Study of the properties of food films based on agar with the addition of functional components

Abstract. In conditions of increasing environmental load from accumulated synthetic packaging materials in environmental objects, there is a need to develop new compositions of biodegradable films that additionally have functional properties to increase the shelf life of products. The scientific novelty of the research lies in the production of new types of biodegradable active films with the addition of protein hydrolyzate as an active component, as well as data on their properties. The purpose of the study is to establish the properties of biodegradable films based on agar with the addition of a suspension of protein hydrolyzate and CMC as active components. Research methods. The control (composed of agar and glycerin) and test samples of films (composed of agar, glycerin and a suspension of MCC and protein hydrolyzate in an amount of 5, 10 and 15 % by weight of the biocomposite) were determined for mechanical properties, microstructure, antioxidant properties, vapor permeability, solubility, and moisture absorption. Results. The introduction of a suspension into the composition of the biocomposite had a negative effect on the mechanical strength of the film – the tensile strength decreased from 9,71 MPa for the control sample to 3,35 MPa for the test sample with 15 % suspension, while the relative elongation was maximum for the sample with 10 % suspension – 54,9 %. The antioxidant properties of the films increased with the addition of the suspension: the antiradical activity of DPPH increased from 57.65 % in the control sample to 63.81 % in the test sample with 15 % suspension, and the phenol content – from 0.253 in the control sample to 0.502 mEq of gallic acid per 1 g for a prototype with 10% suspension. It was noted that the addition of the suspension had a significant effect on vapor permeability and moisture absorption. Thus, the results obtained showed the need for further research into the storage capacity of food products with different humidity levels when packaged in tested films.