HPLC-CAD method to quantify lipolysis products from plant-based oils rich in unsaturated fatty acids

Abstract

Dietary lipids such as oils and fats are mainly composed of triglycerides. These macronutrients play diverse roles in food products from sensorial, over structural to nutritional. Hence, as part of nutrition and health, it is essential to understand biochemical processes occurring during lipid digestion. To this end, it is indispensable to rely on consistent analytical techniques that enable detection, identification, and quantification of lipolysis products. This work proposes a reversed-phase high performance liquid chromatography with a charged aerosol detector (RP-HPLC-CAD) method that permits quantification of the most abundant lipid species present in highly consumed plant-based oils rich in unsaturated fatty acids and the lipid digestion products derived thereof (e.g. oleic acid, linoleic acid, 1-monolinolein, 1/3-monoolein, 1-linolein, 2-olein, 1/3-diolein, triolein, and 1,2-diolein-3-linolein). The development included gradient program and detector settings optimisation along with validation. Additionally, the method was evaluated in terms of lipid digestion kinetics of oil-in-water emulsions. CAD exhibited high sensitivity and allowed the detection of analytes at nano levels (from 1.5 to 9.3 ng). Moreover, the resulting method demonstrated to be simple, quick, robust and able to detect all the analytes with high sensitivity and precision. Importantly, it allowed a better understanding of molecular changes occurring during lipid hydrolysis.