Unique microstructure, physical, and pasting properties of rice grains produced in Thai upland area

Abstract

© 2020 Cereals & Grains Association Background and objectives: Upland rice has unique quality derived from diverse growing environment; however, little is known about rice quality cultivated in the uplands of South-East Asia region. Four highly consumed upland rice varieties are determined their important physical qualities and microstructures. Findings: All four upland rice varieties exhibit different visual appearance and physical quality especially for color, sphericity, and bulk density of rice grain, and viscosity (peak viscosity ranges from 931 to 3,113 cP; p ≤.05) of rice flour. Each variety reveals unique structure of aleurone layer and starch granule wherein the granule size and arrangement are notably different among the four varieties. Conclusions: Physical quality and microstructure are the key features for identifying rice variety cultivated in upland area of Thailand. Significance and novelty: The four varieties of Thai upland rice grains exhibit different macro- and microstructure that are considered a helpful index for variety identification, postharvest handling, and utilization of rice flour.