Effect of corn‐zein coating on the mechanical properties of polypropylene packaging films

Abstract

In this study, a novel film structure of corn zein coated on polypropylene (PP) synthetic films for food packaging applications was developed, and the mechanical properties of the resulting coated film, as affected by the coating formulation, were investigated. Composite structures of PP films coated with corn zein were obtained through a simple solvent casting method. Different amounts of corn zein (5 and 15%) were dissolved in 70 and 95% aqueous ethanol solution at 50 C. Solutions of corn zein plasticized with poly(ethylene glycol) and glycerol (GLY) at various levels (20 and 50%) were applied on corona-discharge-treated PP. A statistical analysis based on full factorial design was performed to examine the influence of the coating formulation on the final properties of the corn-zein-coated PP films. A significant (p < 0.05) improvement in the coated film's mechanical properties was observed compared to those of the uncoated PP. The effect of the plasticization of the coating solutions was also quite significant. In general, GLY provided better improvements in the mechanical properties of the corn-zein-coated PP films. The statistical analysis of the results showed that the corn-zein and plasticizer concentrations and plasticizer type used in the coating formulations were more effective parameters and had significant effects on the mechanical behavior of the coated PP films. In conclusion, corn-zein coatings could have potential as alternatives to conventional synthetic polymers used in composite multilayer structures for food packaging applications.

Influence of glycerol on the molecular mobility, oxygen permeability and microstructure of amorphous zein films

“…Zein, the prolamine from maize seeds, has been extensively investigated as a commercial material for edible packaging because of its thermoplastic properties and excellent film-forming behavior (Lawton, 2002;Sanchez-Grarcia, Hilliou & Lagaron, 2010;Subramanian & Sampath, 2007;Tihminlioglu, Atik, & € Ozen, 2011). Zein is used in the formulation of coatings for nuts, confectioneries, and pharmaceutical tablets.…”

Antioxidant/Antibacterial Electrospun Nanocoatings Applied onto PLA Films

“…Thus, it is possible to obtain a very thin coating (nanocoating) with a very small quantity of materials, which in many cases is enough to obtain the desired antibacterial and antioxidant [ 4 ] or antifungal activity [ 22 ]. In comparison, with the coating thickness obtained by other methods, such as solvent casting or dip-coating with special film applicators (3 μm [ 23 ], 2 ÷ 9 μm [ 6 ], 2 ÷ 3 μm [ 24 ]), the very thin layer (100 nm or even less) has the added advantage of requiring a low amount of the coating material.…”

Barrier properties of corn zein nanocomposite coated polypropylene films for food packaging applications

“…In addition to use of various plasticizers in order to increase flexibility of films (Gioia and Guilbert, 1999;Lawton, 2004;Hernandez-Izquerdo and Krochta, 2008), many hybrid strategies were developed to put corn zein in use in order to utilize its sustainability and excellent barrier to oxygen. These include lamination of zein with other proteins and lipids (Weller et al, 1998;Cho et al, 2002;Ryu et al, 2002;Ghanbarzadeh and Oromiehi, 2008), blending with synthetic polymers or biopolymers (Herald et al, 2002;Wu et al, 2003;Corradini et al, 2004) and coating polyolefin surfaces with corn zein (Lee et al, 2008;Tihminlioglu et al, 2010Tihminlioglu et al, , 2011. Biopolymer coatings such as corn zein may be beneficial in environmental aspect, since identification and separation of layers for recycling of synthetic films are problematic and multilayer structures used for barrier applications constitute for an important amount of waste (Cutter, 2006;Marsh and Bugusu, 2007).…”