Use of transglutaminase for the production of lactose hydrolyzed milk powders

International audience

English. For population with lactose maldigestion, many dairy products with hydrolyzed lactose have been developed. However, spray drying of lactose hydrolyzed milk powder has challenges such as adhesion to the surface of drying chamber, reduced solubility and a tendency for caking (Torres et al., 2017). The use of transglutaminase (TGase) has shown modified techno-functionalities of several dairy products. Moreover, TGase treatment was found to improve flowing behavior and an increase in the transition temperature (Er et al., 2019) of skim milk powder. In our study, we explored the potential of TGase to address challenges related to lactose hydrolyzed milk powder. Four different skim milks (control, lactase-added, TGase-added, lactase and TGase-added) were concentrated 40% dry matter content and spray-dried at the pilot scale (n=3). Key characteristics such as the product adhesion to the equipment, the biochemical composition, particle size distribution and the presence of Maillard reaction markers were determined. Electrophoresis showed a decrease in the intensity of the casein bands in TGase-added powder, confirming glutamine-lysine crosslinking by TGase.. Our findings shows that the use of Tgase.did not affect the dryability of the milk but increased the particle size of the powders without altering their bimodal conformation. TGase did not affect the hydrolysis of lactose nor the color of the powders. However, the content of 5-hydroxymethylfurfural increased significantly in TGase-added powder suggesting different Maillard reaction pathways compared to the other powders. Thus, this study leads to new hypotheses and possibilities for future research to elucidate the influence of TGase addition on Maillard reaction mechanisms. Moreover, investigating the functionality of the powders such as rehydration properties could provide more insights into the potential application of TGase.