title: Variation in phenolic compounds and antioxidant activity in apple seeds of seven cultivars.
abstract: Polyphenols are the predominant ingredients in apple seeds. However, few data are available on the phenolic profile or antioxidant activity in apple seeds in previous researches. In this study, low-molecular-weight phenolic compounds and antioxidant activity in seeds, peels, and flesh of seven apple cultivars grown in northwest China were measured and analyzed using HPLC and FRAP, DPPH, ABTS assays, respectively. HPLC analysis revealed phloridzin as the dominant phenolic compound in the seeds with its contents being 240.45-864.42 mg/100 gDW. Total phenolic content (TPC) measured by the Folin-Ciocalteu assay in apple seed extracts of seven cultivars ranged from 5.74 (Golden Delicious) to 17.44 (Honeycrisp) mgGAE/gDW. Apple seeds showed higher antioxidant activity than peels or flesh; antioxidant activity in seeds varied from 57.59 to 397.70 μM Trolox equivalents (TE)/g FW for FRAP, from 37.56 to 64.31 μM TE/g FW for DPPH, and from 220.52 to 708.02 μM TE/g FW for ABTS. TPC in apple seeds was significantly correlated with all three assays. Principal component analysis (PCA) indicated that Honeycrisp was characterized with high contents of total polyphenols and phloridzin. Our findings suggest that phenolic extracts from apple seeds have good commercial potential as a promising antioxidant for use in food or cosmetics.
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China; School of Food and Biological Engineering, Shaanxi University of Science &Technology, Xi'an, Shaanxi 710021, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Mingtao
authors.initials: M
authors.lastname: Fan
authors.affiliation: School of Food Science, Henan Institute of Science and Technology, Xinxiang, Henan 453003, China.
authors.forename: Junjian
authors.initials: J
authors.lastname: Ran
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Tingjing
authors.initials: T
authors.lastname: Zhang
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Huiye
authors.initials: H
authors.lastname: Sun
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Dong
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Food Science and Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zheng
keywords: AOA, antioxidant activity; Antioxidant activity; Apple seeds; FRAP, ferric reducing/antioxidant power; PCA, principal component analysis; Phenolics; Phloridzin; Principal component analysis; TPC, total phenolic content