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The aim of the present work was the characterization of best-by-date dairy products to evaluate their nutritional value for possible re-introduction in the food or feed chain. The attention was devoted to fatty acids and triacylglycerols characterization and their variation during storage of fresh-cheese products before and after their best-by-date. Three kinds of cheese were selected, namely a classic stracchino, stracchino with the addition of yogurt, and one with the addition of probiotic. The variation of FAMEs and TAGs profiles were studied in order to evaluate the degree of variation occurring in the lipid fraction during storage and after the best-by-date. The extraction method was simply scaled-down by ten-fold, starting from the classical Schmid-Bondzynski-Ratzlaff method. The GC run was sped up after a careful comparison of the result with a conventional analysis. The entire data set of results was evaluated performing both a three-way principal component analysis and a traditional two-way one. The three kinds of samples were well discriminated while a change of the lipid profile over the best-by-date period was particularly significant only for the stracchino added with a probiotic. [ABSTRACT FROM AUTHOR]

Lipid dysmetabolism disease is a condition in which lipids are stored abnormally in organs and tissues throughout the body, causing muscle weakness (myopathy). Usually, the diagnosis of this disease and its characterization goes through dosage of Acyl CoA in plasma accompanied with evidence of droplets of intra-fibrils lipids in the patient muscle biopsy. However, to understand the pathophysiological mechanisms of lipid storage diseases, it is useful to identify the nature of lipids deposited in muscle fiber. In this work fatty acids and triglycerides profile of lipid accumulated in the muscle of people suffering from myopathies syndromes was characterized. In particular, the analyses were carried out on the muscle biopsy of people afflicted by lipid storage myopathy, such as multiple acyl-coenzyme A dehydrogenase deficiency, and neutral lipid storage disease with myopathy, and by the intramitochondrial lipid storage dysfunctions, such as deficiencies of carnitine palmitoyltransferase II enzyme. A single step extraction and derivatization procedure was applied to analyze fatty acids from muscle tissues by gas chromatography with a flame ionization detector and with an electronic impact mass spectrometer. Triglycerides, extracted by using n -hexane, were analyzed by high performance liquid chromatography coupled to mass spectrometer equipped with an atmospheric pressure chemical ionization interface. The most representative fatty acids in all samples were: C16:0 in the 13–24% range, C18:1n9 in the 20–52% range, and C18:2n6 in the 10–25% range. These fatty acids were part of the most representative triglycerides in all samples. The data obtained was statistically elaborated performing a principal component analysis. A satisfactory discrimination was obtained among the different diseases. Using component 1 vs component 3 a 43.3% of total variance was explained. Such results suggest the important role that lipid profile characterization can have in supporting a correct diagnosis. [ABSTRACT FROM AUTHOR]

The determination of the triacylglycerol (TAG) profile in real world matrices is rather difficult as these compounds present a complex composition and are characterized by similar physico-chemical properties. This investigation is based on the high-performance liquid chromatography (HPLC) multidimensional determination of the TAG profile in terms of TAG species and positional isomers in a rice oil sample. The off-line bi-dimensional system was attained through the coupling of non-aqueous reversed-phase HPLC and silver ion (Ag)-HPLC. The primary column eluate was fractionated and the fractions of interest were then injected onto the secondary column, allowing the separation of several TAG positional isomers, unresolved in the first dimension. Peak assignment was carried out by combining retention data with atmospheric pressure chemical ionisation (APCI) MS spectra information. The fatty acid distribution along the glycerol backbone, determined by Ag-HPLC, was confirmed through diglyceride ion ratios derived from APCI-MS analysis. Method validation, where both precision and accuracy were measured, was carried out in preliminary applications on standard compounds. The analytical results obtained show that rice oil TAGs follow a distribution which can be considered typical for vegetable oils. [Copyright &y& Elsevier]

This paper describes the development of a chromatographic system for analysis of commercial ceramides structurally similar to those found in the stratum corneum. The ceramides used in this study contain different amine based (phytosphingosine, sphingosine and dihydrosphingosine) and fatty acids of different chain lengths and with different functional groups (hydroxylated and unsaturated). Non-aqueous reversed-phase (NARP) liquid chromatography with evaporative light-scattering detection (ELSD) were the techniques chosen in accordance with the nature of the ceramides. The eluent strength and the potential selectivity of different organic solvents were investigated. On a C18-bonded silica, the most promising chromatographic conditions employed a gradient from ACN-THF, 95∶5, to ACN-THF-PrOH, 35∶5∶60, in 15 min with a constant concentration of TEA (10 mM) and a stoichiometric amount of formic acid. [ABSTRACT FROM AUTHOR]