Improvement of Food Packaging-Related Properties of Whey Protein Isolate-Based Nanocomposite Films and Coatings by Addition of Montmorillonite Nanoplatelets

Abstract

In this study, the effects of the addition of montmorillonite (MMT) nanoplatelets on whey protein isolate (WPI)-based nanocomposite films and coatings were investigated. The main objective was the development of WPI-based MMT nanocomposites with enhanced barrier and mechanical properties. WPI-based nanocomposite cast films and coatings were prepared by dispersing 0% (reference sample), 3, 6, 9% (w/w protein) MMT, or, depending on the protein concentration, also 12 and 15% (w/w protein) MMT into native WPI-based dispersions, followed by subsequent denaturation during the drying and curing process. The natural MMT nanofillers could be randomly dispersed into film-forming WPI-based nanodispersions, displaying good compatibility with the hydrophilic biopolymer matrix. As a result, by addition of 15% (w/w protein) MMT into 10% (w/w dispersion) WPI-based cast films or coatings, the oxygen permeability (OP) was reduced by 91% for glycerol-plasticized and 84% for sorbitol-plasticized coatings, water vapor transmission rate was reduced by 58% for sorbitol-plasticized cast films. Due to the addition of MMT nanofillers, the Young's modulus and tensile strength improved by 315 and 129%, respectively, whereas elongation at break declined by 77% for glycerol-plasticized cast films. In addition, comparison of plasticizer type revealed that sorbitol-plasticized cast films were generally stiffer and stronger, but less flexible compared glycerol-plasticized cast films. Viscosity measurements demonstrated good processability and suitability for up-scaled industrial processes of native WPI-based nanocomposite dispersions, even at high-nanofiller loadings. These results suggest that the addition of natural MMT nanofillers into native WPI-based matrices to form nanocomposite films and coatings holds great potential to replace well-established, fossil-based packaging materials for at least certain applications such as oxygen barriers as part of multilayer flexible packaging films.

Hybrid Bionanocomposites from Spent Hen Proteins

“…The nanoclay particles act as physical barriers against the movement of water molecules, that is, WVP is decreased by the tortuous path created by the nanoclay particle for diffusion of water molecules. 64,65 The results are well supported by the TEM analysis.…”

Dispersion and Performance of a Nanoclay/Whey Protein Isolate Coating upon its Upscaling as a Novel Ready-to-Use Formulation for Packaging Converters

“…WPI was obtained from Agropur Ingredients (Saint-Hubert, Laval, QC, Canada; previously Davisco Food International Inc.). Aqueous nanoclay dispersions were provided by ITENE, Valencia, Spain, as described in our previously published results [34]. The plasticising agent, as selected in a prior published study that focused on formulation optimization [34], was purchased from Panreac S.A., Barcelona, Spain to be used as a plasticiser for the WPI-based film-forming formulations.…”

“…Aqueous nanoclay dispersions were provided by ITENE, Valencia, Spain, as described in our previously published results [34]. The plasticising agent, as selected in a prior published study that focused on formulation optimization [34], was purchased from Panreac S.A., Barcelona, Spain to be used as a plasticiser for the WPI-based film-forming formulations. As a substrate for the coatings, chemically pre-treated poly (ethylene terephthalate) (PET) with thicknesses of 23 and 100 µm, respectively (PLASTIKA-ANDREJ MESOJEDEC S.P., Polje, Slovenia), were respectively used for the application of coating formulations using a pilot-scale and a semi-industrial-scale processing environment.…”

“…True nanocomposites with enhanced properties comprise an intercalated or exfoliated structure, in contrast to phase-separated micro composites, which do not achieve enhanced barrier properties [31,32]. Previously published studies have compared different coating formulations and been dedicated to selecting a suitable plasticiser and nanoparticle type and concentration necessary to obtain optimized oxygen barrier performance with an emphasis on the processability of the nano-enhanced formulations [33,34].…”

Cheese Whey Processing: Integrated Biorefinery Concepts and Emerging Food Applications

“…Likewise, the use of edible-coated nanosystems has also been considered as a novel approach for food preservation. Findings have lately suggested that novel WPI-based nanocomposites can be part of multilayer flexible packaging films, thus holding great potential to even replace well-established fossil-based packaging materials to support certain mechanical properties during storage [151,153,155,163]. Alternative biomaterials, have also been recently proposed for potential uses in foodstuff applications, via the production of nanocomposites from WPCs activated with lycopene and montmorillonite nanoparticles [164,168].…”