Effects of selected salts on the cooking time, protein content and sensory properties of African yam beans and cowpeas

Legumes (African yam beans and cowpeas) were boiled in tap water with different salts: NaHCO₃, NaCl, CaCl₂, Akanwa (trona¹) at different concentrations² of 0.2, 0.4 and 0.6 g/L, and the cooking time was monitored. Proximate analysis was conducted before and after treatment to determine the effects of these salts on the protein content. Sensory properties were also evaluated. Cooking times for the samples were significantly different (P < 0.05) when cooked in different concentrations of salts. The addition of Akanwa resulted in a shortening of the cooking time but the legumes were darkened. NaHCO₃ and NaCl also reduced the cooking time while CaCl₂ significantly increased the cooking time. The salts also affected the sensory properties. Results of protein analysis showed a significant difference between the treated samples at a concentration of 0.6 g/L. This suggests that heat and salt influence the protein content of legumes when cooked. NaHCO₃-treated samples required the least cooking time but samples treated with NaCl were more accepted. These results and their implications are important for those involved with emergency or disaster feeding.