Characterisation of the lipidic components of margarines by 1H Nuclear Magnetic Resonance

Abstract

In this work, (1)H Nuclear Magnetic Resonance ((1)H NMR) has been used to study the lipidic fraction of margarines of different compositions, determining simultaneously both major components, which is to say triglycerides, and other minor ones, such as 1- and 2-monoglycerides, 1,2-diglycerides, vegetable stanols and sterols, and sorbic acid. The results show a wide variety of acyl group compositions, with polyunsaturated groups ranging from 22% to 50%, monounsaturated from 23% to 50%, and saturated from 21% to 55%. 1,2-Diglycerides and vegetable stanols and/or sterols have been detected in all the studied margarines, in concentrations varying between 2.73 and 26.06 mmol/kg, and between 3.40 and 240.01 mmol/kg, respectively. A good agreement has been found between the results obtained by (1)H NMR and some composition data of these margarines, showing the usefulness of this technique to analyse the lipidic composition of margarine in a quick and easy way.

Keywords: (1)H Nuclear Magnetic Resonance ((1)H NMR); Acyl groups; Diglycerides; Margarine; Monoglycerides; Sorbic acid; Stanols; Sterols.