EFFECT OF LIPID OXIDATION-PRODUCTS ON THE TRANSESTERIFICATION ACTIVITY OF AN IMMOBILIZED LIPASE

The effect of varying amounts of linoleic acid hydroperoxides on the activity of an immobilized lipase, Lipozyme, used for the transesterification of fats has been studied. The initial activity of the enzyme is not significantly reduced even by a peroxide value of 50 mequiv/kg, but the operational stability is reduced if the peroxide value of the oil is above 5 mequiv/kg, with the rate of enzyme inactivation increasing with peroxide value. A sample with initial peroxide value of 50 mequiv/kg caused a 50% loss of activity after eight batch treatments of 10 h per treatment. The loss of activity is due to generation of free radicals in the enzyme following hydroperoxide decomposition.