Determination of non-polar and mid-polar monomeric oxidation products of stigmasterol during thermo-oxidation
Oxidation products of stigmasterol were characterised by their polarity and molecular size using solid phase extraction (SPE) and high-performance size exclusion chromatography (HPSEC) methods. Monomeric oxides were studied further by GC–MS and GC–FID. The focus was on identifying and quantifying no...
| Autores: | , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2010 |
| País: | España |
| Recursos: | Universidad de Navarra |
| Repositório: | Dadun. Depósito Académico Digital de la Universidad de Navarra |
| Idioma: | inglês |
| OAI Identifier: | oai:dadun.unav.edu:10171/22328 |
| Acesso em linha: | https://hdl.handle.net/10171/22328 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Thermo-oxidation Stigmasterol Sterenes Sterones |
| Resumo: | Oxidation products of stigmasterol were characterised by their polarity and molecular size using solid phase extraction (SPE) and high-performance size exclusion chromatography (HPSEC) methods. Monomeric oxides were studied further by GC–MS and GC–FID. The focus was on identifying and quantifying non-polar and mid-polar monomeric oxides after SPE fractionation. Commercial stigmasterol was subjected to 180 °C up to 3 h. Six oxidation products were identified by GC–MS in the non-polar and mid-polar monomeric fractions; all appeared during the first hour of heating. Quantification by GC–FID showed an increase in the non-polar and mid-polar oxidation products during the heating time, and their amounts reached values of 6.1 and 47.0 g/kg of commercial stigmasterol, respectively. Polar oxidation products commonly measured reached a value of 193 g/kg after 1 h of heating, while after 3 h of heating their concentration was only 164 g/kg. Since as much as 550 g/kg of stigmasterol was decomposed, the monomeric products explained only partly the stigmasterol loss. Dimeric and polymeric products contributed to 165 g/kg of the loss showing the importance of polymerisation reactions at 180 °C. |
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