Curdlan is a water-insoluble linear beta-1,3- glucan, a high-molecular-weight polymer of glucose. It consists of β- (1,3)-linked glucose residues and forms elastic gels upon heating in aqueous suspension. It is produced by pure culture fermentation from the nonpathogenic and nontoxicogenic bacterium Alcaligenes faecalis var. myxogenes, which has been reclassified as Agrobacterium species.

Curdlan has numerous applications as a gelling agent in the food industry and has been approved as a food additive by the U.S. Food and Drug Administration (FDA) . It can be used as a formulation aid, processing aid, stabilizer and thickener, and texturizer in foods for which standards of identity do not preclude such use . It can also be used as a fat replacer in meat products, such as sausages and patties, to improve their texture and juiciness .

Curdlan has some unique properties that make it a versatile food additive. It can form thermally irreversible gels at temperatures above 60°C, which can withstand freezing and thawing cycles without losing their strength or elasticity . It can also form transparent gels with a smooth mouthfeel and a neutral taste . Moreover, it can interact with other ingredients, such as proteins and salts, to modify their functionality and enhance their synergistic effects .

Curdlan is also considered as a dietary fiber, since it is resistant to digestion by human enzymes . It has been reported to have some health benefits, such as lowering blood cholesterol levels, modulating immune responses, and stimulating intestinal microflora . However, more studies are needed to confirm its safety and efficacy in humans.

Curdlan is a natural and versatile food additive that can be used to improve the quality and functionality of various food products. It is also a potential source of dietary fiber that may have some health benefits. However, its production and application require careful optimization and regulation to ensure its quality and safety.