Five-Way PPO Activity Data for Enzymatic Browning of Vegetables

Enzymatic browning limits the useful life of fruits and vegetables. This collection uses model solutions containing polyphenol oxidase (PPO) purified from iceberg lettuce to examine how atmospheric and chemical conditions affect the enzyme activity associated with browning. PPO activity was measured as oxygen consumption for a complete factorial design of 405 conditions. Each condition was measured in duplicate, producing 810 assays. The released values are the replicate means. enzymatic.mat contains the Dataset Object enzyme. Its numeric array enzyme.data has shape 3 x 3 x 3 x 3 x 5, ordered pH x substrate x temperature x CO2 x O2. Activity is reported as nanomoles of O2 consumed per second. The factor levels are pH 3.0, 4.5, and 6.0; temperatures 30, 20, and 5 degrees C; CO2 at 20%, 10%, and 0%; and O2 at 80%, 20%, 10%, 5%, and 0%. Substrates are 0.01 M chlorogenic acid (CG), 0.01 M epicatechin (EPI), and an equimolar mixture containing 0.005 M of each (MIX). The oxygen and carbon dioxide levels represent atmosphere conditions relevant to food storage and modified-atmosphere packaging. Original source listing: UCPH Chemometrics datasets Original ERDA package: Enzymatic data If you use these data, please cite:Bro, R.; Heimdal, H. (1996). Enzymatic browning of vegetables. Calibration and analysis of variance by multiway methods. Chemometrics and Intelligent Laboratory Systems, 34(1), 85-102. https://doi.org/10.1016/0169-7439(96)00019-6Heimdal, H.; Bro, R.; Larsen, L. M.; Poll, L. (1997). Prediction of Polyphenol Oxidase Activity in Model Solutions Containing Various Combinations of Chlorogenic Acid, (-)-Epicatechin, O2, CO2, Temperature, and pH by Multiway Data Analysis. Journal of Agricultural and Food Chemistry, 45(7), 2399-2406. https://doi.org/10.1021/jf960975w