Is there a common structure to the molecules which trigger parosmia, across a broad range of foods?
Fri-P2-085
Presented by: Jane Parker
A number of molecules have been identified recently as triggering the perception of disgust when those with parosmia are exposed to coffee (a common trigger). Many of these trigger molecules are highly potent aroma compounds which are formed via the Maillard reaction during thermal processing and have similar structural motifs, often based on sulfur or nitrogen heterocycles.
In an effort to determine whether these molecules, or their structural motifs, are conserved in other trigger foods, we broaden the scope for identification of potential triggers by looking at other foods which are thermally processed (meat, cocoa, toast), those with different volatile profiles (onions and garlic), those that are not traditionally heated (strawberries, bananas, lemons, cucumbers, cola drinks) and toothpaste which is one of the major triggers.
For this study we used GC-Olfactometry – an instrumental method which separates the volatile components in the headspace of any food and allows the participants to smell and assess the molecules one by one as they elute from the end of the GC-column. The participants are asked to describe each aroma, rate its intensity and indicate whether it contributes to the sense of disgust which they perceive when exposed to these trigger foods. GC-mass spectrometry was carried out on the same samples to identify the trigger molecules. The foods were each assed by 3-6 parosmic participants.
For thermally processed foods, we find that the trigger molecules are often the same as those found in coffee, and their common source is the Maillard reaction. For onion and garlic, although the molecules are different, the thiol/sulfide/disulfide motif is present in most of the trigger molecules. For fruits and vegetables, some new trigger molecules were identified.
The implications for our understanding of the underlying mechanism of parosmia will be discussed.
In an effort to determine whether these molecules, or their structural motifs, are conserved in other trigger foods, we broaden the scope for identification of potential triggers by looking at other foods which are thermally processed (meat, cocoa, toast), those with different volatile profiles (onions and garlic), those that are not traditionally heated (strawberries, bananas, lemons, cucumbers, cola drinks) and toothpaste which is one of the major triggers.
For this study we used GC-Olfactometry – an instrumental method which separates the volatile components in the headspace of any food and allows the participants to smell and assess the molecules one by one as they elute from the end of the GC-column. The participants are asked to describe each aroma, rate its intensity and indicate whether it contributes to the sense of disgust which they perceive when exposed to these trigger foods. GC-mass spectrometry was carried out on the same samples to identify the trigger molecules. The foods were each assed by 3-6 parosmic participants.
For thermally processed foods, we find that the trigger molecules are often the same as those found in coffee, and their common source is the Maillard reaction. For onion and garlic, although the molecules are different, the thiol/sulfide/disulfide motif is present in most of the trigger molecules. For fruits and vegetables, some new trigger molecules were identified.
The implications for our understanding of the underlying mechanism of parosmia will be discussed.