Functional properties and anti-nutritional factors in cereal bran

Various cereal brans (wheat, rice, barley and oat) were investigated for proximate composition, functional characteristics and certain anti-nutritional factors to assess their potentiality as protein and fibre sources. The major findings of this study are as follows: crude protein ranged from 9.615.03%, fat 4.07-19.31%, dietary fibre 14.0-38.95%, bulk density 0.39-0.59 g/ml, water absorption 115.20-383.70 g/100g, fat absorption 138.3-302.9 g/100g and free fatty acids 5.20-13.73%. All brans had pleasing flavour. Significant variations were observed with regard to colour of brans. The presence of anti-nutritional factors in brans is one of the major drawbacks, limiting their nutritional and food quality. Phytic, trypsin inhibitor, oxalates, tannins and polyphenols are the major undesirable constituents which restrict direct utilization of brans in diet. An attempt has been made to assess the presence of anti-nutritional components in different cereal brans. All cereal brans had a wide range of phytic acid (27.69-42.82 mg/g). Cereal brans have total polyphenols in the range of 0.54-6.53 mg/g and the content of tannins ranged 0.70-6.23 mg/g in brans. High oxalate content was observed in rice bran and minimum in oat bran (0.309 to 0.445%). Oat bran had a minimum amount of saponin, while a higher concentration of saponins were found in rice bran (1.99 to 3.30 mg/g). Trypsin inhibitor activity was 49.74-54.25 TIU/g. These factors can be eliminated by giving different stabilization treatments. De-fatting treatment given to cereal brans using hexane as solvent represented a marginal decrease in anti-nutritional components in all cereal brans.