pH values limiting the growth of pathogens 3、pH抑制致病菌的生长 Min Max. Escherichia coli 大肠杆菌 4.4 8.5 Salmonella typhi 沙门氏菌 4-4.5 8-9.6 Bacillus cereus蜡状芽孢杆状菌 4.9 9.3 Clostridium botulinum 4.6 8.5 肉毒梭状杆菌 Staphylococcus aureus 4 9.8 全黄色葡萄状球菌 Saccharomyces cerevisiae啤酒酵母2.3 8.6 Aspergillus flavus 曲霉菌 2.0 11.2 Fusarium moniliforme镰刀菌 2.5 10.7 Penicillium verrucosum青霉菌 2.0 10.0 26
26 pH values limiting the growth of pathogens 3、pH抑制致病菌的生长 pH Min Max. Escherichia coli 大肠杆菌 4.4 8.5 Salmonella typhi 沙门氏菌 4 - 4.5 8 - 9.6 Bacillus cereus 蜡状芽孢杆状菌 4.9 9.3 Clostridium botulinum 4.6 8.5 肉毒梭状杆菌 Staphylococcus aureus 4 9.8 金黄色葡萄状球菌 Saccharomyces cerevisiae啤酒酵母2.3 8.6 Aspergillus flavus 曲霉菌 2.0 11.2 Fusarium moniliforme 镰刀菌 2.5 10.7 Penicillium verrucosum 青霉菌 2.0 10.0
pH and other factors pH和其它因素 Microorganisms can grow in lab media at a wider range of pH than would occur in Foods 与在食品中相比，微生物在实验室培养基中能在更宽的PH范围内生长 Here,other factors come into effect e.g.microbial competition: (这里，还存在其它因素的影响，如：微生物的竞争) ◆ oxygen tension 氧气的压力 storage temperature贮藏温度 ◆ reduced aw 降低aw heat damage to cells during processing 如工过程中的热杀菌 27
27 pH and other factors pH和其它因素 Microorganisms can grow in lab media at a wider range of pH than would occur in Foods 与在食品中相比，微生物在实验室培养基中能在更宽的pH范围内生长 Here, other factors come into effect e.g. microbial competition: (这里，还存在其它因素的影响，如：微生物的竞争) ◆ oxygen tension 氧气的压力 ◆ storage temperature 贮藏温度 ◆ reduced aw 降低aw ◆ heat damage to cells during processing 加工过程中的热杀菌
pH Acidification 酸化 >addition of vinegar 添加醋 Fermentation 发酵 >organic acid 有机酸 >competitive exclusion排除竞争性 >antimicrobial agents 抗菌剂 28 窗
28 pH Acidification 酸化 ➢addition of vinegar 添加醋 Fermentation 发酵 ➢organic acid 有机酸 ➢competitive exclusion 排除竞争性 ➢antimicrobial agents 抗菌剂
pH of different foods不同食品的pH Approximate pH ranges of some common food pH commodities常见食品的pH范围 41312 1 Fermented shark发酵鲨鱼 10 Egg white蛋白 8 7 Fish 鱼类 Mlk牛奶 1Flour面粉 Vegetables 6 Meat 肉类 蔬菜 Citrus fruits柑桔 Soft drinks.软饮料 Beer啤酒 3 2 29 窗
29 pH of different foods 不同食品的pH Approximate pH ranges of some common food commodities 常见食品的pH范围 14 13 12 11 10 9 8 7 6 5 4 3 2 pH Fermented shark发酵鲨鱼 Egg white蛋白 Fish 鱼类 Meat 肉类 Citrus fruits柑桔 Milk 牛奶 Soft drinks软饮料 Flour面粉 Vegetables 蔬菜 Beer 啤酒
Food technologies that may kill certain microbes 可以杀死某些微生物的食品如工技术 Heat treatments 加热处理 Irradiation 辐射 Disinfection 消毒 >Freezing (parasites only) 冷冻（仅对寄生虫有效） >High pressure technology高压技术 30 窗
30 ➢ Heat treatments 加热处理 ➢ Irradiation 辐射 ➢ Disinfection 消毒 ➢ Freezing (parasites only) 冷冻（仅对寄生虫有效） ➢ High pressure technology 高压技术 Food technologies that may kill certain microbes 可以杀死某些微生物的食品加工技术