Polyphenol content and antioxidant activity of maqui (Aristotelia chilensis [Molina] Stuntz) during fruit development and maturation in central Chile.

Carolina Fredes1*, Gloria Montenegro1, Juan Pablo Zoffoli1, Miguel Gómez1, Paz Robert2

Maqui (Aristotelia chilensis [Molina] Stuntz, Elaeocarpaceae) is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and antioxidant activity (by ferric reducing ability of plasma [FRAP] assay) of maqui fruits harvested at different fruit maturity stages from two wild populations located in Central Chile. Each maturity stage was determined by days from fruit set, berry size, and soluble solids. Total phenol content declined while total anthocyanin content increased from the green to light red stage. Nevertheless, both total phenol and anthocyanin content increased from the light red to dark purple stage. The highest anthocyanin content and antioxidant activity was found in the late maturity stage (dark purple). The results show that ripening in maqui fruit can be expected with 1100 growing degree-days (91 d after fruit set) in Central Chile. At this moment of harvest, fruits with 18-19 °Brix have the highest anthocyanin content and antioxidant activity (FRAP). This study constitutes the first advances in the understanding of maqui fruit ripening and corresponding antioxidant activity.

Keywords: FRAP, maturity stages, ripening, total anthocyanins, total phenols.
1Pontificia Universidad Católica de Chile, Facultad de Agronomía e Ingeniería Forestal, Vicuña Mackenna 4860, Macul, Santiago, Chile. *Corresponding author (cpfredes@uc.cl).
2Universidad de Chile, Facultad de Ciencias Químicas y Farmacéuticas, Sergio Livingstone 1007, Independencia, Santiago, Chile.