Abstract:

Microporous cassava starch was prepared by combined hydrolysis with glucoamylase andα-amylase. The effects of hydrolysis time and temperature, pH, substrate concentration, enzyme dosage and glucoamylase/α-amylase ratio on hydrolysis percentage and oil adsorption capacity of microporous cassava starch prepared were analyzed. On the basis of this, an orthogonal array design involving 18 tests was employed to optimize the six parameters for maximizing oil adsorption capacity. A maximum oil adsorption capacity was obtained by 7 h hydrolysis of native cassava starch at 60 ℃ and pH 6.0 using a mixture of glucoamylase and α-amylase (1:4, m/m) at the dosage of 2.5%. The oil adsorption capacity (52%) of microporous cassava starch was 4.52 times higher than that (11.5%) of native cassava starch.

Key words: microporous cassava starch, complex enzyme, oil adsorption capacity, hydrolysis percentage