The aim of this B. Sc. thesis was to determine how the roasting temperature of pumpkin seeds influences the formation of polycyclic aromatic hydrocarbons (PAH) and consequently, the presence of PAH in pumpkin seed oil. We wanted to establish which roasting temperature ensures the oil with PAH content within the prescribed limit values and which roasting temperature provides a typical aroma of pumpkin seed oil with the lowest possible content of PAH. We have determined, as expected, that PAH concentration increases with the increase of the roasting temperature. A comparison of three studies has shown that a roasting temperature up to 150 °C provides a safe oil with a very low PAH concentration. The roasting of pumpkin seeds at 150 °C results in a noticeable increase in the PAH concentration, however the content of benzo(a)pyrene and the total content of four PAHs (benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene) do not exceed the prescribed limit values (2.0 μg/kg for benzo(a)pyrene and 10.0 μg/kg for the sum of four PAHs) in any of the samples. The composition of volatile compounds also changes significantly with increase of roasting temperature. We can therefore conclude that the roasting of pumpkin seeds at 120 °C gives an oil which is safe for the consumer, because it contains very low PAH concentration and at the same time provides a characteristic and desirable fresh, green, fruity, and also roasted, nutty aroma of pumpkin seed oil. It is not useful to omit the roasting step because it is necessary for the characteristic sensory properties and does not lead to excessive PAH formation.
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