Abstract: 【Objective】 The objective of this study is to provide theoretical basis for the production of high-quality Tremella fuciformis by studying the effect of different drying methods on quality changes during processing and storage of it. 【Method】Shrinkage, rehydration rate, sensory evaluation of color, contents of protein, reducing sugar, total sugar and polysaccharide, scavenging activity to superoxide anion and hydroxyl radicals of polysaccharides, water content, total bacteria and fungus count, contents bongkrekic acid, hydrogen peroxide and SO₂ were taken as evaluation index. Vacuum drying, vacuum freeze drying and hot air drying were adopted to dry Tremella fuciformis, and then the effects of three drying methods on texture quality and related physicochemical indexes during processing and storage of Tremella fuciformis were studied. 【Result】 For effects of different drying methods on physical properties, Tremella fuciformis processed byhot air had the highest shrinkage rate, browning degree, and the lowest increasing amplitude. Tremella fuciformis dried by vacuum freeze presented the lowest browning degree and shrinkage rate and the highest rehydration rate. As for nutritional ingredient, Tremella fuciformis dried by vacuum freeze drying had the highest contents of soluble protein, total sugar and polysaccharide. Tremella fuciformis dried by vacuum contained the highest reducing sugar content and the lowest contents of soluble protein and polysaccharide. Reducing sugar obtained from hot air dried Tremella fuciformis was lowest. The strongest scavenging activity to superoxide anion and hydroxyl radicals was found for polysaccharides obtained from vacuum freeze dried Tremella fuciformis, while the weakest scavenging activity was observed in Tremella fuciformis dried byvacuum. In aspect of the physical and chemical changes of Tremella fuciformis processed by three different drying methods, in all samples, the content of water and reducing sugar presented an increase trend, while the contents of protein, total sugar and polysaccharide showed a decrease trend with the storage time. After 90 days storage, the largest increase amplitude of contents of water and reducing sugar and the lowest decrease amplitude were observed on Tremella fuciformis dried by hot air. Tremella fuciformis dried by vacuum freeze presented the largest decrease amplitude of contents of protein and polysaccharide and the lowest increase amplitude of reducing sugar content. The lowest amplitude of contents of water and protein were observed in Tremella fuciformis processed by vacuum. As for metabolite of microorganism, the sum of bacteria and fungus, the contents of bongkrekic acid, hydrogen peroxide and SO₂ in Tremella fuciformis processed by three different drying methods all presented an increase trend with storage time. After 90 days storage, the largest increase amplitude of count of bacteria and fungus and contents of bongkrekic acid were observed in Tremella fuciformis dried by vacuum freeze. Tremella fuciformis dried by hot air presented the largest increase amplitude of hydrogen peroxide contents. The lowest increase amplitude of count of bacteria and fungus and hydrogen peroxide contents were observed in Tremella fuciformis processed by vacuum. There was no significant difference among SO₂ contents of samples processed by three drying methods.【Conclusion】The results indicated that the best quality and nutrition was found in Tremella fuciformis processed by vacuum freeze drying, followed by vacuum drying and hot air drying. Tremella fuciformis dried by vacuum freeze was susceptible to microorganisms and had the largest decrease amplitude of nutrition substances.

Key words: drying methods, Tremella fuciformis, processing, storage, quality change