Destruction and Survival of Microörganisms in Frozen Pack Foods

Abstract

The microbiological content of small fruits in sucrose solution stored at -2[degree], -4[degree], -7[degree], -10[degree], and -20[degree] C. tended to decrease most rapidly at the higher temp.,[long dash]e.g., reductions in strawberries being 60% at -20[degree] and 89% at -10[degree] in 4 mos. There is evidence that CO2 from respiration of the fruit is responsible in large part for the destruction of microorganisms. The air-tightness of the container apparently affects the microbial death rate. In vegetables preserved at [long dash]10[degree], lactobacilli and "colon" organisms have been found to persist for 2 yrs. Under aerobic conditions, Cladosporium sp. and Torula sp. grew at [long dash]2[degree], and Pseudomonas sp. at -4[degree]. Yeasts in wort exposed to -10[degree] were largely destroyed in 3 days, when the medium froze; when it remained liquid, approximately 50% were alive after 5 days.