D-(+)-Glucono-1,5-lactone (Gluconic acid lactone)

D-(+)-Glucono-1,5-lactone is a polyhydroxy (PHA) that is capable of metal chelating, moisturizing and antioxidant activity.

D-(+)-Glucono-1,5-lactone is a lactone (cyclic ester) of D-gluconic acid. D-(+)-Glucono-1,5-lactone is commonly found in honey, fruit juices, personal lubricants, and wine. D-(+)-Glucono-1,5-lactone is neutral, but hydrolyses in water to gluconic acid which is acidic, adding a tangy taste to foods, though it has roughly a third of the sourness of citric acid. It is metabolized to glucose; one gram of D-(+)-Glucono-1,5-lactone yields roughly the same amount of metabolicenergy as one gram of sugar. Upon addition to water, GDL is partially hydrolysed to gluconic acid, with the balance between the lactone form and the acid form established as a chemical equilibrium. The rate of hydrolysis of D-(+)-Glucono-1,5-lactone is increased by heat and high pH[1].

[1]. Xu Y, et al. Aggregation and structural changes of silver carp actomyosin as affected by mild acidification with D-gluconic acid δ-lactone. Food Chem. 2012 Sep 15;134(2):1005-10.