Mechanical, Barrier and Structural Properties of Whey Protein Isolate-Based Films Treated by Microbial Transglutaminase

Abstract

Nowadays, polymers obtained from edible resources such as polysaccharides and proteins have attained growing consideration to substitute petroleum-derived polymers. Edible films are a good alternative for the plastic packaging since these films are biodegradable, environmental-friendly and non-toxic. However, protein based edible films have poor water permeability and lower mechanical strength. In this study, edible films based on whey protein isolate (WPI) were produced with different microbial transglutaminase (MTG) concentrations (0, 5, 10 and 15 Unit/g of protein) and the effect of enzymatic treatment on the film properties was investigated. Results showed that as compared to control, the treatment with the lower concentration of MTG (5–10 U/g) significantly increased the tensile strength (TS) and decreased elongation at rapture (ER) values of WPI-films, while at the higher concentration of MTG (15 U/g), TS value slightly decreased and ER values significantly increased. By increasing the enzyme concentration from 5 to 10 U/g, water vapor transferability (WVT) and water soluble fractions (WSF) decreased significantly (P≤0.05). The MTG-treated films except the film treated with 15 U/g TG, had homogeneous and even surface without any crack or fracture. Based on results, treatment with MTG enzyme may be applied as an appropriate technique to modify the structural and barrier properties of WPI-based films.

Microbial Transglutaminase as a Tool to Improve the Features of Hydrocolloid-Based Bioplastics

“…The properties of films were unaffected except their color [29] Whey protein concentrate/nanocrystalline cellulose Mechanical properties enhancement [30] Whey protein isolate Improved mechanical properties, gas permeability, and morphology properties [31] Quinoa protein/chitosan Enhanced thermal stability and tensile strength. Elongation at break reduction [32] Nigella sativa seed proteins Improved mechanical and barrier properties Table 1.…”

“…Bitter vetch proteins/mesoporous silica nanocomposite Decrease in mechanical properties and decrease in gas permeability [24] Grass pea protein Films more resistant and digested to a less extent under gastrointestinal physiological conditions [25] Coconut protein/guar gum Enhancement of physico-chemical properties, such as mechanical, barrier properties and thermal features [26] Two quinoa varieties/chitosan Enhancement of edible film physical properties [27] Collagen fiber/casein, keratin or SPI Improved structure stability and packaging characters [28] Whey protein/heat ultrasounds The properties of films were unaffected except their color [29] Whey protein concentrate/nanocrystalline cellulose Mechanical properties enhancement [30] Whey protein isolate Improved mechanical properties, gas permeability, and morphology properties [31] Quinoa protein/chitosan Enhanced thermal stability and tensile strength. Elongation at break reduction [32] Nigella sativa seed proteins Improved mechanical and barrier properties [33] Proteins from anchovy by-products Improved mechanical, barrier, and surface properties [34] 3.…”

Synergistic Behavior of Plant Proteins and Biobased Latexes in Bioplastic Food Packaging Materials: Experimental and Machine Learning Study

“…Unmodified protein-based plastics, however, lack the mechanical properties and moisture resistance necessary for effective application in food packaging. It has been well observed that protein-based films are inherently brittle and exhibit poor barrier properties. − …”

Computational Protein–Ligand Docking and Experimental Study of Bioplastic Films from Soybean Protein, Zein, and Natural Modifiers

“…Specifically, vegetable proteins are getting more attention in the development of biomaterials applicable to food packaging. ,, Due to the excellent biodegradability, abundance, lower cost, and inherent physicochemical characteristics determined by types of amino acids presented in the structure, soy protein biopolymers have already received much attention and demonstrated the potential for manufacturing of renewable plastics. , Soy protein possesses good film-forming capacity with great biocompatibility and offers better characteristics in terms of barrier properties against oxygen and aroma at low or intermediate relative humidity. However, the main disadvantages of soy protein-based films that need to be overcome are their high sensitivity to humidity and brittleness (lack of elasticity and, respectively, toughness). , Zein proteins, the main residue from the production of corn starch, are also shown to have promising physicochemical properties for the formation of films with good moisture and oxygen barrier performance, high glossiness, and strength .…”

“…Specifically, vegetable proteins are getting more attention in the development of biomaterials applicable to food packaging. 6,12,13 Due to the excellent biodegradability, abundance, lower cost, and inherent physicochemical characteristics determined by types of amino acids presented in the structure, soy protein biopolymers have already received much attention and demonstrated the potential for manufacturing of renewable plastics. 6,14 Soy protein possesses good film-forming capacity with great biocompatibility and offers better characteristics in terms of barrier properties against oxygen and aroma at low or intermediate relative humidity.…”