title: Improved amperometric method for the rapid and quantitative measurement of lipoxygenase activity in vegetable tissue crude homogenates.
abstract: An improved amperometric method for rapid (2 min) quantitative determination of lipoxygenase (LOX) activity in vegetable tissue crude homogenates is presented. Measured LOX activity was linear (R(2) > 0.99) throughout the entire activity range for green bean and for corn below 70% activity. The resolution was 0.4% or 1.11 micromol L(-1) s(-1) of oxygen. The limit of detection was 3.43 micromol L(-1) s(-1) of oxygen. The amperometric method was improved by encapsulating linoleic acid (LA) in beta-cyclodextrin (CD) resulting in a stable substrate-buffer solution at a pH below 8.0. Ethanol and Tween 20 were not effective in solubilizing high LA concentrations required by the assay. A prototype benchtop instrument with the potential for use in an industrial environment is also presented.
authors.affiliation: Department of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164, USA.
authors.forename: José I
authors.initials: JI
authors.lastname: Reyes-De-Corcuera
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Cavalieri
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Powers
mesh_terms: D004563:Electrochemistry / Q000379:methods; D007887:Fabaceae / Q000201:enzymology; D007700:Kinetics; D019787:Linoleic Acid / Q000032:analysis; D008084:Lipoxygenase / Q000032:analysis*; D012680:Sensitivity and Specificity; D014675:Vegetables / Q000201:enzymology*; D003313:Zea mays / Q000201:enzymology
chemical_list: D019787:Linoleic Acid; D008084:Lipoxygenase