Improved amperometric method for the rapid and quantitative measurement of lipoxygenase activity in vegetable tissue crude homogenates.
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.
Reyes-De-Corcuera
José I
JI
Department of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164, USA.
Cavalieri
Ralph P
RP
Powers
Joseph R
JR
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
D019787:Linoleic Acid; D008084:Lipoxygenase