Gas chromatography–mass spectrometry determination of conjugated linoleic acids and cholesterol oxides and their stability in a model system

Yen, T.Y.; Inbaraj, Baskaran Stephen; Chien, John-Tung; Chen, B.H.

doi:10.1016/j.ab.2010.01.031

Cited by 36 publications

(41 citation statements)

References 34 publications

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“…The protective effect of the lipid surrounding matrix to sterol oxidation was also described by Ansorena et al [18], using pure triacylglycerols, and by Yen and co-workers [37,38], who reported that cholesterol was oxidized more slowly within lard than alone.…”

Section: Surrounding Matrix Effectsupporting

confidence: 57%

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: Surrounding Matrix Effectsupporting

confidence: 57%

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

et al. 2015

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“…At the end of the heating process, the lowest remaining values were for PS and PS+S samples (2-10%), followed by PS+O (25%) and finally the polyunsaturated FAME (40-43%). Less cholesterol oxidation has also been reported in samples containing conjugated linoleic acids compared to samples which were free of surrounding lipids (Yen et al, 2010).…”

Section: Fatty Acids Methyl Esters and Phytosterols Degradationmentioning

confidence: 99%

“…Nevertheless, certain unsaturated fatty acids have indeed been used as cholesterol oxidation protectors (Yen, Inbaraj, Chien, & Chen, 2010). Moreover, a recent study suggested that both the presence and the increasing unsaturation degree of triacylglycerides exhibited an inhibitory effect against cholesterol degradation and oxides formation (Ansorena, Barriuso, Cardenia, Astiasarán, Lercker, Rodríguez-Estrada, 2013a).…”

Section: Introductionmentioning

confidence: 99%

Unsaturated lipid matrices protect plant sterols from degradation during heating treatment

2016

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The interest in plant sterols enriched foods has recently enhanced due to their healthy properties. The influence of the unsaturation degree of different fatty acids methyl esters (FAME: stearate, oleate, linoletate and linolenate) on a mixture of three plant sterols (PS:campesterol, stigmasterol and β-sitosterol) was evaluated at 180 °C for up to 180 min.Sterols degraded slower in the presence of unsaturated FAME. Both PS and FAME degradation fit a first order kinetic model (R 2 >0.9). Maximum oxysterols concentrations were achieved at 20 min in neat PS and 120 min in lipid mixtures and this maximum amount decreased with increasing their unsaturation degree. In conclusion, the presence of FAME delayed PS degradation and postponed oxysterols formation. This protective effect was further promoted by increasing the unsaturation degree of FAME. This evidence could help industries to optimize the formulation of sterol-enriched products, so that they could mantain their healthy properties during cooking or processing.

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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%

“…Thus, a deeper understanding of the underlying mechanisms is enabled and kinetic curves can be easily determined. Consequently, a diversity of experimental approaches can be found, from fully modelled studies where only chemical standards are used as components of the experiments (14,15), to intermediate model systems, where chemical standards are mixed within foods (16)(17)(18). This paper aims to evaluate the effect of different factors involved in sterols oxidation, gathering recently published data from our research group (19)(20)(21)(22)(23)(24)(25).…”

Section: Introductionmentioning

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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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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Gas chromatography–mass spectrometry determination of conjugated linoleic acids and cholesterol oxides and their stability in a model system

Cited by 36 publications

References 34 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

Unsaturated lipid matrices protect plant sterols from degradation during heating treatment

Oxysterols formation: A review of a multifactorial process

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