Hydrophilic antioxidant compounds in orange juice from different fruit cultivars: Composition and antioxidant activity evaluated by chemical and cellular based (Saccharomyces cerevisiae) assays

Abstract

Antioxidant capacity was evaluated by a cellular model (Saccharomyces cerevisiae) and chemical methods (FRAP, TEAC and total phenols by Folin-Ciocalteu assay) in the hydrophilic fraction (phenolic compounds and ascorbic acid) of orange juices (OJs) from six varieties (Midknight, Delta Seedless, Rohde Red, Seedless, Early and clone Sambiasi), harvested in two seasons. The contents of phenolic compounds and ascorbic acid analyzed, respectively, by UPLC and HPLC were 370.04±76.97mg/L and 52.05±6.69mg/100mL. Variety and season significantly influenced (p<0.05) composition and antioxidant capacity. TEAC and FRAP values correlated well with individual hydrophilic compounds (R2>0.991) but no correlation with cellular assay was observed. An increase in survival rates between 23% and 38% was obtained, excepting for two varieties that showed no activity (Rohde Red and Seedless). Narirutin, naringin-d, ferulic acid-d2, didymin, neoeriocitrin and sinapic acid hexose and caffeic acid-d1 were the phenolic compounds which contributed to survival rates (R2=0.979, p<0.01).