High Fructose Corn Syrup Kathy Taylor 11/25/08

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

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

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

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)

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

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

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

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

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

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

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

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

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

The Facts: Consumption

The Facts: Consumption compared to obesity

Conclusion

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 (http://www.corn.org) Sugar and Sweeteners Yearbook 2007. U.S. Department of Agriculture, Economic Research Service. National Center for Chronic Disease Prevention & Health Promotion (http://www.cdc.gov/) London South Bank University (http://www.lsbu.ac.uk/biology/enztech/hfcs.html) Is High-Fructose Corn Syrup Really Good for You? Lisa McLaughlin TIME, 2008. http://www.jonbarron.org/diabetes-program/2008-09-29.php 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 (http://www.dow.com/liquidseps/prod/chromato.htm) Ion Exchange: Theory and Practice. Harland and Grimshaw. 1993