1. High Fructose Corn Syrup
Kathy Taylor
11/25/08

2. What is High Fructose Corn Syrup (HFCS)?
Concentrated carbohydrate solution containing primarily fructose and D-glucose
Sweeter than conventional corn syrup
55 wt% fructose is as sweet as sucrose
Found in most soft drinks (55% HFCS) and processed foods ( 42% HFCS)
D-glucose = dextrose
Sucrose = table sugar= fructose+glucose

3. The Useful Properties of HFCS
High solubility: less likely to crystallize
Hygroscopic: keeps bakery products moist for increased shelf life
High osmotic pressure: discourages microbial growth
Liquid: easy to blend and transport
Cheap: thanks to corn subsidies and sugar tariffs (in the US)
Hygroscopic = attracts water, absorbs water from air

4. Production Started in Japan in the 1960s
Fructose desirable as a sweetener for diabetics (little effect on blood glucose and the secretion of insulin)
Corn wet milled to produce corn starch
Corn starch chains broken with enzymes and acids to produce a glucose syrup
Column isomerization of glucose using an immobilized glucose isomerase to produce 42% HFCS
Chromatographic separation to make 90% fructose syrup which is blended with 42% HFCS to produce 55% HFCS

5. Production - 42% Fructose
Glucose Isomerase
Made by bacterial organisms
Enzyme which converts glucose into fructose
Resistant to thermal denaturation
Active even at high fructose concentrations
Enzyme immobilization
Cross-linked with glutaraldehyde
By bacterial cell or
Into an inert carrier after it is released from the bacterial cell (example: a cell-gelatin mixture)

6. Production – 42% HFCS
Purification of glucose to maximize efficiency of the enzyme
Filtration to remove insoluble materials
Ion exchange and activated carbon to remove soluble materials
Evaporated to 40-50% dry basis
Magnesium added as a cofactor
Maintain isomerase stability
Prevent residual calcium from inhibiting the enzyme

7. Production – 42% HFCS
Substrate solution passes through a fixed bed of immobilized glucose isomerase
Optimal production is 42-45% fructose
Possible to reach 50-55% fructose but reaction time excessive
As enzyme activity decreases, residence time increased to compensate
Often have multiple reactors in series or parallel

8. Production – 42% HFCS Product pH adjusted to 4-5
Carbon treated to remove color and off- flavors
Purified with ion exchange chromatography to remove salts and residual color
Evaporated to 71 wt% solids
Good enough for most processed foods, but not soft drinks

9. Production – 90% HFCS Chromatographic Separation
42% HFCS sent through a column of zeolites (porous aluminosilicates filled with cations...usually calcium) or gel resins filled with water and calcium
Fructose and glucose move through the column at different rates causing stationary and mobile phases
Result: glucose moves down the bed faster than fructose
Glucose goes out in the raffinate stream and fructose is extracted with water

10. Chromatographic Separation
Both sugars form weak ligand compexes with calcium ions
Sugar releases H+ from hydroxyl group leaving the oxygen electron rich and active
Calcium links with the available oxygen
Fructose has a stronger interaction with calcium ions than glucose so it absorbed and separated from other components
Fructose
Glucose

11. Chromatographic Separation
Column has multiple inlets and outlets
Feed stock, water and recycled syrup continuously added at various inlets as controlled by computer system
Separated bands of high purity for each sugar exist within the column
The bands are tracked and outlet streams are opened as appropriate to withdraw purified fructose or the raffinate

12. Production – 90% HFCS
Also some size separations performed simultaneously in the column to remove higher saccharides
Glucose recycled to isomerization column
90% HFCS blended with 42% HFCS to produce 55% HFCS

13. HFCS will kill you
Metabolization of fructose promotes weight gain because certain hormones that help regulate appetite and fat storage are not produced
May cause obesity, heart disease, liver damage and diabetes
Genetically modified corn processed with genetically modified enzymes

14. HFCS is a scapegoat 55% HFCS ≈ Table sugar 45% HFCS < table sugar
“Natural”: made from plain old corn, no artificial or synthetic ingredients or color additives

15. The Facts: Consumption

16. The Facts: Consumption compared to obesity

17. Conclusion

18. References
Kirk-Othmer Encyclopedia of Chemical Technology, 5th Edition
Archer Daniels Midland: A Case Study in Corporate Welfare. James Bovard. CATO Institute, 2007
A Sweetener With a Bad Rap. MELANIE WARNER. New York Times, 2006.
Corn Refiners Association (
Sugar and Sweeteners Yearbook U.S. Department of Agriculture, Economic Research Service.
National Center for Chronic Disease Prevention & Health Promotion (
London South Bank University (
Is High-Fructose Corn Syrup Really Good for You? Lisa McLaughlin TIME, 2008.
Soda Warning? High-fructose Corn Syrup Linked To Diabetes, New Study Suggests. Science Daily, 2007
Chromatographic separation of Fructose and glucose with DOWEX MONOSPHERE resins. Dow Liquid Separations. Technical Manual (
Ion Exchange: Theory and Practice. Harland and Grimshaw. 1993