The study of relationship between taste and wheat bran protein isolate fortification during high-protein yogurt manufacturing

Abstract

High-protein (HP) food is becoming a popular and nutritionally valuable commodity. The most common protein fortifiers are milk whey or soy protein isolates. However, one of the potentially promising sources of quality protein isolate is wheat bran, the secondary product of wheat milling. Wheat bran protein isolate (WBPI) can be obtained using a sustainable and environmentally friendly pH shift method. Considering its nutritional properties, incorporating WBPI into people's diet is convenient. This work focuses on protein fortification of plain yogurt using WBPI while maintaining sensory acceptability. Direct fortification of yogurts with WBPI to achieve 5 % and 10 % protein content revealed two main sensory defects - bitterness and sandiness. Several approaches, such as grinding WBPI, protein blending, and WBPI encapsulation, were applied to improve the overall impression score of HP yogurts. It was found that eliminating the sandiness of WBPI-fortified yogurt is not possible by reducing WBPI particle size. Blending WBPI with dried milk decreased bitterness, but the products lacked amino acid diversity. The most effective procedure to mask the sensory defects was WBPI encapsulation using alginate, revealing an appropriate way to incorporate natural plant proteins into HP food.High-protein (HP) food is becoming a popular and nutritionally valuable commodity. The most common protein fortifiers are milk whey or soy protein isolates. However, one of the potentially promising sources of quality protein isolate is wheat bran, the secondary product of wheat milling. Wheat bran protein isolate (WBPI) can be obtained using a sustainable and environmentally friendly pH shift method. Considering its nutritional properties, incorporating WBPI into people's diet is convenient. This work focuses on protein fortification of plain yogurt using WBPI while maintaining sensory acceptability. Direct fortification of yogurts with WBPI to achieve 5 % and 10 % protein content revealed two main sensory defects - bitterness and sandiness. Several approaches, such as grinding WBPI, protein blending, and WBPI encapsulation, were applied to improve the overall impression score of HP yogurts. It was found that eliminating the sandiness of WBPI-fortified yogurt is not possible by reducing WBPI particle size. Blending WBPI with dried milk decreased bitterness, but the products lacked amino acid diversity. The most effective procedure to mask the sensory defects was WBPI encapsulation using alginate, revealing an appropriate way to incorporate natural plant proteins into HP food.