Architectonics of gelatin/biopolymer/transglutaminase for packaging films: a review

Environmental pollution related to plastic packaging waste poses health risks. An approach to solve this problem is the use of biopolymers as the main components of flexible packaging. Among them, gelatin stands out as non-toxicity, biocompatible material. However, pure gelatin films are highly soluble, which prevents them from being used as a packaging material. Combining gelatin with others biopolymers and the addition of excipients such as plasticizers, cross-linking agents, antioxidants, antimicrobial components produces films with improved strength, barrier and special properties. Cross-linking is a commonly used strategy that allows one to directly change the nature of binding between molecules. Among cross-linking agents, transglutaminase is often used as an inexpensive, environmentally friendly component. The key point of this review is to focus on the main properties such as strength, vapor water permeability and solubility of the different films based on gelatin/biopolymer (chitosan, starch, zein, soy protein, collagen, casein) cross-linked with transglutaminase. Since these properties are directly related to the preservation and maintenance of food quality. Recent studies have shown that the addition of transglutaminase can both increase and decrease tensile strength values depending on several factors, such as its concentration, pH, temperature, reaction time, and the order of transglutaminase addition to the reaction mixture. Gelatin films modified with transglutaminase have a more compact surface microstructure, which leads to improved barrier properties. Transglutaminase has been reported to significantly improve water resistant properties. The introduction of active components into gelatin-based film compositions modified with transglutaminase is a promising direction for further development of packaging, and therefore the review includes works on this topic.