关键词: 壳聚糖, 六氢β-酸, 可食性抑菌膜, 机械性能, 释放

Abstract: The mechanical properties of films including tensile strength and elongation at break were used as indexes to optimize the preparation process of chitosan-hexahydro-β-acids edible antibacterial films using single factor and orthogonal test, and the release behavior of hexahydro-beta-acid from films were also investigated in ethanol aqueous solutions at the concentration of 95%, 75%, and 55% (v/v), respectively. Results showed that chitosan concentration exhibited the greatest effect on the mechanical properties of films, followed by interaction of the concentration between chitosan and glycerol, and drying temperature had the weakest effect. The optimized conditions were determined as follows: chitosan concentration 1.75%, drying temperature 40 °C, and the glycerol concentration 1.4%. Under these conditions, the chitosan-hexahydro hexahydro-β-acids edible bacterial films showed the best mechanical properties, tensile strength and elongation at break were up to 29.26 MPa and 81.29%, respectively. Release experiments indicated that the release of hexahydro-β-acids gradually increased with increasing time and temperature, and the release stopped when the equilibrium was reached. According to the Peppas and Peleg equations, the release of hexahydro-β-acids in 95% ethanol followed Fick diffusion, while, 75%/ 55% ethanol accorded with Peleg equation. The diffusion coefficient increased with rising temperature, and the most obvious release was found in 55% ethanol, which indicated the water content and temperature in the release solvent were the major factors affecting the diffusion of the active ingredients.

Key words: chitosan, hexahydro-β-acid, edible bacterial film, mechanical properties, release