MICROENCAPSULATION OF BIOACTIVE COMPOUNDS FROM JAMBOLAN (Syzygium cumini) IN PEA PROTEIN AND POLYSACCHARIDE MATRICES

Jambolan (Syzygium cumini) is a fruit rich in phenolic compounds with recognized bioactive potential, particularly notable for its antioxidant and hypoglycemic activities. However, preserving these phytocompounds after extraction is challenging because of their high chemical instability and low bioavailability. Microencapsulation by spray-drying emerges as a strategy to mitigate these effects by creating a protective physical barrier against light, oxygen, and moisture, extending shelf life, preserving functional properties, and controlling the release of bioactive compounds. In this regard, this study aimed at the microencapsulation of bioactive compounds from jambolan at different concentrations, using pea protein, gum arabic, and maltodextrin as wall materials, as well as the morphological, structural, and physicochemical characterization, and the evaluation of total phenolic content, antioxidant activity, and in vitro cytotoxicity of the encapsulates. The extract was obtained by pressurized liquid extraction (methanol), followed by rotary evaporation and lyophilization. We prepared four formulations (1%, 2.5%, 5%, and 7.5% extract) with 10 g total solids, homogenized them (Ultra-Turrax, 13,000 rpm, 10 min), and spray-dried them. The microcapsules exhibited diameters ranging from 21.16 to 26.22 µm, dimensions that effectively characterize them as microcapsules, as they fall within the 1 to 1000 µm range (with a statistical difference only between 1% and 7.5%), and a zeta potential of –13.48 to –23.83 mV, indicating moderate stability, with negative charges arising from carboxylic or phenolic groups. The total phenolic content ranged from 249.54 to 933.88 µg GAE·g⁻¹. At the same time, the ABTS⁺ antioxidant activity varied from 6.65 to 9.96 µmol TE·g⁻¹, from the lowest to the highest extract concentration in the encapsulates. These results show that the encapsulates enhanced the action of the pure extract, with values of 897.73 µg GAE·g⁻¹ and 2.38 µmol TE·g⁻¹, respectively. SEM images revealed spherical particles with rough surfaces. FTIR spectra demonstrated similar vibrational profiles, with no alterations in functional bands regardless of the concentration, highlighting bands near 3336 cm⁻¹ attributed to -OH and -NH bonds, regions near 1665 cm⁻¹ associated with C=O bonds of amides, and the range between 1361 and 1022 cm⁻¹ attributed to C-O and C-C stretching. XRD confirmed the typical amorphous structure of spray-dried powders, with amorphous halo centers located at 18º, 50º, and 20º. For cytotoxicity, the microcapsule with the highest concentration showed low cytotoxic potential for both cell lines (CHO-K1 and HepG-2), with cell viability above 93% after 24 h and 72 h of exposure. This performance was superior to that of the pure extract, which showed biocompatibility up to 500 µg·mL⁻¹ in CHO-K1 cells, indicating good biocompatibility and no cytotoxicity in the evaluated models. The microcapsules were successfully obtained and proved efficient at protecting and enhancing the bioactive properties of jambolan.

Acknowledgments: Capes, CNPq (Processo nº 403388/2023-6 and nº 304778/2025-7)