Kinetics of Mold Growth and Rice Quality Metrics during Storage As Affected By Pre-Harvest Fungicide Application

Abstract. Proper pre- and post-harvest management of rice is crucial to maintain the grain quality and safety. The objectives of this study were to demonstrate the links among mold growth and/or prevalence to head rice yields (HRYs) deterioration, rice kernel discoloration, and changes in rice functional properties as observed during the grain storage. This study specifically investigated effects of pre-harvest fungicide application on post-harvest rice quality and safety attributes. Freshly-harvested rough rice was store at four moisture content (MC) levels (12.5%, 16%, 19% and 21%), and at five temperatures (10°C, 15°C, 20°C, 27°C, 40°C) for 16 weeks, with samples taken every 2 weeks. Kinetics of mold growth, HRY and rice color were determined. Storage of rice for 16 weeks at 12.5-21% MC and 10-40°C resulted in non-significant reductions in HRYs. There was a direct relationship between mold counts and stored rice MC. Low HRY recovery and significant discoloration of rice kernel was noted for samples lots of non-fungicide treated rice compared to the fungicide treated lot. Discoloration detected in samples stored at 27-40°C and 19-21% MC indicated the role of mold in kernel discoloration under certain conditions. Results from this study may support application of rice cooling technology to preserve HRYs and rice color; moreover, the study suggest a link between the prevalence of fungi and discoloration of rice kernels.