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Polysaccharides

Polysaccharides Definition and Structure

Polysaccharides [Greek poly = many; sacchar = sugar] are complex carbohydrates, composed of 10 to up to several thousand monosaccharides arranged in chains. The most common monosaccharides that appear as parts of polysaccharides are glucosefructose, galactose and mannose.

Polysaccharides examples and structure image

Picture 1. A polysaccharide example:
starch, made of glucose molecules

Three Main Polysaccharides

Three main polysaccharides related to the human nutrition include:

  1. Starch ─ an energy source obtained from plants
  2. Cellulose ─ a structural polysaccharide in plants; when consumed, it acts as a dietary fiber
  3. Glycogen ─ a storage form of glucose in the human liver and muscles

Chart 1. List of Polysaccharides and Food Examples

POLYSACCHARIDE COMPOSITION Kcal/g FOOD SOURCE
DIGESTIBLE
Starch Glucose 4.2 Cereal grains (wheat, oats, barley, corn, rice…) and their products (bread, pasta, pastries, cookies), potatoes, tapioca, yam, legumes
Dextrin (starch gum) Glucose 3.8 An artificially produced food additive
Glycogen Glucose 4 Shellfish, animal liver
NON-DIGESTIBLE (DIETARY FIBER)
Cellulose Glucose 0 Whole grains, green leafy vegetables, beans, peas, lentils
Hemicellulose Arabinose + xylose 0 Cereals bran
Polydextrose Glucose 1.2 A food additive
Inulin Fructose + glucose 1-2 Wheat, onions, chicory root, leeks; a food additive
Beta-glucan Glucose ~2 Barley, whole oats, supplements
Pectin Various monosaccharides 3.3 Fruits, carrots, sweet potatoes; a food additive
Psyllium husk mucilage Various monosaccharides Psyllium seed husk
Galactomannans or gums: beta-mannan, carob, fenugreek, guar and tara gum Galactose + mannose 1-4 A food additive derived from beans and seeds
Glucomannan or konjac gum Glucose + mannose 0 A food additive extracted from konjac plant
Other natural gums: gum acacia (arabic), karaya, tragacanth Various monosaccharides 1.7 Food additives
Artificially produced gums: arabinoxylan (soluble), gellan, xanthan Various monosaccharides <2 Food additives
Seaweed polysaccharides: agar-agar, alginate, carrageenan Galactose Food additives derived from marine algae
Chitin and chitosan Glucosamin Dietary supplements, derived from shells of crustaceans

Polysaccharides Types, Digestion, Function and Benefits

Digestible polysaccharides, such as starch, are digested (broken down) in the mouth and small intestine in several steps that eventually yield glucose, which is absorbed. They are a source of energy; they provide about 4 Calories (kilocalories) per gram. They also provide carbon atoms for the synthesis of fats, proteins and other substances in your body.

Non-digestible polysaccharides or dietary fiber, such as cellulose, promote the passage of food through the gut and thus help maintain bowel regularity. Some non-digestible polysaccharides, such as inulin, may also promote the growth of beneficial intestinal bacteria.

None of the polysaccharides are essential nutrients; you do not need to consume them in order to be healthy.

Non-Starch Polysaccharides

Plant and Animal Sources of Polysaccharides

Plant foods are by far the commonest source of polysaccharides:

  • Starch is in cereal grains (wheat, oats, rye, barley, buckwheat, rice, etc.), potatoes and legumes (beans, peas, lentils).
  • Fiber is mainly in whole grains (whole-grain bread, brown rice, etc.), legumes, vegetables and fruits.

Animal foods are a poor source of polysaccharides:

  • A small amount of glycogen is in shellfish and animal liver.
  • An indigestible fiber chitin and its derivative chitosan are in shells of crustaceans (crabs, shrimps).

Polysaccharides as Food Additives

Naturally-occurring or artificially produced polysaccharides added to commercial foods as thickeners or fibers include various types of starches, dextrin, polydextrose, inulin and gums.

Storage vs Structural Polysaccharides

Storage polysaccharides are a storage form of energy, for example cellulose in plants and glycogen in animals and humans.

Structural polysaccharides give structure to plants; examples include cellulose in plants and chitin in the shells of crustaceans.

Related Nutrients

29 Responses to "Polysaccharides"

  1. isaac says:

    this website is really helping

  2. Kalu s. Onyekachi says:

    With this site, i can have an A in ma BCH201. God bless d mgt. #KALU

  3. Patel Aakash says:

    What is complex polysaccharides?

    • Jan Modric says:

      Patel, “complex polysaccharides” is a term used for polysaccharides that contain atoms and molecules that are otherwise not found in carbohydrates. Examples of complex polysaccharides would be glycosaminoglycans (contains nitrogen) and heparin sulfate (contains sulfur).

  4. Eneowelle Chinenye Cynthia says:

    This site is too helpful and understandable….tnx

  5. METHEW KAHWILI says:

    how can you classify polysacharide based on a) composition b)function? please help me

    • Jan Modric says:

      By composition (by number of sugar units):
      – monosaccharides (1); example: glucose
      – disaccharides (2); example: sucrose
      – oligosaccharides (3-9); example; maltotriose
      – polysaccharides (10 and more); examples: starch, cellulose, glycogen

      By function:
      – storage polysaccharides; example: glycogen
      – structural polysaccharides; examples: cellulose, chitin

  6. Omnia Beker says:

    how can polysccharides have hypoglycemic effect?

    • Jan Modric says:

      Omnia, after a large carbohydrate (polysaccharide) meal, a lot of glucose is absorbed in a short time, which triggers the release of a great amount of the hormone insulin. Insulin allows glucose to move from the blood to the cells quickly, which can result in low blood glucose levels. This is known as reactive or postprandial hypoglycemia and it mainly occurs in individuals with rapid gastric emptying, for example in those who have half of their stomach surgically removed due to cancer or in individuals with gastric bypass.

      • Omnia Beker says:

        thanks, but i mean for example i have studied in genseng , we can use it for treatment diabetes and this because it contains polysaccharide

        • Jan Modric says:

          Some indigestible polysaccharides, for example soluble fiber in guar gum, can slow down the absorption of glucose and thus reduce blood glucose spikes after meals.

  7. pankaj says:

    what is microbial polysaccharides and its types?

    • Jan Modric says:

      Pankaj, microbial polysaccharides are produced by bacteria and fungi. Here’s the Google search result for “microbial polysaccharides”. The first website (springer.com) has a table with a list of such polysaccharides, their composition and which microbe produces it. Examples are: alginate, cellulose, curdlan, dextran, gellan, hyalouran, levan, xanthan and pullulan.

  8. pankaj says:

    May you send link for legume and oil seed technology.
    It can’t search datail on Google.

  9. abdulkabir says:

    Name five known sugar polysaccharide

  10. kian butller says:

    this site is the best site and its really helpful

  11. Beholdenages says:

    Thanks for the list! I’m allergic to some of these polysaccharides and now I know which ones I need to look out for. Xanthan gum and carrageenan cause me to go into lethargy spells that last for days until it wears off, but I’m sure those are not the only ones. Again, thanks!

  12. afaang says:

    How carbs (poly) help in waste elimination . Please help me .

  13. Sama says:

    Thanks a lot for such useful information. I am confused about relation between polysaccharides and gums. Which polysaccharides have potential of being used for making gum? For example if I have 20 percent polysaccharide in a fruit sample, does it mean that the gum potential for that is 20 percent ot not necessarily 20 percent? Thank you

    • Jan Modric says:

      A polysaccharide is a chemical therm that tells that a molecule is composed of many (poly) sugars (saccharides). Gums are mixtures of various polysaccharides. The term “gum” describes more its appearance than the chemical structure. Various gums are listed in the Chart 1 in the article above – you can check for individual articles for each gum. I’m not sure what exactly do you want to get from fruits.

  14. Erez says:

    Great info, wonderfully explained thanks.

  15. Shubhi says:

    Which polysaccharides is present in bread? ..

    • Jan Modric says:

      The main polysaccharide in bread is starch. Whole-grain bread also contains indigestible polysaccharides, that is fiber, such as cellulose and arabinoxylan.

  16. Shubhi says:

    Thanku so much

  17. Tom says:

    Can you help me to identify which polysaccharide will create the most “elastic” viscosity gel when mixed with water? The application will be used to make a slime like substance, but needs to be much more “stretchy” than the standard class room borax based slime. Thank you.

    • Jan Modric says:

      I don’t know. I found this here:

      The non-gelling agents (eg, xanthan and guar gum), and gelling agents (carrageenan and locust bean gum) are commonly combined to achieve increased viscosity or superior properties of food gels, such as higher elasticity.

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