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Biogenní aminy v produktech minipivovarů
SYMONOVÁ, Michaela
The bachelor thesis deals withbiogenic amines (BA) content in beers of selected microbreweries from South Bohemia, where beers from commercial breweries are also used for comparison. This thesis is divided into two parts. The first, theoretical part, is focused on introducing the brewing industry, the process of beer production, the difference in the production process in microbreweries and their characteristics. It also explains what BAs are and their different presentation. The second half of this thesis is focused on the experimental part, where the methodology of the work, determination and evaluation of BA content in different beer samples is presented. The ultraperformance liquid chromatography (UPLC) method by which the content of individual BAs in beer samples was determined is also presented. Subsequently, the results of the experiment are presented and a discussion with a comparison of the results of this work with the results of other studies of the same focus is presented.
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Production of biogenic amines in double moulded cheese
Šuláková, Miroslava ; Standara, Stanislav (referee) ; Veselá, Mária (advisor)
For production of double moulded chesses are used lactic acid bacteria, which can be present in a form of non-starter lactic acid bacteria or as starter or adjunct culture. Genera Lactobacillus spp. and Enterococcus spp. are prevalent microorganisms present in these cultures. Of course, these microorganisms are for us interesting because of their possibility of coagulation, proteolytic possibility, probiotic function and antibiotic resistance, but especially because of their decarboxylation abilities. Bacteria contain decarboxylation enzymes, which are able to decarboxylized free amino acid, which rising at proteolysis during process of manufacturing and cheese ripening. Biogenic amines are the result of proteolytic activity. Biogenic amines occur practically in all foodstuffs as a common product of metabolic processes. BA are mainly presented in fermented food (cheeses), where rice just microbial action. Typical representatives of biogenic amines, which occurs in double moulded cheeses (Sedlčanský Vltavín, Bresse bleu) and in blue cheeses (Bleu des Causses, Bleu d'Auvergne) are cadaverine, putrescine, tyramine a 2 fenylethylamine and in much smaller amount histamine, spermidine and spermine too. On assessment concentration of BA is used high pressure liquid chromatography with reverse phase (RP HPLC) with utilizing simple direct derivatization with dansyl chloride and detection by UV VIS detector.
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Detekce biogenních aminů u konzervovaných výrobků z ryb
Zátopková, Tereza
The aim of my work was to conduct a literature search on biogenic amines and to detect the content of biogenic amines in canned fish products in the laboratory part. Four fish spe-cies were sampled for the determination: mackerel (Scomber scombrus), bluefin tuna (Thun-nus thynnus), sardine (Sardina pilchardus) and cod (Gadus morhua). Two samples were used for the determination of sardines, which differed in the brine in which they were preserved. The detection of biogenic amines was carried out by ion-exchange liquid chromatography with VIS detection. The following specific biogenic amines were determined: histamine, tyramine, putrescine, cadaverine, spermine and spermidine. The highest concentration of biogenic was determined in the sample of liver, in this sample the overall highest contents of histamine, putrescine, cadaverine and spermine were found.
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Vliv receptury a délky zrání na obsah biogenních aminů ve zrajících sýrech
Trusinová, Adéla
The diploma thesis is focused on the content of biogenic amines (cadaverine, histamine, 2-phenylethylamine, tyramine and tryptamine) depending on the ripening time in 3 varieties of maturing cheeses (control sample, sample with laccase in the cheese dough, sample with laccase on the surface of the cheese). Furthermore, the work focuses on the effect of adding laccase to the dough and on the surface of the cheeses. The theoretical part is focused on the importance and occurrence of biogenic amines in food, including possible toxic effects on the organism. The practical part monitored the effect of ripening time on the content of biogenic amines in 3 variants of the same type of cheese in the ripening process. Biogenic amines were determined after derivatization with dansyl chloride by HPLC. The most quantitatively represented biogenic amine was cadaverine, which reached the highest concentration values after 14 days of ripening in cheese with laccase on the surface. The value of the concentration was 336 μg/100 g. The amount of laccase on the surface showed an opposite trend (p ˂0.05) when evaluating the storage time on the content of the concentration of biogenic amines, an opposite trend against cheeses with laccase in the dough. The concentration of the sum of biogenic amines in all cheese samples with laccase in the dough first decreased, then increased according to the equation y = 556.03–165.51x + 22.593x2 (R² = 0.4904; p = 0.14). The concentration of the sum of biogenic amines in cheeses with laccase on the surface, depending on the ripening time, first increased and then decreased according to the equation y = 150.42 + 631.63x - 97.921x2 (R² = 0.1999; p = 0.57). Most of the values measured in this work do not correspond to the normal content of individual biogenic amines in the literature, this fact may be caused by an inappropriate selection of the type of cheese for the determination of biogenic amines, an incorrect technological procedure during production or the fact that the filtration of the supernatants was very difficult and lengthy and with large losses. The influence of laccases on the formation of biogenic amines could not be unequivocally demonstrated due to the great variability of the data and few reference values with which the measured values can be compared. Laccases in food are a relatively new issue that is not sufficiently supported by literature sources and requires further investigation.
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Stanovení biogenních aminů ve víně
Novotná, Michaela
This thesis focuses on the determination of the amount of individual biogenic amines in eight samples of wines coming from four European countries – Czech Republic, Spain, Austria a Hungary. There was chosen one white and one red wine variety from each country. All of wine samples was dry – content less than 9 g sugar per liter. Varieties were: Grüner veltliner (one sample from Austria and second sample from Hungary), Chardonnay (one sample from Czech Republic and second sample from Spain), Zweigeltrebe (from Austria), Cabernet Moravia (from Czech Republic), Blauer Portugieser (from Hungary) and Tempranillo barrique (from Spain). The amount of biogenic amines was determined by ion-exchange liquid chromatography with UV/VIS detection. The bigges amount of biogenic amines was detectected in Zweigeltrebe. The lowest in Chardonnay (Czech Republic). Putrescine was detected in all samples, by contrast histamin was mostly under the detection limit.
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Obranné reakce hmyzu vůči intoxikaci: modelový druh včela medonosná
PROKŮPKOVÁ, Nela
This bachelor thesis aimed to characterize the effect of imidacloprid (neonicotinoid insecticide) on nutrient levels (carbohydrates, proteins, lipids) in haemolymph, on the activity of digestive enzymes (amylases, proteases, lipases) in the gut, and on adipokinetic hormone and biogenic amine levels in the central nervous system of the worker honeybees Apis mellifera. The insecticide was applied topically to the bee body at a dose of 0,04 micrograms per bee. The above-mentioned characteristics were measured 24 hours after insecticide application. The results showed that the effect of imidacloprid on the nutrient level in haemolymph was variable - the level of carbohydrates and proteins decreased, while the level of lipids increased. The activity of digestive enzymes in the gut increased (proteases, lipases) after the application of imidacloprid. On the other hand, the levels of adipokinetic hormone and biogenic amines in the central nervous system were reduced.
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Vliv zavadání, kontaminace píce zeminou a použitých konzervantů na kvalitu a zdravotní bezpečnost siláží vojtěšky seté
Spáčilová, Kristýna
The aim of this diploma thesis was to evaluate the effects of wilting, soil contamination and use of silage additive on selected characteristics of green fodder and lucerne (Medicago sativa) silage. The plan material was obtained from the Research institute for Fodder Crops in Vatín. Unwilted fodder consisted in 24 % of dry matter content; wilted fodder consisted in 33 % of dry matter content. Selected samples were contaminated with soil at 30 g/kg of mass. Silage was in untreated variant (control) and two treated variants (either with biological additive or with chemical additive). Unwilted fodder had significantly (p<0,05) higher content of histamine and spermidine. Wilted fodder had a significantly (p<0,01) higher content of putrescine. In lucerne silage, factor of contamination had more significant (p<0,01) effect on ash content, and used silage additive had a statistically significant effect (p<0,05) on NDF content in silage. Significantly higher (p<0,01) content of clostridia was observed in silage from wilted fodder. The wilting factor had significantly higher effect (p<0,01) on content of ammonia, organic acids (LA, AA, PA, BA) and significant effect (p<0,05) on pH. Silage from wilted fodder was characterized by a higher pH, higher content of LA and lower content ammonia, AA, PA, BA. Contamination had significant effect (p<0,05) on increasing pH, reduction of LA and significant effect (p<0,01) on increased content of ammonia, AA, PA, BA. The silage additives significantly (p<0,05) decreased pH and significantly (p<0,01) decreased ammonia, PA, BA levels and increased LA, AA levels. The most abundant biogenic amines in silage were histamine (969 mg / kg), tyramine (800 mg / kg), putrescin (1754 mg / kg) and cadaverine (501 mg / kg). The biological additive used in the sufficiently wilted fodder works better to prevent the formation of biogenic amines and result in a more suitable fermentation profile.
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