A multilayered coextruded thermoplastic food casing comprising: at least one porous inner layer of which one is the innermost porous layer whose surface is adjacent to food to be encased; at least one layer having a barrier effect for water vapor and/or oxygen; at least one adhesive layer, said adhesive layer optionally being the same as or different from said at least one porous inner layer and/or said one layer having a barrier effect for water vapor and/or oxygen; wherein the porosity of said at least one porous inner layer has been generated by (co)extruding a first polymer composition comprising a polymer and a supercritical pore-forming agent, wherein the group of all porous inner layers of the casing shows a total porosity of from 5 to 90 % by volume, said at least one porous inner layer has a porosity comprising pores having a pore diameter of from 0.01 to 2000 μm, such that at least one of said at least one porous inner layer(s) is able to absorb, retain, desorb and to transfer at least one transferable functional additive from said at least one porous inner layer to food encased in said casing, wherein porosity and pore diameter are measured as indicated in the description, characterized in that the at least one porous inner layer consists of a polymer and a filler and/or a nucleating agent, wherein the filler is selected from the group consisting of silica(s), talc, calcium carbonate(s), barium sulfate, alumina(s), aluminium hydroxide(s), magnesium hydroxide, titania(s), zirconia, silicate(s) and sodium chloride, and the nucleating agent is selected from the group consisting of carbonates, hydrazine derivatives, azo compounds, semicarbazides, tetrazoles, nitroso compounds, citric acid and citric acid derivatives. at least one porous inner layer of which one is the innermost porous layer whose surface is adjacent to food to be encased; at least one layer having a barrier effect for water vapor and/or oxygen; at least one adhesive layer, said adhesive layer optionally being the same as or different from said at least one porous inner layer and/or said one layer having a barrier effect for water vapor and/or oxygen; wherein the porosity of said at least one porous inner layer has been generated by (co)extruding a first polymer composition comprising a polymer and a supercritical pore-forming agent, wherein the group of all porous inner layers of the casing shows a total porosity of from 5 to 90 % by volume, said at least one porous inner layer has a porosity comprising pores having a pore diameter of from 0.01 to 2000 μm, such that at least one of said at least one porous inner layer(s) is able to absorb, retain, desorb and to transfer at least one transferable functional additive from said at least one porous inner layer to food encased in said casing, wherein porosity and pore diameter are measured as indicated in the description, characterized in that the at least one porous inner layer consists of a polymer and a filler and/or a nucleating agent, wherein the filler is selected from the group consisting of silica(s), talc, calcium carbonate(s), barium sulfate, alumina(s), aluminium hydroxide(s), magnesium hydroxide, titania(s), zirconia, silicate(s) and sodium chloride, and the nucleating agent is selected from the group consisting of carbonates, hydrazine derivatives, azo compounds, semicarbazides, tetrazoles, nitroso compounds, citric acid and citric acid derivatives.