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 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◦ Brix in fresh to 50◦ Brix in dry fruit. Frozen fruit retained their soluble
solids content and anthocyanins, while polyphenols increased.