Interferência da lactose e da sacarose no armazenamento refrigerado de iogurtes de consistência firme

Abstract

Yogurt is a fermented dairy food consumed worldwide and it is on the rise in the market. The variety of yogurts found on the shelves of supermarkets increases every day due to the high demand of consumers and aiming to attend the specificities of each group. Lactose-free yogurt is an example of innovation developed to serve a specific group of consumers who have lactose maldigestion. Another version created to meet consumer needs is the yogurt without added sugar. With this large expansion of lactose-free yogurts and no added sugar on the market, it is necessary to develop new research focused on these products. Therefore, the objective of this work was to analyze through comparison the changes occurred in different yogurt formulations due to the presence or absence of sucrose and lactose. Four formulations of yogurt (with lactose/without sucrose, with lactose/with sucrose, without lactose/without sucrose and without lactose/with sucrose) were produced from which chromatographic analyzes were performed to follow the carbohydrate profiles, pH analysis and viable lactic acid bacteria over 42 days. Coliforms, molds and yeasts were analyzed in a complementary manner. For all formulations, pH values decreased significantly by day 14, increased steadily from day 21 and dropped again by day 35. In the sweetened formulations, there was reduction in sucrose concentration from day 1 to day 7, but there was no significant difference. In formulations containing lactose there was a significant reduction in the concentration of this sugar over the course of one week. Regarding glucose concentration, there was no significant difference in the without lactose/ with sucrose formulation, but in the formulations with lactose/with sucrose and without lactose/without sucrose, the concentration decreased significantly. On the first day of analysis, the formulation with lactose/without sucrose had a glucose concentration below the detection level, and on day 7 the concentration was 0.87 ± 0.23 g / L. Further stability of the lactic acid bacteria was observed in the formulation with lactose and without sucrose, which the cultures remained statistically constant over the 42 days of analysis. In all formulations the counts of Streptococcus salivarius subsp. thermophilus were higher than the counts of Lactobacillus delbrueckii subsp. bulgaricus. There was no presence of coliforms, molds and yeasts in any formulation.