Fragrances determine our lives, like the well-known gastronomy and wine specialist Guy Bonnefoit writes in his book "Fascination Wine & Aromas": The human skin has a surface of about two square meters and has up to 300 odor components. Depending on the physical condition and state of mind, the odorants also change. A dog can differentiate exactly between well-disposed and fearful people. Every mood has its own smell - you can smell the state of "happy". An experienced country doctor reports that he is able to recognize certain diseases when entering a hospital room. Every disease develops its typical "scent". Diabetes smells fruity, diphtheria sweet, typhoid after baked bread and gout after lion cage or pet shop (end of quote).
The sense of smell is the ability to perceive gaseous substances or substances dissolved in water at the molecular level. Again taste the smell is one of the chemical senses. The ability is only proven in vertebrates and insects. Smell perceptions are more emotionally charged than any other sense organ. This means that an evaluation is immediately made in pleasant (smells) or unpleasant (smells). In behavioral biology, the smell has a special meaning with regard to food intake, reproductive behavior and detection of enemies. Smells promote appetite and the formation of digestive juices. And the statement "that you can't smell someone" is much more than just a play on words.
Scientific tests have shown that the scent is unconsciously of great importance when choosing a partner. Likewise, smells play an important role in memory and associative brain processes. Smells become olfactory perceived through the yellow olfactory mucosa (about 2 x 5 cm²) in the uppermost part of the nasal cavity directly under the brain. Fragrances are not only guided and perceived nasally (orthonasally, pronasally) when inhaling through the two nostrils, but also retro-nasally when exhaling from the oral cavity via the nasopharynx to the olfactory mucosa. It depends on the amount of an odorant when it is perceived. This is called Perceptual threshold (Limit).
Around 20 million olfactory threads absorb the fragrances. A dog has ten times more olfactory threads, that is around 200 million on 2 x 25 cm². These absorb the smell and act as receptors and pass it on to the olfactory bulb. Here they are first perceived and passed on to the brain for "dissolution". Women have around 50% more nerve cells in the olfactory bulb and therefore better smell. The olfactory bulb (rhinencephalon) is a delimited part below the right hemisphere and is connected to the limbic system (limbis = joint). This is responsible for the entire processing of feelings such as love, sexual arousal, fear and anger. There are also numerous in wine pheromones (Sexual fragrances) are included, wine can also be considered aphrodisiac Act. However, there are two in the sense of smell sensory Systems involved. In addition to the olfactory, that's also trigeminal (regarding the sense of touch) system.
A severe limitation arises with a runny nose, in which you perceive the taste directions, but no smells. Odor impressions are often wrong taste attributed. Because with the enjoyment of food and beverages as of course Weingenuss these impressions of the tongue and nose received in the brain mix to form an overall impression, so that the definitive origin can no longer be traced. The combination of taste and smell sensations creates a complex variety of sensory nuances. The human tongue is primitive with the six flavors opposite the nose. Richard Axel and Linda Buck received the 2004 Nobel Prize in Medicine for unraveling their sense of smell. The two US researchers demonstrated that humans can absorb, memorize and distinguish around 10,000 smells.
In order to recognize the smell, the concentration of the fragrance must be about 50 times higher. Fragrances can open the gates of memory. However, civilized people have forgotten how to identify smells exactly. Because we no longer need it as in primeval times, where survival depended on it. In addition, according to a hypothesis, when “he straightened up” people lost part of their sense of smell and at the same time increased their performance in seeing and hearing. Nevertheless, the nose is still much closer to our psyche than the eye or ear. The numerous cause in wine flavorings the fragrance impressions. Of the University of California became the so-called aroma wheel with the help of which these fragrances can be identified. During normal breathing, only a small part of the scents reach the receptors. That's why you have to wine review "sniff" with the nose deep in the glass. However, this must not be done too intensely, otherwise the fragrances will sweep past the olfactory mucosa and will not be absorbed there.
At the end of June 2014, the Technical University of Munich (TUM) issued the following press release: "Odor code of food decoded". Scientists from TUM and the German Research Institute for Food Chemistry (DFA) performed a meta-analysis of the odorant samples from 227 food samples. The study clarified and identified the molecular fragrance signatures of foods. More than 10,000 different volatile substances are found in food. But only about 230 of them shape the aroma of the most common foods. And only three to 40 of these key flavors encode the typical and unmistakable fragrance of a single food from pineapple to roasted meat to Wien . The scent of sour cream butter, for example, is encoded by a combination of only three key molecules; for fresh strawberries, it is 12 and is the frontrunner cognac at 36.
The chemical odor codes are translated into olfactory stimulus patterns when eating food. To do this, the key odorants have to interact with one or more of the 400 odor receptors in the nose. Prof. Thomas Hofmann (Chair of Food Chemistry and Molecular Sensor Technology) comments: “With the combination of only a few key flavors, an authentic smell perception can be generated. The odor quality of the combinations is not determined by the individual components. The individual aroma components do not simply add up in the perception and neural processing of the odor patterns. Rather, the individual information is translated into a new fragrance. In view of the combinatorial nature of the chemical aroma code and the large number of around 400 odor receptors, the number of perceptible odors seems to be almost unlimited ”.
The identification of the odor codes opens up completely new possibilities for biotechnological applications. For example, at breeding be helpful that the aroma codes of crops and fruits are known at the molecular level: in the past, breeding was less based on the sensory quality than on the increase in earnings and area performance. The findings also form the scientific basis for the next generation of bio aroma production, which uses the potential of optimized biosynthetic pathways in plants for the industrial production of high-quality food fragrances.
With the current odorant mapping, the natural replication of aromas is made possible with increasing precision. Completely new applications in mobile communication systems, such as sending smell messages with a smartphone or developing bioelectronic noses, are within reach. (Publication: Andreas Dunkel, Martin Steinhaus, Matthias Kotthoff, Bettina Nowak, Dietmar Krautwurst, Peterieberle and Thomas Hofmann; genuine scent signatures of nature, perspectives from food chemistry for future biotechnology, applied chemistry).