Physicochemical, Nutritional and organoleptic evaluation of cookies from pigeon pea (Cajanus cajan) and cocoyam (Xanthosoma Sp) flour blends

Abstract

Cookies were made from pigeon pea (Cajanus cajan) and cocoyam (Xanthosoma sagittifolium) flour blends. Pigeon pea flour (PPF) was mixed with cocoyam flour (CF) at ratios of 20:80, 30:70, 40:60, 50:50 and 60:40 respectively. The cookies were evaluated for proximate composition, saponins, oxalate, trypsin inhibitors, in-vitro protein digestibility, in-vitro carbohydrate digestibility, physical and sensory qualities. Standard experimental protocols were employed in the estimation of all indices. The protein contents of the cookies were significantly different (p<0.05) from each other and ranged from 10.89 to 11.60% with cookies from 60:40 PPF to CF having the highest value of 11.60% and cookies 20:80 PPF to CF having the least value of 10.89%. The levels of antinutrients analyzed were low with saponin content ranging from 0.05 to 0.08mg/100g; trypsin inhibitors ranging from 0.08 to 0.11mg/100g and oxalate content between 0.06 to 0.68mg/100g. There were significant differences (p<0.05) observed in the in-vitro digestibility (protein and carbohydrate) with cookies made from 20:80 PPF to CF having the highest protein and carbohydrate in-vitro digestibilities of 64.81% and 67.35%, respectively. Results from the physical evaluation of the cookies revealed that the diameter and spread ratio of the cookies were significantly different (p<0.05) from each other and decreased with increasing levels of pigeon pea flour. Data obtained from the sensory evaluation indicated that the mean scores for taste, colour, general acceptability and texture were generally high for cookies containing at least 50% cocoyam flour. However, cookies made from 20:80 PPF to CF had the highest mean scores for all the parameters assessed and were not significantly (p>0.05)different from the control (100% wheat). It may, therefore be concluded from the strength of this work that cookies produced from 20% pigeon pea flour and 80% cocoyam flour have great potential as they compared favourably with cookies produced from wheat. The use of this composite flour would go a long way in reducing dependency on wheat flour in countries that import wheat.