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Lipoxygenase from Iberian pig Biceps femoris muscle was purified in a process that involves two successive chromatographic steps on DEAE-Sephadex and phenyl-Sepharose CL4B. The purified enzyme had a final specific activity of 52 mU/mg, a purification factor of 3250, a molecular weight of 90 kDA, and a maximum activity at pH 5.5. The K M values obtained 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 linoleic acid as substrate. When purified enzyme was incubated in the presence of linoleic acid, two main products were identified by direct-phase HPLC:  9-hydroperoxy octadecadienoic acid and 13-hydroperoxy octadecadienoic acid in the ratio of 45:55. The presence of lipoxygense activity suggest a possible participation of this enzyme in the biogenesis of flavor and aroma in hams from Iberian pigs. Keywords: Lipoxygenase; purification; hams; Iberian pig; lipid oxidation

In this study, lipoxygenase from potato tuber has been purified by a method involving hydrophobic chromatography and the purified enzyme immobilized by covalent coupling to oxirane acrylic beads. The immobilized lipoxygenase exhibited increased long-term stability without a significant modification of the kinetic parameters. The comparative study on the effects of inhibitors such as dithizone, NDGA, phenidone, and beta-mercaptoethanol on the free and immobilized enzyme highlighted the importance of the lipoxygenase--support interaction, concluding that the immobilization process could cause the protection of the iron atom in the enzyme. The enzymatic specificity was maintained for the immobilized lipoxygenase, and their stability increased as compared to the free enzyme, making if feasible to use the enzyme in a multistep reaction to produce large quantities of leukotriene A4 or other related compounds of interest in the chemical industry and medicine.

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