Reassuring Similarities

High Fructose Corn Syrup and Sucrose:
Reassuring Similarities and Complementary Differences

This article originally appeared in the 2004 Corn Annual Corn: Part of a Healthy Diet.

By John S. White, Ph.D., Founder and Principal, WHITE Technical Research

The U.S. food and beverage industry today is sweetened principally by two sugars - high fructose corn syrup (HFCS) and sucrose (table sugar). HFCS usage has grown tremendously, with a nearly equal decline in U.S. sugar usage, since its commercialization 30 years ago for two fundamental reasons. First, HFCS and sucrose share similarities in sweetness, composition, consumption and metabolism. And second, significant differences in their functionality in foods and beverages are complementary — HFCS has carved a niche in applications in which sucrose use had been unsatisfactory; conversely, sucrose will always be preferred for specific applications because of distinct physical properties (like crystallization) that HFCS does not possess.

Composition
Crystalline sucrose is a disaccharide comprised of equal parts fructose and glucose joined by a covalent bond. Invert sugar is liquid sucrose in which some of the covalent bonds have been broken (inverted), either purposefully or as a result of food product acidification (e.g., carbonated beverages). High fructose corn syrups were commercialized in the 1970s, predominantly as the products HFCS-55 (55% fructose) and HFCS-42 (42% fructose). Fructose in these products is free, not bound as it is in sucrose. Not stated in the name — and therefore overlooked or confused — is the fact that HFCS-55 contains 41% glucose and HFCS-42 contains 53% glucose. An analysis of annual HFCS-55 and -42 production reveals an average fructose content of only 49%: essentially the same as that in sucrose.

HFCS and Sucrose Availability
While free fructose increased with the introduction of HFCS 30 years ago, free and bound fructose from invert and crystalline sucrose decreased at nearly an identical rate, since sucrose was displaced from foods and beverages by HFCS (see sweetener consumption graph). Consequently, availability of fructose from all sources — sucrose, HFCS, honey, fruits and vegetables — has risen only slightly since the introduction of HFCS, in parallel with the modest increase in consumer caloric intake. Equally important, increased use of HFCS has not changed the fructose-to-glucose ratio in the diet. This ratio has remained relatively constant over the last 30 years.

Intestinal Absorption and Metabolism
Ingested sucrose is rapidly absorbed into the bloodstream in the form of monosaccharides glucose and fructose, after hydrolysis of the covalent bond by enzymes in the lining of the small intestine. HFCS too is rapidly absorbed into the bloodstream in the form of monosaccharides glucose and fructose from the small intestine; hydrolysis is not necessary since these sugars are already monosaccharides in HFCS. Once absorbed into the bloodstream, glucose and fructose are metabolized using established biochemical pathways, regardless of whether they originated from HFCS or sucrose — the source of dietary glucose and fructose is indistinguishable to the human body.

It has been argued that increased availability of HFCS in foods and beverages over the past 30 years trends with the rise in obesity in the U.S., and is its cause. This argument is at odds with rising obesity in Europe and Mexico, geographic areas where HFCS sales are minor in comparison with sucrose.

By acknowledging their basic similarities, we see that HFCS is neither better nor worse for consumers than sucrose - in the matter of metabolism, they are virtually identical.

Functionality
HFCS and sucrose are similar in sweetness intensity. Expert sensory panels estimate the sweetness of HFCS-55 and -42 at 99% and 92% of the sweetness of sucrose, respectively. The two sweeteners are sufficiently different in certain physical and functional properties that they have found unique and preferred applications in foods and beverages. The following examples list properties in which HFCS and sucrose differ:

• Delivery form: HFCS is delivered in liquid form, suitable for pumping from one location to another and readily blended with other liquid ingredients. Sucrose is primarily delivered in crystalline form.
• Sweetness stability (carbonated beverages): the bond in sucrose between fructose and glucose breaks down with time under the low pH and elevated summertime storage temperatures of carbonated beverages. This results in constantly-changing sweetness and flavor profiles — both highly undesirable attributes. HFCS is stable under these conditions.
• Crystallization (baking, confections): sucrose readily crystallizes; HFCS does not.
• Freezing point depression (frozen foods), osmotic pressure (frozen and canned fruits): by virtue of its monosaccharide composition, these properties are more pronounced with HFCS than sucrose.
• Surface browning (baking), moisture retention/microbial stability (baking, snack foods): free fructose shows enhanced ability to perform these roles in comparison to either free glucose or sucrose.

The fundamental functional differences between HFCS and sucrose have inspired many innovative foods and beverages consumers enjoy today that were nonexistent 30 years ago.

Summary
HFCS and sucrose are virtually indistinguishable in significant ways, most importantly in fructose/glucose composition and metabolism. Given the long history of sucrose in the human diet, it is reasonable to expect that if fructose-containing sugars like sucrose and HFCS were the cause of obesity and other disease states, this would have become apparent and been substantiated long ago.

HFCS producers, product formulators and consumers should be reassured by the similarities between HFCS and sucrose, and appreciative of the wondrous variety in foods and beverages made possible by the attributes of these two marvelous sweeteners.

Dr. John S. White is the founder and principal of WHITE Technical Research, an international consulting company focusing on the physical, functional and metabolic properties of nutritive sweeteners. With 25 years of experience in the food and beverage industry, Dr. White was an integral player in the application of high fructose corn syrup to carbonated beverages and in the introduction of crystalline fructose to the food and beverage industry.