An experiment was designed to determine whether the response of fish to graded dietary levels of essential fatty acids (n3) was affected by the total dietary lipid concentration. Juvenile coho salmon were fed practical diets varying in lipid source and total lipid content. The diets were fed in duplicate during a 27-week and a 12-week period ran in succession. The effects of the different dietary fatty acid concentrations on body fatty acids composition were determined after each period. The dietary fatty acid classes were expressed either as percent of the dry diet or percent of the dietary lipid. Analysis of the body lipid fatty acid composition was performed for neutral and polar lipid fractions. The effect of dietary fatty acid concentration on growth and mortality was determined over a 12-week growth study (period 2). A 24-hour saltwater challenge was performed at the end of period 2. It was used to examine the effect of dietary fatty acid concentration on saltwater tolerance. Dietary n6 and n3 fatty acids appeared to be selectively incorporated into the body polar lipid pool. Linoleate and linolenate underwent elongation and desaturation which resulted in the inhibition of the elongation and desaturation of 18:ln9. The neutral lipid pool served as a source of n3 fatty acids for the polar lipid when dietary intake was limited by low temperatures during period 1. The body neutral monounsaturated and 18:1 monounsaturated fatty acids consistently reflected the composition of the diet. The n3 fatty acid concentration in the neutral lipid was also directly related to the dietary fatty acid composition during period 2. The effect of dietary fatty acids on the body neutral or polar fatty acid composition did not depend on the manner in which the dietary fatty acids were expressed. There was also no significant effect of dietary total lipid concentration on the relationship between dietary fatty acids and their incorporation into the body lipids. The growth response was difficult to interpret because of the high mortality. There was a significant difference in mortality among treatments. A positive relationship between dietary concentrations of total n3 fatty acids or n3 highly unsaturated fatty acids and mortality became evident following analysis of the regression of mortality as a function of dietary fatty acid composition. The dietary fatty acid composition did not appear to alter the saltwater tolerance of the 1+ coho salmon. / Land and Food Systems, Faculty of / Graduate

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This master thesis deals with the determination of bound and free fatty acids in selected types of cheeses with/without „Protected designation of the Europen Union“ and their mutual comparison. The theoretical part focuses on a milk fat, a brief overview of cheeses, protected designation of the Europen Union, lipids, fatty acids and a possibility of their determination. In the experimental part, free and bound fatty acids profile in 12 selected samples of white mold cheeses was determined. The declared amount of total fat was verified. The cheeses were compared by a content of bound and free fatty acids, the profile of fatty acids was compared based on a type of milk used. Finally, the results were statistically treated by PCA method. The method according to ČSN EN ISO 1735 was chosen for extraction of lipids from the cheese samples. A methanolic solution of boron trifluoride was used for fatty acids esterification. The fatty acids methyl esters were determined by gas chromatography with flame ionization detection.

Oleaginous yeasts posses the ability to accumulate increased amount of lipids under appropriate conditions. These microbial lipids vary in the composition of fatty acids which results in their wide application in the biotechnological industry. This master thesis focuses on the lipid production and fatty acids composition from waste substrates by the yeasts Metschnikowia depending on various cultivation conditions. The influence of temperature, the ratio of carbon and nitrogen in medium, and the concentration of different carbon sources was studied. The cheap and easy available waste substrates as glycerol and animal fat were used for the cultivation. The production characteristics of the yeasts were monitored by various technique including gas chromatography, Raman spectroscopy and fluorescence microscopy FLIM. Moreover, the partial optimalization of the pulse field gel electrophoresis was applied in order to characterize the karyotype of the yeasts Metschnikowia. All the studied strains were able to use the waste substrates and at the same time to produce lipids. The amount of lipids and mainly their compositions vary depending on the yeast strain and on the culture conditions. Nevertheless, the ability of the yeasts to produce significant amount of unsaturated fatty acids by manipulation of culture conditions was proved. The maximum lipid yield was achieved by M. pulcherrima 149 on glycerol medium and by M. andauensis 129 on medium containing waste animal fat.

Edible insects have been part of the diet of many countries across the world for several decades. It is becoming increasingly popular in the europian developed countries, mainly because of the content of nutritionally important substances. The theoretical part of the thesis deals with the characterization of edible insects in terms of nutritional benefits, explains the reasons and method of breeding edible insects. For the analysis of nutritionally active substances, flour of house cricket (Acheta domesticus) was used. A. domesticus belongs to the representatives of insects legalized from 1.1. 2018 on the EU market. Of the significantly nutritional substances, proteins, lipids, fatty acids, fiber and selected minerals were analyzed. In this study, optimalization of vertical electrophoresis SDS-PAGE was performed to determine protein fragment sizes. In the second part the influence of acricket flour addition protein bars was investigated by sensory analysis. In the experimental part that was found that cricket flour contains protein, lipids and fatty acids in significant amounts. It also contains important minerals for human health such as magnesium, potassium, iron or zinc. However, the sensory properties of protein bars for consumers were not very attractive.

This diploma thesis deals with the changes in content of fatty acids in long-lasting stored sterilized processed cheeses. Cheeses were stored under different temperatures 6 ± 2 °C, 23 ± 2 °C and 40 ± 2 °C during 23 months. Measurements was made in 16th and 23rd month of storage. The samples of sterilized processed cheeses were extracted by using mixture of solvents (ethanol, diethylether and petrolether). The obtained fat was then saponified by methanolic solution of potassium hydroxide. The methylesthers were analyzed by gas chromatography with flame ionization detection. Lauric, myristic, palmitic, oleic and stearic acids were the most abundant in cheeses. The yield was measured in these main acids. To summarize the content of fatty acids decreased during time of storage and also by influence of storage temperature higher than in refrigerator.

This thesis deals with the identification and quantification of free and bound fatty acids in model cheese samples of the Moravský bochník type, which were produced at Tomas Bata University in Zlín by a standard technological procedure. In a theoretical part of the thesis, the issues of lipids, fatty acids, as well as the characteristics of high cooked cheeses including Moravský bochník, microbial cultures used in their production, and the possibilities of fatty acids determination are summarized. The ČSN EN ISO 1735:2005 method was chosen for the lipid extraction from cheese samples. Present free and bound fatty acids were identified and quantified by gas chromatography with flame-ionization detection after conversion to methylesters by acid esterification with bortrifluoride as a catalyst. In total 32 fatty acids were identified in cheese samples, the highest amount of caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic acids.

This master thesis deals with the monitoring of fatty acids during production of natural Edam cheeses, i.e. natural hard cheeses with low heat curd, and of processed cheeses, which were produced from them. The theoretical part briefly characterizes the natural Edam cheese and processed cheese, the main attention is paid to lipids, fatty acids and the possibility of their determination. In the experimental part the content of fatty acids in the model samples of natural and processed cheese produced at Tomas Bata University in Zlín was determined. The method according to ISO 1735 was chosen for extraction of lipids from the samples, the method according to ISO 5509 using methanol solution of potassium hydroxide was chosen for the esterification of fatty acids. The resulting methyl esters were determined by gas chromatography with FID detection.

The determination of non-esterified fatty acids (NEFA) in plasma is possible by many routine biochemical methods. For more detailed metabolic studies it is required to analyse the fatty acid (FA) profile. The NEFA profile determination is usually performed by the capillary gas chromatography (GC), but the sample preparation is not uniform. NEFA may be isolated by the extraction process or by the preparative thin-layer chromatography (TLC). The aim of this study was to compare these two separation procedures. The samples of pooled plasma from volunteer donors were analyzed by capillary GC after previous separation procedure by the TLC and the liquid-liquid extraction. The results were compared by the t-test for both the absolute concentration of individual FA provided by the internal standard (margaric acid) method and the relative abundance (Rel%). The reproducibility of the results was significantly better for the liquid-liquid extraction method than the TLC. The relative standard deviations (RSD) of the FA groups (unsaturated, monosaturated and polysaturated) were from 4.3 to 11.3 % vs. 8.6 to 33.8 % for the relative abundance and from 16.5 to 25.5% vs. 15.4 to 47.4% for the absolute concentration. For each FA, which were represented by more than 0.1 Rel %, RSD ranged from 4.5 to 47.8% vs. 9.5 to...

The boundaries between freshwater and terrestrial ecosystems can be areas of important subsidy transfers. These subsidies, such as leaf litter inputs to streams or aquatic emerging insects into riparian zones, link food webs and provide benefits to consumers in the form of nutrients and energy. Subsidies from aquatic systems tend to have high levels of essential long chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) that are only produced by certain forms of aquatic algae. These LC-PUFAs are highly important in growth, development, and other metabolic functions across animal groups (Brett and Muller-Navarra 1997, Gladyshev et al. 2009).