Nanoencapsulação de extrato de compostos fenólicos oriundo da polpa de melão Cantaloupe (Cucumis melo L.): produção e caracterização de partículas, e avaliação do potencial antioxidante in vitro

Abstract

Phenolic compounds (PC) help prevent diseases due to their antioxidant, antimicrobial, and anti-inflammatory properties. However, they are unstable due to changes in pH, heat, and the presence of oxygen and light. Nanoencapsulation can improve bioaccessibility, bioavailability and preserve and/or enhance bioactive properties. The study aimed to produce and characterize nanoparticles containing PC-rich extract from Cantaloupe melon pulp (Cucumis melo L.) and evaluate the effect on antioxidant potential in vitro. The melon pulp was dried in a ventilated oven (55 °C/24 h) to obtain flour, used to extract PC by maceration using 50% methanol (v/v) and 70% v/v acetone (1:4 p/v). The extract (CEPC) was concentrated in a rotary evaporator (28 °C) and lyophilized. The PC concentration was determined by UV-vis spectrophotometry and the PC profile by High-Performance Liquid Chromatography (HPLC). Three formulations were obtained using isolated whey protein (EPWI), concentrated whey protein (EPWC), and isolated soy protein (EPSP) through the nanoprecipitation technique in anti-solvent (acetone), using the Tween 80 as surfactant. The formulations were characterized in terms of incorporation efficiency (EI %) and by different physical and chemical methods: Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Zeta Potential (ZP), Infrared Spectroscopy by Fourier Transform (FTIR), X-ray Diffraction (XRD), and antioxidant potential by ABTS• and Total Antioxidant Capacity (TAC) assay. The PC content determined was 750 (60.73) mg EAG/100 g of melon pulp flour. Ten phenolic compounds were identified in CEPC, with emphasis on procyanidin B1 [213.9 (33.23) mg/kg], fumaric acid [181.6 (30.55) mg/kg], chlorogenic acid [20.54 (3 .03) mg/kg) and trans-cinnamic acid [13.03 (1.46) mg/kg]. The EI results (%) showed high FC retention in EPWC [89.50 (0.23)] and EPSP [90.60 (6.52)], unlike EPWI [74.10 (0.28)] (p<0.05). The micrographs obtained indicated the formation of spherical particles with a smooth surface, and DLS indicated diameters equal to 80.70 (12.94) nm, 74.90 (10.78) nm, and 96.57 (10.17) nm, respectively for EPWI, EPWC, and EPSP. The Zeta Potential results obtained for EPWI, EPWC, and EPSP were equal to +19.60 mV (pH 3.4), +21.68 mV (pH 3.6), and +20.13 mV (pH 3.5), classified as relatively stable, indicating an application in acidic food products. FTIR of the three formulations showed that the materials in the systems interacted chemically, suggesting the encapsulation of the crude extract. According to the X-ray diffractograms, the different nanoencapsulated were characterized as amorphous. The encapsulation process has enhanced the particles' antioxidant activity up to twice for EPWI and up to six times for EPWC and EPSP than for CEPC (p<0.05). Therefore, nanoencapsulation with different encapsulating agents using the antisolvent nanoprecipitation technique presents itself as a promising strategy to promote the encapsulation of phenolic compounds from Cantaloupe melon, expanding the potential for application in foods.