Usefulness of ¹H NMR to Study the Food Lipolysis During in Vitro Digestion Check Access

Obesity and related diseases are an increasing problem in public health care, especially in the western countries. Additionally, the safety and nutritional quality of foodstuffs is the subject of great interest. Knowledge surrounding the physico-chemical events that take place during digestion and in particular during lipid digestion is of paramount importance in order to optimize the nutritional value of foodstuffs and to manage lipid release and absorption in the gastrointestinal tract. However, this knowledge is limited and the extent of lipolysis under in vitro conditions is scarcely characterized. Existing methods for studying in vitro digestion such as direct titration of fatty acids, High Performance Liquid Chromatography (HPLC), High Performance Thin Layer Chromatography (HPTLC) or Gas Chromatography followed by Mass Spectrometry (GC/MS) present some limitations. For example they may yield restricted and inconclusive results and require complex procedures. In this paper, the authors outline the usefulness of ¹H NMR for the development of a new methodology to evaluate food lipolysis during in vitro digestion. By means of this technique it is possible to discriminate samples according to their lipolysis level, by simple observation of those proton signals appearing in three specific spectral regions. Furthermore, different equations can be developed to quantify all the products that may be present during lipid digestion, and thus, to estimate the advance degree of lipolysis reaction. In contrast with other methodologies, ¹H NMR allows a global study of the sample, providing simultaneously detailed information on all the lipolytic products present, in a simple and fast way, and without any chemical modification of the sample.