Abstract: Tartary buckwheat protein consists of well-balanced amino acid with higher biological value, and it has some special physiological properties. In vitro pepsin digestibility assay showed that its digestibility was rather low. Scanning electron microscopy(SEM) was used to examine the microstructure of four protein fractions hydrolysates. The results showed that the four protein fractions were digested by pepsin with different patterns. Albumin and globulin are more digestible, since they are digested by being hydrolyzed from the outer surface to the inner part. Prolamin and glutelin were rather resistant to pepsin digestion because of their complex structure. High performance liquid chromatography was used to determine the molecular weight distribution of the four protein fractions hydrolysates. The results revealed that the hydrolysates of albumin and globulin are composed of low molecular weight fractions, and the zymolysis is better. But the hydrolysates molecular weights of prolamin are rather variable because of its structure.

Key words: tartary buckwheat, protein fractions, SEM, HPLC, in vitro pepsin digestibility