Phenolic and antioxidant composition of cider

Forty-four Asturian ciders were analysed for total phenolic content, phenolic profiles, and antioxidant capacity by the FRAP and the DPPH radical assays. The Folin index of ciders ranged between 446 and 1180 mg gallic acid/L. The phenolic profile of Asturian cider is mainly constituted by phenolic acids, flavan-3-ols, volatile phenols and dihydrochalcones. The methods to determine the antioxidant activity of ciders were optimised in terms of suitable reaction times, within-day and between-day repeatability. Thus, time courses of ciders in the DPPH and the FRAP assays were performed. Mean values for antioxidant activity of cider, expressed in ascorbic acid equivalents were 2.9 mM (as determined by the DPPH assay). When the FRAP assay was used, the antioxidant capacity of cider increased with the reaction time from 3.8 mM (4 min) to 5.4 mM (40 min). Multivariate approaches based on phenolic composition can be useful to predict the antioxidant capacity of cider. Folin index and flavanols and hydrocaffeic acid contents were the best predictors for antioxidant activity.