Food casing with barrier action for oxygen and/or water vapor and suitable for absorbing and storing a food additive and releasing it to the food

A multilayer seamless tubular film as a food casing with barrier action for oxygen and/or water vapor, which is capable of absorbing and storing a food additive and releasing it to the food, comprising:

• a) an outer layer composed of a thermoplastic polymer in a layer thickness of 3 to 35 μm,
• b) one or more middle functional layers with barrier action for oxygen and/or water vapor, composed of thermoplastic polymer, and
• c) a porous inner layer composed of a thermoplastic polymer in a layer thickness of 5 to 40 μm,
• i) the inner layer having a network, which brings about the porosity, of spaces connected to one another, which are formed in the course of production of the tubular film with the aid of a porosity modifier, specifically in such a way that the porosity modifier is added before the coextrusion to the thermoplastic polymer for the inner layer and, after the coextrusion, a phase separation of the thermoplastic polymer for the inner layer and of the porosity modifier is brought about,
• ii) the porous inner layer having a liquid absorption capacity based on the overall composite of the film in the range from 1 to 40% by weight, and
• iii) optionally, the spaces in the inner layer connected to one another at least partially storing the porosity modifier and/or a food additive.