食物致敏原限量确定方法研究进展

食物中致敏原的管理是食品安全的重要内容之一,而食物致敏原限量对消费者、食品监管部门、企业都有着重要的实际意义,但食物致敏原限量却难以被严格、科学地确定。本文综述了欧盟、美国、澳大利亚以及日本等国家和组织食物致敏原限量的确定方法,并提出了我国食物致敏原限量确定的建议。     

Factors affecting the results of T-2 mycotoxin ELISA assay.

Certain substances in the sample may increase or decrease the reaction between the enzyme and substrate in ELISA assays. During a survey of T-2 trichothecene in food and animal feed 75% of milled grain samples gave a higher O.D. value in competitive T-2 toxin ELISA than the negative control. In samples spiked with small quantities (10 micrograms/kg) of T-2 toxin this type of reaction resulted in underestimates of toxin content. However, the effect was weak and, owing to the high sensitivity of the assay, it did not result in false negative reactions. The low efficiency of the carrier solvent and natural peroxidases in food and feed were considered to be the cause of the inaccurate reactions. A few fermented and processed foodstuffs and feed gave positive results in the T-2 toxin ELISA assay, but verification of the results by gas chromatography (GC) showed that the reactions were false. Certain substances in the samples destroyed or decreased the enzyme activity. False positive reactions can be distinguished from correct ones by retesting the extracts in different dilutions.     

Modern analytical methods for the detection of food fraud and adulteration by food category

This review provides current information on the analytical methods used to identify food adulteration in the six most adulterated food categories: animal origin and seafood, oils and fats, beverages, spices and sweet foods (e.g. honey), grain‐based food, and others (organic food and dietary supplements). The analytical techniques (both conventional and emerging) used to identify adulteration in these six food categories involve sensory, physicochemical, DNA‐based, chromatographic and spectroscopic methods, and have been combined with chemometrics, making these techniques more convenient and effective for the analysis of a broad variety of food products. Despite recent advances, the need remains for suitably sensitive and widely applicable methodologies that encompass all the various aspects of food adulteration. © 2017 Society of Chemical Industry     

食品中甲醛及其检测方法

甲醛是我国禁止在食品中添加和使用的物质。本文对食品中甲醛的来源,存在形态及测定方法等进行了概述,并对我国7个标准中有关食品中甲醛检测方法进行了对比和分析。目前有必要重新修订或制定有关食品中甲醛定性、定量检测的新标准,这对于打击违法添加、保障人民身体健康具有积极的社会意义。      

食品中氯虫苯甲酰胺分析方法研究进展

氯虫苯甲酰胺是美国杜邦公司开发的新型邻甲酰氨基苯甲酰胺类杀虫剂,具有杀虫谱广、速效性好、持效期长的特点,在蔬菜、瓜果、水稻等作物上广泛使用。该药对人体健康具有潜在危害性,许多国家对其残留限量做出明确规定。为满足不同氯虫苯甲酰胺限量的检测要求,发展简单、快速、灵敏、可靠的检测方法尤为重要。本文综述了近年来国内外食品中氯虫苯甲酰胺的主要检测技术及其研究进展,包括固相萃取、分散固相萃取等样品前处理方法,以及液相色谱、液相色谱-质谱联用等分析方法,以期为今后食品中氯虫苯甲酰胺的分析研究提供参考。     

植物源性食品中抗生素残留分析方法研究进展

为评估抗生素对人体暴露的健康风险,需建立针对植物样品中抗生素残留的快速筛查及确证检测方法。文章简要介绍了中国抗生素农药的登记情况及其限量标准、植物源性食品中抗生素的来源及在植物中的累积情况,重点对目前植物源性食品中抗生素残留前处理技术和检测技术进行详细的综述,并对该领域的工作进行了展望。     

Natural and socio-economic factors affecting food security in the Himalayas

In the Himalayas, food security of communities primarily depends on local agricultural productivity and food purchasing power. Subsistence agriculture, which is forest based, constitutes the main source of rural food and livelihoods. However, due to constraints of terrain and climate, agricultural productivity is low, resulting in large food deficits and leading to a considerable proportion of the adult male population migrating from the region in search of employment and livelihoods. Remittances from the migrants and local off-farm employment contribute to community purchasing power which may be used to buy food from the open market and government controlled Public Distribution System (PDS). Depletion of natural resources, changing climatic conditions, the recent economic recession and sharply fluctuating food prices have not only decreased local food production but also reduced employment opportunities locally as well as outside the area, rendering the entire region highly vulnerable to food insecurity. This study, which was carried out in the Upper Kosi Catchment in Kumaon Himalaya, India, revealed that not only has annual agricultural productivity declined by nearly 125 Kg per ha (25 %) during the last 30 years, causing an annual food deficit of 1883 tonnes (65 %) and massive decline in per capita food production, but that local off-farm employment opportunities in different traditional rural sectors has also declined. Furthermore, the recent economic recession and the resultant job losses for migrants has decreased incoming remittances by 20 %–25 %, causing the loss of local purchasing power and posing a serious threat to food security. Those particularly affected are marginal and smallholder farmers, and landless households, which mainly include socially backward communities and families with very low incomes. It is therefore imperative that a community oriented framework for the management of land, water and forest resources is planned and implemented in this region, together with the generation of viable means of off-farm employment at the local level     

基于层次分析法的服装裁剪分床影响因素

为了确定影响服装裁剪分床的主要因素,在生产一线实践的基础上采用层次分析的方法,对服装裁剪分床影响因素进行分析归类,建立5个方面22个因素的3层层次分析结构模型。针对层次结构模型中各影响因素的重要性设计调研问卷,对服装企业专家进行调研,对调研结果进行整理构成判断矩阵,并通过一致性检验。根据层次分析法权重计算规则对裁剪分床各影响因素的权重进行计算,从而确定出号型数量、套排件数、铺布层数、排料图数量和铺布长度为影响裁剪分床的关键因素,为裁剪分床方案的制定提供科学量化依据和指导。     

An overview of analytical methods for determining the geographical origin of food products

There is an increasing interest by consumers for high quality food products with a clear geographical origin. These products are encouraged and suitable analytical techniques are needed for the quality control. This overview concerns an investigation of the current analytical techniques that are being used for the determination of the geographical origin of food products. The analytical approaches have been subdivided into four groups; mass spectrometry techniques, spectroscopic techniques, separation techniques, and other techniques. The principles of the techniques together with their advantages and drawbacks, and reported applications concerning geographical authenticity are discussed. A combination of methods analysing different types of food compounds seems to be the most promising approach to establish the geographical origin. Chemometric analysis of the data provided by the analytical instruments is needed for such a multifactorial approach.     

Validation of analytical methods for acrylic acid from various food products

Food Science and Biotechnology - Acrylic acid (AA) chemical that endangers human health through contamination of water, soil, and foods. In this study, the extraction, purification, and detection...     

消费者搜寻食品安全信息行为关键因素的识别研究

在构建影响消费者搜寻食品安全信息行为的因素体系基础上,运用模糊集理论与实验决策案例分析方法,分析17个影响消费者搜寻食品安全信息行为因素的属性及其相互关系,并识别出其中消费者受教育程度、食品安全风险感知水平、对健康关注程度、对食品质量安全关注程度、产品知识、食品品牌和食品有无质量安全认证为关键影响因素。根据研究结论相应地提出食品生产企业需要进一步加强产品品牌建设和质量安全管理,进一步推进产品质量认证工作。     

烤鳗酱油中大豆、小麦过敏原的ELISA检测

烤鳗酱油的最初生产原料中包括了被许多国家和地区认定为过敏物的大豆和小麦,研究应用ELISA法对烤鳗酱油样品进行了大豆、小麦过敏原的测定.结果表明,对于大豆过敏原:绝大部分烤鳗酱油样品中检测不到,少数样品中其含量很低;对于小麦过敏原:绝大部分烤鳗酱油样品中的含量很低,少数样品检测不到.极微量的过敏原就可引起严重的过敏反应,因此应加强烤鳗酱油中过敏原的管理.     

基于总过敏原家族的食物过敏原家族分类

目的 根据过敏原数据库对食品过敏原进行分类。方法 从致敏性蛋白结构数据库SDAP(Structural Database of Allergenic Proteins)中获得已知食品过敏原列表, 将这些食品过敏原在AllFam数据库中进行整理分类。结果 根据分类结果, 得到涵盖食品过敏原数量最多的五个家族分别是Prolamin superfamily、Bet v 1-related protein、EF hand domain、Cupin superfamily和Profilin, 他们包含了大约60%的食物过敏原。研究还发现3个交叉过敏原家族, 分别是Serpin serine protease inhibitor、Thioredoxin和Triosephosphate isomerase。结论 这个分类包含植物性食品过敏原和动物性食品过敏原两大类, 并使用了过敏原家族数据库AllFam, 为科学研究食品过敏原的结构和功能及动物致敏试验、临床致敏试验的设计和开展提供了客观依据。     

Specific factors affecting lead uptake by food from cooking water

Following earlier work, detailed studies have been carried out on the lead uptake of individual foods from soft and hard water containing various amounts of lead. Experiments have also been made to determine whether solutions of lead nitrate in distilled water simulate the behaviour of water containing naturally present lead. The effect of length of cooking time, weight/volume ratio and salt addition have been studied, as well as the depostion of lead on to cooking vessels. In general, green vegetables, carrots, rice and spaghetti were found to take up more lead than do other foods. The difference in uptake observed between hard and soft waters varied according to the particular food being studied. Uptake from lead nitrate solutions showed a very similar pattern to uptake from hard water containing naturally present lead. Equilibrium was reached after only 5 min cooking for cabbage and spaghetti. Varying the solid/volume ratio for cabbage affected the uptake of lead from water, but the addition of sodium chloride or sodium bicarbonate had little effect on lead uptake. There was no sign of saturation in uptake of lead by cabbage from solutions of 11 mg litre^?1 lead as lead nitrate. Deposition of lead occurred on both aluminium and glass saucepans, and cleaning was more effective in removing lead from glass saucepans. Results obtained from the analysis of diets in a small population at Ayr confirmed those obtained previously by laboratory experiments.     

食品检验中乳酸菌鉴定方法的探讨

目的评价GB 4789《食品安全国家标准食品微生物学检验》中乳酸菌的鉴定方法。方法选择5种双歧杆菌、4种乳酸杆菌和1种链球菌共10株乳酸菌,分别采用GB 4789标准中的方法、API生化鉴定系统、16S rRNA基因序列分析法和RiboPrinter全自动基因指纹图谱分析法进行鉴定。结果 GB 4789对乳酸杆菌和嗜热链球菌鉴定效果较好,对双歧杆菌的鉴定能力较弱;API鉴定乳酸菌一般至"属"水平;16S rRNA序列分析和RiboPrinter系统可鉴定乳酸菌至"种"水平,婴儿双歧杆菌的鉴定结果为长双歧杆菌婴儿亚种。结论建议GB 4789标准中增加分子生物学方法作为乳酸菌鉴定方法的补充,同时建议及时更新标准中菌株的分类和名称。     

Reaction kinetics in food extrusion: methods and results

Extrusion cooking is a highly efficient food processing technology. During the extrusion process, there are many desirable and undesirable reactions which will determine final product quality. While being heated and sheared simultaneously, food raw materials experience a non-isothermal process and their residence time in the extruder is distributed. All these factors contribute to the difficulties in determining the kinetic parameters for those reactions. Therefore, this paper attempts to review the reaction kinetics in food extrusion. First of all, the kinetic models for the reactions are outlined. After elucidating how to determine reaction time in an extruder, the methodological approaches for determining the reaction order, rate constant, and activation energy of a reaction under isothermal or non-isothermal conditions with or without residence time distribution (RTD) are presented. Then, different models relating the rate constant to its various impact factors, with especially focusing on shear stress, are reviewed. Subsequently, how shear stress is estimated in an extruder, is illustrated. In the last part of this paper, the reported data of rate constant, reaction order, and activation energy for the reactions occurring during food extrusion are summarized, with detailed impacts of temperature, moisture content, shear stress, and determination method on these kinetic parameters. Finally, future research needs are suggested.     

食物过敏原相关研究新动态

正食物过敏是机体对摄入的某些食物蛋白的异常免疫反应,食物过敏症状大都表现在胃肠道、皮肤和呼吸道等部位。一些国外流行病学调查研究表明,在世界范围内食物过敏影响近6-8%的儿童和2.5%的成年人,食物过敏患者日益增多。除此之外,一些食物过敏症严重影响了人们的生命安全和生活质量,因此食物过敏已成为广泛关注的食品安全问题。1995年,联合国粮食与农业组织(Food and Agriculture Organization of the United Nations, FAO)和世界卫生组织(World Health Organization,WHO)公布了八大类常见过敏食物,包括花生、大豆、鸡蛋、牛奶、甲壳类、