Abstract: The extraction conditions of protein from raw Auricularia auricular and its vortex grinding micropowder were optimized by single test and orthogonal test.The optinmal extraction conditions of protein from the raw Auricularia auricular are as follows:pH 7.6,extraction temperature 30 ℃,time 2.5 h and ratio of material to water 1:45,and for the Auricularia auricular micropowder,those are as follows:pH 7.4,extraction temperature 35 ℃,time 3 h and ratio of material and water 1:50,Under the above optimal conditions,the dissolving ratio of protein from the raw Auricularia auricular was commpared with that of protein from its micropowed,and the protein enrichment regular of micropowed with different particle sizes after vibrating screen was investigated.It was found that the dissolving ratio of protein from the Auricularia auricular micropowed is 2 to 3 times higher than that of protein from the raw Auricularia auricula in average.The dissolving ratio of protein rises with the partein size of the Auricularia auricular micropowder declining in the range of 300,240,200,180,140 and 100 mesh,and the protein is enriched mainly in the Auricularia auricular micropowder between 240 mesh and 300 mesh.

Key words: ultra-fine pulverizing, Auricularia auricular, protein, enrichment