The impact of frozen storage duration on physical, chemical and microbiological properties of pork

The aim of the present study was to evaluate the effect of frozen storage duration (3, 6, 9, 12, 15, 18 months) on physical, chemical and microbial properties of pork in three cuts (loin, ham, and belly rib). During frozen storage, significant alterations in physical and chemical parameters were observed through the increase of the total exudate, pH and lightness (L*), and a decrease of shear force and yellowness (b*). Water content in ham samples decreased, while protein content increased. The lipid oxidation (TBA) values in loin and ham samples increased for up to fifteen months of frozen storage, after which they decreased. The proportion of saturated fatty acids in frozen samples was significantly higher than in fresh meat. The total amount of Enterobacteriaceae, S. aureus and Pseudomonas spp. decreased during frozen storage, indicating that freezing may reduce the number of bacteria found in meat. Frozen pork microflora did not change after eighteen months of storage.