Odour plays an important role in our lives. It evokes emotions and memories, changes cognitive and physical abilities, and of course affects relationships between people. For this reason, the problem of odours has been preoccupying scientists and industrial developers for many years.
We have to consider the subjective perception when talking about pleasant and unpleasant odours. Acceptance of unpleasant odours can be determined by averaging the opinion of the population. The main source of malodours are sulfur and nitrogen containing molecules, such as allicin – garlic, felinine - cat urine, hydrogen sulfide - rotten eggs, ammonia – urine, indole and skatole – fecal, cadaverine and putrescine – rotting flesh, nicotine – tobacco and so on. In addition, there are other odorous substances that are responsible, for example for smell of sweat - isovaleric acid, rancid oil - butanoic acid, tobacco smoke - acetaldehyde etc. In everyday life the numb