The shelf life of various processed foods, such as cold dishes, salads, sandwiches and fresh cakes, pizza, soups and sauces, are also limited. As is known, some of them are low-acid and cooled (-2, + 4 ° C) and only use the frozen mining market. In order to prolong the shelf life of this type of food, thermal processes such as pasteurization and cooking are used in vacuum or modified atmosphere, lowering the pH and water activity, and fluctuations in storage temperatures are not allowed.
Although the optimum CO2 level in MAP application in these products varies according to the product, there is a need for at least 20% CO2 in order to prevent mold growth. On the other hand, adding sauce to foods has a decreasing effect on shelf life. As a matter of fact, in a research, a low acidic (pH 6.6) cream-based sauce and tomato-based meat sauce (pH 4.5) were used. Although the product taken for the trial lasts up to six weeks when it is preserved without sauce; it was preserved for four weeks when meat sauce was added and three weeks when cream based sauce was added. The optimum CO2 Level for sandwiches is reported to be 50% -70%. However, more positive results can be achieved by using 40% CO2.