26 Water activity (3) 水分活度a w 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Aw Reaction rate 反应速率 Lipid oxydation 油脂氧化 Non-enzymatic Browning 非酶褐变 Enzymatic activity 酶的活力 Growth of: Moulds 霉菌 Yeasts 酵母 Bacteria 细菌
26 Water activity (3) 水分活度a w 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Aw Reaction rate 反应速率 Lipid oxydation 油脂氧化 Non-enzymatic Browning 非酶褐变 Enzymatic activity 酶的活力 Growth of: Moulds 霉菌 Yeasts 酵母 Bacteria 细菌
27 Minimum levels of aW permitting growth ( at near optimum temperatures ) 微生物生长必需的最低水分活度（在接近最适温度下） Moulds Aspergillus chevalieri 曲霉 0.71 霉菌 Aspergillus ochraceus 曲霉 0.78 Aspergillus flavus 黄曲霉 0.80 Penicillium verrucosum 青霉 0.79 Fusarium moniliforme 串珠镰孢霉 0.87 Yeasts Saccharomyces rouxii 鲁氏酵母 0.62 酵母 Saccharomyces cerevisiae 啤酒酵母 0.90 Bacteria Bacillus cereus 蜡状芽孢杆菌 0.92 细菌 Clostridium botulinum (proteolytic) 0.93 肉毒梭状芽孢杆菌（蛋白水解型） Clostridium botulinum (non-proteolytic) 0.97 肉毒梭状芽孢杆菌（非蛋白水解型） Escherichia coli 埃希氏大肠杆菌 0.93 Salmonella 沙门氏菌 0.95 Staphylococcus aureus 葡萄球状杆菌 0.83
27 Minimum levels of aW permitting growth ( at near optimum temperatures ) 微生物生长必需的最低水分活度（在接近最适温度下） Moulds Aspergillus chevalieri 曲霉 0.71 霉菌 Aspergillus ochraceus 曲霉 0.78 Aspergillus flavus 黄曲霉 0.80 Penicillium verrucosum 青霉 0.79 Fusarium moniliforme 串珠镰孢霉 0.87 Yeasts Saccharomyces rouxii 鲁氏酵母 0.62 酵母 Saccharomyces cerevisiae 啤酒酵母 0.90 Bacteria Bacillus cereus 蜡状芽孢杆菌 0.92 细菌 Clostridium botulinum (proteolytic) 0.93 肉毒梭状芽孢杆菌（蛋白水解型） Clostridium botulinum (non-proteolytic) 0.97 肉毒梭状芽孢杆菌（非蛋白水解型） Escherichia coli 埃希氏大肠杆菌 0.93 Salmonella 沙门氏菌 0.95 Staphylococcus aureus 葡萄球状杆菌 0.83
28 Range of aW in foods and their microbial flora 食品中aW的范围及其微生物菌群 aw range Foods Microbial flora > 0.98 Fresh meats 鲜肉 Fresh fish 鲜鱼 Fresh fruits 鲜果 Fresh vegetables新鲜的蔬菜 Canned vegetables in brine 罐装盐水蔬菜 Canned fruit in light syrup (<3.5 % salt, 26% sugar) 低盐罐装水果（盐<3.5%，糖<26％） (C. perfringens, 产气荚膜梭菌 Salmonella) 沙门氏菌 (Pseudomonas) 假单孢菌 0.93 - 0.98 Fermented sausages 发酵香肠 Processed cheese 加工干酪 Bread 面包 Evaporated milk 炼乳 Tomato paste 番茄酱 (10% salt, 50% sugar) （10％盐。50％糖） (B. cereus, 蜡状杆菌 C. botulinum, 肉毒梭菌 Salmonella 沙门氏菌) lactobacilli, bacilli and Micrococci 乳酸菌， 芽孢杆菌，微球菌
28 Range of aW in foods and their microbial flora 食品中aW的范围及其微生物菌群 aw range Foods Microbial flora > 0.98 Fresh meats 鲜肉 Fresh fish 鲜鱼 Fresh fruits 鲜果 Fresh vegetables新鲜的蔬菜 Canned vegetables in brine 罐装盐水蔬菜 Canned fruit in light syrup (<3.5 % salt, 26% sugar) 低盐罐装水果（盐<3.5%，糖<26％） (C. perfringens, 产气荚膜梭菌 Salmonella) 沙门氏菌 (Pseudomonas) 假单孢菌 0.93 - 0.98 Fermented sausages 发酵香肠 Processed cheese 加工干酪 Bread 面包 Evaporated milk 炼乳 Tomato paste 番茄酱 (10% salt, 50% sugar) （10％盐。50％糖） (B. cereus, 蜡状杆菌 C. botulinum, 肉毒梭菌 Salmonella 沙门氏菌) lactobacilli, bacilli and Micrococci 乳酸菌， 芽孢杆菌，微球菌
29 Range of aW in foodsand and their microbial flora aw range’ aw范围 Foods 食品 Microbial flora 微生物菌群 S. aureus葡萄球菌 Mycotoxinproducing moulds 能产生霉菌毒素的霉菌 Spoilage yeasts and moulds 腐败性酵母和霉菌 Dry fermented sausages干燥发酵香肠 Raw ham 生火腿 (17% salt, saturated sucrose) （盐17％，饱和蔗糖） 0.6 - 0.85 Xerophilic fungi喜旱真菌 Halophiles 嗜盐生物 Osmophilic yeasts 耐高渗透酵母 Dried fruit 干果 Flour 面粉 Cereals 谷类 Salted fish 咸鱼 Nuts 坚果 < 0.6 No growth but may remain viable 不生长但能残存于其中 Confectionery糖果 Honey 蜂蜜 Noodles 面条 Dried egg, milk 干燥鸡蛋，牛奶 0.85-0.93
29 Range of aW in foodsand and their microbial flora aw range’ aw范围 Foods 食品 Microbial flora 微生物菌群 S. aureus葡萄球菌 Mycotoxinproducing moulds 能产生霉菌毒素的霉菌 Spoilage yeasts and moulds 腐败性酵母和霉菌 Dry fermented sausages干燥发酵香肠 Raw ham 生火腿 (17% salt, saturated sucrose) （盐17％，饱和蔗糖） 0.6 - 0.85 Xerophilic fungi喜旱真菌 Halophiles 嗜盐生物 Osmophilic yeasts 耐高渗透酵母 Dried fruit 干果 Flour 面粉 Cereals 谷类 Salted fish 咸鱼 Nuts 坚果 < 0.6 No growth but may remain viable 不生长但能残存于其中 Confectionery糖果 Honey 蜂蜜 Noodles 面条 Dried egg, milk 干燥鸡蛋，牛奶 0.85-0.93
30 aw can be reduced by : 下述三种方法能减小aw： ◆ Removing water (drying) 除去水分（烘干） ◆ Decreasing availability of water by crystalization (freezing) 通过结晶（冷冻）减少有效水分 ◆ Decreasing availability by binding water with water binding agents e.g. salt, sugar 利用盐、糖这些亲水试剂与水分子的结合减少有效水分 Water activity (4) 水分活度
30 aw can be reduced by : 下述三种方法能减小aw： ◆ Removing water (drying) 除去水分（烘干） ◆ Decreasing availability of water by crystalization (freezing) 通过结晶（冷冻）减少有效水分 ◆ Decreasing availability by binding water with water binding agents e.g. salt, sugar 利用盐、糖这些亲水试剂与水分子的结合减少有效水分 Water activity (4) 水分活度