Avaliação do potencial e estabilidade antioxidante de extrato de carotenoides de melão cantaloupe (Cucumis melo L.) nanoencapsulado visando aplicação em alimentos

Abstract

Nanoencapsulation presents itself as an alternative to promote increased solubility, stability, potentiate, and preserve the antioxidant action of carotenoids. In this study, the antioxidant potential and stability of the carotenoid-rich extract of Cantaloupe melon (CE) nanoencapsulated in gelatin (EPG) for application in food was evaluated. EPG was obtained by oil-in-water (O/W) emulsification, and physical and chemical methods characterized the particles. They were evaluated for antioxidant potential through tests using 2,2-diphenyl-2- picrylhydrazyl (DPPH •) and 2,2´-azino-bis- (3-ethylbenzoatiazolin) -6-sulfonic acid (ABTS •): ( 1) CE (0.05 mg/mL); (2) commercial standard β-carotene (0.009 mg/mL); (3) nanoparticles without CE (4.00 mg/mL); (4) EPG (4.05 mg/mL) and; (4) CE extracted from nanoparticles (0.05 mg/mL). Besides, the stability of CE and EPG was evaluated at room and refrigeration temperature (25 °C and 5 °C, respectively) with and without the presence of light (1600 lux), for 60 days through (1) the concentration of β-carotene by UHPLC; and (2) the antioxidant potential by ABTS•. The characterization showed spherical nanoparticles with a smooth surface [90.9 (7.20) nm and 0.56 (0.08)], and chemical interactions between CE and porcine gelatin, confirming the encapsulation. The percentage of inhibition of ABTS • and DPPH • radicals was equal to: 1) CE: 22.2 (1.37)% and 18.8 (0.95)%; (2) standard β-carotene: 10.7 (1.55)% and 30.6 (0.54)%; (3) nanoparticles without CE: 0.0 (0.0)% and 0.0 (0.0)%; (4) EPG: 0.0 (0.0)% and 0.0 (0.0)%; (4) CE extracted from nanoparticles: 35.0 (2.15)% and 30.0 (0.25)%. Therefore, nanoencapsulation potentiated in the range of 57-59% of the antioxidant activity of CE. The stability study showed that after 60 days, CE showed low retention of βcarotene, in the range of 0 to 43.6%, with the lowest percentages at the light (0.00%) and dark (10.0%) at room temperature. Thus, generating a negative impact on free radicals inhibition, which was completely lost in the four conditions evaluated (0.0%). For CE extracted from EPG, at the end of 60 days, 99.0% retention of β-carotene was observed in the dark at room temperature and under refrigeration. Upon exposure to light, at room temperature, there was a total loss of β-carotene (0.0%) and, under refrigeration, 83.1% retention. Therefore, nanoencapsulation promoted greater protection and stability of the carotenoid under refrigeration and at room temperature in the absence of light (99.0%). Besides, there is an excellent result obtained under refrigeration in the presence of light. Regarding ABTS• inhibition (%), preservation was found in the range of 68.7 - 48.3% after 60 days, also associated with storage conditions in the dark at room temperature and under refrigeration. Therefore, the study demonstrated that Nanotechnology promoted the protection, enhancement, and increased stability of Cantaloupe melon carotenoids. Thus, increasing the potential for applying natural dyes with antioxidant properties in processed foods.