FOOD MATERIAL FILM MATERIAL BASED ON CHITOSAN AND METHOD FOR PRODUCTION THEREOF Russian patent published in 2019 - IPC C08L5/00 C08L5/08 C08B37/08 C08J5/18 

FIELD: chemistry; biology; medicine.

SUBSTANCE: invention relates to chemical and biochemical technology, more specifically to food-grade film materials based on chitosan and methods for their preparation. Food material film based on chitosan can be used primarily in the food industry and agriculture, as well as in medicine, pharmacology, and cosmetology. Method of obtaining food film material on the basis of chitosan, which has biocompatibility, non-toxicity, biodegradability, moisture resistance, water insolubility, sufficient strength, expanded and increased antibacterial and antifungal activity, includes the dissolution of chitosan in organic acid, which is used as 2–4 % acetic acid, with a ratio of components chitosan:acetic acid 1:1–1:2 wt. %, to obtain a solution, the introduction of antibacterial and antifungal additives into the chitosan solution in the form of a nanocluster silver preparation, intensive mechanical mixing of the mixture obtained, applying the obtained molding mixture on a substrate with its subsequent keeping on the substrate until it reaches the film structure, processing the obtained film with a neutralizing reagent followed by washing the film with distilled water and drying. Chitosan is dissolved in 2–4 % acetic acid at a ratio of chitosan:acetic acid components of 1:1–1:2 wt. % to form a solution. Highly purified chitosan with a molecular weight of 300–450 kDa and a degree of deacetylation of 80 mol. % or more is used. Additionally, an antimicrobial additive in the form of nanocluster silver from the Argovit drug in an amount of 40–100 mcg/ml of solution is added to the chitosan solution. Mixture of dissolved chitosan and antimicrobial additive is subjected to intensive mechanical stirring at a temperature of 22 ± 2 °C for 10–20 minutes and get a molding solution. To obtain a film material with a thickness of 50–150 mcm, the molding solution is applied on the substrate in the amount of 0.08–0.20 ml/cm². To achieve a film structure, the molding solution deposited on the substrate is maintained at a temperature of 50 °C for 12 hours. Then, the resulting film with the substrate is treated with a solution of 1M NaOH for 2 hours, followed by washing with distilled water to pH ≥ 8 for converting chitosan in a film material to a water-insoluble basic form. Neutralized and washed film material is separated from the substrate and dried on a non-shrinkable contour-stand or at a temperature of 20 °C for 72 hours, or at 50 °C within 24 hours.

EFFECT: invention makes it possible to obtain food-grade film material based on chitosan, which has moisture resistance and insolubility in water, an antimicrobial effect against pathogenic bacteria and fungi, and a breaking stress at break of at least 40 MPa.

11 cl, 6 tbl