Effect of selected substances on the properties of frozen myofibril preparation obtained from mechanically recovered poultry meat

The experimental material was a myofibrillar preparation obtained from mechanically recovered poultry meat by the washing and separation of fat and connective tissues. Changes occurring during frozen storage were investigated in the preparation without and with the addition of the following substances: 2 g/kg carrageen, 2.5 g/kg sodium tripolyphosphate (TPP) mixture and 80 g/kg polydextrose, and 3 g/kg enzymatic preparation (ACTIVA WM) containing microbial transglutaminase (MTG). Samples with the addition of MTG were pre-incubated at the temperature of 7 ± 1 °C for 1, 3, 5, 24 h. All samples were stored at the temperature of approx. −23 °C for 2, 30, 60, 90 days. The smallest change in protein solubility was observed in samples with added TPP and polydextrose. Along with the extension of pre-incubation time of samples containing the enzyme a gradual decrease was found in the amount of soluble protein. Also the results of the investigations obtained using the DSC technique showed the most advantageous protective effect, i.e., causing the smallest decrease in enthalpy values of samples during freezer storage, in case of the addition of TPP and polydextrose mixture. Analysis of thermal drip volume from gels showed that carrageen was the most advantageous addition to the myofibrillar preparation. Moreover, a gradual increase was observed in the volume of thermal drip along with the extension of pre-incubation time of the protein isolate with enzymatic preparation. Results of gel texture testing indicated that the most advantageous effect on gel quality was found for ACTIVA applied in 3 and 5 h pre-incubation with the myofibrils. Assuming that among the analyzed properties the most important were thermal drip and gel texture, 3 g/kg MTG at pre-incubation time of 3 h was considered the most advantageous additive.