Water Activity of Foods Table
Most microorganisms grow well at 0.91 to 0.99. Clostridium botulinum will grow and produce deadly botulism toxin if the pH is above 4.6 and the water activity is above 0.85.
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Microorganisms grow at this aw and above |
Food examples |
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0.95 Pseudomonas, Escherichia, Proteus,Shigella, Klebsiella, Bacillus, Clostridium perfringens, some yeasts |
Highly perishable foods (fresh and canned fruits, vegetables, meat, fish), milk, cooked sausages, breads, foods with up to 4 oz sucrose or 7% NaCl |
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0.91 Salmonella, Vibrio parabaemolyticus,C. botulinum, Lactobacillus, some molds |
Some cheese (Cheddar, Swiss, Provolone), cured meat, fruit juice concentrates with 55% sucrose or 12% NaCl |
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0.87 Many yeasts, Candida, Torulopsis, Hansenula micrococcus |
Fermented sausage, sponge cakes, dry cheese, margarine, foods with 65% sucrose or 15% NaCl |
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0.80 Most molds, most Saccharomycesspp., Debaryomyces, Staphylococcus aureus |
Most fruit juice concentrates, condensed milk, syrup, flour, high-sugar cakes, pulses containing 15-17% moisture |
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0.75 Most halophilic bacteria, Mycotoxigenic aspergilli |
Jam, marmalade, glace fruits, marzipan, marshmallows |
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0.60 Osmophilic yeasts, few molds |
Dried fruits with 15-20% moisture, caramel, toffee, honey |
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0.03 |
Whole milk powder with 2-3% moisture, dehydrated soups |
