Mechanical Properties of Thermo-moulded Biofilms in Relation to Proteins/Starch Interactions

Abstract

The effects of hydrophilic and hydrophobic characteristics of proteins on the interactions with corn starch were investigated in this study. The model system included corn starch and proteins, i.e. zein, gliadin, gluten, soy protein and rapeseed protein. The blend films were prepared by thermomoulding in gentle conditions at 70°C in order to avoid starch gelatinization, with respect to water content, and avoid protein denaturation. The effects of different kinds of proteins on structure and mechanical behaviour of blend biomaterials were characterised by scanning electron microscopy (SEM) and tensile test, respectively. The effects of different kinds of proteins on intermolecular interactions between proteins and starch were investigated by dynamical mechanical thermal analysis. Based on the solubility measurement results, almost all protein films showed the similar solubility to the natural protein powders, resulting from the weak influence of mild thermo-moulding treatment on protein inner structure. Different morphologies were observed for different proteins and corresponding blends, which are relatively loose protein architecture that appeared for hydrophobic protein and blend films, and uniform and densely packed architecture for hydrophilic ones. Moreover, different mechanical behaviours were obtained for different proteins and corresponding blends.No significantly increased strength for hydrophilic protein blends with starch added can be explained that there is weak intermolecular interaction between both components based on SEM observation. However, the addition of corn starch granules in hydrophobic protein networks was assumed that starch destroyed or weakened the protein network, resulting in the decrease of mechanical strength.

Impact of extrusion parameters on the properties of rice products: A physicochemical and X-ray tomography study

“…If the adhesion between the two phases is low, i.e. if molecular interactions between starch and proteins are weak (as suggested by Chanvrier, Della Valle, & Lourdin, 2006;Guessasma, Benseddig, & Lourdin, 2010;Zeng et al, 2011), during compression of the product, fractures can be expected to propagate at the phases interface; higher interfacial area would thus give more peaks. This is not observed in this study.…”

UV‐shielding antimicrobial zein films blended with essential oils for active food packaging

“…From the images, it was observed that ZF Figure 7(a) at magnification 10,000× and Figure 7(b) at 1000× magnification has a rough bumpy surface as a result of pure zein and glycerol association which is in agreement with Khalil et al 51 and as per Ming Zeng. 52 With the addition of EO, it leads to the formation of a smoother ZEO surface as in Figure 7(c) at 10,000× and Figure 7(d) at 1000× having homogenous nature 42 due to the interaction between EO and protein fibers. It seemed that acetyl eugenol and cinnamaldehyde contents of EOs have good affinity with zein protein driven by physical interactions and increasing the film networking making it homogenous and smooth 46 …”

Incorporation of Rice Starch Affecting on Morphology, Mechanical Properties and Water Vapor Permeability of Glutelin-based Composite Films

“…); soy protein/starch (Zeng et al . ); soy protein isolate (SPI)/carboxylmethyl cellulose (Su et al . ); SPI/propyleneglycol alginate (PGA) (Shih ); SPI/PGA (Rhim et al .…”

“…); gliadin/starch (Zeng et al . ). The interaction of proteins and polysaccharides produced better strength and moisture barrier film properties (Shih ).…”

“…There are many reports on composite films made by mixing protein with polysacchride for example; rice protein concentrate/pullulan (Shih 1996); whey protein isolate (WPI)/mesquite gum (Oses et al 2009); WPI/pullulan (Gounga et al 2007);casein/starch (Jagannath et al 2003); soy protein/starch (Zeng et al 2011); soy protein isolate (SPI)/carboxylmethyl cellulose (Su et al 2010); SPI/ propyleneglycol alginate (PGA) (Shih 1994); SPI/PGA (Rhim et al 1999); SPI/cellulose (Wu et al 2009); soybean flour protein/pectin (Liu et al 2007); gelatin/starch (Arvanitoyannis et al 1998;Jagannath et al 2003); gelatin/ sago starch (Al-Hassan and Norziah 2012); gelatin/gellan (Lee et al 2004);gelatin/pectin (Liu et al 2007); gelatin/ chitosan (Cheng et al 2003); egg white/dialdehyde starch (Gennadios et al 1998);albumen/starch (Jagannath et al 2003;Wongsasulak et al 2006); zein/starch (Zeng et al 2011); gliadin/starch (Zeng et al 2011). The interaction of proteins and polysaccharides produced better strength and moisture barrier film properties (Shih 1994).…”