Abstract

The intensity and duration of heat treatment during parboiling and drying influence the quality. The extent of quality change in low temperature parboiling cum vacuum dry. ing was studied. Three varieties of paddy was parboiled at 200 and 90°C by closed heating for 10min and dried under vacuum at 80°, 90°, 100 and 120°C. The hydration pattern, alkali test value, optimal cooking time, linear elongation and breadthwise expansion in cooked kernel and the palatability were determined, The EMC-S of paddy right after parboiling/ vacuum drying was also determined, Samples parboiled at low temperatures sustained less quality alteration than in the customary open steamed peddy. Rapid vacuum drying by main- taining a high temperature did not alter the quality to such an extent as happened in hot-air drying. Perceptible quality change had occurred only when the grain moisture fell below 17% The starch retrogradation accompanying low temperature parboiling as well as vacuum drying was minimal; the cooking and eating qualities of these samples were comparatively better.

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