Physicochemical, Nutritional and Functional Properties of Composite Flour Blends from Whole Wheat, Sweet Potato, Defatted Peanut and Rice Bran

Abstract

The surge in import duty, which inflated the production cost of baked products, gave an impetus composite flour formulation from locally available crops with improved nutritional and health-promoting benefits. The present study thus, aimed to formulate and determine the nutritional, phytochemical, functional and pasting properties of composite flour from blends of whole wheat, sweet potato, defatted peanut and rice bran while commercial wheat flour (CWF) was used as the control. The raw materials used for the formulation of the composite flour such as whole wheat grains, sweet potato and peanut seeds were purchased from the Shasha market in Akure, Nigeria while rice bran was obtained from a local rice mill in Ise-Ekiti, Nigeria. The food crops were authenticated at the Department of Crop, Soil and Pest Management, Federal University of Technology Akure, Nigeria. The protein (15.81-21.98%) and the fiber (7.93-10.82%) contents of the composite flour were significantly (p≤0.05) higher than that of the control 13.69% and 1.86%, respectively. The composite flour had improved essential minerals elements (magnesium, zinc, calcium and phosphorus). Similarly, the total essential amino acids (26.73-34.27 g/100 g), essential amino acid index (80.03-102.13%) and biological value (75.53-99.62%) of the composite flour were higher than that of the control (25.79 g/100 g, 76.85% and 72.07%), respectively. Moreso, the flour blends also demonstrated better phytochemical and pasting properties over the control samples. This study therefore, established that composite flour with improved macro- and micro-nutrients could be formulated from blends of whole wheat, sweet potato, defatted peanut and rice bran. The composite flour, which could serve as better replacement for commercial wheat flour in baked products, thereby reducing the cost incurred on wheat importation as well as ensuring food security in most developing nations like Nigeria