Glass Transition Temperature of Casein as Affected by Transglutaminase

The objective of this study was to determine glass transition temperature (T g ) of a‐casein with differential scanning calorimetry (DSC) and to study the effect of microbial transglutaminase (MTG) treatment on T g of a‐casein. MTG‐treated a‐casein was fractionated following the MTG treatment. After adjusting water content, T measurements were made by DSC and the dependencies of T g on the water content determined. Oscillation DSC (ODSC) was also used. The determination of T g of MTG‐treated samples by conventional DSC was unreliable. However, by comparing with ODSC data, their T could be detected. The MTG treatment elevated the T g of a‐casein, which maybe the reason for improved stability of dry daily products during storage.