Production of High Fructose Corn Syrup Flashcards
Overall production of HFCS
Liquefaction + saccharifaction of corn starch = Glucose ———-> Fructose in presence of isomerase
What are amylases
Enzymes that hydrolyse starch
What is starch
A glucose polymer
Stages of starch being broken down to glucose
- Starch
- Short chain polymers (dextrins)
- Maltose (disaccharides)
- Glucose
What are the 3 most NB enzymes in starch saccharification process
- Alpha amylases
- Glucose isomerases
- Glucoamylases
What genus is alpha amylase mainly derived from
Bacillus genus
What kinds of Bacillus produce alpha amylases
Bacillus licheniformis
Bacillus stearothermophilus
Bacillus amyloliquefaciens
What can glucose isomerase be produced by
Streptomyces strains
What produces most glucoamylases
Fungi
What is commercial glucoamylase usually produced by
Aspergillus niger
What do alpha amylases catalyse
They catalyse the initial hydrolysis of starch into shorter oligosaccharides
What is cleaved in the initial hydrolysis of starch
Cleavage of alpha-D- (1-4) glycosidic bonds
What do glucoamylases hydrolyse
Glucoamylase hydrolyses polysaccharides from the non reducing ends by cleaving alpha-1,4 and alpha-1,6 glycosidic bonds consecutively
What temp is enzymatic liquification carried out at
110 degrees C
What pH can starch solutions liquefied with amylase be saccharified at
pH 4-5
What temp can starch solutions liquefied with amylase be saccharified at
55-60 degrees C
What does glucose isomerase cause
The isomerisation of glucose to fructose
What determines the composition of the end product
- The specificity of the enzymes used
- The conditions of conversion
