Effect of plasticizers on the qualitative indicators of film­forming coatings for the protection of chilled meat

The result of theoretical research into protection and prolonging the duration of meat and meat products storage has demonstrated that one of the promising directions is the application of protective coatings based on natural biopolymers. We used hydrocolloids as basic components of film-forming protective coatings. The study into mechanical and rheological properties of protective coatings was conducted; a comparative characteristic of these properties, which depend on the added plasticizer, is given. Film-forming coatings must possess high indicators of strength, elasticity, transparency, barrier properties, capability to sorb gases, water vapor. The film is to prevent undesirable effects for meat, to improve shelf life of the product without compromising quality indicators. Adding plasticizers to the composition of film-forming coatings will make it possible to control quality indicators of coatings. We have analyzed and theoretically substantiated the character and mechanisms of interaction between components of a film-forming coating and plasticizers. The viscosity of the film-forming coating without adding a plasticizer has the largest value compared to other solutions. The addition of plasticizers led to an increase in the elasticity of the film; we, however, observed a slight increase in strength. Film-forming coatings with the addition of a plasticizer had a higher yield limit and thus they were stronger than the integrated film-forming coatings without the addition of a plasticizer. On the other hand, the values of deformation of the film-forming coatings without the addition of a plasticizer were higher than those of the integrated film-forming coatings with the addition of a plasticizer, so they were more elastic. Studying the physical properties of the developed film-forming coatings based on hydrocolloids revealed that coatings with a plasticizer possess a larger vapor permeability. We have analyzed and theoretically substantiated the character and mechanisms of interaction between components of a film-forming coating and plasticizers. Based on results obtained in the course of experiments, it was established that the best mechanical, rheological, and physical indicators are demonstrated by the film-forming coating based on sodium alginate, carboxymethyl cellulose, and glycerin.