Cheese analogue with the addition of fish oil

This barchelor thesis deals with the change in nutritional values of fresh cheese after the addition of fish oil. The subject of research is fatty acids, volatile substances and sensory properties. Fish oil was chosen mainly due to the content of healthy essential omega-3 unsaturated fatty acids eicosapentanoic (EPA) and docosahexanoic (DHA). Samples of fresh cheese (standard) and cheese analogues with various additions of fish oil were prepared on the premises of FCH VUT in Brno. Fat was extracted from the samples with a mixture of petrolether and diethylether solvents. The fatty acids in the fat were converted to methylesters by acid esterification in the presence of borontrifluoride as a catalyst. The methylesters were dissolved in isooctane and determined quantitatively by GC-FID. As the fish oil was added, the fatty acid content of the analogues increased as expected. Identification of volatile (aromatic) substances was performer using the HS-SPME-GC-MS method. A total of 30 volatile (aromatic) compounds were found in cheese/analogues and in fish oil. Cheese analogues with fish oil additions had a common volatile base with the standard and also contained compounds common to fish oil. As a percentage of each group, the cheese analogues resembled the control sample rather than the fish oil. A sensory analysis of a control sample with two analogues with different fish oil additions were performed. The evaluation was recorded in a sensory form with graphic scales and the texture (hardness, disintegration), taste (acidity, bitterness, fishy taste, pleasantness) and smell (intensity, pleasantness) were assessed. At the end, a seriál test was included, which clearly showed that the fish oil in both analogues significantly bothered consumers. The results show that the addition of fish oil increased the content of unsaturated fatty acids including very helthy omega-3 fatty acids (EPA and DHA) in the spectrum of unsaturated fatty acids. However, the results of the sensory analysis show that the increase in nutritional value took place at the expense of the sensory quality of the product. The addition on fish oil did not suit the vast majority