Antioxidant Properties of Aqueous Ural Licorice (Glycyrrhiza Uralensis), Common Licorice (Glycyrrhiza Glabra L.) Extracts and Silver Nanoparticles Synthesized on Its Basis

The packaging materials development, that ensure high quality of food products and its protection from pollutants and microbial pathogens, prolong the shelf life of food products and improve mechanical and barrier properties, is an important and urgent task. As one of the approaches to solve this problem man considers the introduction of various additives and nanoscale fillers with antioxidant and antimicrobial properties into the polymer films composition. Promising additives are licorice root extract and silver nanoparticles synthesized using licorice extract in the research. The extraction method impacts on the antioxidant extract properties and its reducing ability in the nanoparticle synthesis. The research aims at studying the extraction method and duration impact on the antioxidant properties of licorice extracts and evaluating the antioxidant activity of silver nanoparticles synthesized using licorice extracts. Using the potentiometric method, a man found that an extraction by the maceration increased the antioxidant activity of Ural licorice and common licorice extracts by 8 and 15 %, respectively, compared with ultrasonic treatment for 30 minutes, however, maceration required significantly more time. The absorption band presence of the surface plasmon resonance in the wavelength range of 420–430 nm in the UV spectra confirms the silver nanoparticles formation occurring in licorice extracts for 20 days at room temperature. The antioxidant activity of silver nanoparticles is almost 7–9 times higher than the antioxidant activity of licorice extracts used for synthesis. With greater antioxidant activity of the plant extract, a man is able to obtain silver sols with higher antioxidant properties. The research results enable to recommend licorice root extracts and silver nanoparticles synthesized with its help as additives to biopolymer packaging matrices to improve the oxidative stability.