Guaran

Structural formula
General
Surname	Guaran
other names	Guar gum; Guar; Guar flour; E 412 ;
CAS number	9000-30-0
Monomers	1,4-β- D - mannose , galactose
Molecular formula of the repeating unit	C 18 H 30 O 15
Molar mass of the repeating unit	486.42 g mol −1
Type of polymer	Polysaccharide
Brief description	yellowish-white powder
properties
Physical state	firmly
solubility	soluble in water
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
Toxicological data	6770 mg kg −1 ( LD 50 , rat , oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Guaran , also called guar gum , is a vegetable gum (a vegetable mucilage ). The chemical compound from the group of polysaccharides is the main component of guar gum (or guar flour for short ). Guaran is used, among other things, as a food additive E 412.

Chemical structure

Guaran consists of D - mannopyranose units , which are linked together in a chain-like manner via β-1,4- glycosidic bonds . In addition, every second mannopyranose unit carries α- D - galactopyranosyl - residues via a 1,6 bond .

Manufacturing

Guar bean ( Cyamopsis tetragonoloba )

Guar gum is obtained from the seeds of the guar bean ( scientifically Cyamopsis tetragonoloba ) by removing the outer layers and the seedling and then grinding the remaining parts. In addition to guaran, the guar gum contains 10 to 15% water, 5% protein , 2.5% crude fiber and less than 1% ash.

The carob tree provides a functionally similar food additive belonging to the galactomannan class .

use

Guaran is used in the pharmaceutical , cosmetic , paper and food industries and also as a tobacco additive . So it serves z. B. as an emulsifier (for example in ice cream ) or natural thickener and is also a more common component of hair gel . In the EU , guaran has limited approval as a food additive (number E 412) for food in general (also for "organic" products ).

In addition, guaran is used in the oil industry in the fracking process as a shear load-dependent, highly viscous solution .

Health aspects

The inactivation of harmful substances (e.g. saponins , fluoroacetic acid or allergenic proteins ) is only partially possible through heating and extraction, so that the thickener guar gum (E 412) can promote the development of allergies or even promote allergic reactions.

Guaran is practically not digested by humans and is not absorbed unchanged in the gastrointestinal system. Bacteria in the large intestine, however, break down the multiple sugars, producing gases. Therefore, if Guaran is consumed frequently, it can affect the intestinal flora and trigger abdominal cramps and flatulence .

If larger amounts of guaran or guar gum in the form of powder, tablets or capsules are taken without sufficient amounts of liquid, the high swelling capacity can damage (block) the esophagus , stomach and intestines . In 1991 it was therefore classified as a risky slimming product by the American FDA .

A new evaluation by EFSA in 2016 came to the conclusion that the use of guar gum in food does not pose a safety risk to the population. It was not considered necessary to establish a maximum permitted daily dose . However, the possible occurrence of indigestion in infants and young children should be subject to further investigation.

Web links

Guaran on x-plainmefood
E 412 - Additives database
List of foods containing guar gum
Udo Pollmer: Hunt for the miracle bean guar. In: Deutschlandradio Kultur. September 23, 2012, accessed February 18, 2017 .

Individual evidence

↑ Entry on E 412: Guar gum in the European database on food additives, accessed on August 6, 2020.
↑ ^a ^b ^c ^d ^e Guar gum data sheet from Fisher Scientific, accessed February 12, 2019.
↑ Additive Admissions Ordinance Annex 4 (to § 5 Paragraph 1 and § 7) Limited additives
↑ ^a ^b Guar Gum - Additives Database (accessed April 28, 2008).
↑ Warning Statements Required for Over-the-Counter Drugs Containing Water-Soluble Gums as Active Ingredients; Clarification Federal Register I Vol. 56, No. 44, p 50
↑ EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Alicja Mortensen, Fernando Aguilar, Riccardo Crebelli, Alessandro Di Domenico: Re-evaluation of guar gum (E 412) as a food additive . In: EFSA Journal . tape 15 , no. 2 , February 1, 2017, ISSN 1831-4732 , p. n / a – n / a , doi : 10.2903 / j.efsa.2017.4669 .

[E-Nummer412-1] Entry on E 412: Guar gum in the European database on food additives, accessed on August 6, 2020.

[fsc-2] Guar gum data sheet from Fisher Scientific, accessed February 12, 2019.

[3] Additive Admissions Ordinance Annex 4 (to § 5 Paragraph 1 and § 7) Limited additives

[zusatzstoffe-4] Guar Gum - Additives Database (accessed April 28, 2008).

[5] Warning Statements Required for Over-the-Counter Drugs Containing Water-Soluble Gums as Active Ingredients; Clarification Federal Register I Vol. 56, No. 44, p 50

[6] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Alicja Mortensen, Fernando Aguilar, Riccardo Crebelli, Alessandro Di Domenico: Re-evaluation of guar gum (E 412) as a food additive . In: EFSA Journal . tape 15 , no. 2 , February 1, 2017, ISSN 1831-4732 , p. n / a – n / a , doi : 10.2903 / j.efsa.2017.4669 .