The physical, microstructural, chemical and sensorial properties of spray dried full-fat white cheese powders stored in different multilayer packages

The spray-dried white cheese powder from full-fat ripened cheese was packaged in three different multilayer plastic materials such as polyethylene terephthalate/aluminum foil/low density polyethylene (PET/Al-foil/LDPE), polyethylene terephthalate/aluminum metalized polyethylene terephthalate/low density polyethylene (PET/Met-PET/LDPE) and oriented polypropylene (OPP). The density, reconstitution, microstructure, color, oxidation, non-enzymatic browning and sensory properties of powders were investigated for 12 months. There were found significant differences for almost all parameters of powders packaged in different materials. The changes in properties were negligible for samples packaged in PET/Al-foil/LDPE and acceptable in PET/Met-PET/LDPE during storage. The most evident changes in all properties were observed in powders packaged in OPP becoming easily wetted and having the highest moisture content, water activity value, oxidation and browning values with a slight oxidized flavor and slight cream color after 6 months of storage. Some powder particles seemed to merge physically, particularly in samples packaged in OPP in the 12th month of storage according to scanning electron micrographs.