高,其中拉伸强度较羧甲基葡甘聚糖提高了117.6%,吸湿增重较羧甲基葡甘聚糖下降了19.02%,透湿系数降至6.7 g/mm·h·Pa,用红外光谱、Tg测定表征了其结构.     

羧甲基葡甘聚糖-大豆分离蛋白复合物膜及性能研究

以溶液共混法制备羧甲基葡甘聚糖-大豆分离蛋白复合物。用红外光谱、紫外分光光度计、扫描电镜、玻璃化温度测定表征其结构,测试复合物膜的力学、抗潮、阻气等性能。结果表明在羧甲基葡甘聚糖与大豆分离蛋白质量比为1.5:1,pH10,6ml/100g干粉重的三氯氧磷作用下,40℃水浴反应3h,羧甲基葡甘聚糖与大豆分离蛋白有良好的相互作用,复合物膜的力学性能、抗潮性能及阻气性能均有明显提高,其中拉伸强度较羧甲基葡甘聚糖提高了117.6%,吸湿增重较羧甲基葡甘聚糖下降了19.02%,透湿系数下降了40.97%。     

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.