App Note: Determination of antioxidant capacity on the Thermo Scientific Varioskan LUX Multimode Reader

This application note describes a method to measure the ORAC of different food and beverage samples with a fluorometric assay…

This application note describes a method to measure the ORAC of different food and beverage samples with a fluorometric assay using the Thermo Scientific^TM VarioskanTM LUX multimode microplate reader.

Microplate reader handling and data analysis was controlled by the Thermo Scientific^TM SkanIt^TM software. We show that with the Varioskan LUX reader, determination of the antioxidant capacity of samples is very fast, sensitive and accurate.

Introduction

Metabolism in living cells generates reactive oxygen species (ROS) as natural byproducts that have important roles in cell signaling and homeostasis. However, in excess levels, ROS may cause damage to cell structures and chronic inflammation called oxidative stress. Oxidative stress is shown to play a significant role in aging and many diseases, including cancer, stroke, heart disease and neurodegenerative diseases.

Antioxidants inhibit the oxidation of other molecules and thus prevent cell damage caused by free radicals. Therefore, antioxidants are believed to promote health and are widely used as dietary supplements. In addition, they are used as food preservatives, including natural antioxidants such as ascorbic acid (AA, E300) and synthetic antioxidants such as propyl gallate (PG, E310), to keep guard against deteriorations of food exposed to oxygen or light. Antioxidant preservatives are also added to fat-based cosmetics, such as lipstick and moisturizers, to prevent rancidity of unsaturated fats.