Natural gum

Natural gums are polysaccharides of natural origin, capable of causing a large increase in a solution's viscosity, even at small concentrations. They are mostly botanical gums, found in the woody elements of plants or in seed coatings.

Natural gum from plum tree

Human uses

Gums are used in the food industry as thickening agents, gelling agents, emulsifying agents, and stabilizers, and in other industrial adhesives, binding agents, crystal inhibitors, clarifying agents, encapsulating agents, flocculating agents, swelling agents, foam stabilizers, etc. When consumed by humans, many of these gums are fermented by the microbes that inhabit the lower gastrointestinal tract (microbiome) and may influence the ecology and functions of these microscopic communities.^[1][2]

Commercial significance

Humans have used natural gums for various purposes, including chewing and the manufacturing of a wide range of products – such as varnish and lacquerware. Before the invention of synthetic equivalents, trade in gum formed part of the economy in places such as the Arabian peninsula (hence the name "gum arabic"), West Africa,^[3] East Africa (copal) and northern New Zealand (kauri gum).

Examples

Natural gums can be classified according to their origin. They can also be classified as uncharged or ionic polymers (polyelectrolytes). Examples include (with E number food additive code):

Source	Classification	Natural gum	E number	biological origin
obtained from seaweeds	Polyelectrolytes	Agar	E406
obtained from seaweeds	Polyelectrolytes	Alginic acid	E400
obtained from seaweeds	Polyelectrolytes	Sodium alginate	E401
obtained from seaweeds	Polyelectrolytes	Carrageenan	E407
obtained from non-marine botanical resources	Polyelectrolytes	Gum arabic	E414	from the sap of Acacia trees
obtained from non-marine botanical resources	Polyelectrolytes	Gum ghatti		from the sap of Anogeissus trees
obtained from non-marine botanical resources	Polyelectrolytes	Gum tragacanth	E413	from the sap of Astragalus shrubs
obtained from non-marine botanical resources	Polyelectrolytes	Karaya gum	E416	from the sap of Sterculia trees
obtained from non-marine botanical resources	Uncharged	Guar gum	E412	from guar beans
obtained from non-marine botanical resources	Uncharged	Locust bean gum	E410	from the seeds of the carob tree
obtained from non-marine botanical resources	Uncharged	Beta-glucan		from oat or barley bran
obtained from non-marine botanical resources	Uncharged	Dammar gum		from the sap of Dipterocarpaceae trees
obtained from non-marine botanical resources	Uncharged	Glucomannan	E425	from the konjac plant
obtained from non-marine botanical resources	Uncharged	Psyllium seed husks		from the Plantago plant
obtained from non-marine botanical resources	Uncharged	Tara gum	E417	from the seeds of the tara tree
produced by bacterial fermentation	Polyelectrolytes	Gellan gum	E418
produced by bacterial fermentation	Polyelectrolytes	Xanthan gum	E415