Extraction of anthocyanins from mortiño (Vaccinium floribundum) and determination of their antioxidant capacity

Mortiño (Vaccinium floribundum) is a wild Andean berry, with a high content of bioactive compounds, especially anthocyanins, with protective effects against various diseases due to their antioxidant capacity. The aim of this study was to determine the best anthocyanin extraction conditions without affecting the mortiño antioxidant capacity. A completely randomized design with factorial arrangement 2³ was applied in the extraction (solvent: ethanol and methanol; concentration: 20 and 60%; temperature: 30 and 60 °C). The anthocyanin content showed that the best extraction conditions were 20 and 60% hydroethanolic solution at 60 °C (P<0.05). For the antioxidant capacity, the treatments were analyzed in a factorial arrangement 2²: ethanol and methanol 20%; 30 and 60 °C. The highest antioxidant capacity was found at 20% ethanol and 60 °C (19,653.3±256.62 µmol TE 100 g^-1 FW (fresh weight)) by the FRAP method (Ferric Reducing Antioxidant Power) (P<0.05), and with the ABTS methodology, methanol and ethanol (20%), at 60 °C (8458.3±127.45 and 8,258.0±325.05 µmol TE 100 g^-1 FW, respectively) (P<0.05). Extraction at 60 °C did not affect the antioxidant properties of anthocyanins. A high correlation was found between both methodologies by Pearson’s Correlation (PC=0.898). In addition, the antioxidant capacity measured by the two methods was highly related to the anthocyanin content of the extracts (PC=0.973 and 0.952, respectively). Other berry species have been extensively investigated for their antioxidant compounds, but there is limited information about the optimization of anthocyanin extraction from mortiño and its high antioxidant capacity important for future industrial applications. As a result, ethanol at 20 and 60%, 60 °C for 4 h are the best conditions to extract and quantify the anthocyanins of the mortiño fruit.