High-fructose corn syrup

High-fructose corn syrup (HFCS), also known as glucose-fructose, isoglucose and glucose-fructose syrup, is a sweetener made from corn starch. As in the production of conventional corn syrup, the starch is broken down into glucose by enzymes. To make HFCS, the corn syrup is further processed by glucose isomerase to convert some of its glucose into fructose. HFCS was first marketed in the early 1970s by the Clinton Corn Processing Company, together with the Japanese Agency of Industrial Science and Technology where the enzyme was discovered in 1965.:5 High-fructose corn syrup (HFCS), also known as glucose-fructose, isoglucose and glucose-fructose syrup, is a sweetener made from corn starch. As in the production of conventional corn syrup, the starch is broken down into glucose by enzymes. To make HFCS, the corn syrup is further processed by glucose isomerase to convert some of its glucose into fructose. HFCS was first marketed in the early 1970s by the Clinton Corn Processing Company, together with the Japanese Agency of Industrial Science and Technology where the enzyme was discovered in 1965.:5 As a sweetener, HFCS is often compared to granulated sugar, but manufacturing advantages of HFCS over sugar include that it is easier to handle and more cost-effective. The United States Food and Drug Administration has determined that HFCS is a safe ingredient for food and beverage manufacturing, where 'HFCS 42' refers to 42% and 'HFCS 55' to 55% fructose composition in manufacturing, respectively. HFCS 42 is mainly used for processed foods and breakfast cereals, whereas HFCS 55 is used mostly for production of soft drinks. There is debate over whether HFCS presents greater health risks than other sweeteners. The number of uses and exports of HFCS from American producers have grown steadily during the early 21st century. In the U.S., HFCS is among the sweeteners that mostly replaced sucrose (table sugar) in the food industry. Factors in the rise of HFCS use include production quotas of domestic sugar, import tariffs on foreign sugar, and subsidies of U.S. corn, raising the price of sucrose and lowering that of HFCS, making it cheapest for many sweetener applications. The relative sweetness of HFCS 55, used most commonly in soft drinks, is comparable to sucrose. HFCS (and/or standard corn syrup) is the primary ingredient in most brands of commercial 'pancake syrup', as a less expensive substitute for maple syrup. Because of its similar sugar profile and lower price, HFCS has been used illegally to 'stretch' honey. Assays to detect adulteration with HFCS use differential scanning calorimetry and other advanced testing methods. In the contemporary process, corn is milled to extract corn starch and an 'acid-enzyme' process is used, in which the corn-starch solution is acidified to begin breaking up the existing carbohydrates. It is necessary to carry out the extraction process in the presence of mercuric chloride (0.01 M) in order to inhibit endogenous starch-degrading enzymes.:374–376 High-temperature enzymes are added to further metabolize the starch and convert the resulting sugars to fructose.:808–813 The first enzyme added is alpha-amylase, which breaks the long chains down into shorter sugar chains – oligosaccharides. Glucoamylase is mixed in and converts them to glucose; the resulting solution is filtered to remove protein, then using activated carbon, and then demineralized using ion-exchange resins. The purified solution is then run over immobilized xylose isomerase, which turns the sugars to ~50–52% glucose with some unconverted oligosaccharides and 42% fructose (HFCS 42), and again demineralized and again purified using activated carbon. Some is processed into HFCS 90 by liquid chromatography, and then mixed with HFCS 42 to form HFCS 55. The enzymes used in the process are made by microbial fermentation.:808–813:20–22 HFCS is 24% water, the rest being mainly fructose and glucose with 0–5% unprocessed glucose oligomers. The most common forms of HFCS used for food and beverage manufacturing contain fructose in either 42% ('HFCS 42') or 55% ('HFCS 55') amounts, as described in the US Code of Federal Regulations (21 CFR 184.1866). Commercial production of corn syrup began in 1964.:17 In the late 1950s, scientists at Clinton Corn Processing Company of Clinton, Iowa, tried to turn glucose from corn starch into fructose, but the process was not scalable.:17 In 1965–1970 Yoshiyuki Takasaki, at the Japanese National Institute of Advanced Industrial Science and Technology (AIST) developed a heat-stable xylose isomerase enzyme from yeast. In 1967, the Clinton Corn Processing Company obtained an exclusive license to a manufacture glucose isomerase derived from Streptomyces bacteria and began shipping an early version of HFCS in February 1967.:140 In 1983, the FDA approved HFCS as Generally Recognized as Safe (GRAS), and that decision was reaffirmed in 1996