Influence of Initial Moisture Content on Freeze-Dried Quality of Instant Tremella fuciformis Soup

Abstract

The drying time was decreasedby concentrating T. Fuciformis soup before drying. Effects of removing moisture content (10%~50%) on the quality of the instant T. Fuciformis soup was explored. Compared with the samples without pretreatment, when the water content of the soup was removed within 40%, rehydration capacity, rheological properties and tribology properties of instant T. Fuciformis soup showed no significant difference. In addition, drying time could be reduced by up to 9.5 h per batch. When 50% of the water in the soup was removed, the tremella pieces were seriously agglomerated during the initial rehydration time, the water absorption rate and the rehydration rate of the product were slow. The rehydration capacity decreased significantly compared with other samples. Therefore, drying time of instant T. Fuciformis soup could be reduced by removing less than 40% of the water in the soup through pretreatment.

Keywords

• instant t. fuciformis soup
• freeze drying
• processing conditions
• pretreatment
• sensory quality
• rehydration property