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Vliv tepelných úprav kuřecích jater na změny obsahu biogenních aminů a polyaminů
Sultana, Michaela
This thesis examined the effects of different cooking methods (boiling, stewing and roasting) on chicken liver in order to measure changes in the levels of biogenic amines (BA) and polyamines (PA). Two other factors were also considered, season and method of chicken liver storage. BA and PA levels were determined using a liquid chromatography method (UPLC). The mean level of BA in the original raw material (six and three samples of refrigerated and frozen livers, respectively) was very low, with the highest being histamine (4,11 mg.kg-1). Tryptamine and fenylethylamin were not detected in any of the samples. The level of PA was significantly higher than the level of BA, with more spermine (135 mg.kg-1) than spermidine (42,3 mg.kg-1). The total content of BA and PA in the dry matter of refrigerated livers was almost twice as high in the summer than in the winter (P < 0,001). When comparing refrigerated against frozen livers, the levels of putrescine and histamine were significantly higher in the refrigerated liver (P < 0,01), while the levels of cadaverine and tyramine were higher in the frozen liver (P < 0,001), and the levels of spermine and spermidine were 20 % lower in the frozen liver (P < 0,01). Roasting had less of an effect in the decline of BA (80 % of the original content) than cooking (65 % of the original content) (P < 0,001). The lowest levels of spermine and spermidine were found in the roasted liver (70 % of the initial content) while stewing and cooking caused a decrease of approximately 80 % (P < 0,01).
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