Abstract:

This study aimed to investigate the correlation between the total phenolic content and antioxidant activity in apple
seeds from seven cultivars. The total phenolic content was determined by Folin-Ciocalteu method, the antioxidant activity
was evaluated by total reducing capacity, 3-ehtylbenzothiazolin-6-sulfnic acid diammonium salt (ABTS) scavenging,
superoxide anion scavenging, hydroxyl free radical scavenging and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical
scavenging assays, and the polyphenol composition of apple seeds was analyzed by high performance liquid chromatography
(HPLC). It was shown that Honeycrisp exhibited the highest total phenolic content and the best antioxidant properties among
seven apple cultivars. Antioxidant activity of polyphenols in apple seeds was significantly positively correlated with total
phenolic content (r = 0.771–0.984), with the exception of DPPH scavenging capacity. Compared to tea polyphenols, vitamin
C (VC) and 2,6-di-tert-butyl-4-methylphenol (BHT), apple seed polyphenols exhibited better antioxidant activity. Phloridzin,
which accounted for 79.76%-86.67% of the total phenolic content as determined by HPLC, was the dominant antioxidant
component in apple seeds. Polyphenols extracted from apple seeds could have a wide application prospect because they act
as the safe, non-toxic natural antioxidants.

Key words: apple seeds, total phenolic, antioxidant, correlation