Effect of dry salting on flavonoid profile and antioxidant capacity of Algerian olive cultivars

Abstract

This study investigated the changes in the flavonoid profile and antioxidant capacity of five olive cultivars after dry salting. The antioxidant activity was determined using ferric reducing ability power (FRAP), oxygen radical absorbance capacity (ORAC), and β-carotene bleaching assays. The results showed that the effects of dry salting on the analyzed parameters were significant (P<0.05). It caused a decrease in total flavonoids with a loss rate of 55%. The HPLC analysis of extracts revealed the presence of four flavonoids: rutin, luteolin-7-glucoside, cyanidin-3-glucoside and cyanidin-3-rutinoside. Among the studied cultivars, Azeradj was characterized by high levels of flavonoids. Concerning the antioxidant activity, diverging results were obtained using different antioxidant assays. Overall, the dry salting induced a reduction in the antioxidant activity with variable values depending on the cultivar. Among the used methods, high correlations were found between flavonoid contents and the FRAP assay.