Effect of fermentation and cooking on protein quality of maize (Zea mays L.) cultivars

Summary Maize like other cereals shows qualitative and quantitative deficiency in protein content. Efforts were made to correct this by fortification, supplementation and fermentation. Two maize cultivars, Hudeiba 1 and Mugtama 45, were used to study the effect of fermentation followed by cooking on their protein quality. Maize flour was fermented for 32 h; samples were withdrawn at 8 h intervals. Results indicated that the proteins fractions albumins plus globulins were significantly ( P < 0.05) increased in the fermented doughs. This is an indication of improvement in the protein quality of maize. Cooking resulted in significant ( P < 0.05) changes in protein solubility. The essential amino acids particularly lysine increased from 1.82 to 2.06 and from 1.88 to 2.60 g/100 g (i.e. an increase of 11.6% and 27.7%) for Hudeiba 1 and Mugtama 45, respectively. The in vitro protein digestibility of cooked samples decreased significantly ( P < 0.05); however, the negative effects of cooking were lower than those of unfermented cooked samples.