Chitosan-based selenium composites as potent Se supplements: Synthesis, beneficial health effects, and applications in food and agriculture

Selenium is an essential micronutrient that plays a vital role in human health. The global selenium deficiency stimulates the development of novel selenium compounds. However, the limitation of various chemical forms of selenium, such as high toxicity, low bioavailability, and instability, restrict their practical applications. Chitosan is an amino-polysaccharide with a unique chemical structure, desirable biocompatibility, biodegradability, and potent bioactivity, making it an attractive carrier for inorganic, organic, and nano-selenium. This comprehensive review summarizes the recent approaches for the rational design and fabrication of chitosan-based selenium composites, including selenium compounds-loaded chitosan nanoparticles, selenium-containing chitosan derivatives, and chitosan stabilized selenium nanoparticles. The beneficial health effects of chitosan-based selenium composites are highlighted. A special emphasis also has been addressed on their potential applications in food and agriculture. The combination of chitosan and selenium could enhance the gastrointestinal retention time, stability, and bioactivity of selenium. The molecular weight, functional groups, and concentration of chitosan, as well as the preparation condition, are the key factors that influence the physicochemical properties of chitosan-based selenium composites. It also demonstrated the anticancer, anti-diabetic, antibacterial, and hepatoprotective activities of chitosan-based selenium composites and their potential as Se supplements to improve the nutraceutical value of animals and crops for human consumption. • A combination of selenium and chitosan has attracted extensive attention. • Strategies for preparing chitosan-based selenium composites are summarized. • The beneficial health effects of chitosan-based selenium composites are discussed. • The potent applications in food technology and agriculture are emphasized. • Future challenges for chitosan-based selenium composites are proposed.