Quantification of free and esterified sterols in Portuguese olive oils by solid-phase extraction and gas chromatography–mass spectrometry

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Sara S. Cunha (Autor) Outra; José O. Fernandes (Autor) FFUP; M. Beatriz P.P. Oliveira (Autor) FFUP

Revista

Título: Journal of Chromatography A

Vol. 1128 Nº 1

Páginas: 220-227

ISSN: 0021-9673

Editora: Elsevier

Indexação

Pubmed / Medline

Classificação Científica

FOS: Ciências médicas e da saúde > Outras ciências médicas

CORDIS: Ciências da Saúde

Outras Informações

Resumo (PT): A simple and accurate method based on solid-phase extraction (SPE), transesterification and gas chromatography–mass spectrometry (GC–MS) was developed for the quantitative analysis of free and esterified sterols of olive oil. In order to achieve better separation of esterified and free sterols, silica and alumina SPE adsorbents were tested. Separations by silica provided more reproducible results. The transesterification of both sterol fractions was found to be more user friendly than saponification as a method to liberate the sterols from the respective esters. The free sterols were then silylated with N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA) with 1% of trimethylchlorosilane (TMCS). The most favourable conditions for exploitation of this reagent were established. The optimized methodology was suitable for evaluation of free and esterified sterols in Protected Designation of Origin (PDO) olive oils and monovarietal olive oils with different maturation indices. The prevailing phytosterols in all olive oils were β-sitosterol and campesterol. The free sterols predominated, although they seemed to decrease with the maturation of the olive fruits. <br> <br> Keywords: Olive oils; Free sterols; Esterified sterols; <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TG8-4KGG5YD-1&_user=2460038&_coverDate=09%2F22%2F2006&_rdoc=27&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235248%232006%23988719998%23631429%23FLA%23display%23Volume)&_cdi=5248&_sort=d&_docanchor=&_ct=38&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=caed23ac23c6f894a0e9185195dff388"> Texto integral </a> <br> <br>

Abstract (EN): A simple and accurate method based on solid-phase extraction (SPE), transesterification and gas chromatography–mass spectrometry (GC–MS) was developed for the quantitative analysis of free and esterified sterols of olive oil. In order to achieve better separation of esterified and free sterols, silica and alumina SPE adsorbents were tested. Separations by silica provided more reproducible results. The transesterification of both sterol fractions was found to be more user friendly than saponification as a method to liberate the sterols from the respective esters. The free sterols were then silylated with N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA) with 1% of trimethylchlorosilane (TMCS). The most favourable conditions for exploitation of this reagent were established. The optimized methodology was suitable for evaluation of free and esterified sterols in Protected Designation of Origin (PDO) olive oils and monovarietal olive oils with different maturation indices. The prevailing phytosterols in all olive oils were β-sitosterol and campesterol. The free sterols predominated, although they seemed to decrease with the maturation of the olive fruits. <br> <br> Keywords: Olive oils; Free sterols; Esterified sterols; <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TG8-4KGG5YD-1&_user=2460038&_coverDate=09%2F22%2F2006&_rdoc=27&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235248%232006%23988719998%23631429%23FLA%23display%23Volume)&_cdi=5248&_sort=d&_docanchor=&_ct=38&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=caed23ac23c6f894a0e9185195dff388"> Full text</a> <br> <br>

Idioma: Português

Tipo (Avaliação Docente): Científica