Nanoencapsulação de carotenoides de melão Cantaloupe (Cucumis Melo L. reticulatus Naud.): caracterização de partículas, avaliação da solubilidade em água e estabilidade de cor em iogurte

Abstract

The objective of this study was to produce and characterize the carotenoid-rich extract of the Cantaloupe melon (Cucumis melo L. reticulatus Naud.) Encapsulated in porcine gelatin (EPG) and whey protein concentrated (EWPC) and isolated (EWPI), to evaluate the solubility in water, and the color stability in yogurt. The total of carotenoids was determined by UV-visible spectrophotometry, and the β-carotene by Ultra High-Performance Liquid Chromatography (UHPLC). The encapsulation was performed by double emulsion W/O/W. The particles were characterized by Laser Diffraction, Zeta Potential (PZ), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectrophotometry (FTIR), and evaluated for the efficiency of incorporation (EI), water solubility, and color stability in yogurt (CIElab). The UHPLC indicated 40 μg (0.02) of β-carotene/g of Cantaloupe melon pulp. The mean particle size and polydispersity index obtained for EPG indicated the presence of homogeneous material at the nanometer scale [59.3 (2.60) nm and 0.3 (0.04)]. The results obtained for PZ were 21.2 (0.10) mV, - 10.8 (0.55) mV and -14.2 (0.25) mV, respectively, for EPG, EWPI and EWPC. SEM showed particles with a smooth surface for all groups evaluated, but only EPG presented homogeneous sizes. All the obtained diffractograms revealed amorphous structures. The FTIR showed, mainly, for EPG and EWPC new bands not observed in the isolated materials, indicating new chemical interactions. The incorporation efficiencies obtained for EPG, EWPC, and EWPI were, respectively, 90% (7.39), 77% (8.65) and, 58.5% (0.71). In the solubility test, EPG showed three times greater solubility [0.073mg / ml (0.007)] compared to the crude extract [0.0263mg / ml (0.003)], and was therefore used in the stability study. EPG added in yogurt show no significant difference (p> 0.05) for any of the evaluated color indexes during 60 days of storage, as opposed to crude extract (p <0.05). The encapsulation with porcine gelatine is a promising strategy for the encapsulation of carotenoids, increasing the potential of application in food.