Water Activity and Growth of Microorganisms in Food*

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Water Activity and Growth of Microo rganisms in Food* * Adapted from L.R. Beuchat, Cereal Foods World, 26:345 (1981) Microorganisms Generally Inhibited Foods Generally within Range of a w by Lowest a w in This Range This Range Pseudomonas, Escherichia, Highly perishable (fresh) foods Proteus, Shigells, Klebsiella, and canned fruits, vegetables, 1.00–0.95 Bacillus, Clostridium perfringens, meat, sh, milk, and beverages some yeasts Salmonella, Vibrio parahaemolyticus, C. botulinum, Some cheeses (Cheddar, Swiss, Serratia, Lactobacillus, Muenster, Provolone), cured meat 0.95–0.91 Pediococcus, some molds, yeasts (ham), bread, tortillas (Rhodotorula, Pichia) Fermented sausage (salami), Many yeasts (Candida, Torulopsis, sponge cakes, dry cheeses, 0.91–0.87 Hansenula), Micrococcus margarine Most molds (mycotoxigenic Most fruit juice concentrates, penicillia), Staphyloccocus aureus, sweetened condensed milk, 0.87–0.80 most Saccharomyces (bailii) spp., syrups, jams, jellies, soft pet food Debaryomyces Most halophilic bacteria, Marmalade, marzipan, glacé fruits, 0.80–0.75 mycotoxigenic aspergilli beef jerky Xerophilic molds (Aspergillus Molasses, raw cane sugar, some chevalieri, A. candidus, Wallemia dried fruits, nuts, snack bars, snack 0.75–0.65 sebi), Saccharomyces bisporus cakes Osmophilic yeasts (Saccharomyces Dried fruits containing 15-20% rouxii), few molds (Aspergillus moisture; some toees and 0.65–0.60 echinulatus, Monascus bisporus) caramels; honey, candies Dry pasta, spices, rice, 0.60–0.50 No microbial proliferation confections, wheat Whole egg powder, chewing 0.50–0.40 No microbial proliferation gum, our, beans Cookies, crackers, bread crusts, 0.40–0.30 No microbial proliferation breakfast cereals, dry pet food, peanut butter Whole milk powder, dried 0.30–0.20 No microbial proliferation vegetables, freeze dried, corn starch, potato chips, corn chips LABCELL LTD FOUR MARKS, ALTON, HAMPSHIRE GU34 5PZ TEL: ++44 (0)1420 568150 FAX: ++44 (0)1420 568151 e: [email protected] www.labcell.com .

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