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 曲零 0.71 霉菌 Aspergillus ochraceus 曲霉 0.78 Aspergillus flavus 黄曲霉 0.80 Penicillium verrucosum 青零 0.79 Fusarium moniliforme 串珠镰孢霉 0.87 Yeasts Saccharomyces rouxii 鲁氏酵母 0.62 酵母 Saccharomyces cerevisiae卑酒酵母 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 ③KH
21 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
Range of aw in foods and their microbial flora 食品中āw的范围及其微生物菌群 aw range Foods Microbial flora Fresh meats 鲜肉 Fresh fish 鲜鱼 (C.perfringens, Fresh fruits 鲜果 产气美膜梭菌 >0.98 Fresh vegetables新鲜的蔬菜 Salmonella) Canned vegetables in brine 沙门氏菌 罐装盐水蔬菜 Canned fruit in light syrup (<3.5%salt,26%sugar) (Pseudomonas) 低盐罐装水果（盐<3.5%，糖<26%） 假单孢菌 Fermented sausages 发酵香肠 0.93- (B.cereus, 蜡状杆菌 Processed cheese 加工千酪 C.botulinum,肉毒梭菌 0.98 Bread 面包 Salmonella沙门氏菌) Evaporated milk炼乳 lactobacilli,bacilli and Tomato paste香茄酱 Micrococci 乳酸菌， (10%salt,50%sugar) 芽孢杆菌，微球菌 22 (10%盐。50%糖】 中
22 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
Range of aw in foodsand and their microbial flora aw range' Foods Microbial flora aw范围 食品 微生物菌群 Dry fermented S.aureus莉萄球菌 sausages千燥发酵香肠 0.85-0.93 Raw ham生火腿 Mycotoxinproducing moulds (17%salt,saturated 能产生霉菌毒素的霉菌 sucrose) （盐17%， 饱和蔗糖) Spoilage yeasts and moulds 腐败性酵母和霉菌 0.6-0.85 Dried fruit干果 Flour 面粉 Xerophilic fungi喜旱真菌 Cereals 谷类 Halophiles 嗜盐生物 Salted fish咸鱼 Osmophilic yeasts Nuts 坚果 耐高渗透酵母 <0.6 Confectionery糖果 No growth but may Honey 蜂蜜 remain viable Noodles 面条 不生长但能残存于其中 23
23 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 0.85-0.93
Water activity 水分活度 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 24 窗田
24 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 水分活度
Concentration of NaCl and glucose at various aw values (at 25 c) 25°C财不同浓度食盐和葡萄糖溶液的aw w/w %w/w aw NaCl Glucose莉萄糖 1.00 0.00 0.00 0.99 1.74 8.90 0.98 3.43 15.74 0.96 6.57 28.51 0.94 9.38 37.83 0.92 11.90 43.72 0.90 14.18 48.54 0.88 16.28 53.05 0.86 18.18 58.45 25
25 aw 1.00 0.99 0.98 0.96 0.94 0.92 0.90 0.88 0.86 Concentration of NaCl and glucose at various aw values (at 25°C) 25°C时不同浓度食盐和葡萄糖溶液的aw % w / w Glucose 葡萄糖 0.00 8.90 15.74 28.51 37.83 43.72 48.54 53.05 58.45 % w / w NaCl 0.00 1.74 3.43 6.57 9.38 11.90 14.18 16.28 18.18