Lipoxygenase activity in seeds from New Zealand native plants

Abstract

Seeds from 48 New Zealand native plants, were tested for lipoxygenase enzymes and subsequent formation of products from linoleic and a-linolenic acid. Lipoxygenases are of interest to the food and biotechnology industries as a means of producing natural flavour substances. Extracts of Gunnera hamiltonii possessed the highest lipoxygenase activity of 5.6.tmol min-1 g-1. Analysis of the 13- and 9-positional isomers of the oxidation products of linoleic acid showed that Melicystus lanceolatus × M. flexuosa, Pseudopanax arboreus, Carmichaelia kirkii, Dianella nigra, and Olearia paniculata produced higher proportions of the 13-derivatives. Hoheria populnea, Solanum laciniatum, and Urtica australis produced predominately the 9-isomers. Analysis of the 13- and 9-positional isomers of the oxidation products of a-linolenic acid showed that all species except Chionochloaflavescens were able to oxidise the trienoic acid to form 13-positional isomers. Olearia ilicifolia produced only 13-positional isomers. Only 11 of the species produced substantial amounts of the 9-derivatives from a-li-nolenic acid. Chionochloaflavescens showed only the activity of a 9-lipoxygenase. © 1999 Taylor & Francis Group, LLC.