Calcium hydroxide

Calcium hydroxide (slaked lime) has a rich history in traditional food processing worldwide. In Mexican and Central American cooking, it is fundamental to nixtamalization — the process of treating corn with lime water that makes the nutrients bioavailable and produces masa for tortillas and tamales. It is also used in the preparation of certain Asian desserts, in pickling (to maintain firmness), in clarifying sugarcane juice, and in the processing of certain Chinese preserved eggs.

JECFA's ADI is "not specified," evaluated in 1965. Calcium hydroxide is neutralised by food acids during processing, forming calcium salts that contribute bioavailable calcium to the diet. The nixtamalization process dramatically improves niacin bioavailability from corn — one of history's most important food processing innovations — and the calcium contribution is nutritionally significant in traditional corn-based diets.

Calcium hydroxide is approved in the EU, US (GRAS), UK, Australia, and globally. It is found in masa-based products (tortillas, tamales, arepas), traditional Asian desserts, pickled vegetables, and sugar products. For healthy consumers there are no safety concerns. The calcium and improved nutrient bioavailability it provides in traditional food preparations can be genuinely nutritionally positive.