Glucose/fructose syrup, production

In comparison with sucrose (the annual production of which is 93 x 106 tonnes) and glucose or glucose-fructose syrups, only relatively small quantities of lactose are produced. However, it attracts commercial interest because it has some interesting properties and is readily available from whey, a by-product in the production of cheese or casein. World production of cheese is c. 1.4 x 107 tonnes, the whey from which contains c. 6 x 106 tonnes of lactose c. 0.3 x 106 tonnes of lactose are contained in the whey produced during casein manufacture. According to Horton (1993),... 

Fructose syrup. In addition to the glucose/fructose syrups mentioned above, a fructose syrup has been produced using inulin as a source. Inulin is the fructose analogue of starch, and the chicory root is the standard source for commercial hydrolysis. Fructose syrups are usually too expensive for routine use in beverage production but they have been employed where a particular claim is to be made for fructose. They have also been used for the adulteration of fruit juices as they are chemically difficult to detect. Detection is possible at the sub-molecular level by techniques such as stable isotope ratio measurement. Fructose is also manufactured using sucrose as a starting material. 

Sweetening orange juice with cane sugar or glucose-fructose syrup from com starch lowers the 8( C) value of sugar, which is —25.5%o in the native juice (Table 18.45). On the other hand, the addition of beet sugar (C3-plant) can be recognized only via the 8( H) value. The addition of synthetic products from petrochemicals (8( C) —27 5%c) to foods from C3-plants cannot be detected via the 8( C) value, but via the 8( H) value in many cases. 

Poulsen, P.B. and Zittan, L. (1976) Continuous production of high-fructose syrup by cross-linked homogenates containing glucose isomerase. Meth. Enzymol., 44,809-821. 

The basic patent coverage for use of xylose isomerase to convert glucose to fructose was lost in 1975 as the result of a civil action suit between CPC International and Standard Brands. Tins enabled development of alternate processes. By 1978. the estimated US production volume was 3.5 x 109 lb and consisted mostly ot syrups containing 42% D-fructose sold at a 71 % solids level (Antrim et al.). The introduction of large scale liquid chromatographic purification of the fructose enabled production of a 55% fructose which could be used in soft drinks in place of invert from sucrose. 

Antrim, R.L.. W. Colilla, and B.J. Schnyder "Glucose Iso me rase Production of High Fructose Syrups, AppL Biochem. Bioeng., 2, New York, NY, 98-154 (1979). Amheim, N. and C.H. Levenson Polymerase Chain Reaction, Chem. Eng. News, 68(40), 38-47 (1990). 

High-fructose com syrups dominate the carbohydrate-sweetened soft drinks sector in some markets - notably in the United States. However, in other markets, for example, Europe, the use of high-fructose glucose syrups (HFGS) is restricted by production quotas, and a variety of carbohydrate products including sucrose, glucose syrups, fructose and fructose syrups are used. 

Isomerases which convert glucose into the sweeter fructose were commercially introduced in the 1960s. Their introduction, coupled with manufacturing technology to immobilize these enzymes, led to the introduction of high-fructose syrup (HFS) in the United States in 1967. Refinements in production processes produced a liquid sweetener that could replace liquid sucrose on a one-to-one basis. At the same time, major upheavals in the world sugar market caused major sugar users to seek such an alternative. 

The conversion step to high-fructose syrup takes place in a reactor containing immobilized glucose isomerase. Although nonenzymic processes to isomerize glucose to fructose have been developed,11 these processes result in undesirable by-products of ash, color, and flavor, and other faults. 

Considerable effort based on research work initiated in the 1950s resulted in enzyme technology able to convert glucose to fructose on a commercial scale.32 34 Current production of high-fructose syrups generally uses immobilized, rather than soluble, enzymes. Sources of the enzyme include Streptomyces, Bacillus, Actinoplanes and Arthrobacter species. 

Glucose Isomerase. The biggest success story in the enzyme industry has to be glucose isomerase. The very first report of an enzyme that converts glucose to fructose was in 1957 (10). In less than 20 years the enzyme was studied, tailored into a cost effective immobilized form and put into production to make a commodity corn syrup product. In less than 30 years from its first description, it became the largest commercially used immobilized enzyme and responsible for making one of the world s major sweeteners. Since... 

SMB bioreactor for high fructose syrup by glucose isomerization Maximization of productivity of fructose and minimizing desorbent used. NSGA-II-JG Both operation and design of the SMB bioreactor were optimized. Zhang et al. (2004)... 

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