Fractionation, solubility and functional properties of wheat bran proteins as influenced by pH and/or salt concentration

The content, fractionation, solubility and functional properties of wheat bran proteins as well as the effects of pH and/or NaCl concentration on some of these functional properties were investigated. The protein content of the bran was found to be 16.80%. Albumin and glutelin are the major fractions of wheat bran proteins. The minimal protein solubility was observed at pH 5.5, the maximum at pH 11.5. The emulsifying capacity, activity and emulsion stability as well as foaming capacity and foam stability were greatly affected by pH and salt concentrations. Lower values were observed at acidic pH and high salt concentration. The least gelation concentration of wheat bran proteins was found to be 16% when the proteins were dissolved in 1.0 M NaCl. The total protein was highly viscous and dispersable with water-holding capacity of 4.20 mL H2O/g protein, oil-holding capacity of 1.70 mL oil/g protein and bulk density of 0.29 g/mL while dispensability was found to be 77.30%.