INVESTIGATION OF THE CORRELATION OF FATTY ACID COMPOSITION AND TRIGLYCERIDE PROFILE WITH THE OXIDATIVE SPOILAGE OF MILK FAT

The article examines the effect of time and storage conditions on the fatty acid composition and the triglyceride composition of milk fat. For this purpose, samples of the fat phase of a commercial oil sample were stored in a refrigerating chamber at a temperature of 3 ± 2°C and at an elevated temperature of 60 ± 0.1°C to create conditions for accelerated aging. Also, to determine the induction period and assess the depth and speed of the process of fatty phase oxidation, the “peroxide number” indicator was measured. The study found out that during storage both in a refrigerating chamber and in conditions of elevated temperature, fatty acids of the composition С4:0, С18:0, С18:1 and С18:2 were subject to the most significant changes. Under the same conditions, the triglyceride composition changes uniformly, indicating the occurrence of oxidative deterioration of lipids. The research found that changes in the fatty acid composition and the composition of triglycerides correlate with the indicator of oxidative processes – “peroxide value.”The data obtained can be used to build model systems to study the rate of oxidation of dairy products’ fat phase and assess its storage capacity.

Differential scanning calorimetry of cocoa butter and chocolate glaze

Nowadays there is a wide market for cocoa butter equivalents, substitutes and improvers for the confectionery and dairy industries. An urgent task is the development of operational instrumental methods for cocoa butter and its substitutes quality control. Thermophysical parameters are among the most important characteristics of the fat phase for the food technology. Differential scanning calorimetry (DSC) is becoming one of the most promising methods for analytical control of fat and oil products. Thermophysical data (temperatures of the maximums of endothermic peaks and their areas) for cocoa butter and chocolate glaze typical samples applied at dairy processing enterprises of the Central black soil region for the production of chocolate glazed curd bars were obtained in the work performed with its help. DSC data were compared with chromatographic data on triglyceride composition of the fat phase of cocoa butter, cocoa butter equivalents, lauric and non-lauric substitutes, and POP and SOS cocoa butter improvers. It was shown that the DSC method can control the quality of cocoa butter and chocolate glaze, identify chocolate products of different origin and triglyceride composition. Melting thermograms obtained by DSC are highly sensitive to the fat phase triglyceride composition. DSC allows reliable identification of samples of cocoa butter and glaze by melting curves in the temperature range from -100 to +50 ° C. It was found that the main melting peak of cocoa butter and its substitutes, due to the presence of a certain set of triglycerides, is observed in the temperature range from -5 to +30 °C. When examining glazes, the melting peak changes: it bifurcates, expands or narrows. Additional application of computer separation of the unseparated peaks superposition on the DSC melting curves increases the information content of the method and improves the reliability of the fat phase identification. The DSC method is characterized by sample preparation simplicity, has good reproducibility and other metrological characteristics and can be an independent method for fat and oil products identifying and quality control..

Lipoprotein Signatures of Cholesteryl Ester Transfer Protein and HMG-CoA Reductase Inhibition

BackgroundCETP inhibition reduces vascular event rates but confusion surrounds its low-density lipoprotein (LDL)-cholesterol effects. We sought to clarify associations of genetic inhibition of CETP on detailed lipoproteins.Methods and ResultsWe used variants associated withCETP(rs247617) andHMGCR(rs12916) expression in 62,400 Europeans with detailed lipoprotein profiling from nuclear magnetic resonance spectroscopy. Genetic associations were scaled to 10% lower risk of coronary heart disease (CHD). Associations of lipoprotein measures with risk of incident CHD in three population-based cohorts (770 cases) were examined.CETPandHMGCRhad near-identical associations with LDL-cholesterol concentration estimated by Friedewald-equation.HMGCRhad a relatively consistent effect on cholesterol concentrations across all apolipoprotein B-containing lipoproteins.CETPhad stronger effects on remnant and very-low-density lipoprotein cholesterol but no effect on cholesterol concentrations in LDL defined by particle size (diameter 18–26 nm) (-0.02SD 95%CI: -0.10, 0.05 forCETPversus -0.24SD, 95%CI -0.30, -0.18 forHMGCR).CETPhad profound effects on lipid compositions of lipoproteins, with strong reductions in the triglyceride content of all highdensity lipoprotein (HDL) particles. These alterations in triglyceride composition within HDL subclasses were observationally associated with risk of CHD, independently of total cholesterol and triglycerides (strongest HR per 1-SD higher triglyceride composition in very-large HDL 1.35; 95%CI: 1.18, 1.54).ConclusionCETP inhibition does not affect size-specific LDL cholesterol but may lower CHD risk by lowering cholesterol in other apolipoprotein-B containing lipoproteins and lowering triglyceride content of HDL particles. Conventional composite lipid assays may mask heterogeneous effects of lipid-altering therapies.