EFFECT OF SOME FACTORS USED TO THE CHICKEN MEAT PRESERVATION AND PROCESSING ON THE PROTEASE ACTIVITY

The obtained results indicated that the cathepsin activity was higher by about 60% in the extract from thigh than from breast muscles. Freez ing and defrosting (not stored) of chicken meat did not influence the breast muscle cathepsin activity while they caused a decrease of activ ity of about 20% in the case of thigh muscles. The increase in catheps in activity was noticed in both kinds of muscles during storage at -20 degrees C up to 4 months (45.6% and 19.4% for thigh and breast muscle s respectively). The activity of cathepsin in extract from 5 months st ored meat reached 80% in case of breast muscles and 83% in case of thi gh muscles in relation to control sample respectively. The cathepsin a ctivity significantly increased during heating of breast muscles up to 60 degrees C, but in case of thigh muscles it was slightly higher tha n at 50 degrees C. The heating of cured chicken breast muscles up to 6 0 degrees C caused a non significant growth in cathepsin activity oppo site to raw muscles. The cathepsin activity from all cured samples hea ted up to 70 degrees C were several times lower in relation to control samples. The cathepsin activity of both thigh and breast muscles were resistant to gamma radiation. The investigated factors caused changes in the activity of cathepsin but none of them caused its total inacti vation The changes of cathepsin activity depended on the kind of muscl es and the kind and the value of acting factors.