Foodstuff cover acting as a barrier for oxygen and/or condensation, designed to contain and store a foodstuff additive and to administer it to foodstuffs

摘要

A multilayer seamless tubular film comprises an outer layer (3-35 mu m thick) comprising a thermoplastic polymer; middle functional layer(s) with barrier action for oxygen and/or water vapor, comprising thermoplastic polymer; and a porous inner layer (5-40 mu m thick) comprising a thermoplastic polymer. A multilayer seamless tubular film comprises an outer layer (3-35 mu m thick) comprising a thermoplastic polymer; middle functional layer(s) with barrier action for oxygen and/or water vapor, comprising thermoplastic polymer; and a porous inner layer (5-40 mu m thick) comprising a thermoplastic polymer. The inner layer has 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. The porous inner layer has a liquid absorption capacity of 1-40 wt.%, based on the overall composite of the film. Optionally, the spaces in the inner layer connected to one another, at least partially stores the porosity modifier and/or a food additive. Independent claims are included for: (1) a process for producing a tubular film comprising providing the thermoplastic polymers intended for the particular layers, preferably in fiber, granule and/or powder form; melting and homogenizing the thermoplastic polymers intended for the particular layers separately from one another; coextruding the thermoplastic polymers intended for the particular layers through a coextrusion die to form a seamless multilayer tube; converting the coextruded multilayer primary tube to the solid state, preferably using intensive air or water cooling; heating the primary tube to a temperature between the glass transition temperature and melting temperature of the thermoplastic polymers used, glass transition temperature and melting temperature being determined using differential scanning calorimetry to DIN 53765; biaxially orienting the heated primary tube using an applied internal pressure which is established between two roll pairs in series; and optionally adjusting the shrinkage properties by heating the stretched tubular film; where a porosity modifier and optionally an inorganic filler are added before the coextrusion to the thermoplastic polymer for the inner layer and, after the coextrusion, the conversion of the coextruded multilayer primary tube to the solid state brings about a phase separation of the thermoplastic polymer for the inner layer and of the porosity modifier; (2) method of encasing a food comprising packaging the food in the tubular film; and (3) a food additive comprising an acidic liquid smoke composition having 2-25 wt.% of a sorbitan compound comprising sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and sorbitan monooleate.