OPTIMIZATION OF ANTIOXIDANT EXTRACTION FROM JABUTICABA PEEL (PLINIA CAULIFLORA): PHYSICOCHEMICAL EVALUATION, ANTIOXIDANT ACTIVITY, AND EFFECTS OF LYOPHILIZATION

“Jaboticaba” (Plinia cauliflora), a fruit native to the Atlantic Forest, has a high phenolic compound content, mainly anthocyanins, which are responsible for its strong antioxidant activity. This study aimed to optimize the extraction of antioxidants from “jaboticaba” peel, characterize its physicochemical properties, and evaluate the effects of lyophilization. Three types of extraction were performed: hydroalcoholic (HE), aqueous (AE), and pectic (PE). After drying and grinding the peel, the extracts were obtained through filtration, centrifugation, and concentration using a rotary evaporator. The extracts were analyzed for solubility, hygroscopicity, monomeric anthocyanin content, and antioxidant activity using DPPH and FRAP assays. Lyophilization was applied only to AE and PE extracts because the HE extracts, due to its ethanol content, did not freeze properly, as the solvent lowered the freezing point and prevented the formation of the solid matrix required for the process. The hydroalcoholic extract showed the highest anthocyanin content (0.182 mg C3G/g) and strong antioxidant activity (162.30 µmol TE/g in DPPH and 54.21 mmol FeSO₄ /g in FRAP), demonstrating the efficiency of bioactive compound extraction. Aqueous and pectic extracts initially showed lower values (3.79 and 3.34 µmol TE/g in DPPH, and 19.18 mmol FeSO₄/g and 20.20 mmol FeSO₄/g, respectively), after lyophilization, they presented an increase in antioxidant activity in the DPPH assay (30.65(AE) and 31.32(PE) µmol TE/g), although with a significant reduction in FRAP values (9.69(AE) and 9.90(PE) mmol FeSO₄/g). These results suggest that drying concentrated compounds capable of neutralizing free radicals may have caused the partial degradation of anthocyanins sensitive to the process. The lyophilized extracts exhibited high hygroscopicity, which is related to the presence of sugars and pectin, in addition to solubility differences attributed to the chemical composition of each matrix. Overall, the solvent type directly influenced the extraction efficiency, with the hydroalcoholic extract being the most effective for obtaining anthocyanins. Lyophilization proved to be a promising alternative for concentrating and partially preserving the bioactivity of aqueous and pectic extracts, expanding their potential applications in food formulations. In conclusion, the proper choice of solvent, combined with appropriate drying techniques, can optimize the use of “jaboticaba” peel as a natural source of antioxidants, with hydroalcoholic extraction being the most efficient method for obtaining bioactive compounds.