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Characterizing the phenolic constituents and antioxidant capacity of Georgia peaches

Author:
Liao, Xiaoxi, Greenspan, Phillip, Pegg, Ronald B.
Source:
Food chemistry 2019 v.271 pp. 345-353
ISSN:
0308-8146
Subject:
antioxidant activity, antioxidants, chromatography, cultivars, flavanols, glycosides, in vitro studies, iron, peaches, phenolic acids, proanthocyanidins, quercetin
Abstract:
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.
Agid:
6109453