OPTIMIZATION OF ULTRASOUND-ASSISTED EXTRACTION OF PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF GABIROBA USING RESPONSE SURFACE METHODOLOGY

Gabiroba (Campomanesia xanthocarpa) is a native Brazilian fruit from the Myrtaceae family that has high potential for obtaining phenolic compounds and antioxidants. However, the efficiency of extracting these compounds can be influenced by various process conditions, making it necessary to use tools to optimize the extraction variables. In this context, the response surface methodology allows for the simultaneous evaluation of the effects of these variables and the determination of conditions that favor the extraction of compounds of interest. Therefore, the objective of this study was to optimize the extraction of total phenolic compounds (TPC), total flavonoids (TFC), and antioxidant activity (DPPH, FRAP, and ABTS) from freeze-dried gabiroba fruits using ultrasound-assisted extraction based on a central composite rotational design (CCRD). The independent variables included ethanol concentration (EC; 20–80%, v/v), extraction time (ET; 20–60 min), and solid-to-solvent ratio (SSR; 1:10–1:30 m/v). The design comprised eight factorial points, six axial points, and three central points, totaling 17 experiments generated using Statistica 12 software. The experimental design used allowed for the obtaining of extracts with TPC values ranging from 65.60 to 121.97 mg GAE/g sample dry extract (DE), while TFC values ranged from 190.20 to 1286.10 mg EC/g DE. The analysis of the effects of the independent variables demonstrated that EC showed a significant linear effect (p ≤ 0.05) on TFC and FRAP, in addition to quadratic effects on TPC, TFC, and FRAP. Interactions were also observed between EC and SSR for FRAP, and between ET and SSR for FRAP and TFC. Regarding radical scavenging activity, DPPH showed a significant quadratic effect of EC, SSR, and ET, in addition to a linear effect of ET. For the ABTS assay, no significant effects of the evaluated independent variables were observed. The optimal extraction conditions were: EC of 79.63% (v/v), SSR of 1:19.04 m/v, ET of 67.06 min, obtained through the desirability function. Ultrasound-assisted extraction promotes mass transfer and the release of compounds from the plant matrix through phenomena associated with acoustic cavitation. However, the recovery of these compounds depends on the characteristics of the matrix and the conditions employed. Thus, this experimental study demonstrates that it was possible to recover significant amounts of phenolic compounds with antioxidant activity from gabiroba, offering a promising opportunity to utilize a highly perishable fruit using sustainable technologies. These extracts and their phenolic compounds can be explored in future research for applications in the food, cosmetics, and pharmaceutical industries, with a view toward developing functional foods, active food packaging, edible films, nutraceuticals, and cosmetics.