Abstract: The compound enzyme was used for the modification of plantain starch in this article. On the basis of single factor tests, orthogonal rotation combination design was used to optimize modification process of plantain starch. The microscopic shape of starch was observed. The results indicated that the optimal conditions for plantain starch modification by compound enzyme were starch milk concentration 5%, compound enzyme concentration 25 U/mL, enzymatic hydrolysis time of 24 h and hydrolysis temperature of 60 ℃. Under the optimal hydrolysis conditions, the hydrolysis rate of plantain starch was 16.17%, which was consistent with the predicted value. The scanning electron microscope revealed a lot of keyholes, smoother shape, reduced and evenly distributed particle size in modified plantain starch. Meanwhile, the quality and taste of modified plantain starch were significantly improved.

Key words: plantain starch, compound enzymatic hydrolysis, enzymatic modification, microscopic structure