Fructan

A fructan is a polymer of fructose molecules. They occur in foods such as:
*Artichokes
*Asparagus
*Green beans
*Leeks
*Onions (including spring onion)
*Wheat

In animal fodder, fructans also appear in grass, with dietary implications for horses and other equidae.

There are 3 types of fructans:
# Inulin - linear fructans generally linked by β(2→1) glycosidic bonds
# Levan - linear fructans generally linked by β(2→6) glycosidic bondscite book |author=Kang et al|year=2009|chapter=Levan: Applications and Perspectives|title=Microbial Production of Biopolymers and Polymer Precursors|publisher=Caister Academic Press|id = ISBN 978-1-904455-36-3]
# Graminan - branched fructans linked by both β(2→1) and β(2→6) glycosidic bonds

Fructan content of various foods

Artichoke, Jerusalem: 16.0-20.0%SUSAN J. SHEPHERD, M Nut Diet, APD*; PETER R. GIBSON, MD, MB, FRACP, "Fructose Malabsorption and Symptoms of Irritable Bowel Syndrome: Guidelines for Effective Dietary Management," J Am Diet Assoc 2006:106:1631-1639. [http://sacfs.asn.au/download/SueShepherd_sarticle.pdf] ]

Artichoke, Globe: 2.0-6.8%.]

Asparagus: 1.4-4.1%.]

Barley kernels (very young): 22%Department of Food Science and Nutrition, University of Minnesota, Joanne L. Slavin, PhD, RD, "Mechanisms for the Impact of Whole Grain Foods on Cancer Risk," Journal of the American College of Nutrition, Vol. 19, No. 90003, 300S-307S (2000) [http://www.jacn.org/cgi/content/full/19/suppl_3/300S] ]

Cheese spread: 4.5%Leon Prosky and Hubert Hoebregs, "Methods to Determine Food Inulin and Oligofructose," Journal of Nutrition. 1999;129:1418S-1423S. [http://jn.nutrition.org/cgi/content/full/129/7/1418S/T4] ]

Chocolate: 9.4%.]

Onion: 1.1-10.1%.]

Rye bran: 7%Karppinen, Sirpa. Dietary fibre components of rye bran and their fermentation in vitro. Espoo 2003. VTT Publications 500. 96 p. + app. 52 p. [http://www.vtt.fi/inf/pdf/publications/2003/P500.pdf] ]

Rye grain: 4.6-6.6%.]

Wheat flour: 1-4%.]

Pasta: 1-4%.]

White bread: 0.7-2.8%.]

Functions

Plants storing their food as fructans are able to thrive at low temperatures since fructans confer tolerance to freezing.They bind to membranes, thereby helping to keep cells intact.

ee also

*Fructooligosaccharide
*Fructose intolerance
*Fructose malabsorption
*Prebiotic (nutrition)
*Sucrose
*Levan polysaccharide

References

Footnotes

General references

*"Sugar - Chemical, Biological and Nutritional Aspects of Sucrose". John Yudkin, Jack Edelman and Leslie Hough (1971, 1973). The Butterworth Group. ISBN 0-408-70172-2

External links

* [http://www.geocities.com/CapeCanaveral/4409/ The Fructan Page]