Calcium sulphate

Calcium sulphate, commonly known as gypsum, is a naturally occurring mineral used in food as a firming agent, calcium supplement, and flour treatment agent. Its most widely known food application is in tofu production, where calcium sulphate is one of the primary coagulants used to set soy protein — this is the traditional Chinese tofu-making method. It is also used to improve the texture of flour, in brewing water treatment, and as a calcium supplement in fortified foods.

JECFA's ADI is "not specified," evaluated in 1965. Calcium sulphate provides bioavailable calcium and sulphate — both normal dietary and physiological components. The body absorbs calcium through intestinal mechanisms and excretes sulphate renally. No adverse effects have been identified at any realistic dietary exposure. The calcium contribution is nutritionally beneficial.

Calcium sulphate is approved in the EU, US (GRAS), UK, Australia, and globally. It is found in tofu, fortified flour, bread, certain cereals, and beverage products. For the general population it is one of the most nutritionally positive additives available — simultaneously a firming agent and a calcium source. People with hypercalcaemia should monitor total calcium, but for healthy adults E516 is entirely benign.