The Effect of Solution Properties on the Photochemical Ability of Pulsed Light to Inactivate Soybean Lipoxygenase

Abstract

Abstract Inactivation of pure soybean lipoxygenase (LOX) by pulsed light (PL) technique was found to occur due to a photochemical effect, while inactivation of soybean LOX in a real food (soymilk) was due to the photothermal effect of PL. The effect of solution properties on the photochemical ability of PL to inactivate and degrade LOX was investigated. LOX was placed in different conditions and treated with PL at a 7 cm distance with different times. The result showed that LOX was less stable during PL operation at pH 9 compared with pH 6.8. Increasing LOX concentration, adding starch, and making a colored solution did reduce the photochemical ability of PL to inactivate LOX. PL and thermal treatment of partially purified LOX degraded the LOX band (measured by using SDS-PAGE) when no protease inhibitors were added. Controlling protease activity led to degradation of LOX by PL but not by thermal treatment.