물리ㆍ화학적 처리에 의한 멸균 초콜릿 우유 오염균의 생육억제 효과

This study was conducted to investigate the cause of microbiological contaminants in aseptic chocolate milk and evaluate the effect of a physicochemical treatment on the growth inhibition of isolated bacterial strains. The bacterium isolated from aseptic chocolate milk was identified as Bacillus lentus and was named B. lentus M1. In the heat and pH treatment, the growth of B. lentus was inhibited at 110℃ for ＞15 min and at pH’s ＜5 and ＞10. An electrolyzed water treatment against B. lentus M1, revealed 5 ㎜ growth past the inhibition zone. The effect of ozone gas on B. lentus M1 growth was evaluated using viable cell counts. When the initial number of B. lentus M1 was 10² and 10³ CFU, the bacteria were completely suppressed by ozone gas treatment for 10 and 30 min, respectively. In a microwave treatment, B. lentus M1 was sterilized following microwave treatment for 1 min. As the result of γ-irradiation against B. lentus M1, numbers decreased as the γ-irradiation dosage increased. These results show the growth inhibition effects against contaminants in aseptic chocolate milk using physicochemical treatments.