engleski

Schematic overview of dry food packaging material selection

Storing food in the right way, particularly dried food such as infant formulas, soups and cereals, implies to maintain a certain relative humidity, freshness, and gases mixtures within the packaging. Shelf-life extension and preservation of packed food is possible by selecting the appropriate packaging material. The aim of the study was to investigate the influence of different polymeric films on the simplicity of processing, packaging, and product shelf-life. Products have been packed in normal atmosphere conditions and in the modified atmosphere (N2 97-100%). For this purpose, different polymers, such as PET, PP, Al and PE can be used. Film thickness, oxygen transmission rate (OTR) and water vapour transmission rate (WVTR), were determined. A schematic overview and comparison of two materials, mostly used in dried food industry, are presented. As the polarity of a polymer influences its resistance to gases and water vapour permeation, the most convenient materials to use are non-polar polymers such as PE and PP. Therefore, dry food is packed in the laminates in which each layer provides additional barrier properties. Metalized films provide high barrier, designed to be used in lamination for the packaging of product requiring excellent oxygen and moisture barrier. In practice, PPmet is more acceptable than aluminium foil. PPmet in this investigation was laminated in PET/PPmet/PE and PPmet/PE and aluminium was laminated in PET/Al/PE. OTR (1.5 – 22.6 cm3m-2day-1bar-1 and 0.3 – 1.7 cm3m-2day-1bar-1 for PETmet/PE and PPmet/PE, respectively) and WVTR values (0.9 – 3.3 gm-2day-1 and 0.3 – 0.9 gm-2day-1bar-1 for PETmet/PE and PPmet/PE, respectively) have been analyzed at 23oC. PP provides excellent mechanical properties, water vapour barrier, and when metalized, it provides great barrier towards oxygen, aroma and odour protection as well as easy convertibility on both sides, during processing.

dehydrated food; laminates; packaging; polymer; shelf-life

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