IMPACT OF PARTIAL FREEZING WITH MODIFIED ATMOSPHERE PACKAGING ON PORK’S QUALITY

To preserve the original quality of fresh pork and prolong its shelf life, this study aimed to seek a no ionic residue efficient storage method. The partial freezing with modified atmosphere packaging (PF-MAP, -1°C, 75%O2+20%CO2+5%N2) method was proposed and it was used to preserve fresh pork, and the storage effects with methods of refrigeration with MAP (R-MAP, 4°C), partial freezing with vacuum package (PF-VP, -1°C), refrigeration with vacuum package (R-VP, 4°C), partial freezing (PF, -1°C) and refrigeration (R, 4°C) were compared. The results indicated that after 8 days of storage, the total volatile basic nitrogen (TVB-N) content and total viable count (TVC) of pork under PF-MAP and R-MAP were much below the safety threshold limits, while the TVB-N content and TVC of the pork under PF-VP, R-VP, PF, R exceeded the safety limits. The drip and stewing losses of PF-MAP pork were lowest, which were 0.98% and 27.54%, respectively. The hardness and shear force of PF-MAP pork were 37.78 N and 38.38 N, respectively, which were significantly higher than other methods. The color of PF-MAP pork was bright, with a pH value of 6.08, an intense pork aroma, and perceived freshness. After 12 days of storage, the TNB-N content and TVC of PF-MAP pork remained significantly lower values, while the TVC of R-MAP pork approached the safety limit. After 20 days of storage, the TVB-N content and TVC of PF-MAP pork were 10.92 mg/100 g and 4.84 Ig CFU/g, respectively, significantly lower than the threshold limits. Its drip loss, stewing loss, hardness, shear force, pH, and color (L*, a*, b* values) were all satisfactory, resembling fresh pork in color and aroma. In conclusion, PF-MAP can better maintain the quality of fresh pork.