Effect of temperature and soluble solid on and spore inactivation and quality degradation of pineapple juice.

and spores can survive processing temperatures used in the thermal processes of high-acid foods. Therefore, this study investigated the thermal inactivation of and spores in pineapple juice at different temperatures (85-100°C) and soluble solids (SS, 11-30°Brix). The quality of juices and microbial loads after the thermal treatments during storage at 4 °C for 35 days was then checked. A linear decrease in D-value was observed with increasing temperature of treatment. Furthermore, the D-values determined in pineapple juice were: D=13.2 ± 0.5 mins, D = 6.8 ± 0.9 mins and D = 2.1 ± 1.7 mins for spores, and D = 16.6 ± 0.4 mins, D = 7.6 ± 0.5 mins and D = 3.6 ± 1.5 min, for Generally, the susceptibility of the bacteria to soluble solid change was affected by the interaction between temperature, SS and strain. In addition, pasteurization processes of ≥95°C for ≥33.8 mins was needed to ensure a recommended 5-log reduction of spores and limit vitamin C degradation of pineapple juice within three-week of storage at 4 °C.