Thermal Resistance of Spores from pH, Elevating Strains of Bacillus licheniformis

Abstract

The thermal resistance of Bacillus licheniformis spores from strains originally isolated from home‐canned tomatoes was examined. In tomato puree at pH 4.4, D95 and D100 values of 4.5 and 2.0 min, respectively, were obtained. The z value was 14.9 C°. The D95 in pH adjusted tomato puree increased at the rate of 50% per pH unit over the range pH 4–5.5. The D95 in pH 7.2 buffer was 7.8 min. The B. licheniformis spores could survive the USDA raw pack process for home‐canned tomatoes and elevate the pH to greater than 5.2 under aerobic but not anaerobic conditions. Copyright © 1981, Wiley Blackwell. All rights reserved