Kinetic Model of the Cholesterol Oxidation during Heating

Chien, John-Tung; Wang, H. C.; Chen, B. H.

doi:10.1021/jf970788d

Cited by 69 publications

(98 citation statements)

References 32 publications

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“…A wide diversity of results has been noticed, even when comparing results from the same research group (15,27,28). Several studies performed sterol degradation at 150 °C using cholesterol samples.…”

Section: Effect Of Heating Treatmentmentioning

confidence: 99%

“…Several authors have performed sterols kinetic studies (46), most of them using elegant approaches and complex mathematical calculations. Chien et al (27) found cholesterol degradation and oxysterols formation to follow first order and second order reactions and calculated the corresponding equations. Their work, as well as others, efficiently contributed to elucidate the mechanisms by which sterol oxidation occurs.…”

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confidence: 99%

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Oxysterols formation: A review of a multifactorial process

Barriuso

Ansorena

Astiasarán

2017

The Journal of Steroid Biochemistry and Molecular Biology

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Highlights1-Heating sterols at 180 °C produced a high extent of oxidation.2-The presence and unsaturation degree of the surrounding lipids protected sterols from oxidation.3-Plant aqueous extracts protected cholesterol from oxidation.4-Greater amounts of campesterol-derived oxidation products were observed, followed by sitosterol, cholesterol and stigmasterol.5-In 5 out of 7 of our studies, 7-keto derivatives were the most abundant oxysterols formed. AbstractDietary sterols are nutritionally interesting compounds which can suffer oxidation reactions. In the case of plant sterols, they are being widely used for food enrichment due to their hypocholesterolemic properties. Besides, cholesterol and plant sterols oxidation products are associated with the development of cardiovascular and neurodegenerative diseases, among others. Therefore, the evaluation of the particular factors affecting sterol degradation and oxysterols formation in foods is of major importance. The present work summarizes the main results obtained in experiments which aimed to study four aspects in this context: the effect of the heating treatment, the unsaturation degree of the surrounding lipids, the presence of antioxidants on sterols degradation, and at last, oxides formation. The use of model systems allowed the isolation of some of these effects resulting in more accurate data. Thus, these results could be applied in real conditions.

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Section: Effect Of Heating Treatmentmentioning

confidence: 99%

mentioning

confidence: 99%

Oxysterols formation: A review of a multifactorial process

Barriuso

Ansorena

Astiasarán

2017

The Journal of Steroid Biochemistry and Molecular Biology

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“…Some authors pointed out that polymers and/or other products of relatively high molecular weight are also formed during sterol oxidation at high temperatures (Kim & Nawar, 1993;Chien, Wang & Chen, 1998;Soupas, Huikko, Lampi & Piironen, 2006).…”

Section: Introductionmentioning

confidence: 99%

Determination of non-polar and mid-polar monomeric oxidation products of stigmasterol during thermo-oxidation

et al. 2010

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Oxidation products of stigmasterol were characterized by their polarity and molecular size using solid phase extraction (SPE) and high performance size exclusion (HPSEC) methods. Monomeric oxides were studied further by GC-MS and GC-FID. The focus was on identifying and quantificating non-polar and mid-polar monomeric oxides after SPE fractionation. Commercial stigmasterol was subjected to 180 ºC up to 3 hours. Six oxidation products were identified by GC-MS in the nonpolar and mid-polar monomeric fractions, and they appeared already after the first hour of heating. Quantification by GC-FID showed an increase in the non-polar and mid-polar oxidation products during heating time, and their amounts reached values of 6.1 and 47.0 μg/mg of commercial stigmasterol, respectively. Polar oxidation products commonly measured reached a value of 193 μg/mg after 1 hour of heating, while after 3-hour heating, the amount was only 164 μg/mg. Since as much as 550 μg/mg of stigmasterol was decomposed, the monomeric products explained only partly the stigmasterol loss. Dimeric and polymeric products contributed to 165 µg/g of gap showing the importance of polymerization reactions at 180 ºC.2

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“…Previous studies have attempted to regulate the formation of cholesterol oxidation products by means of radical inducers and radical scavengers [3,9,26,28]. These studies have mainly been done in solution.…”

Section: Cop Induction and Inhibitionmentioning

confidence: 99%

“…There was no obvious reason for these presumably short-lived open-shell cations to be present on the target. Cholesterol oxidation kinetics have been studied [9], and it is believed that any oxidation intermediates that correspond to radicals should have been transformed into the ultimate oxidation products rather rapidly.…”

Section: Introductionmentioning

confidence: 99%

Laser-Induced Oxidation of Cholesterol Observed During MALDI-TOF Mass Spectrometry

McAvey

Guan

Fortier

et al. 2011

J. Am. Soc. Mass Spectrom.

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Conditions for the detection of three odd-electron cholesterol oxidation peaks were determined and these peaks were shown to be artifacts of the matrix-assisted laser desorption time of flight (MALDI-TOF) process. Matrix choice, solvent, laser intensity and cholesterol concentration were systematically varied to characterize the conditions leading to the highest signals of the radical cation peaks, and it was found that initial cholesterol solution concentration and resultant density of solid cholesterol on the MALDI target were important parameters in determining signal intensities. It is proposed that hydroxyl radicals, generated as a result of laser irradiation of the employed 2, 5-dihydroxybenzoic acid (DHB) matrix, initiate cholesterol oxidation on the MALDI target. An attempt to induce the odd-electron oxidation peaks by means of adding an oxidizing agent succeeded using an acetonitrile solution of DHB, cholesterol, and cumene hydroperoxide. Moreover, addition of free radical scavengers reduced the abundances of some oxidation products under certain conditions. These results are consistent with the mechanism of oxidation proposed herein involving laser-induced hydroxyl radical production followed by attack on neutral cholesterol. Hydroxyl radical production upon irradiation of dithranol matrix may also be responsible for generation of the same radical peaks observed from cholesterol in dithranol by an analogous mechanism.

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Kinetic Model of the Cholesterol Oxidation during Heating

Cited by 69 publications

References 32 publications

Oxysterols formation: A review of a multifactorial process

Oxysterols formation: A review of a multifactorial process

Determination of non-polar and mid-polar monomeric oxidation products of stigmasterol during thermo-oxidation

Laser-Induced Oxidation of Cholesterol Observed During MALDI-TOF Mass Spectrometry

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