Determinación del porcentaje óptimo de alginato de sodio en la obtención de encapsulados de frutos rojos.

Abstract

Ecuador has a wide variety of products based on red fruits, such as jams, beverages, and yogurt, among others. However, one of the less commonly employed techniques is spherification, a method used to protect, preserve, and enhance the properties of these foods. Therefore, this research aimed to determine the optimal percentage of sodium alginate in the encapsulation of red fruits. The methodology for this research included three treatments with different levels of sodium alginate solution (0.50%, 1.00%, and 1.50%), each with five repetitions. The statistical analysis employed a completely randomized design subjected to an analysis of variance (ANOVA), with mean separation using Tukey's test (P<0.05). The physicochemical analyses included pH, density, titratable acidity, ash content, and water activity. Subsequently, the microbiological analyses included (mold, yeast, and E. coli), sensory analysis with a 7-point hedonic scale, and an antioxidant capacity analysis of the red fruit extracts in Trolox/ml of ABTS. The final results demonstrated that the variables of density and water activity showed significant differences due to the levels of sodium alginate solution. The resulting encapsulates with a 1.50% sodium alginate solution exhibited the best characteristics, with a density of 1.2 g/ml, a pH of 3.85, a titratable acidity of 0.85%, an ash content of 0.45%, and a water activity of 0.97. In the sensory analysis, they received ratings between 6 and 7, considered very good. The microbiological analyses for all three treatments reported the absence of microorganisms. Regarding antioxidant capacity, the blackberry extract demonstrated the best capacity with a value of 5395.33 Trolox/ml. Finally, the optimal percentage of sodium alginate is 1.50%, allowing to produce stable encapsulates with appropriate consistency and appearance.