CRITERIA TO DETERMINE THE FRESHNESS OF CHICKEN MEAT USING BIOPHYSICAL AND MORPHOLOGICAL METHODS
The article is dedicated to the experimental impedancemetry of fresh chicken meat (fillet) after storage in the refrigerator and the meat with signs of damage. It was determined that passing an alternating current of different frequencies through pieces of meat of different freshness results in the change of its overall electrical resistance. It was experimentally proved that the resistance dispersion curve for fresh chicken meat is in the range from 754.4 to 3720.0 Om, for the meat with signs of aging (damage) - in the range from 141.3 to 156.1 Om, which testifies to the dependence of the tissue electrical impedance module from its physiological condition. Along with the impedancemetry histological studies of the selected samples of chicken fillet and studies of surface structure of meat by scanning electron microscopy to confirm the effectiveness of the proposed method to determine the freshness of chicken meat was conducted. Histologically, the fresh muscle fibers were located densely, under sarcolema numerous elongated-oval nuclei of dark blue colour appeared. In the chicken meat, which is being stored in the refrigerator for 6 days, in contrast to the fresh one, a stratification and local destruction of sarcolemma, the swelling of muscle fibers, the destruction of connective tissue, the deformation and ruptures of deep layers of muscle tissue were observed. Electronic microscopic study of lengthwise superficial muscle tissues detected pressed in muscle clusters and separate fibers, sarcolemma exfoliates from the sarcoplasm, protein mass accumulated in intercluster layers. The histological examination of chicken meat samples with signs of damage, indicated a strong swelling of muscle fibers, loss of transverse and longitudinal streakiness, lysis of most nuclei, between several muscle fragments the colonies of microorganisms were revealed. The scanning electron microscopy of the medicinal products showed the thickening of internal layer with densely located fibers, the formation of small number of bags where the colonies of microorganisms are likely to multiply.