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Highlights

Statistical models used to understand how inter-kernel moisture content (MC) variability reduction in dried rice can improve head rice yield and end-use functionality.

Abstract. Variability in moisture content between rice kernels due to the drying process within a harvest batch can result in irregularities in yields and the functional quality of the final product. Investigating strategies to achieve greater uniformity in inter-kernel moisture content within dried rice batches is a crucial avenue of research for the rice industry. The objectives of this study were to use a statistical modeling approach to (1) study the influence of moisture content (MC) variability on head rice yield (HRY) and pasting properties, and (2) describe if preheating rice kernels with microwaves (MW) of the 915 MHz frequency prior to natural air drying influences MC variability within single rice kernels. Natural air drying used a chamber with a 25°C air temperature and 56% relative humidity. MW heating was administered at a 3 kW power level for 60, 120, 180, 240, and 300 s. Statistical models were developed to describe the interrelationships among treatments and MC variability, head rice yields, and functionality of the rice. There was a strong correlation (r = 0.9323) between the initial average MC of the rice bulk and the inter-kernel MC variability. The MW heating duration (p<0.0275) significantly impacted MC variability and HRY. MW treatments reduced MC variability within rice kernels and positively influenced rice‘s milling yield and pasting properties. All treatments did not significantly impact the pasting properties of rice. This study demonstrates the feasibility of employing MW treatments in tandem with natural air drying to reduce inter-kernel MC variability within dried batches of rough rice.