Gas chromatographic properties of common cholesterol and phytosterol oxidation products

Apprich, Silvia; Ulberth, Franz

doi:10.1016/j.chroma.2004.08.123

Cited by 36 publications

(31 citation statements)

References 43 publications

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“…Their chromatographic analysis, identification and quantification were performed according to the validated method of Menéndez-Carreño et al [25]. Calibration curves of COPs were also used to quantify StOPs, as it has been demonstrated that the response factor obtained for cholesterol oxidation products are also valid for quantitative work regarding phytosterol oxidation products [26]. Seven different SOPs from each sterol were determined: 7α-hydroxy (7α-H), 7β-hydroxy (7β-H), 5,6β-epoxy (β-E), 5,6α-epoxy (α-CE), 3,5,6-triol (T), 25-hydroxy (25-H), 7-keto (7-K).…”

Section: Sterol Oxidation Products Determinationmentioning

confidence: 99%

Cholesterol and stigmasterol within a sunflower oil matrix: Thermal degradation and oxysterols formation

et al. 2015

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The characteristics of the lipid matrix surrounding sterols exert a great influence in their thermal oxidation process. The objective of this work was to assess the oxidation susceptibility of equal amounts of cholesterol and stigmasterol within a sunflower oil lipid matrix (ratio 1:1:200) during heating (180 ºC, 0 to 180 min). Remaining percentage of sterols was determined and seven sterol oxidation products (SOPs) were analyzed for each type of sterol along the heating treatment. Evolution of the fatty acid profile and vitamin E content of the oil was also studied. Overall oxidation status of the model system was assessed by means of Peroxide Value (PV) and TBARS. PV remained constant from 30 min onwards and TBARS continued increasing along the whole heating treatment.Degradation of both cholesterol and stigmasterol fitted a first order curve (R 2 = 0.937 and 0.883, respectively), with very similar degradation constants (0.004 min -1 and 0.005 min -1 , respectively). However, higher concentrations of oxidation products were found from cholesterol (79 µg/mg) than from stigmasterol (53 µg/mg) at the end of the heating treatment. Profile of individual oxidation products was similar for both sterols, except for the fact that no 25-hydroxystigmasterol was detected. 7α-hydroxy and 7-ketoderivatives were the most abundant SOPs at the end of the treatment. PUFA and vitamin E suffered a significant degradation along the process, which was correlated to sterols oxidation.

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Section: Sterol Oxidation Products Determinationmentioning

confidence: 99%

Cholesterol and stigmasterol within a sunflower oil matrix: Thermal degradation and oxysterols formation

et al. 2015

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“…Along 45 minutes the oxyderivates from cholesterol, campesterol, stigmasterol, and sitosterol eluted in the order shown in figure 1, showing slight differences in the pattern compared to oxysterol separations performed in other works with different columns. Apprich et al [35] pointed out the importance of the type of stationary phase of columns but also the length of the capillary column for the order of the elution of sterol oxidation products. The most difficult part of the chromatogram to be resolved was that comprising RRT from 1.436 to 1.455, which included 4 compounds.…”

Section: Selectivitymentioning

confidence: 99%

“…There are not POPs standards commercially available, so the analytical methods for POPs have been carried out using commercial COPs as model substances, assuming that the ionization efficiency of both types of molecules and their behaviour is very similar, as they have similar structures. Response factors obtained for COPs are also valid for quantitative work regarding POPs [34][35][36].…”

Section: Introductionmentioning

confidence: 99%

Validation of a gas chromatography–mass spectrometry method for the analysis of sterol oxidation products in serum

Menéndez-Carreño

García-Herreros

Astiasarán

et al. 2008

Journal of Chromatography B

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A validated gas chromatography-mass spectrometry (GC-MS) detection method for the quantitative analysis of sterol oxidation products (SOPs) in serum is described. After a lipid extraction procedure with chloroform/methanol, a cold saponification and purification by solid phase extraction, oxysterols were derivatizated to form trimethyl-sylil-ethers which were subjected to GC-MS analysis. Calibration curves for cholesterol oxidation products showed determination coefficient (R 2 ) of 1.0, with low values for the coefficient of variation of the response factors (<1%). Detection and quantification limits were below 5 ng/mL and 10 ng/mL, respectively. Recovery data were between 77.65 and 110.29% (CV<10% for all compounds).Good results were obtained for within and between day repeatability, with values below 10%. In conclusion, the method performed is suitable for the determination and quantification of SOPs in serum.2

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“…Values followed by the same letter were not found to differ significantly for each row using Duncan's multiple range test (p<0.05) (n=3). Both cholesterol and phytosterols are oxidized by heat [8]. Cooking oils and Product 1 were analyzed by GC-MS for oxidation products.…”

Section: Resultsmentioning

confidence: 99%

“…To date, there have been fewer studies published on phytosterol oxidation products (POPS). Work done with model systems and synthesized compounds showed that POPS are produced, but few studies are available on total food systems [8][9][10]. The few studies available focused on potato products cooked in vegetable oils [11][12][13].…”

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confidence: 99%

Characterization of Lipids and Their Oxidation Products in Baked or Fried Breaded Shrimp Products

Dean¹,

Fenner²,

Boyd³

2009

TOFSJ

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Baking and frying are two common food preparation methods, but there is limited knowledge about the lipid oxidation events that occur in food products prepared in these ways. Two commercially available breaded shrimp products were examined using gas chromatography, for changes in cholesterol, phytosterols, and fatty acids as a result of baking and deep frying after separation into breading and shrimp components. Additionally, changes in oil quality factors were determined for the cooking oils used to prepare the fried products. Sterol concentrations changed in both shrimp products due to degradation. Oxidation products of cholesterol and fatty acids were found in the shrimp portions of both the baked and fried samples as well as the oils used for frying using gas chromatography in tandem with mass spectroscopy. Phytosterol oxides were detected in the frying oils, but not in the baked or fried shrimp products. The frying oils showed some oxidative losses of phytosterols. This work demonstrated that measurable lipid oxidation occurred, even over the short time periods needed to prepare these products. This may have implications for human health effects.Keywords: Shrimp, frying, oxidation, fatty acids, sterols.Thermal processing of foods typically induces changes that make products more appealing for consumption and improves nutrient availability and food safety. Baking or roasting involves exposure of products to high temperatures in air, often on metal surfaces. Deep frying relies on the use of an oil medium to transfer heat to the food product. This process also involves exposure of the food and its lipid components to air and metal surfaces from processing equipment. The oxidation of fatty acids and sterols is a free radical process [1]. The exposure of these compounds to conditions of high heat, air and light and often in the presence of metal ions as catalysts can result in the breakdown of unsaturated carbon-carbon bonds found in these compounds, accelerating lipid oxidation.The oxides of cholesterol produced in food products have been studied and discussed for almost two decades and have been reviewed [1,2]. Shrimp in particular have been the subject of recent studies on cholesterol oxidation products [3,4]. Investigations into the types of products formed and their effects on biological systems have shown that cholesterol oxides (COPS) are cytotoxic and mutagenic and have been implicated in the onset of arteriosclerosis and coronary heart disease in humans [5,6]. The structural similarity of plant sterols or phytosterols to cholesterol (Fig. 1) would indicate that similar types of oxidation products could be formed when phytosterol containing foods are subjected to the oxidizing conditions of many food processing operations. In the past, the main focus was on the oxidation of cholesterol from lard, tallow and meat containing products [7]. To date, there have been fewer studies published on phytosterol oxidation products (POPS). Work done with model systems and synthesized compounds showed that PO...

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Gas chromatographic properties of common cholesterol and phytosterol oxidation products

Cited by 36 publications

References 43 publications

Cholesterol and stigmasterol within a sunflower oil matrix: Thermal degradation and oxysterols formation

Cholesterol and stigmasterol within a sunflower oil matrix: Thermal degradation and oxysterols formation

Validation of a gas chromatography–mass spectrometry method for the analysis of sterol oxidation products in serum

Characterization of Lipids and Their Oxidation Products in Baked or Fried Breaded Shrimp Products

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