Polyphenol, anthocyanin and antioxidant content in different parts of maqui fruits (Aristotelia chilensis) during ripening and conservation treatments after harvest

Maqui, Aristotelia chilensis (Mol.) Stuntz, Elaeocarpaceae, is a berry with one of the highest antioxidant activities known, and which is exploited from the wild as raw material for nutraceutical products. The present work studies factors that might affect fruit quality in further industrial processing and proposes HPTLC fingerprint methods for routine quality control of metabolites and radical scavengers. Polyphenol and anthocyanin concentrations in fruit were determined in cultivated maqui. Polyphenol concentration did not vary significantly during the ripening process, but differed from one growing season to another (2.1 and 2.8 g GAE/100 g dry weight). Anthocyanin concentration increased during maturation from 0.07 to 1.13 g Cy-3-glu/100 g dry weight, whereas antioxidant ORAC value remained stable (194-241 mu mol TE/g DW). Anthocyanins were concentrated only in the fleshy parts of ripe fruits (4.2 g Cy-3-glu/100 g DW), while other polyphenols were found in the seeds (2.1 g GAE/100 g DW). Polyphenol and anthocyanin contents did not decrease during desiccation, cooling or freezing processes. Desiccation approximately doubled sugar contents, from 24.5 degrees Brix in fresh to 50 degrees Brix in dry fruit. Frozen fruit retained their soluble solids content and anthocyanins, while polyphenols increased. (C) 2015 Elsevier B.V. All rights reserved.