Avaliação físico-química durante a vida útil de leite UHT produzido e comercializado no Rio Grande do Sul

The shelf life of food is important because it defines the period in which the food remains safe microbiologically and physicochemical and sensory quality suitable for consumption. In case of UHT milk, there are regulations that aim to determine parameters that denote quality and safety for processing and commercialization of the product, in order to avoid risks to the consumer's health. Therefore, the present study aimed to analyze the physicochemical characteristics over the shelf life of whole and skimmed UHT milk from nine brands marketed in the Vale do Taquari region, since its raw material produced in the state of Rio Grande do Sul. The experiments were carried out along the shelf life period of products (180 days), and physicochemical evaluations were carried out on the intervals of days 0, 45, 90, 120, 150 and 180 for pH, titratable acidity, stability, density, fat content, cryoscopic index and defatted dry extract (ESD). The results were statistically evaluated, and the samples showed, in general, a decrease in their parameters, except for acidity, which showed an increase as the storage time increased. These results allowed us to observe that some milk brands have presented non-conformities with the Brazilian legislation since the beginning of the analyzes, leading us to conclude that the raw material processed can be considered of low quality.