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Characterizing the phenolic constituents and antioxidant capacity of Georgia peaches

Liao, Xiaoxi, Greenspan, Phillip, Pegg, Ronald B.
Food chemistry 2019 v.271 pp. 345-353
antioxidant activity, antioxidants, chromatography, cultivars, flavanols, glycosides, in vitro studies, iron, peaches, phenolic acids, proanthocyanidins, quercetin
Acetonic crude phenolic extracts of six Georgia peach cultivars were prepared and separated into low- and high-molecular-weight (LMW and HMW) fractions by Sephadex LH-20 column chromatography. Further characterization via RP-HPLC-ESI-MS identified the main phenolics as hydroxycinnamates, (+)-catechin, and proanthocyanidins with degrees of polymerization up to seven. The LMW phenolics of the commercial cultivar, ‘July Prince’, were further chromatographed and examined by RP-HPLC-ESI-MS. Derivatives of phenolic acids and flavan-3-ols, along with eriodictyol and quercetin diglycosides, were identified. Antioxidant capacities of the LMW and HMW fractions were determined using in vitro assays. H-ORACFL and FRAP assays gave values of 872 to 2428 μmol Trolox eq./100 g f.w. and 309 to 432 μmol Fe²⁺ eq./100 g f.w., respectively. The total phenolics content (TPC) was also measured; correlations between TPCs and antioxidant assays indicated that the HMW fractions of peach extracts were major contributors to the antioxidant capacity of the cultivars analyzed.