Effect of lipid‐mediated moisture status on casein characteristic in two types of milk powders during accelerated storage

Abstract This study aims to investigate the relationship between casein oxidation and moisture status in the presence of milk fat to clarify the role of fat on water in milk powder. The results showed that at the same water activity (aw), the faster oxidation of whole milk powder (WMP) is attributed to the high proportion of free water and immobilized water in them, indicating that the adsorption of milk fat mainly depended on multilayer water and the entrapped water. In the diffusion‐limited reaction, changes in water state affected more than radicals on casein oxidation. Glass transition temperature (Tg) was also affected by the water state of lipid adsorption. At low aw (