LAUSR

Abstract The buriti ( Mauritia flexuosa L.f.) is a highly nutritious fruit with a yellowish-orange pulp and a bittersweet taste. Its endocarp is surrounded by a spongy material made of starch and oil, while the fruit skin is hard, consisted of small reddish-brown scales. This work aimed to characterize the bioactive compounds and the antioxidant activity of buriti fruits, during the postharvest time, harvested at different ripening stages. The fruits were harvested in a transitional environment savannah/forest at private properties in the city of Boa Vista, Roraima, Brazil. Fruits were analyzed for five consecutive years (2012–2016), at three different ripening stages: immature (with up to 75% green color between the scales), mature (with up to 50% green color between the scales) and ripened (with up to 25% green color between the scales). The selected fruits were standardized on the basis of their appearance, such as color of the epidermis and phytosanitary conditions, and later sanitized. Different fruit variables were analyzed every 2 days during a 10-day postharvest period including loss of fresh mass, pH, total acidity, soluble solids, total pectins, pectin methyl esterase and polygalacturonase enzyme activity, respiratory behavior (CO 2 and ethylene), and functional activity such as phenolic compounds, carotenoids and antioxidant activity (ORAC and DPPH). High antioxidant activity, in both methods, was observed in buriti fruits at different ripening stages during the postharvest storage period, characterized by high phenolic and carotenoid compounds. Fruits harvested at mature and immature stages showed a longer postharvest shelf life. It was observed a climacteric behavior of the buriti fruits here analyzed, that showed an increase in the respiration rate and ethylene production, indicated by the peak of CO 2 and ethylene production. Similar changes were observed in the fruit pH, total acidity and soluble solids, as well as in the activity of peptic enzymes whereas a decrease was observed in the total pectin contents. The fruits showed reasonable amount of phenolic compounds, carotenoids and antioxidant activity, thus confirming the functional potential of these fruits.