Konjac gum

Konjac gum, extracted from the dried root of Amorphophallus konjac, is a high-viscosity dietary fibre and gelling agent. It is the primary component of traditional shirataki noodles and konjac jelly, and is used commercially as a fat replacer, thickener, and texture modifier in low-calorie foods, gluten-free products, and processed meats. With the highest viscosity of any known dietary fibre, it is effective even at very low concentrations, typically 0.5–2%.

JECFA's ADI for konjac gum is "not specified," evaluated in 2004. As an insoluble, highly viscous fibre, it passes through the gut largely undigested, contributing to satiety, slowing glucose absorption, and providing prebiotic benefits. These properties are associated with positive effects on blood sugar control and LDL cholesterol levels at higher intakes. No toxicological concerns have been identified at food additive doses.

Konjac gum is approved in the EU, US, UK, Australia, and most global markets. One specific EU safety restriction applies to konjac jelly products sold in mini-cup format, due to a choking hazard in young children and elderly adults when large firm gel pieces are swallowed whole. This restriction does not apply to konjac at low concentrations in normal food applications. For most consumers, E425 is a benign and nutritionally positive additive, increasingly popular in weight management and diabetic-friendly food formulations.