The structural and functional properties of corn starch treated with endogenous malt amylases

Abstract To significantly decrease the cost of enzyme-modified starch production and improve the functionalities of corn starch derivatives, the effects of endogenous malt amylases at different incubation time on the structural and functional properties of corn starch were investigated. The results indicated that the amylase activity in malt incubated on the third day was highest (103.3 U/g). Compared to native corn starch, the higher activity of malt enzyme significantly destroyed the integrity of starch granules, resulting in lower ratio of 1047 cm-1/1022 cm-1 (from 1.042 to 0.838) and relative crystallinity (from 35.30 % to 28.76 %) but higher gelatinization temperature (increased by about 5 °C). The pasting viscosity of the enzyme-treated starches showed the increase in peak viscosity, breakdown, final and setback viscosity. This outcome would provide a valuable method to obtain desirable malt amylases instead of commercial enzyme to prepare starch derivatives with lower cost and higher performance.