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Stanovení biogenních aminů v sortimentu zrajících sýrů
Bubelová, Kristýna
The diploma thesis focuses on the content of biogenic amines (BA: tyramine, histamine, kadaverine, tryptamine, phenylethylamine) and polyamines (PA: putrescine, spermine, spermidine) in eidam, emmental and parmesan cheese. The theoretical part describes the origin, occurrence and importance of BA and PA, and the various factors influencing their occurrence. In the practical part, the influence of the type of cheese, temperature and storage time on the content of individual amines was monitored. The most significant amines in all types of tested cheeses were tyramine (eidam 173,3 mg/kg > emmental 4,4 mg/kg = parmesan 10,9 mg/kg) and putrescine (eidam 188,4 mg/kg > emmental 77,5 mg/kg = parmesan 36,4 mg/kg). When compared to all types of monitored cheeses stored for 3 weeks, there was a tendency (p > 0,05) to increase the BA content and decrease the PA content in the cheeses stored at 20 °C compared to the cheese stored at 5 °C (tyramine 128,1 mg/kg vs. 62,9 mg/kg, putrescine 61 mg/kg vs. 100,8 mg/kg). During storage (X, weeks), the tyramine content (Y; mg/kg) in eidam and emmental was increased by the following equation: y = 82,2 + 28,9x (R2 = 0,34, p = 0,005) and y = -10,7 + 5,17x (R2 = 0,23, p = 0,025). The corresponding regression for the content of PUT (on the other hand, the reduction of content) in emmental and parmesan was as follows: y = 230,1 – 63,63x + 4.249x2 (R2 = 0,92, p < 0,001) and y = 48,6 – 6,07x2 (R2 = 0,24, p = 0,024).
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Biogenní aminy ve fermentovaných mléčných výrobcích
Bubelová, Kristýna
This bachelor thesis is focused on biogenic amines in fermented dairy products, particularly in cheeses. Biogenic amines are low molecular weight nitrogenous base formed mainly by decarboxylation of free amino acids by treatment with bacterial de-carboxylation enzymes. The most important bacteria forming biogenic amines in cheese are part of contaminating microflora (e.g. Enterococcus) and starter cultures (e.g. Lactobacillus). The cheeses are most prone to histamine, tyramine, cadaverine, putrescine. Furthermore, the work described effects, factors affecting the incidence and methods of determination.
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