Effect of drying process on oil, phenolic composition and antioxidant activity of avocado (cv. Hass) fruits harvested at two different maturity stages

Abstract Drying processes differently affected the chemical compositions of avocado parts, and enhanced the oil content, total phenolic contents, antioxidant activity values of the pulp. Drying processes increased the amounts of most phenolic compounds and fatty acids in all parts of both ripe and unripe fruits. Total phenolic contents of unripe and ripe avocado pulps varied between 53.14 (air) and 190.53 mgGAE/100 g (oven) to 88.71 (air) and 309.48 mgGAE/100 g (oven), respectively. The oleic and linoleic acid contents of the oils extracted from unripe and ripe avocado pulp dehydrated in different drying systems were detected between 56.19 (air) and 59.43% (oven) to 51.96 (fresh) and 57.41% (oven), respectively. In addition, (+)-catechin amounts of unripe and ripe avocado pulps were identified between 43.12 (MW) and 130.08 mg/100 g (air) to 44.45 (air) and 121.51 mg/100 g (MW), respectively. It reduced the moisture content, oil and total phenolic contents of the peels and seeds, few phenolic compounds and fatty acids of different fruit parts. By-products (seeds and peels) of avocado fruits contain at high levels of bioactive compounds, and their levels enhanced by drying treatments. Results can help in proper utilization of these important by-products as supplements to in various food after suitable drying process.