Development and properties of zein/Tremella fuciformis polysaccharides blend as a hard capsule material

Abstract Replacement of animal‐derived capsules with those of plant origin, which are safe and stable, is the development tendency at present. However, properties of pure plant materials, such as high hydrophobicity, low solubility, and poor film‐forming ability, restrict the popularization and application of plant capsules. In the present study, a novel blend of zein and Tremella fuciformis polysaccharides (TPS) was developed by a facile one‐step shear method. Properties of the blend were investigated to show its potential in being used as raw materials for capsule shells. According to viscosity, rheological behaviors, and microscopic morphology of the blends, TPS molecules enhance both the stability and gelling functions of the mixture by wrapping around the zein aggregations. It was revealed that the viscosity of the zein/TPS system increases with the zein content, while the elasticity of it increases with the TPS content. The films obtained from the blends were characterized by mechanical properties and SEM, showing a zein/TPS mass ratio of 7:3 leads to the most appropriate TS and highest EAB among all films tested. The FTIR and XRD analysis suggested the physical mixing of zein and TPS in the blend films. As shown by the DSC curves, the glass transition temperature ( T g) of the blend film gradually dropped with the addition of TPS, which was a consequence of the weakening of intermolecular interactions. The paper introduced the whole process, from raw material preparation to ZT capsule production, further verifying the application potentials of such a novel plant material.