Liquefaction:
Starch in its natural state is made up of tiny particles, each with a more complex internal structure, which are normally insoluble. The crystalline structure of starch particles is resistant to enzymes. For example, bacterial α-amylase hydrolyzes starch granules at a rate ratio of 1:20000 to gelatinized starch. For this reason, amylase cannot directly act on starch, so it is necessary to heat starch milk first to make starch particles absorb water and expand, gelatinize, and destroy their crystalline structure. Starch gelatinization is the first necessary step in enzymatic process. Starch gelatinization has great viscosity, poor fluidity, difficulty in stirring, and also affects heat transfer. It is difficult to obtain uniform gelatinization results, especially in the case of high concentration and a large number of materials. α-amylase has a strong catalytic hydrolysis effect on gelatinized starch, which can be quickly hydrolyzed to dextrin and oligosaccharide small molecules. The viscosity decreases rapidly, the fluidity increases, and the non-reducing end is added. This process of starch molecules is called "liquefaction" in industry. Another important purpose of liquefaction is to create favorable conditions for the next step of saccharification. The glucoamylase used in saccharification is an exoenzyme, and the hydrolysis is carried out from the non-reducing tail of the substrate molecules to the extent of dextrin and oligosaccharide. As the number of substrate molecules increases, the chances of saccharifying enzyme action increase, which is conducive to the saccharification reaction.
Application:
Liquefaction system is applied to many fields, such as food, beverage, biomedicine, fermentation, fine chemical industry and so on.