Various sugars produced by acid or enzyme hydrolysis of corn starch are collectively referred to as starch sugar. Among them, liquid products include malt syrup, glucose syrup and fructose syrup; Solid products include crystalline glucose, anhydrous glucose, crystalline fructose, maltodextrin, oligosaccharide and whole sugar powder. Mainly used as sweetener in food industry. Anhydrous glucose can be used as a sweetener for pharmaceutical injection, tablet embedding agent and pharmaceutical syrup. Glucose and maltose can be hydrogenated to produce sorbitol and maltitol, which can be used in food and toothpaste to prevent dental caries. In addition, sorbitol can be hydrocracking to produce a series of polyols, so that renewable corn can enter the field of petrochemical products.
2. The main factors affecting liquefaction and saccharification of corn starch are temperature and pH enzyme.
① When the temperature is within a certain temperature range, the higher the temperature, the faster the reaction rate of amylase to starch saccharification. Starch is easy to gelatinize and liquefy at high temperature. However, if the temperature is too high, the enzyme will be inactivated. Therefore, the temperature of liquefaction and saccharification should be strictly controlled so as not to be too high or too low. In the traditional process, because of the bilateral fermentation during saccharification, the temperature should be the suitable temperature for microbial growth, not too high, generally at 33? 35°C, with a maximum of 37 c.
Alfa laval WideGap series wide channel plate heat exchangers can be used to control the temperature during saccharification.
Features:
（ 1）? Wide channel plate heat exchanger is suitable for fiber fluid and fluid containing coarse particles. Its typical applications are sugar, bioethanol, pulp and paper making. Wide-wide channels or wide-narrow channels can be configured to meet different heating, cooling and heat exchange requirements.
（2）? Free-flowing plate type, reducing protein sedimentation and improving production efficiency; Plate corrugation improves heat exchange efficiency and achieves the purpose of energy saving and consumption reduction; Accurate cooling of liquefied starch ensures enzymolysis efficiency, improves liquid sugar yield and ensures stable enzymolysis quality.
Operating principle
The heat transfer area of the gasket plate heat exchanger consists of a group of corrugated plates, which are assembled between the frame plate and the pressure plate to maintain the design pressure. The sealing between plates is completed by gaskets. In order to achieve the highest thermal performance and as close to the temperature as possible, the fluid is usually designed to pass through the heat exchanger in countercurrent. WideGap wide channel plate heat exchanger is specially designed for treating fiber fluid, high viscosity fluid and fluid containing coarse particles. Due to the design of plate type and pressing depth, these fluids can easily pass through.
High-speed turbulence between plates can provide high heat transfer coefficient, but it is easy to cause pressure drop. The design engineer of Alfa Laval Thermodynamics will help you to design and select the model and configuration suitable for your application requirements, so as to provide efficient heat exchange and minimize pressure drop.
WideGap wide channel plate heat exchanger can be configured in many ways, including wide/wide and wide/narrow channel selection. Generally, WideGap is configured as multi-process to ensure sufficient turbulence.
② The action of pH enzyme has an optimum pH range, beyond which the activity of glucoamylase will be greatly reduced. The pH value of liquefaction of Bacillus subtilis T amylase is controlled at 6. About 2, the optimum pH value of Aspergillus for starch saccharification is 5. 0? 5。 8, Aspergillus Niger is 4. 0? 4。 6。 In the high-temperature saccharification method, the soaking time of raw materials before cooking should be appropriate. If the soaking time is too long, the acidity of raw materials will increase and the pH value will decrease due to microbial activities, making liquefaction difficult, which is easy to happen in summer.