| Description |
Isolated from many plants, free and combined. Alkyl esters of 4-hydroxybenzoic acid (see below) are used as food and cosmetic preservatives, mainly in their Na salt form, which makes them more water soluble. They are active at low concentrations and more pH-independent than the commonly used Benzoic acid <ht>DVN38-Z</ht> and 2,4-Hexadienoic acid <ht>GMZ10-P</ht>. The taste is more detectable than for those preservatives. Effectiveness increases with chain length of the alcohol, but for some microorganisms this reduces cell permeability and thus counteracts the increased efficiency. 4-Hydroxybenzoic acid is found in many foods, some of which are chicory, corn, rye, and black huckleberry. |
