Bahareh Sotoudeh,Nazanin Z and and Maryam Tajabadi Ebrahimi
The effect of different concentrations of two gas mixture (Carbon dioxide, Nitrogen), and also vacuum conditions and the usage of flexible multi-layer films has been studied for shelf life extension of spicy chicken meal at refrigerator (T= 4 0C). Ordinary condition as a control packaging were compared with two type of modified atmosphere packaging : {(N270% + CO230%), (N230% + CO270%)} and vacuum conditions in this project .These samples (spicy chicken meal) were packaged into one kind of barrier flexible pouch” 3 layers with thickness 124 μ (PET / AL / LLD)” under modified atmosphere packaging (MAP). Samples were performed microbial tests (Total count of bacteria, Lactobacilli count and Clostridium botulinum count), chemical test (pH) and sensory evaluation in different times. The usage of MAP was not adequate for controlling spoilage, but the spoilage process was delayed. The shelf life of chicken meals with spices under (30% Co2 + 70% N2) , ( % 70 CO2 +% 30 N2 ) and also vacuum conditions in this container were 10 days. The best condition belonged to ( N2 30% + CO270% ). Other hand sensory properties showed that increasing the amount of CO2 increased retention time, and can adversely affect the taste of spicy chicken meal under modified atmosphere. The PH variable has not decreased rapidly, in each treatments during storage times(28 days), while can be explained by characteristic of this multi layer flexible pouch with less water vapor and oxygen permeability, caused to control some chemical reactions in samples. Maximum change of pH was related to vacuum conditions, then treatment under % 30 CO2 and the lowest changes belonged to treatment under % 70 CO2 .
