RAPID METHODS FOR LIPOXYGENASE ASSAY IN SWEET CORN

Potential methods for rapid assay of sweet corn lipoxygenase (LPO) wer e evaluated and compared by visual inspection. Both model system (part ially purified) and vegetable (LPO extract) system studies were carrie d out. Model system studies indicated that LPO had maximum activity at pH 6.0 and 2.0 mM linoleic acid. Methylene blue bleaching (MBB), caro tene bleaching (CB), and potassium iodide-starch (KI-S) methods were e valuated both spectrophotometrically and visually. Both MBB and KI-S m ethods were effective for the model system. For the vegetable LPO extr act systems (sweet corn and green beans), the MBB method indicated pos itive results for both, the CB method was not effective for either, an d the KI-S method was very effective for green beans but not for sweet corn.