The Influence of Heating and Cooling Process on the Water Binding in Transglutaminase-Modified Chicken Protein Preparation, Assessed Using Low-Field NMR

The study analysed mechanically deboned chicken meat subjected to washing and separation of fat and connective tissue in order to produce a preparation of myofibrillar proteins (MP). The preparation was modified using microbial transglutaminase (MTG). For this purpose, MP was supplemented with 3 g/kg MTG and modified at 6-7 A degrees C for 5 h. Changes in the dynamics of water binding, which occurred in the course of heating and cooling within the temperature range of 20-70-20 A degrees C, were analysed in the tested systems. Relaxation times T (1) and T (2) were determined using the low-field nuclear magnetic resonance (NMR). Enzymatic modification of MP and heating resulted in significant changes in the dynamics of bulk water binding in the tested protein systems. Due to the presence of transglutaminase in the preparation, the changes begin and end at lower temperatures. Analysis of relaxation time T (1) showed that the addition of the enzyme to MP causes water binding in the sample up to 48 h after gel cooling. The addition of the enzyme to MP reduces the energy barrier determined, based on activation energy.