Gellan Gum

What is Gellan Gum? Gellan gum is a nature-based ingredient produced through the fermentation of the gram-negative bacteria Pseudomonas elodea, which was initially discovered in a lily pond in Pennsylvania. It is a microbial extracellular polysaccharide that can be dried and milled into a powder for easy incorporation into various products. Gellan gum is known for its versatile texture, stability, and ability to form gels with adjustable setting temperatures and melting points. It has been approved for use in food, non-food, cosmetic, and pharmaceutical applications by numerous countries, including the U.S., Canada, China, Korea, and the European Union, and is recognized for its safety and multi-functional properties[1][2][3]. Common Uses in Food and Beverages Gellan gum is widely used in the food and beverage industry for its thickening, stabilizing, and suspending properties. It is commonly found in dairy products, such as yogurt, sour cream, and cheese, where it improves texture and prevents the separation of solids and liquids. In baked goods, it enhances texture, increases moisture retention, and extends shelf life. In confectionery, gellan gum is used to create gels and textures in products like gummy candies and jelly beans. It is also used in beverages to stabilize suspensions, prevent sedimentation, and improve mouthfeel in products such as sports drinks, juices, and plant-based milks. Additionally, gellan gum is utilized in sauces and dressings to create stable emulsions and in plant-based alternatives to dairy products to provide a smooth, creamy texture and improve stability and shelf life[4][2][3].

The production of gellan gum involves a multi-step process that begins with fermentation. Gellan gum is produced by the bacterium Sphingomonas elodea, which is cultivated through a multi-stage inoculum build-up process. This process starts from an agar plate and progresses through shake flasks, small seed fermentation vessels, and finally to large final fermentation vessels. The fermentation medium typically consists of glucose syrup, inorganic nitrogen sources such as ammonium or nitrate salts, organic nitrogen sources like protein, and trace elements. The fermentation is carried out under aerobic conditions, with strict aseptic techniques to ensure the culture remains pure and free from contamination[1][2][3].

Once the fermentation is complete, the bacterial cells are killed through pasteurization to optimize the polymer conformation. The gellan gum is then recovered from the fermentation broth by adding an alcohol, usually isopropyl alcohol, which causes the gellan gum to precipitate. The precipitated gellan gum is then separated from the liquid using techniques like filtration or centrifugation. The gum is further purified through washing, filtration, and centrifugation to remove impurities. After purification, the gellan gum is concentrated and dried using methods such as vacuum drying, boiling drying, or other drying techniques to achieve the desired moisture level. Finally, the dried gellan gum is ground into a powder and packaged in a controlled environment, undergoing extensive quality control testing before being released for sale[1][2][3].

The safety profile for human consumption of Gellan Gum is highly favorable. It has been extensively evaluated and approved by regulatory bodies such as the European Food Safety Authority (EFSA), the U.S. Food and Drug Administration (FDA), and the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Studies have shown that gellan gum does not cause adverse dietary or physiological effects even at high levels of ingestion. Repeated oral intake up to 200 mg/kg body weight per day for 3 weeks had no adverse effects in humans, and chronic studies in animals did not reveal any toxic effects at the highest doses tested[1][2][3]. There is no concern regarding carcinogenicity, genotoxicity, or allergic reactions, and no numerical acceptable daily intake (ADI) is deemed necessary due to its safe profile.

Regarding potential contamination risks, gellan gum is subject to strict specifications and testing to ensure its safety. The manufacturing process involves steps to remove potential impurities such as polyhydroxybutyrate (PHB), enzymes, and viable cells from the production organism, which are inactivated during the alkali-heat treatment step. The final product is tested for residual isopropanol and ethanol, with set limits to ensure compliance. Heavy metal contamination is also closely monitored, with specifications setting maximum permissible levels for lead, arsenic, and other heavy metals. For example, the maximum permissible level for lead in gellan gum is 2 ppm, which is well below the levels that could pose a risk to human health, especially in products like infant formula[4][3]. Additionally, the risk of pathogen contamination is mitigated through stringent microbiological criteria, including tests for the absence of pathogens such as Escherichia coli, Salmonella spp, and Staphylococcus aureus[3]. Overall, the rigorous testing and specification standards minimize the risks associated with contamination.