Rapid phase-compositional assessment of lipid-based food products by time domain NMR

摘要

In food science and technology, assessment of phase-compositional behaviour of lipids is critical for understanding many product properties and for effective process control. Time Domain NMR is a rapid and easy-to-handle technique, and is already well appreciated as a tool for phase-compositional assessment in foods. The phase-compositional detail that can be obtained with the established methodology is limited, however. In this work, we set out to obtain more phase-compositional details of lipids as currently feasible with the already established 'classical' NMR methods. We deployed a combined FID-CPMG experiment, and analyzed the Transversal Relaxation Decays by Deconvolution (TRDD) with semi-empirical mathematical functions for solid, semi-solid and liquid components. Within the solid component, different lipid crystal polymorphs can be discerned in a quantitative manner, i.e. alpha, beta and beta'. The TRDD method was validated against established NMR SFC methods, in terms of accuracy ('trueness') and precision. The solid fat content (SFC) of a large collection of fat blends was measured by the commonly employed NMR Direct and Indirect SFC methods and a good correlation with the results of the TRDD was observed, thereby demonstrating accuracy. Furthermore, TRDD was found to be equally precise as the established NMR SFC methods. Copyright (c) 2006 John Wiley & Sons, Ltd.