The study was conducted on mechanically recovered poultry meat subjected to washing and separation of fat and connective tissue in order to produce a myofibril protein isolate. The myofibril preparation (MP) was modified by microbial transglutaminase (MTG). For this purpose MP was supplemented with 3 g/kg MTG and modified at a temperature of 6-7 degrees C for 5 h. The character of changes in the mechanical properties of modified MP, occurring during heating and cooling within the temperature range of 20-80-20 degrees C, was analysed. Stiffness modulus (G(1)), loss factor (tg delta) and dynamic viscosity (eta) were determined by dynamic mechanical thermal analysis. Enzymatic modification of MP and heating caused significant changes in the structure of the tested protein systems. Heating of MP samples made it possible to identify two areas of change in G(1) values (up to 45 degrees C and >50 degrees C). Samples with an addition of MTG were characterised by higher values of the modulus in comparison to the control system. The cross-linking action of the enzyme resulted in a variation of G(1) and tg delta values between the tested systems. (C) 2014 Elsevier Ltd. All rights reserved.