Lactones, in English, refers to an organic compound containing both carboxyl and hydroxyl groups in the same molecule, which are dehydrated to form. It is one of the main raw materials for making tofu and tofu brain.

In the traditional tofu production, gypsum and brine are mostly used as coagulants, which have the characteristics of complex technology, low yield, short storage period and difficult absorption by human body. Using gluconolactone as coagulant to produce tofu can reduce the loss of protein and improve the water retention rate. The yield is greatly increased, and the tofu is white, delicate, shiny, good in taste and long in storage time.