Chemical composition of refrigerated milk from the mesoregions of the Brazilian savanna

The aim of this study was to assess the quality of milk in terms of its chemical composition in the mesoregions of the state of Goiás. Samples were collected during both the rainy and dry seasons from 2011 to 2014. A total of 17,393 data points on milk composition were extracted from the Milk Quality Laboratory’s database. To determine whether the year, rainy and dry seasons, and mesoregion had an influence on milk components, we conducted a multiple linear regression analysis and used the Wald test to assess the significance of the model coefficients. Apart from fat and lactose, all the other components showed positive correlations with each other, and all these correlations were statistically significant. During the dry season, the percentages of fat, protein, non-fat dry extract, and total dry extract were more significant compared to the rainy season. Lactose exhibited antagonistic behavior compared to other milk components with respect to seasonality, as the lactose content was higher during the rainy season. The chemical composition of milk displayed both seasonal and regional variations.