Bentonite

Bentonite is a naturally occurring clay mineral belonging to the smectite group, composed primarily of montmorillonite — a layered aluminium phyllosilicate with a high capacity for swelling and adsorption. In food and beverage production it serves primarily as a clarifying and fining agent, particularly in wine and fruit juice making, where it removes proteins, tannins, and other haze-forming compounds by adsorbing them onto its surface. It is also used as an anti-caking agent in some powdered food applications.

No specific JECFA numerical ADI is on file for bentonite in the food additive context. Given its negligible absorption in the gastrointestinal tract and its long history of safe use in food processing, no upper intake limit has been established as necessary under normal use conditions. Bentonite is used in a processing rather than additive role in most applications — it is added to a liquid, allowed to adsorb unwanted components, and then removed by filtration before the product reaches consumers — meaning residual levels in final products are very low.

Bentonite is approved in the EU and in many other jurisdictions for use in food processing aids and as an anti-caking agent. Its food-grade specification differs from industrial grades used in drilling fluids and construction. In the context of beverages, bentonite is considered a processing aid rather than an additive in many regulatory frameworks, meaning it does not appear on the final product label in those applications. Where it is used as a direct additive, it appears as E558. It is considered safe for the general population at the low residual levels encountered in processed food and beverage products.