Antioxidant Activity and Persistence of Cottonseed Protein and Oil from Two Cultivars as Determined by Their Ability to Scavenge Peroxyl and Alkoxyl Radicals

Short-term antioxidant activity (AA) and long-term antioxidative persistence (AP) of protein and oil fractions extracted from two cultivars of cotton, namely PIMA 3.79 056-7900 (Gossypium barbadense) and TM1 123-1452 (G. hirsutum) were investigated. This was based on their efficacy to scavenge peroxyl and alkoxyl radicals generated in-vitro by pyrolysis of 2,2’-Azobis(2-methylpropionamidine) dihydrochloride. Luminal induced chemiluminescence resulting from unquenched radicals was used to monitor the relative changes in such efficiency in real time. Results showed significantly greater (P<0.05) AA and AP of protein and oil extracts from both the cultivars compared to the control. Unlike the proteins, the oil extracts did not exhibit a significant difference among themselves regarding AA.They also showed a considerable deterioration in their AP. Such decline in the antioxidative efficacy of the hydrophobic non-protenaceous ether extractfrom cottonseeds has not been reported before.