Evaluation of release and antibacterial properties of alginate hydrogel containing beta-cyclodextrin nanoparticles loaded with Thymus daenensis essential oil

Because of antioxidant, antimicrobial, and medical properties, bioactive compounds extracted from plants have grown significantly in the development and trade of functional foods containing food-medicine and dietary supplements.However, the volatility, insolubility in the aqueous matrix, and sensitivity to environmental conditions such as temperature, oxygen, and light limite the use of essential oils. Therefore, this study was conducted to investigate the encapsulation technique as a suitable method to protect the essential oil and increase its efficiency. The main purpose of this study was to produce alginate hydrogels containing Thymus daenensis essential oil (Td-EO) loaded with beta-cyclodextrin. The structural properties and antimicrobial features of alginate hydrogel beads incorporated with Td-EO active ingredients were evaluated. The results of hydrogel analysis showed that the particle size and particle size distribution were less than 180 nm and 0.31, respectively, and the encapsulation efficiency of Td-EO for the hydrogel beads was about 90%. A maximum swelling capacity of ~610.3 % was obtained for alginate beads. FESEM, showed that the particle sizes were in the nanometer range and the particles were homogeneous and spherical shapes. FTIR analysis indicated no significant interaction between essential oil, beta-cyclodextrin and alginate, so alginate hydrogel is a suitable material for encapsulating active compounds. Hydrogels had an inhibitory effect on the growth of two strains of bacteria, S. aureus and E. coli. The release of Td-EO from alginate beads in two short-term and long-term periods were studied. The release rate of bioactive compounds can be reduced by encapsulating in β-cyclodextrin and producing its alginate hydrogel, and thus can be used as a suitable tool to control release in food and pharmaceutical systems.