Effects of drying conditions on quality of brittle polyporus frondosus slice

To investigate the effects of drying conditions on the quality of polyporus frondosus , fuzzy mathematic was used in evaluating the polyporus frondosus sensual quality. The texture and rehydration ratio of polyporus frondosus prepared by vacuum freeze-drying and hot air –drying were assayed periodically. The results showed that the optimized conditions of vacuum freeze-drying were as follow: the vacuum degree 20Pa, the board temperature 50℃, the thickness of materials 5mm, time 12h, and the optimal hot air-drying conditions were as follow: temperature 100℃, time 11h, and the thickness of materials 16 mm. The shape and color of polyporus frondosus were kept well after vacuum freeze-drying, which were better than those of hot-air drying. The value of vacuum freeze-drying and hot air-drying by fuzzy mathematic evaluating was 0.5 and 034, divided into good and middle respectively.