Naslov
RP-HPLC Evaporative Light Scattering Detection Method for Determination of Free Amino Acids in Cheese

Autori
Mikulec, Nataša ; Habuš, Ivan ; Antunac, Neven ; Havranek, Jasmina ; Kalit, Samir ; Vitale, Ljubinka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstract: 5th IDF Symposium on Cheese Ripening / Butikofer, Ueli - Bern : Agroscope Liebefeld-Posieux Research Station ALP, 2008, 171-171

Skup
5th IDF Symposium on Cheese Ripening

Mjesto i datum
Bern, Švicarska, 09.03.2008. - 13.03.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
RP-HPLC-ELSD; ewe’ s milk cheese; cheese ripening; amino acids; peptides

Sažetak
Ample literature proceedings describing methods for determination of free amino acids and peptides in variety of cheeses have been published. The methods are mostly based on chemical modifications of free amino acids and small peptides and their separation by RP-HPLC using UV/VIS or fluorescence detectors. Amino acids and small peptides soluble in trichloroacetic acid were treated with phenylisothiocyanate, o-phthaldialdehyde, 9-fluorenylmethylchloroformate, or 1, 4, 5-trinitrobenzenesulfonic acid to obtain derivatives suitable for HPLC analysis. In order to simplify these procedures we have tried to omit chemical modification step and to analyse free amino acids from cheese by HPLC combined with Evaporative Light Scattering Detection (ELSD). Separations were performed on the Prevail 5µ ; m, 250  4.6 mm, C18 reversed phase column using water containing trifluoroacetic and heptafluorobutyric acids – acetonitrile gradient. Good separation of a standard mixture of 17 amino acids with norleucine, added as the internal standard, was achieved in 25 minutes run. Developed method was applied for the analysis of a semi-hard full-fat ewe’ s milk cheese, that possesses a specific flavor and smell, collected at the farms located on the island Krk which are breeding Croatian autochthonous sheep. It was found that glutamic acid, leucine, valine, phenylalanine and proline dominate in trichloroacetic acid soluble fraction of the mature cheese. The results are in accordance with the data reported in literature for the similar type of cheeses obtained by other methods. Developed RP-HPLC – ELSD method is a simple and reliable, and could be adopted for determination of free amino acids in cheeses during their production.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Poljoprivreda (agronomija)

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