苏州市一起疑似类志贺邻单胞菌引起的食物中毒调查与分析

目的分析2019年6月苏州市某幼儿园食物中毒的原因,了解病原菌的基因分型和耐药谱情况。方法通过问卷调查、电话访谈,查阅医院就诊记录、餐厅订餐记录等主动搜索病例,开展病例个案调查和现场卫生学调查,采集相关样品进行实验室检测。以分离培养,质谱快速鉴定,VITEK-2 Compact全自动细菌鉴定仪生化鉴定进行鉴定分析,脉冲场电泳(pulsed-field gel electrophoresis,PFGE)进行基因分型,药敏试验采用微量肉汤稀释法。结果共搜索到17位病例(包括确诊病例4人),临床表现为腹痛、腹泻等胃肠道不适症状,均无头痛、发热等其他不适症状。6月20日中餐为可疑餐次,此外无其他共同饮食史。现场共采集47份样本(包括菜品、环境样本和肛拭子),其中4份学生肛拭子检出类志贺邻单胞菌。PFGE分型结果显示其中3株菌100%同源,属于同一型别,另一株菌与其差异较大,属于不同型别。对14种抗生素的药敏分析显示,3株菌(同一型别)除对氨苄西林耐药外还对甲氧苄胺嘧啶/磺胺甲噁唑耐药,对其它抗生素均敏感。另1株菌对氨苄西林耐药,对其它抗生素均敏感。结论此次事件很可能是一起由类志贺邻单胞菌引起的食物中毒,并且可能来源于不同的传染源。     

基于工程认证驱动的食品包装课程体系改革探索

目的 探究将成果导向（OBE）的教育理念应用到食品包装学的教学中,提升食品专业人才培养质量,达到工程认证对学生工程能力的要求。方法 紧扣专业培养目标,围绕课程教学目标定位,探索课程教学持续改进的方法。以学生的学习效果为驱动,针对课程目标设计教学方法和课程考核。结果 优化课程教学内容,明确课程教学目的,在教学过程中应用项目驱动教学、分组讨论教学、虚实结合教学,充分调动学生学习的积极性。将考核过程量化处理,注重过程考核,实现教师、学生多元化考核体系。结论 运用OBE的教学理念,使学生具备“解决复杂工程问题”的能力,培养学生自主学习,终身学习意识,为提高课程教学质量、实现毕业要求指标点提供支撑。     

超高效液相色谱-串联质谱法测定动物源性食品中硝基呋喃代谢物

目的建立动物源性食品中四种硝基呋喃代谢物的超高效液相色谱串联质谱(ultra pressure liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)的快速检测方法。方法样品经盐酸溶液水解,邻硝基苯甲醛(2-NBA)37℃衍生16 h后,调节衍生液的pH=7.6,用乙酸乙酯提取。分析物采用电喷雾电离,正离子扫描,多反应检测模式(MRM),基质匹配内标标准曲线法定量。结果四种代谢物的工作曲线在0.1～10.0μg/L浓度范围内线性良好,相关系数R2均达到了0.995以上,氨基脲(SEM或SCA)与1-氨基-乙内酰脲(AHD)最低检出限均为0.1μg/kg,5-吗啉甲基-3-氨基-2-恶唑烷基酮(AMOZ)与3-氨基-2-恶唑烷基酮(AOZ)最低检出限均为0.05μg/kg。平均回收率在91.8%～107.0%之间,相对标准偏差均小于10%。结论样品前处理简单、测定时间短、灵敏度高,适用于猪肉、牛肉、鸡肉、猪肝和水产品(鱼类及虾类)中硝基呋喃类代谢物残留的快速测定。     

离子迁移谱及其在食品监测中的应用

离子迁移谱(ion mobility spectrometry,IMS)是近年来快速发展起来的一项检测技术。由于其操作简便、检测快速、灵敏度高、体积小等明显优势,现已被应用到危险品检测、医药、环保、食品安全、过程控制等诸多领域的研究中。本文简要地介绍了其结构和工作原理,重点阐述其在国内外食品监测领域中的最新进展。目前在食品工业中的应用研究包括:食品与农产品中农药、兽药等的残留检测,食品生产加工储蓄保鲜等过程中的质量控制如控制啤酒发酵程度、储藏保鲜过程监测,食品原产地及真实性的快速检验如橄榄油和葡萄酒等级鉴定、原产地鉴定等。在此基础上也与现行的常规检测技术(高效液相色谱、气相色谱)进行了比较。简要讨论了其在食品安全和质量检测中的可能应用前景,认为IMS具有提高食品质量、优化生产过程、规范市场行为的巨大潜力。     

二苯甲酮和1-羟基环己基苯基甲酮从食品包装纸向奶粉与Tenax迁移研究

对二苯甲酮和1-羟基环己基苯基甲酮在高温条件下从食品包装纸（白卡纸和牛皮纸）向脂肪类模拟物Tenax以及全脂奶粉中的迁移规律进行研究。为避开奶粉中杂质色谱峰的干扰,气相色谱的升温条件为柱温：80 ℃保留3 min,温度以20 ℃/min 的速率升到150 ℃,保留10 min,然后再以30 ℃/min 升到290 ℃保留10 min。结果表明：温度越高,光引发剂向食品的迁移率就越高,且迁移速率也越大,达到平衡的时间也越短。纸张本身对脂肪的渗透能力是影响污染物迁移的重要影响因素,在高温下包装含脂量较高的食品时,应尽量避免选用脂肪渗透能力较强的纸张。光引发剂由同种纸质食品包装材料分别向Tenax和全脂奶粉迁移的研究表明,光引发剂向奶粉迁移的迁出率较高,奶粉作为一种真实的食品,有很好的吸附能力,因而适合用于做迁移研究,且奶粉成分复杂,更能代表真实食品的特性。     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

公共行政视角下的食品安全监管-风险与问题的辨析

针对目前在食品安全问题上千篇一律的分析方式,本文从公共行政的角度,通过客观辨析食品安全问题和风险二者之间的关系,推断出主要是由于人类对食品中天然风险因素控制不力的行为、对食品安全风险的认识水平与生产、加工安全食品的认知能力不足和生产经营者的主观故意行为促使了食品安全风险向食品安全问题转化。食品安全监管并不是产生食品安全问题的直接原因,但却是防控食品安全问题的关键因素。     

暴露限值法评估广西食用植物油中黄曲霉毒素B1的暴露风险

目的评估广西食用植物油中黄曲霉毒素B_1的暴露风险。方法结合广西植物油中黄曲霉毒素B_1污染状况和人群消费量的调查结果,应用暴露限值(margin of exposure,MOE)法对植物油中黄曲霉毒素B_1膳食暴露情况进行分析。结果此次调查中植物油样品黄曲霉毒素B_1含量范围为0.50~320.00μg/kg。其中,花生油的检出率为78.08%(114/146),远高于其他植物油,超标率为31.51%(46/146),平均含量为30.80μg/kg,人群日膳食暴露量为17.30 ng/kg BW,MOE值为18。定型包装花生油中黄曲霉毒素B_1平均含量为6.33μg/kg,低于国家安全标准,处于安全范围;而散装花生油黄曲霉毒素B_1平均为41.50μg/kg,含量高出国家标准1.08倍,人群日膳食暴露量25.59 ng/kg BW,MOE值为12,是定型包装的MOE值的1/8。结论对于散装花生油应优先采取风险管理措施,加大监管力度,并做好人群健康饮食习惯指导。     

高效液相色谱法同时检测饮料中十二种食品添加剂

检测多种食品添加剂在食品中的含量,通常需要分别进行检测。由于各种检测方法的样品前处理及检测仪器条件有很大的区别,因此常规检测不但增加了工作量,延长了工作时间,还降低了工作效率。利用高效液相色谱仪的梯度洗脱和波长切换,实现对饮料类食品中防腐剂、甜味剂、合成着色剂等共12种食品添加剂的同时检测,缩短了检测时间。同时该方法回收率高,精密度和检出限均可满足食品安全检测工作需要,是一种简便、快捷、准确的方法。      

Development of a Risk-Ranking Framework to Evaluate Potential High-Threat Microorganisms, Toxins, and Chemicals in Food

ABSTRACT:  Through a cooperative agreement with the U.S. Food and Drug Administration, the Institute of Food Technologists developed a risk-ranking framework prototype to enable comparison of microbiological and chemical hazards in foods and to assist policy makers, risk managers, risk analysts, and others in determining the relative public health impact of specific hazard–food combinations. The prototype is a bottom-up system based on assumptions that incorporate expert opinion/insight with a number of exposure and hazard-related risk criteria variables, which are propagated forward with food intake data to produce risk-ranking determinations. The prototype produces a semi-quantitative comparative assessment of food safety hazards and the impacts of hazard control measures. For a specific hazard–food combination the prototype can produce a single metric: a final risk value expressed as annual pseudo-disability adjusted life years (pDALY). The pDALY is a harmonization of the very different dose–response relationships observed for chemicals and microbes. The prototype was developed on 2 platforms, a web-based user interface and an Analytica® model (Lumina Decision Systems, Los Gatos, Calif., U.S.A.). Comprising visual basic language, the web-based platform facilitates data input and allows use concurrently from multiple locations. The Analytica model facilitates visualization of the logic flow, interrelationship of input and output variables, and calculations/algorithms comprising the prototype. A variety of sortable risk-ranking reports and summary information can be generated for hazard–food pairs, showing hazard and dose–response assumptions and data, per capita consumption by population group, and annual p-DALY.