Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
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Effect of Drying Methods of Rice Flour on Growth Properties of Bacillus cereus and Enterobacter sakazakii

쌀가루의 건조방법에 따른 Bacillus cereus와 Enterobacter sakazakii 생육 억제 특성

  • Published : 2007.06.30
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Abstract

In order to sterilize Bacillus cereus and Enterobacter sakazakii in rice flour, hot-air drying ($65^{\circ}C$/15 min, HT) and microwave drying (700 watt/30 sec, MT) treatments were evaluated and a storage study performed. Color changes (${\Delta}E$) appeared to be less in the MT rice flour than in HT treated rice flour. The effectiveness of the MT treatment showed reduced growth rates for B. cereus (0.54 log CFU/g) and E. sakazakii (1.45 log CFU/g). The populations of B. cereus in the control (NT) rice flour greatly increased during storage at 4, 10 and $20^{\circ}C$ as storage times increased. However, the growth of B. cereus was minimized in the MT rice flour. In conclusion, MT treatment is considered to be a good drying method when substituted for HT treatment to assure microbial safety in rice flour.

본 연구는 쌀가루의 저장온도 및 저장기간에 따른 병원성 미생물 생육특성을 조사하고 안전성과 유효성을 고려한 상업적 열풍 및 마이크로파 처리방법을 사용하여 쌀가루의 미생물학적 안전성, 저장성 및 품질유지를 최적화하고자 하였다. 마이크로파 처리(700 watt/30 sec, MT)와 열풍 처리($65^{\circ}C$/15 min, HT) 후 쌀가루의 처리전과 대비한 색차변화값(${\Delta}E$)은 각각 0.15와 0.27로 측정되어 마이크로파 건조가 열풍 건조보다 색깔의 변화가 적은 것으로 나타났다. B. cereus와 E. sakazakii의 살균력은 MT 처리 후 각각 0.54 log CFU/g, 1.45 log CFU/g으로 감소하여 HT 처리 보다 살균효과가 강하였다. 대조구(NT) 쌀가루의 B. cereus는 4, 10, $20^{\circ}C$ 모든 온도에서 빠른 성장을 보였으나, MT 처리시 성장이 최소화 되었다. E. sakazakii는 4, 10, $20^{\circ}C$ 모든 온도에서 그리고 HT, MT 모든 처리구에서 성장하지 못하였는데, MT 처리시 생존균수가 가장 적었다. 결론적으로 쌀가루의 품질면에서나 미생물학적 안전성 측면에서 마이크로파 처리는 열풍건조 처리를 대체할 수 있는 건조방법으로 평가되었다.

Keywords

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