ORIGINAL ARTICLE Control of Bacillus cereus spore germination and outgrowth in cooked rice during chilling by nonorganic and organic apple, orange, and potato peel powders Vijay K. Juneja 1 | Mendel Friedman 2 | Tim B. Mohr 3 | Meryl Silverman 4 | Sudarsan Mukhopadhyay 1 1 Eastern Regional Research Center, U. S. Department of Agriculture, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19039 2 Healthy Processed Foods Research, Western Regional Research Center, U. S. Department of Agriculture, Agricultural Research Service, Albany, California 94710 3 USDA-FSIS-Office of Public Health Science/Science Staff, 530 Center Street, NE, Suite 401, Salem, Oregon 97301 4 USDA-FSIS-Office of Policy and Program Development/Risk, Innovations, and Management Staff, Washington, DC Correspondence Vijay K. Juneja, Eastern Regional Research Center, U. S. Department of Agriculture, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19039. Email: vijay.juneja@ars.usda.gov Abstract The inhibition of Bacillus cereus growth from spores in cooked rice by nine fruit and vegetable peel powders was investigated. The powders were mixed into rice at 10% (wt/wt) along with four- strain B. cereus cocktail to obtain a spore concentration of about 2.04 log spores per gram. Aliquots (5 g) of cooked rice were cooled from 54.5 to 7.2 8C in 12, 15, 18, or 21 hr, resulting in 1.93, 2.82, 3.83, and 3.58 log cfu/g increases, respectively, in B. cereus levels. Both organic and nonorganic naval orange peel, nonorganic red delicious apple peel as well as organic and nonorganic golden delicious apple peel supplemented in cooked rice were most effective in restricting growth after cooling in 21 hr. The results show that incorporation of 10% food-derived peels into rice may reduce the potential risk of B. cereus germination and outgrowth during abusive cooling regimes, thus reducing the risk to consumers. Practical applications The results presented will play a significant role in eliminating hazards associated with Bacillus cereus in rice. 1 | INTRODUCTION Bacillus cereus, a foodborne pathogen, causes two forms of foodborne diseases: emetic food poisoning which occurs when the pathogen pro- duces cereulide, a heat resistant cyclic dodecadepsipeptide toxin, during vegetative cell growth in foods; and diarrheal food poisoning, which occurs when ingestion of high numbers of viable cells in food results in heat labile enterotoxin production in the small intestine of the host (Granum, 2005; Soni, Oey, Silcock, & Bremer, 2016). B. cereus is, there- fore, of concern to the food industry and associated regulatory agencies. Bacterial toxin-mediated outbreaks caused by B. cereus occur worldwide, as indicated by recent reports of such outbreaks in Australia (May, Polkinghorne, & Fearnley, 2016), Austria (Schmid et al., 2016), France (Glasset et al., 2016), the United Kingdom (Nicholls et al., 2016), and Germany (Kamga Wambo et al., 2011). These outbreaks might be associated with morbidity and mortality in humans consuming food contaminated with B. cereus (Kim et al., 2016; Oh, Chang, Choi, Ok, & Lee, 2015; Tschiedel et al., 2015). The consumption of processed rice products contaminated with B. cereus seems to contribute to the reported outbreaks. To place the results of the present study in proper perspective, selected reported studies on the contamination of raw and processed rice products by B. cereus are being briefly mentioned. These include Korean raw rice affected by production area and degree of milling (Kim et al., 2014); Korean rice during storage (Zhang et al., 2016); cooked rice (Dong, 2013; Hariram & Labb e, 2016; Jawad & Mutalib, 2016; Jawad, Mutalib, & Abdullah, 2015; Rachtanapun, Tantala, Klinmalai, & Ratanasumawong, 2015; Wang, Ding, & Oh, 2014); fried rice (Jawad, Mutalib, & Abdullah, 2016); rice cake (Wang, Park, Choi, Ha, & Oh, 2016); and refined and turbid rice wines (Jeon et al., 2015; Kim et al., 2015). Such reports suggest the need to reduce or prevent germination, outgrowth and multiplication of B. cereus vegetative cells in ........................................................................................................................................................................ Published 2017. This article is a US Government work and is in the public domain in the USA J Food Process Preserv. 2017;e13558. wileyonlinelibrary.com/journal/jfpp | 1 of 7 https://doi.org/10.1111/jfpp.13558 Received: 12 October 2017 | Revised: 30 October 2017 | Accepted: 3 November 2017 DOI: 10.1111/jfpp.13558