Designing liquefaction and saccharification processes of highly concentrated starch slurry: Challenges and recent advances

Abstract

Starch‐based sugars are an important group of starch derivatives used in food, medicine, chemistry, and other fields. The production of starch sugars involves starch liquefaction and saccharification processes. The production cost of starch sugars can be reduced by increasing the initial concentration of starch slurry. However, the usage of the highly concentrated starch slurry is characterized by challenges such as low reaction efficiency and poor product performance during the liquefaction and saccharification processes. In this study, we endeavored to provide a reference guide for improving high‐concentration starch sugar production. Thus, we reviewed the effects of substrate concentration on the starch sugar production process and summarized several potential strategies. These regulation strategies, such as physical field pretreatment, complex enzyme‐assisted, and temperature control, can significantly increase the starch concentration and mitigate the challenges of using highly concentrated starch slurry. We believe that highly concentrated starch sugar production will achieve a qualitative leap in the future. This review provides theoretical guidance and highlights the importance of high concentration in starch‐based sugar production. Further studies are needed to explore the fine structure and enzyme attack mode during the liquefaction and saccharification processes to regulate the production of more targeted products.

Exploring a novel GH13_5 α-amylase from Jeotgalibacillus malaysiensis D5T for raw starch hydrolysis

“…Conventional industrial starch processing involves two main stages: liquefaction and saccharification. Starch granules are gelatinized at a high temperature in the liquefaction process, typically around 100 °C (Li et al 2023 ). In the subsequent saccharification process, a combination of several GH13 enzymes (i.e., α-amylase, type I pullulanase, and glucoamylase) is used to further degrade the starch slurry to produce sugar syrups (e.g., glucose and maltose) (Li et al 2023 ), which serve as essential raw materials for various applications, including food products (e.g., beverages and baking) and non-food industries (e.g., biofuels) (Farooq et al 2021 ).…”

Influences of the Carbohydrate-Binding Module on a Fungal Starch-Active Lytic Polysaccharide Monooxygenase

“…10,11 Starch hydrolysis with enzymes to fermentable sugars is an important step for starch sugar production which is envisioned to be energy-saving with lower-cost industrial processes in the near future. 4 One such means to reduce production cost is through the elevation of glycoside hydrolase activity under relevant conditions using starch-active AA13 LPMOs which would increase the overall efficiency of the hydrolytic enzymes in starch sugar production.…”

“…Amylose is a linear polymer of glucose linked via α-1,4-glycosidic linkage, while amylopectin is a hyperbranched molecule linked by α-1,4-glycosidic bond and α-1,6-glycosidic bond. , The key to utilizing starch as a carbon source for bioethanol production is to degrade it into fermentable sugars such as glucose or maltose. Currently, the main technique for starch saccharification is enzymatic liquefaction using thermostable α-amylase at high temperature (105 °C) and subsequent saccharification using glucoamylase or β-amylase. , It is difficult for α-amylase to hydrolyze recalcitrant starch with a high crystallinity at ambient temperature.…”

“…LPMOs that can act on starch by oxidizing α-1,4 glycosidic linkages were classified as family AA13 . LPMOs have been shown to act synergistically with glycoside hydrolase to improve the hydrolysis efficiency of cellulose and chitin polysaccharides driven by hydrolytic enzymes. , Starch hydrolysis with enzymes to fermentable sugars is an important step for starch sugar production which is envisioned to be energy-saving with lower-cost industrial processes in the near future . One such means to reduce production cost is through the elevation of glycoside hydrolase activity under relevant conditions using starch-active AA13 LPMOs which would increase the overall efficiency of the hydrolytic enzymes in starch sugar production.…”

“…Currently, the main technique for starch saccharification is enzymatic liquefaction using thermostable α-amylase at high temperature (105 °C) and subsequent saccharification using glucoamylase or β-amylase. 3,4 It is difficult for α-amylase to hydrolyze recalcitrant starch with a high crystallinity at ambient temperature.…”