Influence of parboiling on rice starch structure and cooked-rice texture

Four varieties of rice having very high (29.4%) to low (17.6%) amylose-equi valent (AE) were parboiled by steaming at atmospheric (PB-0) smd at 3 kg/cm 2 (PB-3) gauge pressure. The cooked rice texture of the raw, PB-0 and PB-3 rice was determined by Viscoelastographe. Gel permeation chromatography of rice flour starch on Sepharose CL-2B, in general, indicated thermal breakdo wn of starch. The extent of starch breakdown and the firmness values of coo ked PB-0 and PB-3 rices were reasonably well correlated suggesting that sta rch breakdown during parboiling may have some role to play in varying the t exture of rice by parboiling. The chain profile of rice starch remained una ltered after parboiling.