Leuconostoc/radish root ferment filtrate is a natural preservative created through the fermentation of radish roots (Raphanus sativus) with the microorganism Leuconostoc, a lactic acid bacteria that has traditionally been used to make kimchi. The use of preservatives in cosmetics is important because these types of products have a high potential for microbial contamination and growth. The most susceptible products are creams and lotions that are packaged in jars, opened frequently, and applied to the skin with the fingers. Inadvertent contamination may also occur after the use of makeup brushes around the eyes or other parts of the face that touch the skin and the cosmetic repeatedly. Microbial contamination can lead to significant health problems, from skin irritation to infections.

Initially, it was believed that Leuconostoc/radish root ferment filtrate contained natural peptides and acids that provided its preservative activity. However, recent studies have determined that the two compounds responsible for this ingredient’s preservative action are salicylic acid and an ammonium salt. Interestingly, these compounds do not come from the fermentation process, but are present because they are used in soil to manage the growth of radishes, ensuring consistent sizes and coloration.