Microencapsualação de extrato de melão de São Caetano (Momordica charantia L.)

Abstract

The harmful effect of artificial dyes on health raises concerns for consumers. It is studied the substitution of artificial dyes by natural dyes with antioxidant activity. Momordica charantia L. is popularly known as Melão de São Caetano and has been gaining ground in the world scientific scene and being credited mainly for its antioxidant activity. The microencapsular technique is an efficient way of preserving the characteristics of the dyes. The objective of this work was to characterize the bioactive compounds present in the Melão de São Caetano extract in terms of antioxidant activity, total phenolic compounds, total flavonoids and total carotenoids. In addition, we obtained spray dryer capsules in gum arabic (GA) and whey protein concentrate (WPC), characterized as microencapsulation yield, solubility, wettability, water activity, moisture, color parameters, encapsulation, carotenoid retention and microparticle morphology. In relation to the bioactive compounds present in the Melão de São Caetano extract, the following contents were observed: phenolic compounds of 73.00 mg EAG g-1, total flavonoids of 30.39 mg quercetin 100g-1 and total carotenoids, expressed in β-carotene of 580.25 μg g-1. Regarding the characterization of microcapsules, the microencapsulation yield was 59.77% for GA and 42.06% for WPC. Both GA and WPC showed high solubility, above 82%. The microcapsules obtained with GA and WPC showed low water and moisture activity. In relation to the efficiency of encapsulation and retention of carotenoids, it was observed that the test using WPC was the one that obtained the highest values of 90.30% and 19.27% respectively. In the color analysis, the difference between the microcapsules and the extract was found, with parameter L* = 25.74, a* = 3.40 and b* = 1.98, indicating a dark color due to the low luminosity and coloration between the red and yellow due to the positive coordinates of a* and b*, respectively. The microparticles showed similarity in morphology presenting in irregular shape. Therefore, these results indicate the fruit of Melão de São Caetano with high potential of bioactive compounds and the possibility of using these microcapsules as natural dye applicable in food products.