Glucono delta-lactone (GDL) is a cyclic ester of D-gluconic acid. The latter is obtained by fermenting glucose, then crystallized in GDL form. GDL exists in its natural state in particular in honey and grape juice. GDL is an acidifying agent that enables progressive acidification, unlike other food acids. It is used in Panner, cheeses, meat-based products, tofu and cooking products. Roquette is the world leader in Glucono delta-lactone production.