Preparation and characterization of whey protein isolate/polydextrose-based nanocomposite film incorporated with cellulose nanofiber and L. plantarum: A new probiotic active packaging system

There is growing interest in bioactive packaging systems due to their potential for extending the shelf life of food products. In this regard, the aim of this study was to prepare cellulose nanofiber (CNF) and polydextrose incorporated whey protein isolate (WPI) based probiotic nanocomposite film containing Lactobacillus plantarum. The prepared film samples were characterized by FT-IR, FE-SEM, DSC and XRD analyses. The results revealed good compatibility between WPI matrix, CNF and polydextrose, such that CNF and polydextrose had no adverse effect on the morphological and thermal properties and the crystallinity of WPI-based probiotic films. Furthermore, the CNF and polydextrose incorporated WPI-based films exhibited low water vapor permeability and good mechanical properties. The viability of probiotic bacteria was significantly (p < 0.05) enhanced following the incorporation of CNF and polydextrose during the storage time. Moreover, the probiotic film containing 5 g/100 g CNF and 20 g/100 g polydextrose exhibited inhibition zones against P. aeruginosa (14.6 +/- 0.5 mm), S. aureus (14.0 +/- 1.0 mm), and E. coli (12.6 +/- 0.5 mm) bacteria. In conclusion, the CNF and polydextrose incorporated WPI-based probiotic nanocomposite film can be applied in bioactive food packaging system owing to its unique features.