Isoglucose

from Wikipedia, the free encyclopedia

Isoglucose ( isomerose , isoglucose ) is a mixture of grape sugar ( glucose ) and fruit sugar ( fructose ). To produce isoglucose, glucose is partially converted into fructose by the catalytic action of the enzyme glucose isomerase , which is where the term isomerate sugar comes from. In contrast to isoglucose, invert sugar is produced as a mixture of glucose and fructose through the hydrolysis of sucrose.

properties

Glucose is produced industrially from starch by enzymatic hydrolysis using glucose amylase . The result is glucose syrup (or corn syrup made from corn starch ) with an annual worldwide production volume of 20 million tons (as of 2011). This is where the name "starch sugar" was used in the past. Corn, potatoes , rice , wheat , cassava and sago are used as starch sources . In the USA, corn is used almost exclusively for the production of isoglucose, which is a mixture of glucose and fructose, since fructose has a higher sweetness with a similar physiological calorific value. The amylase mostly originates from Bacillus licheniformis , Bacillus subtilis (strain MN-385), Bacillus coagulans , Streptomyces rubiginosus or Streptomyces phaeochromogenes . The glucose produced from starch is used to produce fructose after calcium ions have been removed , since calcium ions are cofactors of amylase, but inhibitors of glucose isomerase (more precisely xylose isomerase) in the subsequent conversion to fructose - magnesium ions are the cofactors.

The glucose is used to produce high fructose corn syrup (HFCS) with the help of immobilized glucose isomerase . The annual worldwide production of isoglucose is eight million tons (as of 2011). The conversion reaction is carried out at 55 ° C., the half-life of the enzyme activity of the immobilized glucose isomerase is over 100 days. HFCS is sold as HFCS-42 (with 42% fructose and 53% glucose in the dry matter) and HFCS-55 (with 55% fructose and 41% glucose in the dry matter, second generation HFCS from 1976). The enzymes have been immobilized since about 1972, which kept the cost of producing HFCS in the US below the cost of importing sucrose. At the same time, this was also the first large-scale application of immobilization of enzymes and it represents the largest technical use of immobilized enzymes in the world in terms of quantity. Corn syrup has between 20% and 95% glucose. In addition, HFCS-90 with 90% fructose content is produced by chromatography , which is used for the production of HFCS-55 by dilution with HFCS-42. Most soft drinks in the United States use HFCS-55 while most other HFCS-sweetened foods use HFCS-42.

In the USA, this high fructose corn syrup has become the most important product in the corn starch industry and has largely supplanted household sugar ( sucrose ), especially in lemonade and soft drinks.

Web link

Individual evidence

  1. ↑ a b Thomas Becker, Dietmar Breithaupt, Horst Werner Doelle, Armin Fiechter, Günther Schlegel, Sakayu Shimizu, Hideaki Yamada: Biotechnology , in: Ullmann's Encyclopedia of Industrial Chemistry , 7th edition, Wiley-VCH, 2011. ISBN 978-3- 527-32943-4 . Volume 6, p. 48.
  2. ↑ Starch sugar . In: Merck's Warenlexikon . 3rd ed. 1884 ff., P. 457 f.
  3. ↑ a b The Amylase Research Society of Japan: Handbook of Amylases and Related Enzymes. Elsevier, 2014, ISBN 978-1-483-29939-6 , p. 195.
  4. ↑ a b c d e f Andreas Liese: Industrial Biotransformations. John Wiley & Sons, 2008, ISBN 978-3-527-61417-2 , pp. 17, 388.
  5. ↑ Ashok Pandey: Industrial Biorefineries and White Biotechnology. Elsevier, 2015, ISBN 978-0-444-63464-1 , p. 488.
  6. ^ Atsuo Tanaka: Industrial Application of Immobilized Biocatalysts. CRC Press, 1992, ISBN 978-0-824-78744-8 , p. 185.
  7. ↑ a b c d Byong H. Lee: Fundamentals of Food Biotechnology. John Wiley & Sons, 2014, ISBN 978-1-118-38491-6 , p. 332.
  8. ↑ James N. BeMiller, Roy L. Whistler ,: Starch: Chemistry and Technology  (= Food Science and Technology), 3rd. Edition, Academic Press, New York 2009, ISBN 008092655X .
  9. ↑ High Fructose Corn Syrup: Questions and Answers . US Food and Drug Administration. November 5, 2014. Archived from the original on January 25, 2018. Retrieved December 18, 2017.
  10. ↑ Enzymes: The Transformation of Starch into Sugar , accessed April 9, 2018