Gellan Gum Description
Gellan is a high molecular weight polysaccharide produced by the micro-organism Pseudomonas elodea. This organism was found during an extensive screening programme seeking naturally occurring hydrocolloids with useful properties. Gellan gum is a multi-functional gelling agent that can produce a wide variety of interesting textures. It is extremely effective at low use levels and is available in two forms. High acyl gellan gum forms soft, elastic gels. Low acyl gellan gum forms firm, brittle gels.
Gellan gum, which forms gels on cooling, is a versatile and effective gelling agent. It is available in two forms (high or low acyl content). The acyl groups have a profound influence on gel characteristics. The high acyl form produces soft elastic gels, while the low acyl form produces firm brittle gels. They may be used alone or blended to give products with the desired characteristics.
A further benefit of gellan gum is that it can be used at very low concentrations to produce products with excellent flavour release and no flavour masking.
In most practical situations, gels made with low acyl gellan gum are not thermally reversible and will be retort or bake stable.
Gellan gum can form fluid gels, which are in effect solutions with a weak gel structure. They exhibit an apparent yield stress, ie a finite stress which must be exceeded before the system will flow. Their highly pseudoplastic flow properties provide extremely efficient suspension combined with low viscosity at higher shear rates. This results in low viscosity in the mouth, making them particularly effective in suspending a wide variety of solids and emulsified oils. Suspension can be achieved without affecting the mouthfeel.
Gentle agitation of a weak gellan gum after it has set is also sufficient to form a weak, pourable fluid gel. This means fluid gels can be formed using standard filling operations.
Extensive investigations with respect to toxicology and safety have shown that gellan gum is a safe food additive. It was cleared by the FDA (the US Food and Drug Administration) in 1969 and registered in the Code of federal Regulations.
Gellan gum is approved as a food additive in the European Community under the number E 418, with ADI (acceptable daily intake) “not specified” confirming its status as a safe food additive. The gellan gum food grade produced by Biopolymer members fully meets the standards and the purity criteria issued in different regions of the world or internationally, such as the Food Chemicals Codex and JECFA, the US Pharmacopoeia/National Formulary, and the European Directives.
Due to the extraordinary properties as stabiliser and thickener gellan gum is used in the food, cosmetic, pharmaceutical and also in various industrial applications.