Differential Thermal Analysis of Milk Proteins

Abstract

Differential thermal analysis (DTA) was used for study of milk protein denaturation. Protein solutions produced an endothermic peak of characteristic shape and temperature of peak minimum. The peak minimum is considered the coagulation temperature of the protein.The influence of pH and additives such as sugars and NaCl was clearly observed on the thermograms of β-lactoglobulin solution. Addition of κ-casein to β-lactoglobulin solution showed an inhibitory effect on the heat coagulation.Solid proteins produced two-stage exothermic peaks between 200°C and 400°C.DTA was a useful method in the study of heat denaturation and degradation of protein.