CHANGES IN HISTOLOGICAL STRUCTURE AND PHYSICOCHEMICAL PROPERTIES OF RAW, CURED, SMOKED PORK LOINS RESULTING FROM FREEZING NEAR CRYOSCOPIC TEMPERATURE

The aim of the study was to determine the effects of unintended freezi ng during cold storage (eep chilling conditions) and low freezing temp eratures (-10 degrees C) of raw pork loins, cured and smoked, on their histological structure and some physicochemical characteristics. The experimental products after freezing at -10 degrees C, were stored al the same temperature for 0, 2, 4 and 6 days, thawed thereafter and imm ediately deep chilled at near cryoscopic temperature (-3 degrees C) fo r 0, 2, 4 or 6 days. These conditions were changing the histological s tructures of pork loin, the water holding capacity (WHC) was reduced b y frozen storage but improved by deep chilling; the maximum shear forc e and energy were increased. The more the freezing at -10 degrees C wa s prolonged, the more unfavourable were the changes in structure, WHC and tenderness. Deep chilling at -3 degrees C after thawing of the exp erimental material on the other hand favourably affected the parameter s measured. Freezing at -10 degrees C and deep chilling at -3 degrees C did not affect the electrophoretic picture of pork loin proteins nor the water activity. Freezing itself had no influence on WHC. Changes were due to storage.