Changes in the quality characteristics of chapati during storage.

Abstract

The tearing resistance tester and Warner Bratzler shear press were successfully adapted to evaluate quality changes in chapatti during storage. Tearing strength, indicative of development of brittleness, decreased markedly from 72.5 to 31.0 g and only slightly during 3 days' storage, when chapatti was packed in polyethylene pouches and in waxed paper, respectively. Warner Bratzler shear value served as an index of texture and decreased by 21 and 46% for chapattis packed in waxed paper and polyethylene pouches, resp. A simple pliability tester was devised to measure chapatti pliability. When chapattis were packed in waxed paper, pliability decreased from 2.3 to 1.2 cm, but increased from 2.1 to 4.4 cm when packed in polyethylene pouches. Although no significant difference was observed in salt-soluble proteins and ether extractives during storage, starch was affected significantly. This was indicated by decreases in water retention capacity, falling number, enzyme-susceptible starch, and soluble starch. Both amylose and amylopectin decreased, possibly contributing to staling of chapatti. Although heat treatment of chapatti packed in a polyethylene pouch delayed mold attack from 3 to 90 days, the chapatti had a somewhat cooked flavor and was brittle, as indicated by the marked decrease in shear value. Addition of salt (1.25%), glycerol monostearate (0.5%), sorbic acid (0.2%), and fat (4%) minimized development of brittleness.