Influence of oven and microwave roasting on bioproperties, phenolic compounds, fatty acid composition, and mineral contents of nongerminated peanut and germinated peanut kernel and oils

Abstract

While antioxidant activity values of nongerminated peanut kernel extracts change between 46.58% (raw peanut) and 49.63% (oven), this values of germinated kernel extracts varied between 38.67 (oven) and 44.83 mgGAE/100 g (germinated). In addition, total phenolic contents of both nongerminated and germinated peanut kernels changed between 12.68 (oven) and 19.73 mgGAE/100 g (raw) and 23.81 (oven) and 41.62 mgGAE/100 g (germinated), respectively. p-Hydroxybenzoic, vanillic, ferulic, quercetin, and p-coumaric and cinnamic acids were the dominant compounds of both germinated and nongerminated peanut kernels. It was observed statistically differences in fatty acid composition of peanut oils (p < .05). The highest oleic acid contents (62.74%) were determined in nongerminated kernel oil roasted in oven. The contents of α-tocopherol in nongerminated peanut ranged from 16.58 mg/100 g (oven roasted) to 18.64 mg/100 g (raw),while α-tocopherol contents of germinated kernel oils change between 14.72 mg/100 g (microwave roasted) and 16.49 mg/100 g (germinated). Mineral contents of germinated peanut kernels decreased partially compared to nongerminated peanut kernels. Practical applications Nut oils are receiving growing interest due to their high concentration of bioactive lipid components, which have shown various health benefits. Germination produced high phenolic content and antioxidant activities in lupin seeds. Phenolic compounds are generally secondary metabolite produced in plants, and they might be correlated to antioxidant activity, which has been shown to retain various biological benefits; microwave energy and conventional heating are currently being used for food processing operations, including cooking, drying, tempering, baking, pasteurization, and sterilization.