江南大学 第1章 绪论2食品安全基本知识课件

1、第一章绪论2ContentIntroductionEconomic and social impact of food contaminationBiological contaminationChemicals and toxicants in food知识预测了解你对食品安全基本知识有多少认识？基本概念食品安全 Food Safety污染 Contamination危害 Hazard绝对安全性 Absolute safety相对安全性 Relative safetyWhat is food safety?The toxicant and injurant could not exist i

2、n food,which may harm or threaten the health of population and their offspring.食品中不应含有可能损害或威胁人体健康的有毒、有害物质或因素，从而导致消费者急性或慢性毒害或感染疾病，或产生危及消费者及其后代健康的隐患。The degree of confidence that food will not cause sickness or harm to the consumer when it is prepared,served and eaten according to its intended use.*De

3、fine:Food SafetyProtecting the food supply from microbial, chemical (ie rancidity, browning) and physical (ie drying out, infestation) hazards or contamination that may occur during all stages of food production and handling-growing, harvesting, processing, transporting, preparing, distributing and

4、storing. The goal of food safety monitoring is to keep food wholesome.Foodborne illness or food poisoning is caused by consuming food contaminated with pathogenic bacteria, toxins, viruses, prions or parasites. Such contamination usually arises from improper handling, preparation or storage of food.

5、 Foodborne illness can also be caused by adding pesticides or medicines to food, or by accidentally consuming naturally poisonous substances like poisonous mushrooms or reef fish. . Researchers in these disciplines have interacted to minimize the potential health hazards to consumers, by establishin

6、g standards that both guarantee the safety and nutritional value of food items consumed and permit regulatory and control measures to be implemented, thereby recognizing that good science is imperative for effective regulations, and that adequate control must be based on these regulations.CodexAlime

7、ntarius1984年，世界卫生组织文件 食品安全在卫生和发展中的作用“食品安全”与“食品卫生”作为同义语，定义为：生产、加工、储存、分配和制作食品过程中确保食品安全可靠，有益于健康并适合人消费的种种必要条件和措施。Despite substantial progress in the knowledge and application of food safety techniques, contaminated food is the direct cause of a high proportion of disease. 随着科技的进步，我们认识到污染食物造成了大部分的人类疾病。De

8、finition of Hazard 危害的定义It refers to the contamination which were harmful to human health.指能引起人类致病或伤害的污染或情况 Contamination 污染The situation exist naturally or by man-made, which may be harmful to people 可能会造成危害的人为或自然存在情况造成污染的各环节污染的来源哪些物质或成分应划作有毒、有害类?“不应”或“不能”代表的界限是什么？除明显致病的以外，所谓慢性毒害、慢性病、健康隐患、对后代的后效等，如

9、何解释？绝对安全性：被认为是指确保不可能因食用某种食品而危及健康或造成伤害的一种承诺，也就是食品应绝对没有风险。由于在客观上人类的任何一种饮食消费甚至其他行为总是存在某些风险，绝对安全性或零风险是很难达到的。“喝凉水都塞牙”1、任何食物成分，尽管是对人体有益的成分或其毒性极低，若食用数量过多或食用条件不当，都可能引起毒害或损害健康。如：食盐摄入过量会中毒，过度饮酒伤身体。2、饮食的风险不仅来自生产过程中人为施用的农药、兽药、添加剂等，还大量来自食品本身含有的天然毒素。3、过度偏食可能使食品中某些化学成分在人体超量积累达到有害程度。一种食品是否安全，取决于： 制作过程 食用方式是否合理 食用数量

10、是否适当 食用者自身的一些内在条件毒性：物质在任何条件下对有机体产生任何种类(慢性或急性)损害或伤害的一种能力包括：损害正在发育的胎儿(致畸胎) 改变遗传密码(致突变) 引发癌症(致癌)的能力等。“三致”传统的看法：评价一种食物或成分是否安全，并不是根据其内在的固有毒性，而是看其是否会造成实际危害。食品风险等级安全食品 Safety food常规食品 Conventional food无公害食品 Free-pollutant food绿色食品 Green Food有机食品 Organic food各地各级高风险食品1、国家质检总局2、浙江实行食品风险分级管理3、美国警惕：七种“风险食品”4、广

11、西首次划定高风险食品5、福州食品小作坊将禁产11类产品6、北京将糕点、乳制品列为“高风险食品” 1、国家质检总局五类食品被挂牌高风险食品分别是乳制品、肉制品、酱腌菜、食醋、饮料，国家将对食品实行分类管理,被国家重点监管。国家质量监督检验检疫总局近日下发关于进一步加强食品质量安全监管工作的通知，乳制品、肉制品、酱腌菜、食醋、饮料等5类产品被列为高风险食品。增加的发证检验项目具体包括：乳制品增检微生物、肉制品增检胭脂红、苯甲酸；对酱腌菜增检苏丹红、工业盐和对羟基苯甲酸酯；食醋增检工业冰醋酸；饮料增检香精香料和甜味剂。重点检验涉及人身安全健康的项目，如食品添加剂、重金属和微生物等。 2、浙江实行食品

12、风险分级管理浙江省质量监督管理局经过对食品风险程度分析后，于日前发布了食品及食品用产品质量安全分级目录(试行)，把食品分为高风险、中风险和低风险三类进行管理。 根据风险程度，该局把食品分为高风险、中风险、低风险三类。其中高风险食品包括肉制品、乳制品、食品添加剂、婴幼儿食品、配制酒、发酵酒等7类；中风险食品包括饮料、禽蛋、蜂产品等15类食品和编制物品、木制品、食品用纸制品等9类食品用产品；低风险食品包括加工或保藏的蔬菜、水果和坚果等4类食品和铁、钢或铝等金属的罐、桶和容器等3类食品用产品。 3、美国警惕：七种“风险食品” 根据美国科学家的最新研究成果，有7种食物是能够携带传染病菌的“风险食品”。

13、加利福尼亚州卫生服务部的公共卫生硕士维斯等研究者近日公布了他们的研究报告，向人们发出警告，有7种食物是能够携带传染病的“风险食品”：制作过于精致的汉堡、牛肉酱、生鱼、牡蛎、生的或未经高温处理的牛奶、半生不熟的鸡蛋、紫花苜蓿芽。4、广西首次划定高风险食品 把食品及食品用产品的风险水平分为“低风险、中风险、高风险”类。其中，“高风险”食品包括肉类加工制品、乳制品、食品添加剂、婴幼儿食品、白酒类食品。 5、北京将糕点、乳制品列为“高风险食品” 肉制品、乳制品、饮料、蜜饯、婴幼儿配方乳粉、豆制品、糕点制品及酱腌菜被确定为“高风险食品”。 Who is the higher group？食品污染和危害因

14、素分析Where comes from the hazards?危害来自何方？Biological 生物危害Chemical 化学危害Physical 物理危害The majority of disease agents that contaminate food are biological, posing a wide range of health consequences, but chemical contamination has also become a cause for public health concern. 主要危害是生物危害，但化学危害也威胁着人类健康。Biolo

15、gical hazard生物危害Biological hazard including bacterial, virus, and parasite生物危害包括致病菌、病毒、寄生虫。Resource: food material and food processing 食品中的生物危害既有可能来自于原料，也有可能来自于食品的加工过程。DiarrheaWhile traditionally it was thought that contaminated water supplies were the main source of pathogens causing diarrhea, it i

16、s now shown that up to 70% of diarrheal episodes may be foodborne.25% of all diarrheal episodes in infants and children were caused by E. coli ,5-15 by campylobacteriosis and 10-15% by Shigellosis; The diarrhea illness due to Cyclosypora cayetanensis was attributed to consumption of imported fresh r

17、aspberries,probably contaminated through water. The parasites may be transmitted through the fecal-oral route. Hepatitis AHepatitis A is common all over the world:some 10-50 persons per 100,000 are affected annually.Shellfish grown in contaminated water have often been recognized as a source of this

18、 disease.Food infected by food handlers and not subsequently sufficiently heated and restaurant are known to transmit hepatitis A.E. Coli O157:H7Outbreaks of E. Coli O157:H7 are causing concern in many countries( such as Australia, Canada, Japan, the United States, Scotland and Africa), because the

19、pathogen caused severe damage to health, and even death, particularly in children.Drinking water , cooked maize,fresh radish sprouts and cold cooked meat were the vehicle for transmission.Salmonella enteritidisIn many countries, poultry meat, eggs, and foods containing eggs have been identified as t

20、he predominant sources of this pathogen.In certain countries, up to 60-100% of poultry meat is contaminated with Salmonella spp. and Campylobacter, and meat, frogs legs, chocolate, and milk have also been implicated.In 1985, some 170,000-2000,000 persons were involved in an outbreak of salmonellosis

21、 in Chicago, which was caused by contaminated pasteurized milk.Chronic health problemSome foodborne diseases(e.g., listeriosis and toxoplasmosis) are particularly dangerous during pregnancy, as they can either be fatal to the fetus or cause severe deformation.About 3 fetus/infant of every 1,000 preg

22、nancies are affected by toxoplasmosis.Chronic conditions such as joint disease, immune system disorders, cardiovascular disease, disorders of the renal system, and possibly even cancer.MycotoxinsMycotoxins, the toxic metabolites of certain microscopical fungi (molds), may cause serious adverse effec

23、ts in humans and in animals, besides acute intoxication,which are capable of causing carcinogenic, mutagenic, and teratogenic effects. Currently several hundred mycotoxins have been identified.Aflatoxin is the most well-known and important mycotoxin from an economic point of view.Plant toxicantsToxi

24、cants in edible plants, and poisonous plants that resemble them(mushrooms, certain wild green plants), are important causes of ill health in many areas of the world. In some places, the poorer sections of the population eat grains known to be potentially toxic out of hunger. Seeds of plants producin

25、g pyrrolizidine alkaloids have accidently contaminated wheat and millet, leading to acute and chronic liver disease. In Europe misidentification of toxic mushrooms is by far the leading cause of illness and health in this category.Where do the biological contaminants come from ?Factors responsible f

26、or the high prevalence of foodborne diseases caused by biological contaminantsIn developing countries, food and drinking water are frequently contaminated with pathogens.1. Lack of basic sanitation , lack of fuel for cooking , inappropriate food storage facilities, and use of of untreated night-soil

27、 as fertilizer contribute to the introduction of pathogens into the food chain.2. People do not know that diseases such as diarrhea, hepatitis A, and poliomyelitis are to a great extent foodborne. That is ,lack of knowledge about basic food-safety measures.How to prevent and control the biological h

28、azard?生物危害的控制措施The health problems related to food contaminant often differ between countries and regions of the world. But the basic principles for prevention and control are similar.1. Improving the hygieneic quality of raw foodstuffs at the agriculture level, by applying the principles of good ag

29、ricultural practice and animal husbandry and improving the environmental conditions under which animals are raised.2. Application of food-processing technologies. Pasteurization, sterilization, fermentation, or irradiation can increase the availability of foods by extending their shelf life and can

30、contribute to their safety by reducing or eliminating the pathogenic microorganisms. Application of a good food safety assurance system during operations are essential. HACCP is important, which would ensure safety of processed and manufactured foods.3. When the above two methods fail, the third lin

31、e need apply. Education of food handlers in the principles of safe food preparation. For example: (1) Insufficient cooking or reheating of food. (2)Preparation of food several hours prior to consumption, combined with inadequate storage conditions (3)Use of contaminated raw food material (4)Cross-co

32、ntamination in the food preparation premises (5)Infected or colonized persons charged with the preparation of mealsEspecially the women and children (1). Microbiological hazards 致病菌危害和预防措施Control控制措施: Time and Temperature(heating and cooking, cooling and frozen时间/温度控制（加热和蒸煮，冷却和冷冻）Fermentation/pH发酵/或

33、PH值控制Salt and Antiseptic reagent盐或其他防腐剂的添加Drying干燥Material来源控制(2). Virus 病毒危害及其预防 Control 控制措施: Cooking 蒸煮(3). Parasite 寄生虫的危害极其预防 Control 控制措施: Controlling the diet 饮食控制inactive/remove 失活/去除。What is chemical hazard?化学危害Chemical hazards exit any step of the food procedure 化学污染可以发生在食品生产和加工的任何阶段.Main

34、component, foe example, pesticide, veterinary drugs and food additives are no harmful at a suitable level, but if exceed the limit level, they are harmful. 化学品，例如：农药、兽药和食品添加剂等适当地、有控制地使用是没有危害的，而一旦使用不当或超量就会对消费者形成危害。Classified 分类：Existed naturally: Environmental chemical 天然存在的化学物质：环境中的污染物多氯联苯，重金属等Envir

35、onmental chemicalPolychlorinated biphenyls(PCBs), may caused acute and carcinogenic effects, Levels of PCBS found in adipose tissue of women in the united States have been associated with developmental and behavioral deficits in their infants.Two large-scale incidents occurred in Japan and in Taiwan

36、, China,after consumption of contaminated edible oil. DDT has been shown to be associated with an increased risk of pancreatic cancer and breast cancer, which was widely used as an insecticide for agricultural purposes and for the control of vectorborne diseases.Added intentionally: food additive 有意

37、加入的化学物质：食品添加剂（防腐剂、如：亚硝酸盐和亚硫酸盐；营养强化剂、色素等）加工过程中产生的化学污染物多环芳烃氯丙醇 Added unintentionally: pesticide, PCBs,chemical 无意或偶尔进入食品的化学物质Veterinary drug residuesPesticide residuesHow to control chemical hazard?化学危害及预防措施Material来源控制Process生产控制Label标示控制the quantities of added chemicals lie within the limits permitt

38、ed by current legislation.For this purpose, the primary industry (producers of the agricultural, animal, and fishery products) and the processing industries have to comply with laws and regulations and must observe the principles of food agricultural, animal husbandry, and manufacturing practices.Th

39、e second line of defense is the application of technologies that can prevent or reduce the use of chemicals in food.For example, by drying crops to prevent mold growth and the production of mycotoxins in food during storage. Biotechnology can be used for the selection of plants resistant to diseases

40、 and in this way decrease the need for pesticide use. Food irradiation can replace the use of potentially harmful chemicals for insect disinfestation and inhibition of sprouting.3. The third line of defense is the rigorous control and monitoring of chemical levels in food, the responsibility foe whi

41、ch lies with governments and their food control agencies. The work of the food control agencies must be supported by up-to-date food legislation.What is and How to control the Physical hazard?物理危害及预防措施Material found in food unnaturally and inherent harmfully, for example: metal, glass 物理危害包括任何在食品中发现

42、的不正常的有潜在危害的外来物。例如：金属、碎玻璃。木头木头Metal is detected by metal detector对金属采用金属探测器探测Control控制措施: material来源控制 process 生产控制How to ensure the food safe in our daily life?日常生活中我们如何保证食品安全？The WHO Golden Rules for Sale food Preparation 世界卫生组织(WHO)对食品安全食用提出十大建议，告诫消费者进行自我保护，十大建议为：(1) Choose foods processed for saf

43、ety 应选择已加工处理过的食品，例如已加工消毒过的牛奶而不是生牛奶；While many foods, such as fruits and vegetables, are best in their natural state, others simply are not safe unless they have been processed. For example:*Always buy pasteurised as opposed to raw milk and , if you have the choice, select fresh or frozen poultry tre

44、ated with ionizing radiation.*When shopping, keep in mind that food processing was invented to improve safety as well as to prolong shelf-life.*Certain foods eaten raw, such as lettuce, need thorough washing.(2) Cooked food thoroughly 食物须彻底煮熟食用，特别是家禽、肉类和牛奶；Many raw foods, most notably poultry, meats

45、, and unpasturised milk, are very often contaiminated with disease-causing pathogens.Thorough cooking will kill the pathogens, but remember that the temperature of all parts of the food must reach at least 70C.If cooked chicken is still raw near the bone, put it back in the oven until its done-all t

46、he way through.Frozen meat, fish, and poultry must be thoroughly thawed before cooking.(3) Eat cooked foods immediately 食物一旦煮好就应立即吃掉，食用煮后在常温下已存放4-5h食物最危险；When cooked foods cool to room temperature, microbes begin to proliferate.The longer the wait, the greater the risk.To be on the safe side, eat cooked foods just as soon as they come off the heat.(4) Store cooked foods carefully 食物煮好后难以一次全部吃完