Naslov
D-tryptophan contents of alkaline digested meat flours

Autori
Lóki, Karol ; Kalambura, Sanja, Mándoki, Zsoltan ; Kricka, Tajana ; Pohn, Gortan ; Albert, Cs., Csapó-Kiss, Zsoltan ; Csapó, Janos

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

Izvornik
Zbornik sažetaka XV međunarodna konferencija KRMIVA 2008 / Slavko Lulić - Zagreb : Krmiva, 2008, 89-90

Skup
XV Međunarodni skup Krmiva 2008

Mjesto i datum
Opatija, Hrvatska, 02.06.2008. - 05.06.2008

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
tryptohan ; enantiomer ; p-toluensulfonic acid ; 3-indole-propionic acid ; meat flour

Sažetak
In the last couple of years the aim of our researches has been the determination of the tryptophan enantiomers in different biological samples, with special respect to feeding stuff raw materials. We have developed a method for the determination of the tryptophan enantiomers by HPLC, in which diastereomers were formed from the tryptophan enantiomers with o-phthaldialdehyde (OPA)/ 1-thio-β-D- glucose tetra acetate (TGTA) derivatizing reagent mixture, and the derivatives were separated on a non-chiral column, in a reversed- phase liquid chromatographic system. Amino acids were released from proteins by hydrolysis with p-toluenesulfonic acid in order to avoid racemization. In order to reduce decomposition of tryptophan, 3- indole-propionic acid was used as protecting agent in the same amount as the expected protein content of the sample weighed in. By this in case of samples with high protein content we obtained a recovery of above 90% for tryptophan. We wanted to examine the change in the Trp content of alkaline treated meat flour samples, as well as the racemization of Trp content as a result of the treatments. The original aim of the treatments was to find out whether it is possible to kill the microorganisms that are possibly present in the sample and destroy other substances that can be harmful to the health, by such a treatment, and so to make the meat flour suitable for feeding stuff application purposes. The treatments were done using sodium and potassium hydroxide solution, respectively, for 2, 3 and 6 h at 135, 150 and 153 ºC. Based on the obtained results it can be established that even the half of the tryptophan content can decompose as a result of the treatments. Due to the strongly alkaline circumstances the racemization is almost complete for the remaining tryptophan content. Thus, it can be said that even if this method is suitable for the destruction of the health damaging materials, it has to be taken into consideration that both loss of tryptophan and racemization is substantial. We must also assume that similar results would be obtained also for other amino acids.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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