Survival during Cooking and Growth from Spores of Diarrheal and Emetic Types of Bacillus cereus in Rice

Author:

ANKOLEKAR CHANDRAKANT1,LABBÉ RONALD G.1

Affiliation:

1. Food Microbiology Laboratory, Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA

Abstract

Bacillus cereus is a gram-positive, spore-forming, facultative anaerobe that is responsible for two types of gastrointestinal diseases: emesis and diarrhea. A significant difference in the D95°C-values of spores of the emetic and the diarrheal types was initially determined. A mixture of B. cereus spores of the diarrheal type was inoculated into cooked rice. At inoculation levels of 2.5 × 102 spores per g of rice, cell numbers of 6.64 log were detected after 22 h at 20°C and 6.81 log after 34 h at 17°C, whereas at 12°C the counts did not go above 4.0 log even after 48 h. When added to raw rice before cooking at inoculum levels of 103/g, the number of viable spores decreased by 2 log, and a <1-log increase in cell numbers occurred after holding at 20°C for 24 h. In contrast, the emetic spores survived and increased ~20-fold. Nonhemolytic enterotoxin was not detected in cooked rice at cell numbers of 8.0 log. Results here provide evidence that the absence of foodborne illness caused by the B. cereus diarrheal biotype with rice as the vehicle is due to the inability of their spores to survive and grow following standard heat processing procedures.

Publisher

International Association for Food Protection

Subject

Microbiology,Food Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3