Isomerization And Dextrinization S

1. ISOMERIZATION AND
DEXTRINIZATION

2. ISOMERIZATION
Isomers : same molecular formula but different
configuration/structure
In carbohydrate chemistry
Glucose isomerase (D-glucose ketoisomerase)

3. HIGH FRUCTOSE CORN
SYRUPS
Source : Applexion® Process for the Production of HFS 55 from Starch, Novasep

4. GLUCOSE ISOMERASE
(GI)
D-Glucose/xylose isomerase : most important industrial enzyme
The production of HFCS by using glucose isomerase was developed first
in Japan and later in the United States.
This isomerase also has capability to convert xylose into xylulose , in
vivo . This property is utilized in bioethanol formation(as xylose
accumulation forms a metabolic block in ethanol formation)
HFCS, an equilibrium mixture of glucose and fructose (1:1) is 1.3 times
sweeter than sucrose and 1.7 times sweeter than glucose
High fructose corn syrup is composed of either 42 percent or 55 percent
fructose, with the remaining sugars being primarily glucose and higher
sugars.
Major Use of HFCS :
In food and beverage industry : AS SWEETNER (Replacing sucrose)

5. GIS IN MARKET
Brand NameProducer MO System
Sweetzyme Novo-NordiskBacillus coagulans suspension
Swetase Nagase Streptomyces
phaeochromogenes
suspension
Sweetzyme TNovo-Nordisk S. murinus
Bacillus coagulans
Whole cell
immobilization
Spezyme Genencor
International
S. Rubiginosus Cell free
immobilization
IMMOBILIZED ENZYME SYSTEMS– MORE EFFICIENT

6. DEXTRINIZATION
Browning Reaction in Food material :
Reasons :
Caramelization [ at High Temp, sugar/starch
breakdown]
Dextrinization [Starch in Dry conditions]
SEnzymatic Browning [at low/moderate temp]
nSugar-Amine Browning [usually at cooking temp]

7. DEXTRINS
Dextrins : carbohydrate intermediates between sugar
and starch , produced by enzymatic or thermal
degradation of starch
Oligomers (-glucose-)
n

Amorphous Yellow or white powder
Partially water soluble
Low viscosity (compared to starch)
DE*(degree of hydrolysis on dextrose equivalency)
=< 20
*DE (starch)= 0 , DE(dextrose)=100, DE(Corn syrup)=20-99.4

8. DEXTRINIZATION-
PROCESS
Not fully understood
Apparently 3 steps*
pHydrolysis (acidic) – α (1-4) and α(1-6) glycosidic bonds
(controlled hydrolysis using endo amylases)
lTransglucosidation
oRepolymerization
Endo-amylases and Debranching enzymes (isoamylase
,pullulanase and amyolpullulanase) are used.
*Source : Modified Starches: Properties and Uses", O. B. Wurzburg, CRC Press Inc., 1987.

9. DEXTRINS
Malto-dextrins (Enzymatic)
Pyro-dextrins (Thermal) – Non food applications
Cyclo-dextrins : closed ring oligosaccharide(6,7 or 8 residue)
(Intramolecular transglycosylation)
3 types of Dextrins in Market
6.British gum
7.White Dextrin
8.Yellow Dextrin

10. COMPARATIVE
ACCOUNT
Property White DextrinYellow DextrinBritish Gum
Hydrolysis - - Low (higher
pH)
Transglucosidation- higher -
Repolymerization- Very high -
Temperature 80-110 C 150-170 C High temp
Water solubilitypoor high Poor

11. COMMERCIAL PRODUCTS
SEBAmyl XCP ( alpha amylase) – Advanced Enzymes
(Grain Processing and bakery)
SEBAmyl MTL (alpha amylase) - Advanced Enzymes
(Malting and Brewing)
SEBStar MTL (alpha amylase) (malting)

12. APPLICATIONS OF
DEXTRINS
Thickener in Sauces and Soups
Gel Former in Puddings
Suspension Stabilizer
Bodying agent in Baking
adhesive industry AND the paper industry,
 the pharmaceutical industry(cyclo-dextrins in controlled drug
release )
the food industry, and the textile industry.
Rocket Propelent Binder (Nitropulse Ltd.)

13. THANK
YOU!