Contact Us
Site Map
E-mail Notification
Site Search
Members Area
Maps Forum
User Name : 
Password : 
About Us
»  Enzymes
  - Textile
  - Leather
  - Baking
  - Alcohol
  - Brewing
  - Detergent
  - Starch
  - Animal feed
»  Know Enzymes
  What are enzymes?
  History of enzymes
  Making of Enzymes
»  Microorganisms
Bio Happenings
Bio Forum
 Home Products Enzymes Starch

Enzymes for Starch

In the early 19th century, it was discovered that by boiling starch with acid it could be converted into a sweet­tasting substance, which consisted mainly of glucose. Since then acids have been used widely for breaking down starch into glucose. This technique does have a number of drawbacks.

The DE (dextrose equivalent) value is used as an indication of the degree of hydrolysis of syrup. The DE value of starch is zero and that of dextrose is 100. In the last 25 years, as new enzymes are available, starch hydrolysis technology has move away from acids to enzymes.

Enzymatic starch conversion, depending on the enzymes used, syrups with different compositions and physical properties of starch. There are three basic steps in enzymatic starch conversion: liquefaction, saccharification and isomerisation.

Starch liquefaction

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.

| TOP |   

Starch Saccharification

Saccharification is the second step in the process. Depending of the desired end product, a glucoamylase or a fungal alpha amylase is used further break down the Maltodextrins. The glucoamylase can hydrolyse starch completely to glucose along with, a little maltose and isomaltose. A pullulanase is a de-branching enzyme that can also be used to aid saccharification. Fungal alpha amylases can also be added in order to produce syrups with a higher maltose content, which means high fermentability and a relatively high degree of sweetness.

| TOP |   


Further going one step ahead, a proportion of the glucose can be isomerised into fructose, which is about twice as sweet as glucose. An immobilized glucose isomerase is used.

Maps offers a range of amylases and glucoamylase for starch conversion depending on the desired end product.


Palkolase HT Heat-stable alpha amylase for starch liquefaction
Palkolase LT Alpha amylase for starch liquefaction
Palkodex Glucoamylase for starch saccharification
Palkoamylo Fungal alpha amylase for starch saccharification



 Site Search

Our Starch Enzymes
Palkolase HT
Palkolase LT
 © Copyright Maps Enzymes Ltd. (Formerly Maps (India) Ltd.). 2010
Privacy  |   Legal
Web Designing and Development by STWI