Biomedical subjects

Luisito Cercaci

Publications and source records attributed to Luisito Cercaci.

3 recordsLinked to original sources

PubMed2006

Preliminary study on health-related lipid components of bakery products.

The purpose of this study was to evaluate the presence of health-related lipid components, in particular trans fatty acids and sterol oxidation products, in four bakery products. Both types of components are known for their adverse biological effects, especially the increase of atherogenic risk, and therefore it is advisable to monitor their presence in food products. Trans fatty acids were determined by silver-ion thin-layer chromatography-gas chromatography, whereas sterol oxidation was assessed by gas chromatography and gas chromatography-mass spectrometry determination of 7-keto derivatives (tracers of sterol oxidation). The amount of trans fatty acids (0.02 to 3.13 g/100 g of product), sterols (34.9 to 128.3 mg/100 g of product), and 7-keto derivatives of sterols (1.88 to 3.14 mg/kg of product) varied considerably among samples. The supply of phytosterols (22.5 to 64.0 mg/100 g of product) was not significant, and the extent of oxidation of most phytosterols to its corresponding 7-keto derivative was low (0.29 to 0.84%), except for that of brassicasterol (2.01 to 3.11%). The quality of ingredients and raw materials seems to have greatly influenced the fatty acid profile, stability, safety, and quality of the final product; these ingredients should be chosen with extreme care to decrease their potential negative health effects and to increase safety of these products.

Chromatography, Gas↗

PubMed2005

Levels of phytosterol oxides in enriched and nonenriched spreads: application of a thin-layer chromatography-gas chromatography methodology.

The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).

Cholesterol↗

PubMed2003

Solid-phase extraction-thin-layer chromatography-gas chromatography method for the detection of hazelnut oil in olive oils by determination of esterified sterols.

The sterol composition of extra virgin olive oil is very characteristic and, thus, has become a helpful tool to detect adulterations with other vegetable oils. Special attention has been addressed to the separate determination of the free and esterified sterol fractions, since both have different compositions and can thus provide more precise information about the actual origin of the olive oil. In the case of admixtures with small amounts of hazelnut oil, this approach can be extremely useful, because the similarity between the fatty acid compositions of both oils hampers the detection of the fraud. A hyphenated chromatographic method was developed for a sensitive and precise determination of esterified sterols in olive oils. The oil was subjected to silica solid-phase extraction (SPE) fractionation, cold saponification of the collected fraction and purification on silica TLC. The sterol band was then injected into an SPB-5 (30 m x 0.25 mm I.D., 0.25 microM film thickness) and the ratio [% campesterol x (% 7-stigmastenol)2]/(% 7-avenasterol) was calculated. The method was tested on extra virgin olive oil; good sterol recoveries and repeatability were obtained. The results were compared with another method. which has a different sample preparation sequence (silica column chromatography, hot saponification and silica TLC). Similar results were achieved with both methods; however, the SPE-cold saponification-TLC-capillary GC was faster, required less solvent and prevented sterol decomposition. The SPE-method was applied to an admixture with 10% of hazelnut oil and to a screening of 11 oils (husk oil, virgin and refined olive oils) from different Mediterranean countries.

Chromatography, Gas↗