Accumulation of delphinidin derivatives and other bioactive compound in wild maqui under different environmental conditions and fruit ripening stages

Abstract

There is a growing interest in food and bioactive compounds with health benefits. Several studies on wild fruits have reported high anthocyanin contents and antioxidant potential mainly influenced by abiotic stress, particularly in native berries. Maqui (Aristotelia chilensis (Mol.) Stuntz), a Chilean native berry, has been referred as a “superfruit” due to its phytochemical composition and antioxidant activity. The content of bioactive compounds in wild maqui, specifically delphinidin, is influenced by collection time, genetic traits, and environmental conditions (location). The objective of this study was to evaluate the phenolic content, levels of anthocyanins and flavonols, and antioxidant capacity of maqui at three fruit ripening stages (unripe, preripe and ripe) in three different locations of central Chile (Coihueco, Cayumanque and Tregualemu) for two consecutive seasons (2019–2020 and 2020–2021). There was an interaction (p ≤ 0.05) between location and fruit ripening stage in all the bioactive compounds evaluated. Total polyphenol content varied in accordance with the biosynthesis pathway transformation in the different ripening stages, ranging from 2290 (ripe stage) to 1025 mg gallic acid equivalent 100 g−1 (fresh weight) (unripe stage). An accumulation of delphinidin derivatives was found at the ripe stage, while these compounds accounted for a significant proportion of around 80% of the total anthocyanins in both seasons. The antioxidant capacity varied depending on the season, location, and fruit ripening stage. The highest values were recorded in Cayumanque, with an average value of 8926 µmol Trolox equivalent 100 g−1 (fresh weight) for both seasons. In order to supply raw material of similar quality, which is a key issue for the food and pharmaceutical industries, and allow for sustainable production, seasonal and environmental variations in bioactive compounds as well as chemical characteristics of wild fruit need to be regulated according to edaphoclimatic conditions.