Anotace:
Traceability of poultry meat quality imported into Kazakhstan is an urgent task. To increase their benefits, some suppliers resort to falsification – they misrepresent thawed meat for chilled raw materials or carry out several cycles of freezing-thawing meat. The objective of these studies is to develop reliable methods for determining the quality and freshness of frozen natural semi-finished poultry meat, including the number of cycles of freezing and thawing meat. Dressed broiler chickens developed by the manufacturer from the Russian Federation using gas and electric stunning of poultry were selected as the research objects. A synchronous analysis device was used for thermal analysis in the heating-cooling process. Histomorphological studies were carried out on a microscope with an eyepiece magnification of x7. Histological examination revealed alterations in the structure of re-frozen and thawing lean tissue. The differential scanning calorimetry (DSC) analysis showed that the specific heat of thawing broiler fillets stunned by electric current during the first thawing is 218.8 J/g, at the second 209.5 J/g, and the third 201.4 J/g, and the specific heat of thawing broiler fillets stunned by gas during the first thawing is 176.5 J/g, at the second 171.9 J/g, and the third 162.6 J/g. Samples of broiler fillets stunned by electric current lost about 2.5% at each thawing stage, and with gas stunning 3% of moisture. The obtained results and research methods can be used to establish the falsification of the thermal state of broiler chicken meat by its undeclared freezing-thawing.