Essential Amino Acid Composition of Noodles Analogue from Aerial Yam, Rice and African Yam Bean Flour Blend Using Response Surface Methodology

Abstract

Response surface technology was used to evaluate the essential amino acid of noodles analogue from Aerial yam (Dioscorea bulbifera), Rice (Oryza sativa), and African yam bean (Sphenostylissternocarpa) flour mixture. Flours from Aerial yam, rice, and African yam bean were individually produced blended in the ratio of 50%: 25%: 25%, respectively and extruded using Brabender single screw laboratory extruder (Duisburg DCE 330 Model) filled with 3.0mm die nozzle diameter. A central composite rotatable design ( CCRD) with three variables, namely barrel temperature, feed moisture content and screw speed and fire level coded -a, -1, 0, +1, +a, was used in the experimental design to obtain 20 samples of noodles analogue. Essential Amino Acid profiling was done on the noodles analogue and data was analyzed by regression analysis. Results showed that lysine content ranged from 4.55 to 7.55mg/100g, valine content ranged from 3.81 to 5.06mg/100g, methionine content ranged from 0.86 to 2. 24mg/100g, phenylalanine content ranged from 5.06 to 5.45mg/100g, histidine content ranged from 3.09 to 4.20mg/100g, tryptophan content ranged from 0.83 to 1.96mg/100g, leucine content ranged from 6.87 to 7.90mg/100g, isoleucine content ranged from 2.91 to 4.91mg/100g, threonine content ranged from 3.55 to 4.44mg/100g. The coefficients of determinations (R2) were high and ranged from 0.8987 to 0.9916 at 5% level. The response surface plots suggest that the models developed had a good fit and the CCRD was effective in explaining the effect of the process condition on noodles analogue as influenced by barred temperature, feed moisture content and screw speed of the extruder. The data obtained from the study could be used for the control of product characteristics. The study indicated improved noodles analogues from Rice, Aerial yam, and African Yam Bean can be produced as noodles analogues.