Impact of transglutaminase treated micellar casein concentrate and milk protein concentrate on the functionality of process cheese product slice formulations.

Milk protein concentrate (MPC) is used as an ingredient in processed cheese product (PCP) formulations. However, its use can result in texture defects such as a soft body and restricted melting characteristics. The use of micellar casein concentrate (MCC), which has a higher level of casein and less serum protein, improves the texture of PCP. Further improvement in PCP products may be possible using transglutaminase (TGase), an enzyme that can crosslink proteins. This study aimed to determine the effect of TGase treatment of MPC and MCC retentates on the functionality of MPC and MCC when used in a PCP slice formulation. Three lots of MCC and MPC retentate were produced using microfiltration and ultrafiltration, respectively. Each replicate of retentate was divided into three equal portions and treated with transglutaminase enzyme at three different levels: 0.3 U/g of protein, 3.0 U/g of protein, and no TGase addition. The retentates were spray-dried, and powders were used in PCP slice formulation. Functional properties of PCP were analyzed using a penetration test, Dynamic stress rheology (DSR) for transition temperature (TT), and Schreiber melt test. As the TGase addition increased, there was a significant (p ≤ 0.05) increase in TT and a significant (p ≤ 0.05) decrease in the Schreiber melt area. The PCP made from MCC had higher TT and Schreiber melt area values than that made from MPC as an ingredient (TGase or no TGase). It was concluded that TGase treatment modifies the melt characteristics of MCC and MPC in PCP applications.