Storage stability of packaged baby formula in poly(lactide)-whey protein isolate laminated pouch

The use of biodegradable polymeric materials has been proposed as an environmentally-friendly alternative to petroleum-based packaging. To extend the shelf life of food products, these bioplastics must possess appropriate barrier properties and food-package stability. In the present study, shelf life analysis of packaged baby formula in biopolymeric, multilayer film, fabricated from poly(lactide) (PLA) and whey protein isolate (WPI), PLA/WPI/PLA and PLA pouches was performed at 4-35 ^o C and 50-59% relative humidity.

Despite the possible sorption of food components into contact PLA surfaces, the results demonstated that the transparency and barrier properties of PLA-based pouches were insignificantly changed over time (P > 0.05), although the films showed a slow rate of color change. The baby formula packaged in PLA/WPI/PLA had a delayed lipid oxidation compared to the sample in the PLA pouch, especially at a higher temperature. The application of WPI in the multilayer structure shifted the shelf life determination factor from lipid oxidation to moisture gain.

The results indicate that the PLA/WPI/PLA pouch has good storage stability. The film could be used to package dry food properly at 4-35 ^o C and 50-59% relative humidity for an extended period of time. © 2016 Society of Chemical Industry.