Effects of storage temperature and duration on the milling properties of rice

Abstract

To maximize rice quality, it is essential to quantify the various factors that affect milling properties of rice. Rice aging, a process during which rice undergoes a series of chemical and physicochemical changes, affects head rice yield (HRY) and the rate at which HRY changes with degree of milling (DOM). This study examined effects of storage duration (0, 2, and 4 months) and storage temperature (4, 21, and 35°C) on milling properties of ‘Wells’ (long-grain) and ‘Jupiter’ (medium-grain) rice cultivars. In general, HRY increased with storage duration, most significantly for Wells cultivar. Millability curves were developed by plotting HRY vs. surface lipid content (SLC) of milled rice. Millability curves of Wells had greater slopes, 11.3 pp decrease in HRY for every 1.0 pp decrease in SLC, than those of Jupiter, 8.5 pp decrease in HRY per 1.0 pp decrease in SLC.