What Is Gellan Gum Low Acyl (E418)? Applications, Dosage, Alternatives & Specifications

Gellan Gum, also known as Gellan Gum or Kelco Gum, is a novel high-molecular-weight linear polysaccharide produced by microbial fermentation. It belongs to the important category of microbial-derived hydrophilic colloids, with wide application value in the global food industry, pharmaceutical field, cosmetics, and daily chemical industry. Its CAS number is 71010–52–1. The molecular structure consists of a tetrasaccharide repeating unit composed of D-glucose, D-glucuronic acid, D-glucose, and L-rhamnose linked by glycosidic bonds. Gellan gum was discovered and commercialized in the 1970s by the American Kelco company from the fermentation broth of Sphingomonas paucimobilis (formerly Pseudomonas elodea). It is one of the most valuable food microbial polysaccharides developed after xanthan gum in the 1980s. Because gellan gum can produce gels at extremely low usage levels, and the gels exhibit excellent transparency, thermal stability, and flavor release, it has been widely applied in the food industry within a short period and has become an irreplaceable hydrophilic colloid. Gellan gum dry powder appears as white to off-white powder, odorless and tasteless, with no special taste or odor, and decomposes at approximately 150°C without melting. Gellan gum is insoluble in non-polar solvents and cold water, but disperses in water with slight stirring. It dissolves into a transparent solution upon heating, forming a transparent and firm gel upon cooling. In aqueous solution, gellan gum exists in a double helix form. The double helix structures further aggregate to form a three-dimensional gel network, and the presence of cations in the system promotes gel formation. Gellan gum is divided into two major types based on the acyl content of the molecular structure: High Acyl Gellan Gum and Low Acyl Gellan Gum, with significant differences in gelling properties and applications.

High Acyl Gellan Gum: Contains acetyl and glyceryl groups in the natural structure. High acyl gellan gum can form stable elastic gels with good water-holding capacity, acid resistance, excellent suspension stability for fruit pulp and insoluble components, and good compatibility with other hydrocolloids. It forms a toothpaste-like paste upon preheating and cooling, suitable for applications such as pectin, toothpaste, beverage thickening, protein beverage suspension, and jam thickening.

Low Acyl Gellan Gum: Produced by alkali treatment to remove O-acyl groups from natural gellan gum. Low acyl gellan gum exhibits extremely high gel strength at very low usage levels, very high gel transparency, strong adjustability of gel elasticity and hardness, good flavor release, compatibility, thermal stability, acid resistance, and anti-enzymatic properties. It forms high-quality gels at low concentrations (0.05%-0.25%) with high brittleness, high hardness, and high transparency, suitable for applications such as jellies, puddings, plant-based yogurts, and other scenarios requiring high-strength transparent gels.