The coexistence of carboxymethylcellulose and transglutaminase modified the physicochemical properties and structure of whey protein concentrate films

Abstract

Summary Whey protein concentrate (WPC) and carboxymethyl cellulose (CMC) were abundant in nature and biodegradable raw materials, which have a wide range of prospects for developing bioactive food packaging. In order to exploit the complementary functional properties, in this study CMC was incorporated into WPC films and modified by transglutaminase (TG). The physicochemical properties and structure characteristics of the composite films were investigated. Results showed that CMC as a filler of the protein network significantly improved the properties of WPC films, while TG contributed to the mechanical properties. The composite (1:1) film containing 10 U/gprotein of TG possessed a maximum tensile strength of 13.34 MPa compared to the WPC film. The addition of CMC and TG effectively improved the structure of the film, reducing the pore diameterr, so the composite film with TG at 10 U/gprotein showing a dense structure, with improved light transmission (37.42%) and water vapour transmission (5.06). FT‐IR and SEM results reflected that TG induced covalent cross‐linking between proteins and WPC and CMC had good compatibility. These suggest that the coexistence of CMC and TG has positive effect on the formation of composite films prepared by TG cross‐linking WPC and CMC blends, which provided a promising alternative method for the development of good edible films or coatings for food packaging in the future.

Protein-Based Films and Coatings: An Innovative Approach

“…Thin layers of edible or nonedible proteins can be used as protein-based films or coatings on food or other surfaces. There may be certain drawbacks of biodegradable materials (coating/films), such as the low mechanical strength and water barrier qualities [76,77]. The qualities of coatings/films based on proteins can be enhanced using a variety of formation techniques, as shown in Figure 1 and Table 3.…”

“…Enzymatic cross-linking techniques are one efficient way to enhance the mechanical strength and barrier characteristics of protein-based edible films. Enzymes, such as lipoxygenase, lysyl oxidase, polyphenol oxidase, transglutaminase, and peroxidase, have been employed to cross-link proteins [76]. However, a specific enzyme capable of catalyzing covalent crosslinking processes between proteins, resulting in the formation of high-molecular-weight (MW) biopolymers, is known as transglutaminase.…”