LIPOXYGENASE ACTIVITY IN PIG MUSCLE - PURIFICATION AND PARTIAL CHARACTERIZATION

Lipoxygenase from Iberian pig Biceps femoris muscle was purified in a process that involves two successive chromatographic steps on DEAE-Sep hadex and phenyl-Sepharose CL4B. The purified enzyme had a final speci fic activity of 52 mU/mg, a purification factor of 3250, a molecular w eight of 90 kDA, and a maximum activity at pH 5.5. The K-M values obta ined for linoleic acid (K-M = 0.28 mM), arachidonic acid (K-M = 3.8 mM ), and linolenic acid (K-M = 0.43 mM) reveal a preferential use of lin oleic acid as substrate. When purified enzyme was incubated in the pre sence of linoleic acid, two main products were identified by direct-ph ase HPLC: 9-hydroperoxy octadecadienoic acid and 13-hydroperoxy octade cadienoic acid in the ratio of 45:55. The presence of lipoxygense acti vity suggest a possible participation of this enzyme in the biogenesis of flavor and aroma in hams from Iberian pigs.