Measurement of phenolic compounds and antioxidant capacity in apple and strawberry fruits by using different extractors

Abstract

The aim of this study was to determine the effectiveness of different solvents in extracting phenolic compounds and the evaluation of antioxidant capacity in apple (Malus domestica Borkh) and strawberry (Fragaria ananassa Duch). The values of phenolic compounds and antioxidant capacity found in the literature show a large discrepancy, even when it comes to the same species, or even the same cultivar. The existing literature shows ethanol, acetone and methanol, as the mainly extractors of polyphenols in fruits at different concentrations. There is no consensus on the most effective. In the present study we tested methanol, ethanol and acetone at concentrations of 0, 25, 50, 75 and 100% extractor/H2O (v/v) in peel and pulp of apple and strawberry. Our findings show that acetone 75% is the best extractor for phenolic compounds and their corresponding antioxidant capacity, better estimating the actual composition of strawberries and apples for both tissues studied. Methanol, known for its high toxicity showed the lowest extraction capacity among the tested extractors followed by ethanol. It was also observed that apples peel has phenolic compounds and antioxidant levels substantially higher than apple pulp and strawberry.

Keywords

• Malus domestica
• Fragaria ananassa
• soluble phenolics
• antioxidante capacity
• solvente
• extractors