ASABE Technical Library - Abstract

Abstract. Mold growth in rice during storage poses significant health risk to consumers, and may result in rice spoilage leading to massive economic losses for producers and processors. Depending on storage conditions, some molds may produce aflatoxin – a potent carcinogenic mycotoxin produced by the Aspergillus flavus mold. At present, there is very little understanding about the growth of molds and their links to mycotoxin formation, especially for the popular, recently-introduced hybrid rice cultivars. For this two-year study, three long-grain hybrid rice cultivars, XL753 (2014) and CL XL745 (2014, 2015) and XL760 (2015), were stored in rough rice form in sealed glass jars at moisture contents (MC) of 21%, 19%, 16%, and 12.5% (wet-basis) at temperatures of 10°C, 15°C, 20°C, 27°C, and 40°C for a total of 16 weeks, with samples taken at 2, 4, 6, 8, 10, 12 or 13, and 16 weeks. For all cultivars, a direct relationship between mold counts and MC was observed – as the MC level increased, the mold counts increased, whereas more complex trends were observed for the effect of temperature and the duration of storage on mold growth. Additionally, dry matter loss (DML) constants for reduced oxygen storage conditions were found to be significantly different than the typical constants for the DML equation provided for long-grain rice in literature. The study findings are useful in guiding the rice industry on making decisions regarding storage conditions for hybrid rice to prevent mold growth and thus prevent economic losses due to spoilage and health concerns.