Enzymes play a crucial role in breaking down starch, a complex polysaccharide of glucose units, into simpler sugars from various sources, including corn, cassava, rice, and wheat. Liquid sugar or glucose syrup is a concentrated solution obtained from starch through enzymatic hydrolysis. Industries such as and food and Beverages, Pharmaceuticals, Nutraceuticals & Feed rely on sugar as a key Sweetening agent often choosing liquid sugar for its energy-saving advantages.
The enzymatic process for starch hydrolysis is more efficient and straightforward compared to acid hydrolysis. In the past, strong acids were necessary to break down starch into individual sugars, but today, enzymes are predominantly used.
The enzymatic process for starch hydrolysis can be divided into two main phases:
1. Liquefaction and
2. Saccharification
A purified form of ethanol is produced from grain alcohol by the distillation of fermented grains. Generally, fermented molasses and sugar residues are used to produce ethanol at an industrial scale. Still, it can also be produced by fermentation of grains under different climatic conditions and variant needs. Enzymes for alcohol accelerate the fermentation of grains like maize, starch, corn grain, millet, wheat, sweet sorghum, tapioca, and sugar beet, depending on availability and trends of usage
Firstly, there is a liquefaction process. A starch suspension containing 30-40% dry matter is first gelatinised and liquefied. By using heat-stable bacterial alpha amylase, ‘maltodextrin’ is obtained which contains mainly different oligosaccharides and dextrins. Maltodextrins are only slightly sweet and they usually undergo further conversion.
In most starch conversion plants, starch liquefaction takes place in a jet-cooking process. The heat stable alpha amylase is added to the starch slurry after pH adjustment, and the slurry is pumped through a jet cooker. Live steam is injected here to raise the temperature to 105° C and the slurry is then passed through a series of holding tubes for 5-7 minutes, which is necessary to gelatinise the starch fully.
Then the temperature of the partially liquefied starch is reduced to 90-100 °C by flashing, and the enzyme is allowed to react further at this temperature for 1-2 hours until the required DE (Dextrose Equivalent) is obtained
The saccharification process of starch is extremely important in the production process of maltose syrup. In addition to a small amount of glucose, the liquefied liquid after liquefaction is mainly a large amount of dextrin and oligosaccharides, so the liquefied liquid must be continuously converted into high-purity maltose by the action of saccharifying enzyme. Pulp. The key to this process is the ability of the Starch Input Corn/ wheat Gelatinisation Starch is heated in water to form viscous gel Liquefaction The Gel is treated with Alpha amylase to break down starch molecules into shorter dextrin Saccharification Dextrin is treated with glucoamylase to convert dextrin into glucose by breaking down the glycosidic bonds Glucose saccharifying enzyme to cut the oligosaccharides and limit dextrin in the liquefied liquid into maltose as much as possible.
During the saccharification process of starch, the temperature is controlled within the range of 58 ° C to 60 ° C, and the pH is controlled within the range of 5.8 to 6.0 to ensure that the saccharification enzyme exerts the best catalytic action. That is, the saccharification enzyme cleaves the α1,4 glycosidic bond or the maltose molecule sequentially from the non-reducing end or the reducing end of the substrate starch molecule. In the actual production process, some of the branched enzymes are often added during the saccharification process of starch because of the presence of many amylopectin. For example, pullulanase and isoamylase can cleave the α-1,6 glycosidic linkage at the amylopectin branch, thus forming more oligosaccharides that can be hydrolyzed to maltose by the saccharification enzyme. Through the synergy between various saccharification enzymes, the α-1,4 glycosidic bond and the α-1,6 glycosidic bond are continuously cleaved, and a large amount of maltose is finally produced, thereby producing a high-quality maltose syrup.
(Using Glucoamylase Enzyme)
• Following the liquefaction process, the solution enriched with dextrin is cooled to a temperature suitable for glucoamylase activity.
• Glucoamylase is added to convert dextrin into glucose.
• This process occurs at a moderate temperature of 55 – 65 °C and pH of 3.5 – 5 for a few hours.
