COMPARISON OF UNHEATED AND HEATED BRAN ON FLOUR QUALITY: EFFECTS OF PARTICLE SIZE AND ADDITION LEVELS

The paper was to examine the effects of different adding amount of heated and unheated bran with varied particle size on dough rheological properties and steamed bread quality. Results indicated that these effects mainly depend on the bran quantity rather than the size. In comparison with unheated bran, flour with heated bran is more stable over time and undergoes less softening. For example, the stability time for flour with 100-mesh unheated bran decreased from 5.3 to 3.6, while that of heated bran increased from 5.3 to 6.2 min, as addition amounts increased from 0 to 25%. Adding bran also increased red and yellow coloration and decreased brightness of the steamed bread. The L* of the steamed bread with 60-mesh bran was about 75% of the steamed bread without bran. The best quality was obtained by the steamed bread added with 15% heat-treated bran having a particle size of 100 meshes.