Effect of selected commercial substances with cryoprotective activity on the quality of mechanically recovered,washed and frozen stored poultry meat

Investigations were conducted on mechanically recovered poultry meat (MRPM) and on protein preparation obtained from MRPM by washing it first with 1% water solution of sodium chloride and with water afterwards. The raw materials were frozen at the temperature of -23 C. The effect of added stabilizers on the quality of gels produced from fresh raw materials, and after freezing and frozen storage was assessed. The following additives were used: 1% pork hydrolizate (Pork Stock), 0.5% Cremodan containing carrageens, and 1.5% bovine blood plasma (AMP 600N). Freezing and frozen storage caused a significant reduction of functional properties of MRPM and its protein preparation. None of the examined additives protected simultaneously all the investigated functional properties of the frozen samples. The amount of thermal drip, the gel texture and the amount of protein transition heat were determined by scanning differential calorimetry. The lowest thermal drip in gels obtained from frozen-stored samples was observed when bovine blood plasma was used as a stabilizer. On the other hand, the most advantageous protective effect on the proteins of the frozen MRPM and on the preparation, determined by mechanical strain resistance of the gels, was found with 1% pork hydrolizate added. The results of thermodynamic investigations of proteins revealed that the best protective effect on the frozen preparation was observed with 1.5% blood plasma added. No protective activity of added Cremodan on proteins of the frozen protein preparation was noted.