The preservation effect of composite natural antibacterial film on Cheddar cheese

The preservation effect of different composite natural antibacterial films ( blank control without film, sodium caseinate-chitosan-natamycin film, also named film M1, sodium caseinate-chitosan-natamycin/lysozyme film, also named film M2) on Cheddar cheese were studied. Sensory evaluation index, and moisture content, p H value, titratable acidity, soluble nitrogen content ( SN) , meltability, oil precipitation properties, textural properties, SDS-polyacrylamide gel electrophoresis ( SDS-PAGE) and microbial indexes of cheese in different storage time were measured under refrigeration at 4 ℃.The results showed that compared with the blank control, the sensory evaluation index, the physical and chemical indexes and textural properties of cheese packaged with film M1 and M2 were better, and the pattern of SDS-PAGE showed that the degree of proteolysis of cheese packaged with film M1 was relatively low, the colony counts ( 3.5 × 10⁴CFU/m L) of the solution of cheese packaged with film M1 laying flat plate after 48 h were less than those ( 6.8 × 10⁴CFU/m L and 9.2 × 10⁴CFU/m L respectively) of the solution of cheese packaged with film M2 and the blank control under the same conditions.So film M1 was significantly better than film M2, and both of them had good antibacterial and preservation effects to effectively prolong storage period of Cheddar cheese.