Modification of Functional Properties of Whey Protein Isolate Nanocomposite Films and Coatings with Nanoclays

Whey protein based films have received considerable attention to be used for environment friendly packaging applications. However, such biopolymers are prevented for use in commercial packaging due to their limited mechanical and barrier performance. The addition of nanofillers is a common method to overcome those drawbacks of biopolymers. Whey protein isolate (WPI) based nanocomposite cast films and coatings were produced using montmorillonite and vermiculite clay as nanofiller in different concentrations. Uniform distribution of filler within the polymeric matrix was confirmed by scanning electron microscopy. Mechanical properties such as tensile strength as well as Young’s modulus were increased after increasing the filler content, while elongation at break values decreased. All samples showed weak barrier potential against water vapor. Nanoclay incorporation, however, reduced water vapor transmission rates by approximately 50%. The oxygen barrier performance was improved for all nanocomposites. Results also indicated proportionality with the filler ratio according to applied models. The highest barrier improvement factors (BIF) were greater than five for the cast films and even greater than sixteen for the coatings. Developed WPI-based composites depicted nanoenhanced material properties representing a promising alternative to fossil-based packaging films.

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

Polymers ◽

10.3390/polym11091410 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1410 ◽

Cited By ~ 1

Author(s):

Elodie Bugnicourt ◽

Nicola Brzoska ◽

Esra Kucukpinar ◽

Severine Philippe ◽

Enrico Forlin ◽

...

Keyword(s):

Electron Microscopy ◽

Solid State ◽

Whey Protein ◽

Oxygen Permeability ◽

Whey Protein Isolate ◽

Protein Isolate ◽

Morphological Properties ◽

Industrial Scale ◽

Barrier Performance ◽

Coating Formulations

Studies on composition optimisation showed that the mixing of nanoclays to whey protein-isolate (WPI)-based coating formulations offers an effective strategy to reduce the oxygen permeability of coated polymer films. The scaling up of the various processing stages of these formulations was undertaken to prove their industrial feasibility. The aim was to investigate the effect of various preparation methods at different production scales (pilot- and semi-industrial scale) on the barrier performance and morphological properties of the applied nanocomposites. A nano-enhanced composition was converted into a so-called “ready-to-use” formulation by means of a solid-state pre-dispersion process using ball-milling. The process yielded a nearly dust-free, free-flowing powder containing agglomerated particles, which can easily be mixed with water. The preparation of a coating formulation using the ready-to-use granules and its upscaling for roll-to-roll converting at pilot- and semi-industrial scale was also successfully implemented. The effects of both the production at various scales and ultrasound treatment on the morphology and barrier performance of the nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, as well as oxygen permeability measurements. Results have shown that the addition of nanoclays to WPI-based coating formulations ultimately led to significantly reduced oxygen permeabilities to 0.59 cm3, 100 µm·m−2·d−1·bar−1 (barrier improvement factor, BIF of 5.4) and 0.62 cm3, 100 µm·m−2·d−1·bar−1 (BIF of 5.1) in cases of pilot- and semi-industrial-processed coatings, respectively, compared to a reference without nanoclay. In both cases, a similar degree of nanoparticle orientation was achieved. It was concluded that the solid state pre-dispersion of the nanoplatelets during the production of the ready-to-use formulation is the predominant process determining the ultimate degree of nanoparticle orientation and dispersion state.

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Properties of Cast Films Made from Different Ratios of Whey Protein Isolate, Hydrolysed Whey Protein Isolate and Glycerol

Materials ◽

10.3390/ma6083254 ◽

2013 ◽

Vol 6 (8) ◽

pp. 3254-3269 ◽

Cited By ~ 47

Author(s):

Markus Schmid

Keyword(s):

Whey Protein ◽

Whey Protein Isolate ◽

Protein Isolate ◽

Cast Films

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Mechanical Properties and Water Vapor Permeability of Edible Films from Whey Protein Isolate and Sodium Dodecyl Sulfate

Journal of Agricultural and Food Chemistry ◽

10.1021/jf9505234 ◽

1996 ◽

Vol 44 (2) ◽

pp. 438-443 ◽

Cited By ~ 72

Author(s):

Peter Fairley ◽

Frank J. Monahan ◽

J. Bruce German ◽

John M. Krochta

Keyword(s):

Mechanical Properties ◽

Water Vapor ◽

Sodium Dodecyl Sulfate ◽

Whey Protein ◽

Sodium Dodecyl ◽

Water Vapor Permeability ◽

Whey Protein Isolate ◽

Edible Films ◽

Protein Isolate ◽

Vapor Permeability

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Mechanical and Barrier Properties of Potato Protein Isolate-Based Films

Coatings ◽

10.3390/coatings8020058 ◽

2018 ◽

Vol 8 (2) ◽

pp. 58 ◽

Cited By ~ 1

Author(s):

David Schäfer ◽

Matthias Reinelt ◽

Andreas Stäbler ◽

Markus Schmid

Keyword(s):

Whey Protein ◽

Functional Properties ◽

Barrier Properties ◽

Whey Protein Isolate ◽

Protein Isolate ◽

Cross Linking ◽

Potato Protein ◽

Water Sorption Isotherm ◽

Barrier Performance ◽

Cross Links

Potato protein isolate (PPI) was studied as a source for bio-based polymer films. The objective of this study was the determination of the packaging-relevant properties, including the mechanical properties and barrier performance, of casted potato protein films. Furthermore, the films were analyzed for cross-linking properties depending on the plasticizer concentration, and compared with whey protein isolate (WPI)-based films. Swelling tests and water sorption isotherm measurements were performed to determine the degree of swelling, the degree of cross-linking, and the cross-linking density using the Flory–Rehner approach. The effects of different plasticizer types and contents on compatibility with potato protein were studied. Glycerol was the most compatible plasticizer, as it was the only plasticizer providing flexible standalone films in the investigated concentration range after three weeks of storage. Results indicated that increasing glycerol content led to decreasing cross-linking, which correlated in an inversely proportional manner to the swelling behavior. A correlation between cross-linking and functional properties was also reflected in mechanical and barrier characterization. An increasing number of cross-links resulted in higher tensile strength and Young’s modulus, whereas elongation was unexpectedly not affected. Similarly, barrier performance was significantly improved with increasing cross-linking. The overall superior functional properties of whey protein-based films were mainly ascribed to their higher percentage of cross-links. This was primarily attributed to a lower total cysteine content of PPI (1.6 g/16 g·N) compared to WPI (2.8 g/16 g·N), and the significant lower solubility of potato protein isolate in water at pH 7.0 (48.1%), which was half that of whey protein isolate (96%). Comparing on an identical glycerol level (66.7% (w/w protein)), the performance of potato protein isolate was about 80% that of whey protein isolate regarding cross-linking, as well as mechanical and barrier properties.

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