Influence of stabilization by intermolecular copigmentation on the antioxidant capacity of antocianines of the fruit of Vaccinium Floribundum Kunth.

Abstract

Anthocyanins from mortiño ( Vaccinium floribundum Kunth) were extracted by percolation, and stabilized by intermolecular copigmentation with rosmarinic acid, ferulic acid and a mixture 1:1 of these phenolic acids at concentrations of 120 and 960 mg/L. The antioxidant capacity of the non-copigmented antho- cyanin extract, copigmented extracts, pure copigments, ascorbic acid and cyani- din-3-glycoside was determined by the DPPH method. Curves Δ Absorbance vs Concentration were obtained by linear regression with experimental data. The slopes of the curves were used as comparison parameter. A relation was estab- lished between the slope of the ascorbic acid standard and slopes of the an- tioxidant compounds studied. The percentage ratio between the slope of the standard and the slope of antioxidants analyzed was calculated as increase or decrease antioxidant capacity. The chemical expression of the results was ob- tained by an inverse relation between the slope of the standard and samples. These results were named as: Antioxidant Capacity Equivalent to Ascorbic Acid, CAEA (acronym in Spanish). The results indicated that the antioxidant capacity of non-copigmented extracts is lower than from stabilized extracts. Copig- mented extracts with rosmarinic acid have a higher antioxidant capacity than copigmented extracts with ferulic acid. The anthocyanic extracts stabilized with mixture 1:1 have different behavior. The antioxidant capacity increases are caused by synergistic effect of the copigments.