[Nanocellulose in the food industry and medicine: structure, production and application].

Cellulose is the most abundant polymer in the biosphere and has many technical applications, including food production. The development of cellulose technology in the 21st century has led to the emergence of nanocellulose (NC), which has widely varying chemical and physical properties and, therefore, has fundamentally new areas of application in biomedicine and the food industry. The aim of this work is to review the literature on the structure, sources, methods for obtaining nanocelluloses, including methods for their chemical modification, current and prospective applications in the food industry, packaging materials, biomedicine, etc. Material and methods . For the analysis, sources were selected mainly for the period from 2014 to 2022, contained in the international databases PubMed, WoS and Scopus and meeting the requirements of scientific reliability and completeness. Results . Among the main types of NC there can be identified nanofibrous cellulose (NFC), consisting of fibers longer than 500 nm and about 10-20 nm thick, and nanocrystalline cellulose (NCC) with particles 100-500 nm long and less than 100 nm in diameter. A special group of materials includes bacterial NC (BNC) produced by microorganisms and representing entangled coils or layers of cellulose fibers with a thickness of less than 100 nm. Significant changes in the physical, chemical and functional properties of NC can be achieved by its physical and chemical modification, which leads to a change in swelling, an increase in the mechanical strength and stability of hydrogels, and compatibility with synthetic polymers. NFC, NCC and BNC are offered as food ingredients for inclusion both in mass consumption products and in specialized foods for dietary and therapeutic uses, as well as in the so-called «functional products», for which manufacturers declare the ability to influence actively on the state of intestinal microflora and digestive function. In biomedical applications, of great interest is the biocompatibility of BNC with various cell types in combination with biodegradability, which makes it possible to create new types of materials for reconstructive surgery, effective and safe dressings. When used as packaging materials, NC products successfully compete with synthetic polymers without causing long-term environmental pollution. Factors hindering the introduction of NC products into practice are the gaps of knowledge of NC biological action, combined with the risks caused by possible residual amounts of chemicals and biochemical reagents, bacterial toxins, enzyme preparations and microorganisms-producers in the composition of NC. Conclusion . There is an important task to develop a system for regulating NCs and products with its content, in accordance with the technical regulations of the Customs Union of the EAEU.