Staling and Texture of Bread Prepared from New Japanese Bread Wheat Varieties with Slightly Low-Amylose Starch

Abstract

The bread-making quality of flour made from two new Japanese bread wheat varieties, Haruyokoi and Kitanokaori, was evaluated, and the staling and texture of bread made from these flour types were compared with those of flour made from representative bread wheat classes, No.1 Canada western red spring (1CW) and Hard red winter (HRW). There was not a large difference in the bread-making quality of the above four flour types, except that the water absorption of the Kitanokaori flour was high, and the gassing power of the dough was low. Bread made from the two above-mentioned Japanese flour types (two new bread varieties) were quite soft after baking, and the degree of staling (changes in hardness) were somewhat lower than those made with 1CW and HRW. The cohesiveness of the two new bread varieties, i.e., the index of bread elasticity, showed higher values than those of others up to 1 day of storage. From the analysis of bread staling and the retrogradation of starch in bread, it was proven that the staling rate and starch retrogradation rate constants of the two new bread varieties were approximately the same as those of bread made from 1CW and HRW but the starch retrogradation of the new bread varieties was somewhat slower than that of the others up to 2 days of storage. The analysis of hardness and cohesiveness of the flour and starch gel from the above four flour types indicated that the softness and high cohesiveness of the two new bread varieties after baking were, to a great extent, the result of the soft texture of starch gel in these varieties. These results showed that the somewhat slow staling, especially staling in the early stage, and the extreme softness after baking of the two new bread varieties were attributed to the soft texture and low retrogradation of starch gel in the bread, which was related to the lower amylose content of these new flour types.