ARS | Publication request: Hydrophilic Lipophilic Antioxidant Activities of Commercially Available Peanut Flours and Peanut Seed Roasted to Differing Intensities

Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 16, 2008
Publication Date: July 16, 2008
Citation: Davis, J.P., Price, K.M., Dean, L.L., Sanders, T.H. 2008. Hydrophilic Lipophilic Antioxidant Activities of Commercially Available Peanut Flours and Peanut Seed Roasted to Differing Intensities. American Peanut Research and Education Society Abstracts.

Technical Abstract: Peanut flours are commercially available, high protein ingredients prepared from partially defatted roasted peanut seed. Peanut flours have differing roast intensities and residual fat contents, which allows for these ingredients to be utilized in a variety of food formulations. Antioxidant properties of an ingredient are important in both human nutritional considerations and in predicting food product shelf stability; however, no antioxidant information for peanut flours has been published. Accordingly, four classes of peanut flours: light roast-12% fat, dark roast-12% fat, light roast-28% fat and dark roast-28% fat were evaluated for both hydrophilic and lipophilic antioxidant capacity using the Oxygen Radical Adsorption Capacity (ORAC) assay. Flours were extracted according to standard procedures using a Dionex 200 Accelerated Solvent Extractor. Hydrophilic antioxidant capacities were significantly (P < 0.05) higher for low fat flours (approximately 6900-7400 'Mol Trolox/100 g) as compared to high fat flours (approximately 5500-6200 'Mol Trolox/100 g). Lipophilic ORAC’s ranged from approximately 600 to 1100 'Mol Trolox/100 g; values that were an order of magnitude lower than the hydrophilic scores, which is typical of most foods and ingredients. High fat flours had significantly (P < 0.05) higher lipophilic ORAC scores. Peanut flour ORAC data was compared with ORAC data for whole peanut seed that had been roasted to differing intensities to better understand the effects of Maillard browning chemistry on both the hydrophilic and hydrophobic antioxidant activities. Both hydrophilic and hydrophobic ORAC scores significantly (P < 0.05) increased with increasing roast intensity; however, the relative rates of these increases were not equivalent. Total phenolic content, GC, HPLC and SDS PAGE analyses of the various extracts will be discussed to suggest potential compounds and mechanisms for these antioxidant phenomena.