Effectiveness Of Modified Atmosphere packaging In Preserving A Prepared Ready-to-eat Food

摘要

The effectiveness of modified atmosphere packaging (MAP) was evaluated for a combination prepared food (Korean braised green peppers with dry anchovies). From a preliminary storage test of the ready-to-eat dish at 10℃, the aerobic bacterial count on the green peppers was selected as a primary quality index. The effect of MAP with different CO_2 concentrations on the product quality at 10℃ was also studied. MAP with a CO_2 concentration of ≥30% extended the lag time and/or reduced the growth rate of bacteria. Finally, the effect of different storage temperatures (5, 10, 15 or 20℃) on the shelf life of the product was investigated. Mathematical modelling of bacterial growth curves under stretch-wrap air packaging and MAP with 60% CO_2/40% N_2 showed that MAP increased the hypothetical minimum temperature in the square root model that describes the temperature dependence of the lag time and growth rate. MAP conditions of 60% CO_2/40% N_2 extended the shelf life at 10℃ by 130% (to 18.4 days) relative to that achieved with stretch-wrap air packaging (7.9 days) based on the time taken to reach the quality limit of an aerobic bacterial count of 10~5 CFU/g. The relative extension of shelf life achieved with MAP was greater at lower temperatures.