67B-27 |
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J. YU1, M. Ahmedna1, and A. Proctor2. (1) Dept. of Human Environment & Family Sciences, North Carolina A&T State Univ., 161 Carver Hall, Greensboro, NC 27411, (2) Dept. of Chemistry, North Carolina A&T State Univ., 116 Hines Hall, Greensboro, 27411 The peanut industry is a multi-million dollar industry in the United States. Peanut skin is a by-product of the peanut processing industry that is typically used as animal feed. However, peanut skin is rich antioxidants such as phenolics, which can be extracted for use in industrial and pharmaceutical applications thereby adding value to the peanut industry. The objective of this study was to identify/quantify phenolic compounds in peanut skin as affected by processing methods. Three peanut processing methods (direct peeling, blanching, and roasting) were used to remove peanut skin. The composition of ethanol and water extracts of peanut skin obtained from each method were analyzed by HPLC and LC-MS. Total phenolics (TP) and total antioxidant activity (TAA) of peanut skin extracts were determined and compared to those of green tea extracts under identical extraction and analytical conditions. Three classes of phenolics were found in peanut skin extracts, including phenolic acids (caffeic acid, chlorogenic acid, ferulic acid and coumaric acid), flavonoids (catechins and procyanidins) and stilbene (resveratrol). These compounds are potent antioxidants, particularly flavonoids and resveratrol, because of their inhibition of human LDL oxidation and prevention of DNA damage caused by oxidative stress. Results show that one gram of peanut skin contained 90-125 mg TP. TAAs of water and ethanol extracts of peanut skin and green tea were 3.39 and 3.59, 1.91 and 2.46 (mM Trolox/mM phenolics), respectively. The skin processing method affected the total extractable phenolics. Skin removal by roasting yielded the highest concentration of TP while blanching had lowest TP recovery. This study showed that peanut skins, a by-product of the peanut processing industry, has the potential to provide an inexpensive source of phenolic antioxidants that can be used as functional ingredients or dietary supplements. Such novel use would add value to the peanut industry and enhance its profitability.
Session 67B, Food Chemistry: Antioxidants and bioactive agents
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