단일 및 단계적 저온 열처리에 따른 Clostridium sporogenes Spores의 저감 효과

초록

This study investigated the effects of low-heat treatments on the reduction of Clostridium sporogenes spores in suspension at 85°C and 90°C. At 85°C, the initial population (5.16 log CFU/mL) showed limited reduction (0.17–0.39 log CFU/mL) within 1 min, with reductions exceeding 1 log CFU/mL after 3 min and reaching 4.83 log CFU/mL after 15 min without complete inactivation. In contrast, treatment at 90°C resulted in greater inactivation, achieving complete spore inactivation after 15 min. Thermal inactivation data obtained at both temperatures were analyzed using a first-order kinetics model. The resulting D-values were 2.99 min at 85°C and 2.06 min at 90°C, with correlation coefficients (R²) of 0.99 for both conditions, indicating a high degree of model fitness and reliable description of the spore inactivation behavior. In addition, based on the FDA-recommended thermal processing conditions for pathogen control, stepwise low-heat treatments (67°C for 5 min, 72°C for 1 min, and 75°C for 1 min) were applied to C. sporogenes. The initial spore population was 5.24 log CFU/mL, and reductions of 0.26, 1.46, and 3.06 log CFU/mL were achieved after sequential application of the respective heating steps. These findings confirm the high thermal resistance of C. sporogenes spores and demonstrate that both prolonged single-temperature and stepwise heating effectively enhance spore reduction.

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