1、Yeast & Mold 酵母菌和霉菌,Yeast are single-cell plant. They can live only on sugars and starch, and producing CO2 and alcohol. 酵母菌是单胞植物体。它们只能生存在糖和淀粉中，并产出CO2和酒精。 Some yeast can grow at temperature below 10oC. They grow also under conditions of high salt and sugar content. 某些酵母菌在10以下可以生长。而在高盐和高糖量的条件下，它们仍旧可以
2、生存。 Molds are spore-forming microbes, and reproduce by releasing spores into the air. 霉菌是孢子类的微生物，通过在空气中释放孢子来繁殖再生。,Yeast & Mold 酵母菌和霉菌,Like,yeast, molds can withstand low temperature, high salt and,high sugar medium. 和酵母菌一样，霉菌也能适应低温、高盐和高塘的介质环境。,Certain molds are dangerous to health as they produces m
3、ycotoxin which will not destroy even after cooking. 某些霉菌对人体有害，它会产生毒忮霉菌，即使通过烹调也不能除去这种有害菌。,The well known example is Aflatoxin from Aspergillus. 举个众所周知的例子,曲霉菌中的黄曲霉毒素就是这种毒菌.,.,Food Poisoning 食物中毒,Human illnesses caused by food-borne microorganism. 人类生病通常是由于食物中携带了微生物而引起的.They are caused by pathogenic in
4、fection or by their toxins produced. 这些微生物通过致病菌感染或是产生毒素而引起人类生病.The time between the consumption of contaminated foods and the appearance of illness is called incubation period. 从食物开始污染到食物表面出现病班的这段时间叫做孵化期.,Food Poisoning 食物中毒,Minor cases of food poisoning causes vomiting, abdominal cramps and diarrhe
5、a. 未成年人如果发生食物中毒就会有呕吐,腹部绞痛和腹泻等症状. Examples of incidents required concern areE. coli 0157:H7 found in contaminated ground ,meat, milk and fruit juices may cause kidney failure in children. 在污染的地面，肉类，牛奶和果汁中都发现有 的存在，这种致病菌会伤害儿童的肾脏。,Food Poisoning 食物中毒,Improper processed low-acid canned food (green beans,
6、 mushroom, beef, fish) may cause Botulism which is life-threatening. 低酸罐装食品（青豆、蘑菇、牛肉和鱼）如果处理不得当就会导致致命的波特淋菌中毒。Undercooked chicken and related foods may exposed to Campylobacter, causing bloody diarrhea and fever. 烹调不当的鸡肉和相关食物？，会引起严重的腹泻和高烧。,Food Spoilage 食物变质,Food spoilage occur when the microorganism
7、grow on the food and alter the chemicals and physical properties of foods. 当食物中生长了微生物并且改变了食物的物理和化学特性时，食物就会变质。Blue green color on bread by Penicillium. 面包上的蓝绿色是因为长了青霉菌。Black rot on grains by Aspergillus. 粮食上有黑色腐烂物是因为长了曲霉菌。,Food Spoilage 食物变质,Slimy on poultry by Pseudomonas. 假单胞菌会使家禽分泌粘液。 Souring on m
8、ilk by Streptococcus. 链球菌会使牛奶变酸。Putrefaction of meats by Escherichia. 埃希氏菌会使肉类腐败。These affect the shelf life of foods. 这些菌类都会影响食物的货假期。,Control of Microbial Growth 抑制微生物生长,1) Heat 热处理 Sterilization, 121oC for 15 min 121oC下保持15分钟就可以有效杀菌 Pasteurization, 63oC/30 min or 72oC/15 seconds 巴氏消毒： 63oC/30分钟或72
9、oC/15秒 2) Chemical Agents 化学处理 Disinfectant, chlorine compounds, copper sulfate 消毒剂：氯化合物，酸酸铜 Antiseptic, iodine solution, alcohol 杀菌类：碘溶液，酒精 Preservative, sodium nitrite, propionic acid 防腐剂：亚硝酸钠，丙酸,Control of Microbial Growth 抑制细菌生长,3) Physical Condition 物理方法Alter the foods storage condition, pH, te
10、mperature, Aw, modified atmosphere 改变食物的储存条件，pH值，温度，Aw，通风。 4) Prevention of cross-contamination 防止交叉污染Factory sanitation 工厂的卫生条件 Good Manufacturing Practices (GMP) 良好的行业惯例,Useful Microorganism 有益的微生物,Not all microbes are bad. 并不是所有的微生物都有害。 Microbes are important in our ecology system, breaking down
11、waste products (biodegradation). 在我们的生态环境中，微生物是很重要的，因为它们可以消灭掉废物产品（生物降解）。 Microbes, Lactobacillus are important in maintaining good digestive system of our body.细菌和乳酸菌对于维护我们身体的消化系统很重要。 Microbes are developed for certain industrial purposes (biotechnology and enzymes technology). 在某些工业用途中微生物也有很大的发展（生物工艺学和酶技术）。,Thank You,
