Wet refining: A novel approach for modification of wheat bran fiber

Abstract

To address the poor physiochemical and functional properties a novel wet refining (using Valley Beater) treatment was adopted for modification of wheat bran fiber. Valley Beater, which is valuable equipment in the pulp and paper industry to improve fiber properties, was optimized for wheat bran using response surface methodology. The obtained modified bran fiber was further compared, separately and in combination with the moist heat modified wheat bran. The effect of modifications was accessed in terms of physiochemical, functional, morphological, structural, and antioxidant properties. Particle size, SEM, FT-IR spectroscopy, and XRD analysis depicted the successful modification effects with a good explanation of different improved properties. The wet refining process significantly improved the bran fiber water absorption, oil absorption, water swelling, and sedimentation properties along with increasing the fines content. Although, the moist heat modification showed a positive effect on soluble dietary fiber, and glucose absorption capacity. Still, the wet refining modification was found to ameliorate bran fiber antioxidant properties such as total phenolic content, DPPH scavenging capacity, and total reducing power. Categorically, the combined (wet refining followed by moist heating) modification process was most suitable with more desirable effects. Our research manifested that the wet refining process in combination with moist heat treatment can be used to improve nutritional and product-making characteristics of wheat bran fiber and thus can be adopted for preparing high-fiber food products.