Lipoxygenase (LOX) is one of the most widely studied enzyme in plants and animal kingdom which is found in more than 60 species. Lipoxygenase catalyses the bioxygenation of polyunsaturated fatty acids (PUFA) containing a cis,cis- 1,4-pentadiene unit to form conjugated hydroperoxydienoic acids. Lipoxygenases have food-related applications in bread making and aroma production; they also have negative implications for the color, off-flavour and antioxidant status of plant-based foods. The significance of plant lipoxygenase for fruit and vegetables are reviewed with particular reference to the enzymes from plants. Various aspects of the sources of lipoxygenases, their oxidation mechanism, isozymes and inhibition of oxidation are discussed. (c) 2006 Elsevier Inc. All rights reserved.