Incorporation of Lipids into Wheat Bran Cellulose/Wheat Gluten Composite Film Improves Its Water Resistance Properties.

Guanghui Shen,Xiaoyan Hou,Anjun Chen,Xingyan Liu,Guoxian Yu,Qingye Li,Man Zhou,Shanshan Li,Hejun Wu,Zhiqing Zhang,Meiliang Li

doi:10.3390/membranes12010018

Abstract

This work evaluated the improvement effects of lipids incorporation on water resistance of composite biodegradable film prepared with wheat bran cellulose/wheat gluten (WBC/WG) using an alkaline–ethanol film forming system. Four types of lipids, paraffin wax (PW), beeswax (BW), paraffin oil (PO), and oleic acid (OA), were tested. We found that PW, BW, and PO incorporation at 5–20% improved water vapor permeability (WVP) and surface hydrophobicity of prepared films. Particularly, incorporation of 15% BW could best improve the water resistance properties of the film, with the lowest WVP of 0.76 × 10−12 g/cm·s·Pa and largest water contact angle (WCA) of 86.18°. Incorporation of OA led to the decline in moisture barrier properties. SEM images revealed that different lipids incorporation changed the morphology and of the composite film, and cross-sectional morphology indicated BW-incorporated film obtained more uniform and compact structures compared to other films. Moreover, Fourier transform infrared spectra indicated that the incorporation of PW or BW enhanced the molecular interactions between the film components, confirmed by the chemical shift of characteristic peaks at 3277 and 1026 cm−1. Differential scanning calorimetry results revealed that incorporation of PW, BW, and PO increased films’ melting point, decomposition temperatures, and enthalpy values. Furthermore, the presence of most lipids decreased tensile strength and elongation at the break of the film. Overall, the composite film containing 15% BW obtained the most promising water resistance performance and acceptable mechanical properties, and it thus most suitable as a hydrophobic biodegradable material for food packaging.

Highlights

Introduction published maps and institutional affilFood packaging is essential for protecting the quality and safety of food products during their storage and distribution
In view of the good film forming and oxygen barrier properties of Wheat gluten (WG) and the excellent mechanical reinforcing effect of wheat bran cellulose (WBC), we developed an alkaline-ethanol film forming system to improve the compatibility of WBC with WG protein, in which we found that the addition of 40%
Wheat bran was purchased from a local market (Ya’an, Sichuan, China)

Summary

Introduction

Introduction published maps and institutional affilFood packaging is essential for protecting the quality and safety of food products during their storage and distribution. Plastic films are widely used as food packaging materials due to their properties including light weight and water resistance, as well as their low cost. Most of these plastic films are hardly degradable, and can cause serious environmental pollution. Natural polymers, including polysaccharides and proteins, are the best candidates for producing food packaging materials. Can these polymers be extracted from agricultural by-products, but they have many advantages, one of which is their degradability in the environment [3]. Wheat gluten (WG) is a by-product from wheat starch iations

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