1. Isomerization is the process of converting a carbohydrate like glucose into another with the same molecular formula but different structure. Glucose isomerase catalyzes the conversion of glucose into fructose, which is used to produce high fructose corn syrup. 2. High fructose corn syrup is composed of 42% or 55% fructose and is sweeter and cheaper than sucrose, making it widely used as a sweetener in foods and beverages. It is produced through the isomerization of glucose into fructose using immobilized glucose isomerase enzymes. 3. Dextrinization is the breakdown of starch into smaller carbohydrate molecules called dextrins through enzymatic

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 IMMOBILIZED ENZYME SYSTEMS– MORE EFFICIENT Brand Name Producer MO System Sweetzyme Novo-Nordisk Bacillus coagulans suspension Swetase Nagase Streptomyces phaeochromogenes suspension Sweetzyme T Novo-Nordisk S. murinus Bacillus coagulans Whole cell immobilization Spezyme Genencor International S. Rubiginosus Cell free immobilization

6. DEXTRINIZATION Browning Reaction in Food material : Reasons : Caramelization [ at High Temp, sugar/starch breakdown] Dextrinization [Starch in Dry conditions] Enzymatic Browning [at low/moderate temp] Sugar-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* Hydrolysis (acidic) – α (1-4) and α (1-6) glycosidic bonds ( controlled hydrolysis using endo amylases ) Transglucosidation Repolymerization Endo-amylases and Debranching enzymes (isoamylase ,pullulanase and amyolpullulanase) are used. * Source : Modified Starches: Properties and Uses&quot;, 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 British gum White Dextrin Yellow Dextrin

10. COMPARATIVE ACCOUNT Property White Dextrin Yellow Dextrin British Gum Hydrolysis - - Low (higher pH) Transglucosidation - higher - Repolymerization - Very high - Temperature 80-110 C 150-170 C High temp Water solubility poor 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!