The effect of varied maturity on the antioxidant activity of peanut hulls was investigated. Methanolic extracts of peanut hulls of varied maturity exhibited a similarly marked antioxidant activity, 92.9-94.8% inhibition of peroxidation of linoleic acid. The content of both luteolin and total phenolics increased significantly with maturity and seemed to show no correlation with antioxidant activity. However, the antioxidant activity remained constant after 1.671 mg/g of hulls of total phenolic content was reached. Total phenolics (1.671 mg/g of hulls) in peanut hulls seemed to be an initial point of maximum antioxidant activity. High total phenolic content in peanut hulls of varied maturity is associated with a high antioxidant activity and with an important role in the stability of lipid oxidation.

Peanut kernels were gamma irradiated at 0,2.5,5.0,10, and 20 KGy, and stored 1 yr at ambient and frozen (-14°C) conditions. Irradiated peanuts lost germination capabilities during storage. Molds were detected only on peanuts irradiated with 2.5 KGy and stored at ambient temperature. Peanut oil in kernels stored at -14°C was comparatively more stable than that in peanuts stored at ambient temperature. Oxidation of oil was not significantly changed by irradiation. Changes in fatty acid content varied slightly with exception of linoleic and linolenic acids which decreased with increased radiation depending on storage temperature. The SDS-PAGE protein patterns of peanuts revealed no noticeable variation of protein subunits resulting from irradiation and storage.

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