Modeling Heat-Resistance of Alicyclobacillus acidoterrestris in Different Fruit Juices: Combined Effects of pH and Temperature

This study evaluated the efficacy of pH and temperature on the thermal resistance of Alicyclobacillus acidoterrestris endospores in different fruit juices. A polynomial equation was used to describe the pH x temperature impact on the D-values of endospores. Endospore resistance was influenced by fruit juice matrices. Maximum heat resistance was found in passion fruit juice (D value 24.7 +/- 2.8 min, 90 oC, pH 4.5) and the greatest thermal destruction was observed in papaya juice (D value 1.7 +/- 2.8 min, 95 degrees C, pH 2.5). Regardless of the fruit juice, endospore thermal destruction was more effective at 95 degrees C. In both temperatures analyzed, the effect of pH on the reduction of heat resistance was more pronounced in papaya juice. According to the mathematical models, the interaction pH x temperature had the greatest impact on endospores thermal reduction. These results emphasize the relevance of time forward slash temperature binomials to prevent spoilage by A. acidoterrestris in thermal treated fruit juices.