Ultrasonic pretreatment improves the high‐temperature liquefaction of corn starch at high concentrations
2017
Li, Caiming | Liu, Wenjing | Gu, Zhengbiao | Fang, Dan | Hong, Yan | Cheng, Li | Li, Zhaofeng
The effects of ultrasonic pretreatment on the liquefaction of corn starch at a high concentration were investigated using viscosity and reducing sugar content as the endpoints. The mechanism of the process was also analyzed. The results showed that the viscosity of sonicated starch paste was lower and the reducing sugar content was higher than those of a native control. Therefore, ultrasonic pretreatment could lead to more efficient liquefaction of corn starch at a high concentration. The main reasons are likely to be that ultrasonic pretreatment increase the specific surface area of the starch granules, producing a rough and holey surface, looser granule structure, and lower crystallinity. Also, ultrasonic pretreatment decreases the weight average molar mass, and increases the amylose content. As a result of these changes, the starch granules undergo increased enzymatic degradation during gelatinization. Ultrasonic pretreatment may also directly break starch chains to a certain extent.
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