Effect of replacement of corn starch by whey protein isolate in biodegradable film blends obtained by extrusion

Abstract

The aim of this study was to evaluate the effect of replacing corn starch by whey protein isolated (WPI) in biodegradable polymer blends developed by extrusion. X-ray diffraction showed the presence of a Vh-type crystalline arrangement. The films were homogeneous, indicating strong interfacial adhesion between the protein and the thermoplastic starch matrix (TPS) as observed in scanning electron microscopy. The addition of WPI on TPS matrix promoted an increase in the thermal stability of the materials. It was observed 58.5% decrease in the water vapor permeability. The effect of corn starch substitution by WPI on mechanical properties resulted in a more resistant and less flexible film when compared the TPS film. The addition of WPI caused greenish yellow color and less transparent films. The substitution of corn starch by WPI made it possible to obtain polymer blends with improved properties and represents an innovation for application as a packaging material.

Thermoplastic starch/whey protein isolate/rosemary essential oil nanocomposites obtained by extrusion process: Antioxidant polymers

“…Starch is a biopolymer present in many plants, such as corn, potato, wheat, rice, and others. The chemical and physical properties of this material have been extensively studied due to its ability to be transformed into thermoplastic starch (TPS) materials through processes of extrusion, injection molding, and thermos‐pressing to produce dense or porous materials . However, TPS has reduced mechanical properties and high sensitivity to moisture.…”

Effect of Mussel‐Inspired Poly(Dopamine)‐Functionalized Carbon Nanotubes/Graphene Nanohybrids on Interfacial Adhesion of Soy Protein‐Based Nanocomposites

“…c. All SPI‐based film exhibited two basal reflection diffraction peaks at 2θ = 8.7 and 19.8°, respectively, which were attributed to the α‐helix and β‐sheet structures of the SPI secondary conformation . After incorporating PDCNTs, the characteristic peak (α‐helix) of the SPI/G/PDCNTs film slightly shifted to a higher angle and became weaker, which suggested that the original crystalline structure of the SPI nanocomposite film had partially collapsed during the interaction between the SPI chains and PDA‐coated CNTs .…”

“…After that, there were two main stages of the thermal decomposition of the SPI‐based films. The first stage from 120 to 280°C was mainly attributed to the glycerol degradation . The second stage was from 280 to 450°C, which could be associated with the decomposition of protein backbone .…”

“…This remarkable increase in the WCA value could be explained by the compact structure of the nanocomposite film originated from the hydrogen bonding interactions between the PDCNTs and SPI matrix and the interfacial cross‐linking of PDA in the system . In addition, a certain amount of polar amine acids might be consumed by the surface functionalized PDCNTs and there were less hydrophilic surfaces, therefore the nanocomposite film could effectively prevent the moisture permeation into the SPI matrix .…”

Effect of active films incorporated with montmorillonite clay and α‐tocopherol: Potential of nanoparticle migration and reduction of lipid oxidation in salmon

“…The simple use of packaging reduces the oxygen concentration with the product, aiding in the reduction of oxidation of pigments. 26 Chroma is a measure of colour saturation, 46,47 and it describes the vividness or dullness of a colour, ie, how close the colour is to either grey or the pure hue. 48 A decrease in chroma value was observed for the salmon samples during storage time, indicating a lower colour intensity, ie, an opaque colour.…”