Effect of Physical Processing on Quality of Flour and Cookies from De-oiled Rice Bran

Experiments were conducted to assess the effect of physical processing using hammer mill and ultra-fine grinder on bio-chemical and bio-functional component of de-oiled rice bran fractions as well as quality characteristics of developed cookies. Sieve analysis showed that moisture content remained unaffected whereas, crude protein, crude fiber, ash and silica varied from 10.9–16.1%, 10–14%, 8–11% and 0–0.6% respectively, after passing though hammer mill and ultrafine grinder. The samples of size 0.355mm both for hammer mill and ultrafine grinder had higher protein content, crude fiber and lower ash and silica content. Bio-functional component i.e. antioxidant capacity was found to be superior in case of ultrafine ground sample retained on 0.355mm sieve size. The fineness modulus, average particle diameter and uniformity index of physically processed samples (hammer milled and ultra fine ground) were found to be 1.25, 0.3 and 0:4:6, and 1.07, 0.26 and 0:3:7, respectively. The proximate analysis of rice bran substituted cookies prepared by using physically treated rice bran flour yielded improved quality with adequate sensory characteristics. Overall acceptability was maximum for cookies at 10% level of substitution of flour with hammer mill treated de-oiled rice bran.