Micronized Wheat. II. Influence on in Vitro Digestibility, in Vitro Gas Production and Gelatinization

Abstract

Two studies were conducted to determine the influence of micronizing hard red winter wheat (dry heat processed) on 6-, 12- and 24-hr in vitro dry matter disappearance (IVDMD), in vitro gas production and gelatinization. Micronized wheat (MW) was compared with dry rolled wheat (DRW). No significant differences (P>.05) existed between MW and DRW for 6-hr IVDMD in either trial (31.2 vs 32.2% in trial 1; 39.2 vs 3 7.9% in trial 2). In both trials, the 12-and 24-hr IVDMD values, however, were lower (P<.05) on MW than DRW — the 24-hr IVDMD values being 71.5 (MW) vs 77.9% (DRW) in trial 1 and 68.8 vs 78.5% in trial 2. The lower 12- and 24-hr IVDMD values observed for MW may have been due to reduced protein solubility from heat treatment. Nevertheless, the 12-and 24-hr IVDMD values for both MW and DRW are much higher (approximately 50%) than those prviously reported for sorghum, suggesting much more rapid starch degradation and better starch availability in wheat. Gas production studies showed approximately a twofold increase or more (P<.05) in rate of gas production for MW after 1 or 2 hr of incubation with yeast and amyloglucosidase enzyme, indicating greater starch alteration in MW. Little treatment difference existed in total 24-hr gas production. Moreover, degree of gelatinization was greater (P<.05) for MW. Like IVDMD, gas production values for both treatments were much higher than previously reported for sorghum. Wheat starch appears highly susceptible to enzymatic degradation. Copyright © 1977. American Society of Animal Science . Copyright 1977 by American Society of Animal Science.