Otimização de geleia de guabiroba (Campomanesia xanthocarpa) adicionada de prebiótico

Abstract

The industrialization of fruit allows to increase the period of offer and to guarantee the availability in seasonal times, as well as, to take advantage of the surplus of the production. The South of Brazil has a great diversity of native fruits, which have good industrialization capacity, but are little explored. Among the native fruits, we have the guabiroba, which although of little industrial interest, can be used for the elaboration of several types of products, such as jellies. These are generally high in sucrose (up to 50%), and the reduction of this ingredient by total or partial substitution by dietary fibers, in effect, prebiotic such as fructooligosaccharides (FOS), can be considered a good strategy. The objective of this work was to optimize gel formulations, following a Central Rotatable Composite Design (CRCD 2 3). The independent variables analyzed were the concentration of sucrose in relation to the concentration of FOS (S / FOS), pectin concentration (P) and citric acid concentration (AC). The effects on the response variables were water activity, yield, soluble solids, pH, titratable acidity, instrumental color (luminosity, chroma and hue angle) and texture profile (adhesiveness and hardness). After analysis of the results, the optimized formulations were characterized for moisture content, ashes, protein, lipids, total carbohydrates, reducing sugars, water activity, pH, titratable acidity, soluble solids, total phenolic compounds content, carotenoids and acid ascorbic acid. The results obtained through the CRCD indicated that the citric acid concentration exerted a linear effect with respect to the pH and the acidity of the jellies, and the acidity also had a quadratic effect of the S/FOS concentration. It was also verified that the higher the concentration of citric acid the lower the pH and the greater the acidity of the jellies. Already the pectin exerted linear effect for the hardness of the jellies. Thus, it was found that the samples containing 0.5% and 1% of pectin were sufficient for gel formation, both concentrations being defined as adequate. The optimized formulations (F2, F6 and F9) and submitted to the analysis of the chemical composition presented difference only with respect to moisture, in which F9 (containing 1% pectin and citric acid, and ratio of 42.5 / 7.5% of sucrose/FOS) presented higher value than the others. The acidity was higher for the formulations in which more acid was added (1.5% for the F2 and F6 formulations) and the pH was more acidic as expected. Regarding bioactive compounds, all jellies presented high levels of phenolic compounds and carotenoids. In view of the above, it is possible to conclude that the addition of FOS in jellies elaborated with native fruits can be an interesting alternative to improve the nutritional characteristics of the product.