Physical Properties of Brown and White Malaysian Glutinous Rice Kernels (Oryza sativa L.)

Abstract

Glutinous rice, also known as waxy rice, is a variety of short or long rice grains that become sticky when cooked. The physical properties (length, width, thickness, equivalent diameter, aspect ratio, surface area and colour) of brown and white glutinous rice kernels from cultivar Siding were determined in this study. The physical properties of the glutinous rice kernels differed significantly (p<0.001). For brown glutinous rice kernels, the length, width, thickness, equivalent diameter, and aspect ratio were 6.95 ± 0.27 mm, 1.83 ± 0.08 mm, 1.42 ± 0.07 mm, 2.64 ± 0.06 mm, and 0.26 ± 0.01, respectively. The white glutinous rice kernel had mean values of 6.24 ± 0.38 mm (length), 1.70 ± 0.09 mm (width), 1.41 ± 0.06 mm (thickness), 2.47 ± 0.08 mm (equivalent diameter), and 0.27 ± 0.02 (aspect ratio). The obtained colour values showed that the glutinous rice kernels were light brown and white. Based on the results, the dimensions (length, width, thickness, equivalent diameter, aspect ratio, surface area) decreased due to the milling process applied to brown glutinous rice kernels, producing white glutinous rice kernels. The physical properties of glutinous rice significantly impact the design of postharvest machinery, handling equipment, grading, and other applications.