Physicochemical properties of flour produced from different cowpea (Vigna unguiculata) cultivars of Southern African origin.

Abstract

The variability and magnitude of interactions for food components and physicochemical properties of flour produced from five cultivars of cowpea (Glenda, Vegetable Cowpea 2, Vegetable Cowpea 3, Makathini, Embu Buff) were analysed using chemometrical techniques, for effective application as legume-based ingredients across different food product applications. Cowpea flour produced was defatted by extraction with n-hexane for 90min (flour/solvent ratio of 1:3 w/v). Principle component analysis showed variation in chemical composition and physicochemical properties amongst cowpea flour studied. Flour produced are important sources of protein (24.30-26.33%), starch (50.99-51.33%), fiber (9.36-12.86%) and mineral elements. Pearson correlation analysis showed significant correlations amongst starch, mineral elements and physicochemical properties. Starch was found positively correlated with mineral elements sodium and calcium. Vegetable Cowpea 3 (50.55%) was found suitable for use in food products that are thawed for consumption. Mineral elements manganese, magnesium, phosphorous and sodium were found to significantly influence the pasting parameters (peak, trough, breakdown viscosity) studied. Understanding the magnitude of interactions between food components and physicochemical properties of cowpea flour would enable decisiveness over ingredient selection, improvement and management of quality for various legume-based food products. Furthermore, findings have the potential to assist in the development of improved cowpea cultivars.