High throughput prediction of chylomicron triglycerides in human plasma by nuclear magnetic resonance and chemometrics

<p>Abstract</p> <p>Background</p> <p>The lipid content of the chylomicrons is a key biomarker and risk factor of cardiovascular diseases and for the understanding of obesity. A high throughput determination of chylomicrons in human blood plasma is outlined.</p> <p>Methods</p> <p>The new method, which uses a combination of Nuclear Magnetic Resonance (NMR) analysis and multivariate calibration analysis (chemometrics), is based on a correlation analysis towards the established standard method (ultracentrifugation and colorimetric test kit) and enables extraordinarily fast, inexpensive, and robust prediction of triglyceride (TG) content in chylomicrons. It is the position and shape of the complex lipid methylene resonance band that determines the chylomicron TG status and this information is extracted by the multivariate regression method.</p> <p>Results</p> <p>The resulting method is a relatively simple multivariate model that facilitates parsimonious and accurate prediction of chylomicron lipids from NMR spectra of blood. The chemometric model predicts the chylomicron TG content with a correlation coefficient (R) of 0.96 when plotted against density gradient ultracentrifugation data.</p> <p>Conclusions</p> <p>The new rapid method facilitates large scale clinical and nutritional trials with inclusion of diagnostics of chylomicron status and thus creates new opportunities for research in lifestyle diseases and obesity.</p

Vibrational microspectroscopy of food. Raman vs

FT-IR and Raman spectroscopy are complementary techniques for the study of molecular vibrations and structure. The combination with a microscope results in an analytical method that allows spatially resolved investigation of the chemical composition of heterogeneous foods and food ingredients. The high spatial resolution makes it possible to study areas down to approximately 10Â10 mm with FT-IR microspectroscopy and approximately 1Â1 mm with Raman microspectroscopy. This presentation highlights the advantages and disadvantages of the two microspectroscopic techniques when applied to different heterogeneous food systems. FT-IR and Raman microspectroscopy were applied to a number of different problems related to food analysis: (1) in situ determination of starch and pectin in the potato cell, (2) in situ determination of the distribution of amygdalin in bitter almonds, (3) the composition of blisters found on the surface of bread, (4) the microstructure of high-lysine barley and (5) the composition of white spots in the shell of frozen shrimps.

Assessment of the Effect of High or Low Protein Diet on the Human Urine Metabolome as Measured by NMR

The objective of this study was to identify urinary metabolite profiles that discriminate between high and low intake of dietary protein during a dietary intervention. Seventy-seven overweight, non-diabetic subjects followed an 8-week low-calorie diet (LCD) and were then randomly assigned to a high (HP) or low (LP) protein diet for 6 months. Twenty-four hours urine samples were collected at baseline (prior to the 8-week LCD) and after dietary intervention; at months 1, 3 and 6, respectively. Metabolite profiling was performed by 1H NMR and chemometrics. Using partial least squares regression (PLS), it was possible to develop excellent prediction models for urinary nitrogen (root mean square error of cross validation (RMSECV) = 1.63 mmol/L; r = 0.89) and urinary creatinine (RMSECV = 0.66 mmol/L; r = 0.98). The obtained high correlations firmly establish the validity of the metabolomic approach since urinary nitrogen is a well established biomarker for daily protein consumption. The models showed that trimethylamine-N-oxide (TMAO) is correlated to urinary nitrogen. Furthermore, urinary creatine was found to be increased by the HP diet whereas citric acid was increased by the LP diet. Despite large variations in individual dietary intake, differentiated metabolite profiles were observed at the dietary group-level

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan