Process optimization of spray-dried buffalo milk Bubalus bubalis bubalis (Linnaeus, 1758) using response surface methodology

Buffalo milk has higher fat and solids-not-fat contents, consisting mainly of proteins, carbohydrates, and minerals, making it more nutritious than cow’s milk. However, its composition also makes the product more perishable. Thus, preservation techniques like spray drying must be employed to extend its shelf life and facilitate efficient transportation and distribution. Spray-drying conditions for cow's milk have already been established. However, because of differences in physicochemical properties and composition, these conditions may not be applicable to buffalo milk. Therefore, optimizing the processing conditions for buffalo milk is necessary. This study aimed to optimize the spray-drying conditions for buffalo milk to produce an acceptable milk powder. Response surface methodology was used to evaluate the effects of three key variables: maltodextrin (10-20%w/w), feed pressure (8-12Hz), and inlet temperature (190-210°C). The goal was to determine their effects on the response variables, including moisture content, water activity, hygroscopic moisture, and insolubility index. The optimal spray-drying conditions were obtained at a maltodextrin concentration of 20% (w/w), a feed pressure of 12 Hz, and an inlet temperature of 210°C. These conditions produced a milk powder with a moisture content of 1.98%(w/w), a water activity of 0.227aw, a hygroscopic moisture content of 16.04g/100 g solids, and an insolubility index of 0.67. The model used to predict the responses was reliable because the experimental outcomes closely matched the predicted values. The spray-dried buffalo milk produced met the European Pharmacopoeia classification criteria for powdered milk and may serve as an ingredient in various milk-based products, such as yogurt.