Effect of Callosobruchus maculatus infestation on the nutrient-antinutrient composition, phenolic composition and antioxidant activities of some varieties of Cowpeas (Vigna unguiculata)

Abstract

Cowpea (Vigna unguiculata L. Walp.) is an important legume crops in most part of the world and is of health benefit in addition to the nutritional potential. However, this important nutrient and disease preventing crop, is prone to post harvest infestation damage, mostly by Callosobruchus maculatus. Therefore, the present study is to evaluate the antioxidant activities, nutrient composition, anti-nutrient content and phenolic composition of Callosobruchus maculatus infested and non-infested cowpeas commonly consumed in Nigeria. The result revealed that infestation brings about an increase in the evaluated anti-nutrients (phytate, oxalate and alkaloids) and a marked reduction in protein, carbohydrate content, whereas a marked increase was recorded for the fibre content. The result of the antioxidant activities revealed a significant reduction for total phenol, total flavonoids and reducing power and a slight reduction was recorded for the inhibitory action against lipid oxidation, hydroxyl radical scavenging, 2, 2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging and 1, 1-diphenyly-2-picrylhydrazyl radical scavenging activities after infestation. The present investigations revealed that Callosobruchus maculatus infestation do not only affect the nutrient composition of the studied cowpeas by reducing the nutritional value, but would also have an adverse effect on their potential to prevent free radical mediated diseases. © 2014 Maxwell Scientific Organization.