Gluconolactone

Gluconolactone is a lactone derived from gluconic acid, the oxidative product of glucose. It is a six-membered ring polyhydroxy compound and is typically classified as a polyhydroxy acid (PHA). In water, gluconolactone slowly hydrolyzes to gluconic acid, with the balance between the lactone and acid forms depending on pH and temperature.

Production and properties: Gluconolactone can be formed by intramolecular cyclization of gluconic acid or by chemical/enzymatic pathways that promote lactonization of glucose derivatives. It is highly soluble in water and generally stable under neutral to mildly acidic conditions. The compound is non-volatile and has a sweet-tasting, slightly tart character in some contexts, though it is mainly valued for its functional properties rather than flavor.

Applications: In cosmetics and personal care, gluconolactone is used as a gentle exfoliant and humectant, categorized among polyhydroxy acids. It provides milder keratolytic activity compared with some other exfoliants and can improve skin texture and moisture retention when formulated in creams, serums, and cleansers. In skincare, it is often preferred for sensitive or reactive skin types. In the food industry, the ingredient is used only in select applications as a minor additive, where it may act as a buffering or stabilizing agent; its primary value lies in its chemical compatibility and controlled hydrolysis to gluconic acid.

Safety and regulation: Gluconolactone is regarded as safe for cosmetic use when used as directed, with low irritation potential for most users. As with all ingredients, individuals with sensitive skin should perform patch tests and follow product labeling. Regulatory status varies by jurisdiction and product category.