IMPACT OF EVAPORATION AND DRYING METHODS ON COLOR PARAMETERS OF WHOLE MILK POWDER

Milk is an essential food in the diet of billions of people worldwide. The demand for powdered milk products has increased considerably due to their durability, prolonged shelf life, and greater ease of transport and storage. However, the process of producing milk powder can significantly influence its physicochemical and sensory characteristics. Color is one of the most important sensory attributes of food quality because it is related to visual perception and acceptance by the consumer. Therefore, this research aimed to study the effect of different concentration methods—open pan (OP) and rotary evaporator (RE)—and drying techniques—spray dryer (SD) and freeze-dryer (FD)—on color parameters (L*, a*, and b*) and the browning index (BI) of whole milk powder. Four samples were assessed in triplicate, and variance (ANOVA) with a significance level of p < 0.05 was used for the statistical analysis. The L* parameter (representing luminosity) and the b* parameter (representing the intensity of the yellow-blue colors) showed significant differences (p < 0.05) between the treatments, indicating that the evaporation and drying conditions could have drastically affected the appearance of the product, which impacts visual perception and consumer acceptance. The OP-SD milk powder showed the highest b* value (23.12 ± 0.76), while the FD-SD treatment showed more negative BI values (-359.01 ± 21.90), suggesting the formation of dark-colored compounds. These findings can be attributed to processing conditions, such as high temperatures, which can promote non-enzymatic browning reactions, such as caramelization and the Maillard reaction. Overall, the processing method can affect the final quality of the product, especially its color and appearance, which are related to consumer acceptance of milk powder.