Chemical and microbial stability of cowpea paste: influence of ingredient combination and whipping time

Abstract

This paper reports the effect of pepper content (PC = 0.5-2.5%), salt content (SC = 0.5-3.0%), moisture content (MC=60-70%), whipping time (WT = 0-120 s) on the quality of cowpea paste (CP) held at ambient temperature for 24 h. The pH and lactic acid bacterial (LAB) and total plate counts of the CP and sensory acceptability of akara- a fried cowpea product were studied over 24 h of holding. Longer whipping time reduced LAB counts in freshly prepared CP. Increased pepper powder content significantly enhanced microbial counts (p<0.05). Increased salt content reduced souring rate (k.). Shorter WT enhanced sensory acceptability of akara. The optimum WT, MC, SC, PC predicted for maximum sensory acceptability and minimum souring rate and LAB growth were 28.02 s, 60%, 2.45%, 0.5%, respectively. Sensory acceptability scores of optimized CP reduced linearly with time (R²>0.97). The best before (BBT) and expiry times (ET) of the CP were 5.60 and 11.64 h, respectively.

Keywords: Cowpea paste, ingredient combination, lactic fermentation, optimization