Jabuticaba (Myrciaria jaboticaba Vell. Berg) syrup as colouring and pH indicating agent for an intelligent sheep milk yogurt

Resumo

Consumers are demanding for healthier and safe products. In this context, we proposed the development of an intelligent sheep milk yogurt, with a natural coloring agent, that changes color as the acidity increases, an indicative of shelf life decay. For that propose, jabuticaba (Myrciaria jaboticaba) syrup (15%, 30%, and 45% soluble solids) was added to the milk before fermentation. Yogurts ability in reporting acidity by changing color was observed by correlating yogurt titratable acidity (Dornic) and pH with visual and colorimetric parameters (L, a, and b). Other physical-chemical parameters as fat, protein, moisture, and ash were also analyzed to evaluate the syrup addition effect on yogurts composition. Statistical analysis of the data was performed through analysis of variance and the means were compared by the Tukey test at 5% of probability. Results have indicated that intelligent yogurts naturally colored with jabuticaba syrup, was able to change color from light purple to dark purple pigmentation, indicating pH decrease. Jabuticaba syrup affected yogurts composition, increasing titratable acidity, fat and ash as jabuticaba syrup soluble solids concentration increased.