Effect of drying methods on the physicochemical characteristics of dried mucilage from Dictyophora indusiata

Abstract

Dictyophora indusiata known as bamboo mushroom is an edible mushroom in Genus Dictyophora, Family Phallaceae that could produce highly viscous mucilage (DIM) encased in a peridium of egg-shaped immature fruiting body. In this study, DIM were dried by three different techniques; lyophilization, spraydrying and heat-drying. The physicochemical properties of dried DIMs including morphology, crystallinity, viscosity after reconstituted and swelling index were evaluated. The effect of mannitol as an additive in each process was also investigated. The dried DIMs showed amorphous nature with different morphology depended on the drying processes. The viscosity of 50%w/w fresh DIM solution was 10890±135.07 cps at 25 oC. After reconstitution, the viscosity decreased. Lyophilization with mannitol was found to be the most suitable technique to maintain DIMs viscosity. The swelling index values of the dried DIMs from lyophilization and spray-drying techniques were clearly higher than other DIMs from heat-drying. Therefore, heat-drying may affect the structure conformation of substances in DIMs. The lyophilization and spraydrying were seem to be the promising methods. According to the physicochemical properties, especially high swelling ability and high viscosity nature, dried DIMs showed the possibility to be a novel pharmaceutical excipient.