engleski

The influence of ascorbic acid and honey addition on the antioxidant properties of fruit tea infusions

The influence of ascorbic acid and honey addition on the total phenol (TP) content and antioxidant capacity of ten commercial fruit tea infusions was studied. The Folin-Ciocalteu assay was used to determine the TP content, ferric reducing antioxidant power (FRAP) assay for reducing capacity and 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and 2, 2′ -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays for radical scavenging capacity. High pressure liquid chromatography (HPLC) was employed to quantify polyphenolic compounds in infusions. The addition of ascorbic acid (22.5 mg) increases the TP content as well as antioxidant capacity of all fruit tea infusions. The addition of honey (1.5 g) to infusions containing ascorbic acid resulted in an average 28% decrease in the TP value, and a significant average (22%) decrease in the DPPH radical scavenging capacity. Chlorogenic acid is the predominat phenolic acid in tested infusions (range: 12.86 – 91.55 mg/L), while epigallocatechin-gallate (EGCG) is the most concentrated among analyzed catechins (range: 19.26 – 161.41 mg/L).

fruit tea; ascorbic acid; honey; polyphenols; antioxidant activity; reducing capacity

nije evidentirano