Impact of Simulated Low-Leakage Enclosure Transportation and Storage Environment on Milled Rice Breakage and Quality Characteristics

Highlights Milled rice quality during postharvest transportation and storage, in Low-leakage enclosure environment, was influenced by prevailing environmental conditions of temperature and relative humidity across different U.S. regions and seasons. Environmental conditions in the winter, particularly for transportation to Michigan when compared to Texas and California, resulted in minimal fissuring, higher mechanical strength, and better moisture retention of milled rice. ANOVA showed cultivar and seasonal effects were highly significant (p < 0.05) for moisture content, fissure percentage, and mechanical strength, highlighting the importance of region- and season-specific transport strategies. Abstract. There is an increasing need to understand the impact of environmental conditions on milled rice quality during postharvest handling and transportation, especially in real industrial scenarios. In this study, the quality responses of three rice cultivars—CLL16 (Long-grain Pureline), XP753 (Long-grain Hybrid), and Titan (Medium-grain Pureline)—were evaluated during transportation in low-leakage enclosures and storage environments across multiple U.S. locations and seasons. The specific objective was to assess how environmental variables such as temperature and relative humidity (RH) during transit influenced the stability of moisture content (MC), fissure formation, and mechanical strength (MS) of milled rice. Rice samples were cleaned, dried to 12.5% moisture content (wet basis), stored at 4°C, then equilibrated to room temperature and milled. Each 500 g milled rice package was dispatched to three locations of interest to the mid-southern rice industry—Texas (TX), Michigan (MN), and California (CA)—during spring, summer, and winter, with three replications per treatment. Initial (pre-transportation) and post-transportation MC, fissure percentage, and MS were recorded to evaluate changes. Winter storage conditions, characterized by lower temperatures and relatively stable RH, were most favorable for preserving milled rice quality. Among the locations, transportation to Michigan resulted in minimal fissure development, higher MS, and moderate MC changes. In contrast, transportation of milled rice in summer to Texas presented the most challenges, with the prevailing high temperature (26.21 ± 2.84°C) and RH (63.69 ± 3.19%) contributing to significant fissuring in the medium-grain rice Titan (49.33 ± 1.15%) and decreased MS in the long-grain hybrid rice XP753 (22.92 ± 0.70 N). Milled rice transported during the Spring displayed moderate fissure development and grain strength loss relative to winter. California, especially during winter and spring, showed the most stable environmental profiles, supporting better moisture retention and structural stability. XP753 showed greater resistance to fissure formation, maintaining the lowest fissure percentages under most conditions, while Titan displayed the highest MS, peaking at 29.14 ± 0.62 N for samples transported to California during spring. Analysis of variance (ANOVA) revealed that cultivar and seasonal effects were highly significant (p < 0.05) for all studied quality attributes, including MC, fissure percentage, and MS, while location-specific factors had notable influence on fissure development and MS. These findings emphasize the need for optimizing milled rice storage and transportation strategies based on seasonal and regional factors, and for selecting resilient cultivars to mitigate quality losses during distribution. Keywords: Environmental conditions, Fissures, Rice breakage, Seasonal effects, Transportation.