Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Identification of conjugated isomers of linolenic acid and arachidonic acid in cheese
Autore:
Winkler, K; Steinhart, H;
Indirizzi:
Univ Hamburg, Dept Food Chem, Inst Biochem & Food Chem, D-20146 Hamburg, Germany Univ Hamburg Hamburg Germany D-20146 Food Chem, D-20146 Hamburg, Germany
Titolo Testata:
JOURNAL OF SEPARATION SCIENCE
fascicolo: 8, volume: 24, anno: 2001,
pagine: 663 - 668
SICI:
1615-9314(200109)24:8<663:IOCIOL>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
PERFORMANCE LIQUID-CHROMATOGRAPHY; FATTY-ACIDS; LIVER LIPIDS; DOUBLE-BONDS; SILVER-ION; DERIVATIVES; DIENE; METABOLITES; CLA;
Keywords:
conjugated arachidonic acid (CAA); metabolites of conjugated linoleic acid (CLA) cheese; RP-HPLC; Ag+-HPLC;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
20
Recensione:
Indirizzi per estratti:
Indirizzo: Steinhart, H Univ Hamburg, Dept Food Chem, Inst Biochem & Food Chem, Grindelallee 117, D-20146 Hamburg, Germany Univ Hamburg Grindelallee 117 Hamburg Germany D-20146 ermany
Citazione:
K. Winkler e H. Steinhart, "Identification of conjugated isomers of linolenic acid and arachidonic acid in cheese", J SEP SCI, 24(8), 2001, pp. 663-668

Abstract

A method has been developed for the separation and identification of conjugated fatty acid isomers as distinct from conjugated linoleic acid (CLA). Cheese fat was extracted using n-hexane and converted into fatty acid methylesters (FAMEs) with potassium methylate. Because of the low concentration of conjugated fatty acids isomers, a prefractionation was performed to enhance and to separate these isomers from CLA and other fatty acids common in cheese fat. The separation was carried out by preparative reversed phase (RP)-HPLC. The FAMEs were detected with a UV detector at a wavelength of 208 nm, so all FAMEs were detectable, including non-conjugated ones. All prefractions were analysed on a high polarity GC column fitted with a split-splitless injector and a flame ionisation detector. In addition prefraction 2, which contained linolenic acid and arachidonic acid, as well as their isomers, was fractionated by silver ion (Ag+)-HPLC. Two columns were used in series with 0.1 % acetonitrile in n-hexane as isocratic mobile phase. All conjugated compounds were detected with a photodiode array detector at 234 nm and the spectrum from 200 to 400 nm was recorded. Thus characteristic spectraof conjugated dienes and conjugated trienes could be distinguished. For identification of the position of double bonds, each fraction collected afterAg -HPLC was converted into 4,4-dimethyloxazoline (DMOX) derivatives. These derivatives were analysed by gas chromatography-electron impact ionization mass spectrometry (GC-EI-MS). With the proposed method, 13 conjugated isomers of arachidonic acid (CAA) and six conjugated isomers of linolenic acid(CLnA) could be identified with regard to the position of their double bonds.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 12:16:13