Umami, one of the five basic tastes, gives a special deliciousness, richness and meatiness to many vegetable and meat dishes. The special feature of umami compounds, mainly free glutamic acid and free 5´-nucleotides, is their synergistic interaction, which significantly enhances the taste sensation of umami when these compounds are simultaneously present in food. Even though umami compounds themselves do not taste particularly pleasant, the unique characteristic of umami is that it functions best when combined with other basic tastes. Although considerable research has been done on umami taste related compounds, there is less research on the effect of cooking on the concentration of these compounds and any possible changes in their concentration during heat treatment. The aim of this thesis was to investigate the overall change in the concentrations of umami compounds in Nordic food induced by cooking. Multiple simultaneous reactions, both in the formation and loss of umami compounds are likely to occur during cooking. Changes in the content of the compounds may result from both enzymatic and chemical reactions, possibly accelerated or stabilized by the increase in temperature. The raw materials studied in this thesis, including meat, mushrooms and potatoes represent fauna, fungi and flora, differ from each other in terms of protein, carbohydrate and fat content. However, they all contain detectable concentrations of umami compounds, both free amino acids and nucleotides. The concentrations of the compounds in the examined raw materials, both fresh and cooked, were determined quantitatively by chromatographic techniques. Cooking is essential for most food ingredients. This study showed cooking influenced the concentration of umami compounds in food raw materials, and the cooking temperature was more important variable than the cooking time. However, from the perspective of the synergy, heat treatment may have different effect on release and the content of certain umami compounds. Increase in temperature can accelerate inherent enzymatic activities in the raw material and result in changes in the content of compounds. In particular, the concentrations of nucleotides may increase or decrease until the temperature reaches the enzyme deactivation point. In addition, heat may promote the participation of free amino acids in chemical reactions with other compounds present in the raw material and lead to a decrease in the concentration of amino acids. The water-binding capacity of the raw material is affected by many factors. As sous vide cooking progresses, the denaturation of proteins and other structural changes caused by heat are important factors contributing to the weakening of the water-binding capacity. As a result, umami compounds are released into the liquid. Thus, the cooking juice is also a valuable source of umami. In pork, the concentration of the nucleotide 5´-IMP and the free amino acid glutamic acid remained almost at the same level at the three different sous vide cooking temperatures 60, 70 and 80 °C and three different cooking times 60, 120 and 180 min. The 5´-IMP content of the corresponding cooking juice released from meat also remained unchanged. However, the increase in the glutamic acid concentration in the cooking juice at the highest investigated temperature was statistically significant. In addition, the increase in the relative share of cooking juice from the total sample at the highest cooking temperature studied increases the role of juice as a source of umami. The increase in 5´-nucleotide content due to the effect of sous vide cooking temperature was seen especially in the study of mushrooms. The concentrations of the umami nucleotide 5´-GMP was detectable only in samples cooked at a sufficiently high temperature 70, 80 or 90 °C for cooking time 10 minutes but was negligible at 60 °C and fresh mushrooms. Instead, the concentration of free amino acids both in the mushrooms and in the released cooking juice partially either decreased or increased during cooking. For different mushroom species, the amount and direction of the change varied as the cooking temperature increased. This indicates the presence of chemical reactions of free amino acids, as well as differences in concentrations between fungal species . Growth conditions are known to have a major impact on potato quality. The results of our study showed that the concentration of umami FAA glutamic acid, as well as most of the other FAAs was significantly higher in short day (SD) conditions (8h light, 16h dark) developed tubers than long day (LD) tubers (15 h light, 9h dark). This study focused on the umami compounds of Nordic food raw materials. The results of the research can be applied in the product development of delicious and tasty meals, for example, to increase the consumption of plant-based alternatives. The study also showed the potential of the cooking juice released from meat and mushroom as a source of umami. This result can be utilized in the efforts to use raw materials more efficiently and in the attempts to reduce food waste. In addition to cultivated mushrooms, the study showed the potential of forest mushrooms as a source of umami. Moreover, in the breeding of potatoes and in the selection of cultivars and the growing conditions used, more attention should be paid to the taste properties of the potato tubers and thereby to the possibilities of increasing potato consumption.