Study On The Processing Technology Of Instant Tremella

Convenient foods are increasingly favored by consumers because of the fast life style in the modern life. As the traditional precious edible fungus, tremella (Ttremella fuciformis) has been loved by people. However, because the tremella need long time cooking, it is difficult to fit the demand of consumers now. Therefore, the development of tremella convenient food can be a good way to expand the tremella production industry and improve the economic value of tremella. This paper mainly discussed the influence of high-pressure steaming process and drying process on the tremella quality. Also the process parameters and the formula of the instant temella production were studied in this paper.The process parameters of high pressure steaming and their influences on the textural properties of instant tremella were studied in this paper. On the basis of pre-trail results, the three levels of the ratio of water to material, steaming time and temperature were picked to formulate a central composite experiment design. By response analysis, the prediction models were established and the optimum process conditions were obtained as follows:water to material ratio:0.64:1, steaming time:15min, steaming temperature:110.19℃. Under these conditions, the predicted product quality parameters are as follows:whiteness:88.6, rehydration rate:22.3, hardness:143.3g. The prediction was confirmed by verification experiment with the following results:whiteness:88.5, rehydration rate:21.9, hardness:145.8g.For improving the quality of instant tremella, hot air drying and hot air-microwave combined drying were compared. Hot air drying curves and product quality were determined at different temperatures. On the basis of these results, the three levels of microwave power, hot air drying temperature, moisture conversion were picked to formulate an orthogonal experiment. Drying rate, rehydration ratio, whiteness, hardness, stickiness, sensory score were picked for evaluation and a composite score derived from weighted membership scores were used as the ultimate target of process optimization. The results indicated that the significance order of the effects of drying parameters on the overall quality of instant tremella were moisture conversion point, hot air drying temperature, microwave power. The optimum process conditions were obtained as follows:microwave power:5.8W/g; hot air drying temperature:50℃; moisture conversion point:20%.The overall quality of the produced with hot air-microwave combined drying is better than that with hot air drying method.On the basis of the single factor experiment, the three factors of major instant tremella components, namingly dried tremella grains, lotus root starch and composite sweeteners were picked to formulate an orthogonal experiment. The sensory score was the target of process optimization. The optimum formula was obtained as follows:tremella grains:3g; lotus root starch:3.5g; composite sweeteners:12g.The quality index and main nutrients of tremella solid beverage were analyzed, the results shows that this production has higher rehydration rate, whiteness, stickiness and lower hardness than instant tremella. Also, it contains high level of tremella polysaccharide, vitamin C, calcium and iron.