The effect of chilling and freezing on histological structure in slaughter poultry

This study focused on the evaluation of morphometric histological changes in the muscles of chicken carcasses before and after two types of cold treatment. Air-spray chilling and the IQF (individual quick freezing) method were used. The diameter of the muscle fibres in breast and thigh muscles was measured. A statistically highly significant increase (P < 0.001) in muscle fibre diameter was found between the control group and air-spray chilling group and a statistically significant decrease was found between the control group and the thigh muscle IQF freezing group. Air-spray chilling caused a statistically significant increase (P < 0.05) in muscle fibre diameter in breast muscles, though a statistically highly significant decrease (P < 0.001) in muscle fibre diameter was found after IQF freezing. Muscle fibre diameters were higher in the control group, air-spray chilling group and breast muscle IQF freezing group. According to the results obtained, we can conclude that histology is a reliable method for the study of muscle fibre damage and, therefore, the loss of biological value in chicken meat after different types of low-temperature preservation.