Effect of modified atmospheric packaging and flexible films on the microbial population of Liquvan cheese

In this project, the effect of three types of flexible multilayer films and different concentrations of three types of gaseous mixtures (carbon dioxide, nitrogen, oxygen) as well as conditions under vacuum and also ordinary conditions as control to increase the shelf life of Liquvan cheese at ambient temperature (250C) were evaluated. Non-gas injection packaging as a control sample were compared with four type of modified atmosphere packaging (70% CO2 + 30% N2) , (30% CO2 + 70% N2) , (47.5% N2 + 47.5% + 5% O2) and under vacuum. For packing samples were used different flexible multi-layer films, 3-layer{PET(12)/ AL(12)/LLD (100)},4-layer {PET(12)/AL(7) /PET(12)/LLD (100) } , and 3-layer { PET(12)/ AL(7)/LLD (100)}. Experiments were performed on samples as follows microbial test (aerobics count; mold and yeast count ; coliform count and chemical pH test, at different times 5,10 15,20 (during twenty days). The results were performed in a completely randomized design by SPSS (Ver:22) and Duncan’s new multiple range test, with confidence level of 95% (P <0.05). Using MAP was not enough to control spoilage, but it was delayed the spoilage process. Therefore, the using of packaging with 4-layers as a low water vapor transmition and gas composition (70% CO2 + 30% N2) as a high antimicrobial properties were used to maintain the long-term of Liquvan cheese during twenty days and have a good effect on the amount of pH was better.