SUMMARYMicrobial growth patterns of rehydrated shrimp were investigated at 4, 20, and 37°C. Storage temperature greatly influenced the growth rates. The lag period was longest at 4°C and shortest at 37°C. The maximum population, almost a million times that of the initial population, was reached twice as fast at 37°C as at 20°C. Samples stored at 4°C increased 10,000‐fold in total aerobic counts but required two weeks to do so.Growth patterns indicate a shift in microbial spectrum in response to temperature. This was pronounced when rehydrated shrimp was stored at 4°C, the essentially mesophilic population becoming a minority.It is apparent that, in common with other types of perishable food products, rehydrated shrimp can have a storage life significantly extended by low temperatures. The shrimp storage life was 7 times as long at 4°C as at 20°C, and 20 times as long as at 37°C.

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SUMMARY Microbial growth patterns in rehydrated freeze‐dried chicken at 4, 20, 30, and 37°C are similar to those of rehydrated freeze‐dried shrimp, and are greatly influenced by storage temperature, time, and initial number of microorganisms present. Lag time was shortest at 37 and 30°C, four times as long at 20°C as at 37°C, and 120 times as long at 4°C as at 37°C. At 37°C, the maximum population was 300,000 times the initial population, while at 30°C it was 115,000 times wafter 26 hr. The microbial population increased 100,000‐fold at 55 hr at 20°C, and 500‐fold at 15 days at 4°C. A natural contaminant in the freeze‐dried chicken examined, eoagulase‐positive Staphylococcus aureus, was found to be at a level of 3040 organisms per gram, out of a total population of 10° organisms per gram. Fecal enterococci were also present in the freeze‐dried material at a level of about 10° to 10° per gram. Rehydration studies show that Staphylococcus aureus and “fecal enterococci” as natural contaminants in freeze‐dried chicken can grow in competition with the natural flora at 20 °C or above and that the competition may be due to the nature of the microbial distribution on the chicken surface. Refrigeration temperatures in the vicinity of 4°C completely suppressed the growth of S. aureus and greatly extended the shelf life of rehydrated chicken.

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