The effect of the substitution of acha (Digitaria exilis) and soybean on the chemical composition and sensory properties of maize masa

Abstract

Masa is a traditional food mainly produced from maize, rice, and millet. Different concentrations of acha, an underutilized cereal rich essential acid and soybean, was used to enrich masa. This study investigated the effect of the substitution of acha and soybean on the nutritional and organoleptic properties of masa produced from maize. The proximate composition, mineral composition, and antinutrients were determined using standard methods. Sensory evaluation was also carried out to determine the acceptability of the masa products. The result of the proximate composition showed an increase in crude protein, crude fat, and total ash, and a decrease in crude fibre and carbohydrate content, during the period of fermentation. Moisture, crude protein, crude fat, total ash, crude fibre, and carbohydrate contents of masa ranged between 17.10 – 23.80 %, 6.86- 10.67%, 12.78- 18.78 %, 0.58-1.24 %, 0.79 – 1.07 %, and 42.95 – 61.89 %, respectively. Crude protein, total ash, and crude fat content increased with the increase in substitution with soybean. Calcium, magnesium, iron, potassium, and zinc contents were within the range of 5.79 – 13.70 mg/kg, 2.54 – 7.20 mg/kg, 1.14 – 2.65 mg/kg, 2.96 – 6.03 mg/kg, and 0.76 – 1.05 mg/kg, respectively. Masa produced from 100% acha had the highest calcium, magnesium, and iron contents. Tannin, phytic acid, and trypsin inhibitor activity decreased during fermentation and were lowest in masa produced from 100% acha. Substitution of masa with soybean improved the colour, taste, and aroma of fried masa samples. Substitution of maize with 20% acha and 20% soybean increased the nutritional quality and overall acceptability of masa. This study therefore suggested the use of acha and soybean in the production of masa with a high nutritional and sensory profile.