Physicochemical and functional properties of starches of two quality protein maize (QPM) grown in Côte d’Ivoire

Abstract

Starches from four varieties of maize, namely two ordinary (white and yellow varieties) and two QPM (white and yellow varieties) were extracted and their physico-chemical and functional characteristics were determined. Statistical analyses were performed on data obtained. Protein and fat contents (0.35-0.37 ± 0.06%; 0.53-0.57 ± 0.05%) of white and yellow QPM starches were lower than that (0.38-0.39 ± 0.06%; 0.63-0.66 ± 0.05%) of white and yellow ordinary maize. The particle size of the four starches varied from 4.75 to 22.79 µm for white QPM; 5.28 to 22.62 µm for white ordinary maize; 5.98 to 22.88 µm for yellow QPM and 5.63 to 21.47 µm for yellow ordinary maize. Solubility white QPM starch showed the highest solubility (19.43%) and yellow QPM was characterized by highest value (20.39g/g) of swelling power. The percentage of water expelled from white QPM starch was 40.39% at -15°C and 37.05% at 4°C after the first week of storage while yellow QPM starch was characterized by syneresis values of 40.09% at -15°C and 36.92% at 4°C. The paste clarity of all starches decreased quickly during the first week and then stabilized at about 0.74 to 1%. Conclusions and application of findings: Starches from white and yellow QPM present better properties than ordinary maize and could be a valuable alternative for exploitation in food and non-food industries.