Evolution behavior of volatile components of shiitake mushrooms during infrared-assisted spouted bed drying

The present study aimed to investigate the effect of different drying temperatures and airflow speeds on the number and species of volatile components in infrared-assisted spouted bed dried (IRSBD) Shiitake mushrooms. The dynamics changes in volatile components (determined by HS-SPME-GC-MS) during drying under optimal conditions were also monitored. Results revealed that the maximum number of volatile components (69 species) was observed at a temperature of 55 degrees C and airflow speed of 8.0 m/s, of which the volatile components in Shiitake mushrooms varied significantly over the drying process at this condition. Fresh Shiitake mushrooms mainly composed of volatile substances such as alcohols, ketones and acids. During the early drying stage (0-40 min), the levels of alcohols and ketones gradually decreased, while the species and levels of aldehydes, esters, and volatile sulfur-containing compounds (VSCs) increased. In the middle stage (40-120 min), levels of alcohols, esters, aldehydes, acids, and alkanes species increased, while the levels of VSCs decreased. For the last stage (120-200 min), the levels of sulfur-containing heterocyclic compounds, aldehydes, esters, acids, pyrazines, and alkanes were all increased. The findings of this study provide insights into the flavor formation mechanism during IRSBD of Shiitake mushrooms and offer a theoretical reference for the production of industrial flavorful dried goods.