Heat Sterilization Conditions to Ensure Commercial Sterility of Hot-Filling Tomato Juice

Abstract

In the production of hot-filling tomato juice products, which pH value are below 4.6 and distributed at normal temperature, the heat sterilization condition is setting at 121℃ for 0.7 min with Bacillus coagulans as an indicator, and it is widely used throughout the world. This study covered the three studies, 1) investigate bacterial spore contamination level of raw tomato material, 2) discover the best heat sterilization indicator, and 3) set the heat sterilization conditions in order to determine the ensured commercial sterility. In the production of hot-filling tomato juice products, which pH value are below 4.6, B. coagulans is unlikely to cause deterioration. Tainted tomatoes are often contaminated by Bacillus subtilis group and Genus Thermoanaerobacterium. In this repot, spores of Genus Thermoanaerobacterium, which is identified from spoiled tomato juice and have been known to cause deterioration, should be used as a heat sterilization indicator for hot-filling tomato juice products. We used the heat resistance of hot-filling tomato juice (pH 4.6) with Genus Thermoanaerobacterium as an indicator. The required heat treatment conditions for proper sterilization were a D_121℃-value of 0.3 min, a z-value of 8.2℃, and an F_121℃-value of 1.5 min (D value×5). As a result of the above findings, the current heat sterilization conditions with 121℃ for 0.7min are not sufficient for proper sterilization.