Fantastic Flavours Pty Ltd
For an aroma compound to be smelt it needs to be volatile
Aroma compounds have different strengths, so a combination of vapour pressure and threshold value determine the strength of their odour. Another factor is the partition coefficient.
If an aroma compound dissolves in a solid or liquid then its concentration in the air above is reduced and so consequently is its odour
Other influences are heat, pH and stability.
The biggest and most powerful molecule is Exaltolide which was discovered as the key aroma in musk (from the Chinese musk deer).
Researchers' at Firminich won the Nobel Chemistry prize for elucidating its structure. The largest known ring structure.
Noble prize Chemistry Leopold Ruzicka The Nobel Prize in Chemistry 1939
It has a very sweet aroma and is used in tiny amounts in blackberry flavours.
It is mainly used in perfumes where its low vapor pressure and aroma strength (very low aroma threshold) make it very long lasting on the skin.
I have seen many articles about the safety of flavour chemicals and flavour ingredients.
Most of the ingredients used in the flavour industry by volume are natural essential oils. Flavour chemicals are often chemical duplicates of those found in nature.(called nature identical) There is a relatively small number of exclusively artificial chemicals.
So the question is how safe?
In the USA you can only use substances listed on the FEMA GRAS list. (see Legal)
When you look at nature it is often the concentration rather than the chemical that is the problem. Ethanethiol found in durian and added for safety to natural gas is toxic as well as H2S which has an egg aroma at very low concentrations and is toxic at high concentrations.
Acetaldehye found in wine, orange juice and apples is also a problem at high concentrations. Diacetyl is another flavouring with problems at high concentration (see legal)
Caffine is toxic to dogs and snails but we all drink Tea or coffee.
Now before I go on further let me tell you that I am not an expert on this subject so the article is just my opinion.
Most of the problems with aroma chemicals happen in a flavour/perfume factory where workers are exposed to high concentrations. Even with natural vanilla beans workers exposed to high levels of vanillin have problems.
At the levels in the final food it is difficult to see that there is a problem.
I doubt if anyone really knows what components are responsible for bread flavour but the following are often mentioned:-
6-Acetyltetrahydropyridine FEMA 3251
2-Acetyl-1-pyrroline FEMA 3202
Methional FEMA 2747
2-Ethyl-3,5-dimethylpyrazine FEMA 3149
5-Ethyl-3-hydroxy-4-methyl-2(5H)-furanone FEMA 3153
Malt Flavour Maillard Reactions
Identification of the key odorants in barley malt (caramalt)
Application of the Aroma Extract Dilution Analysis on a distillate prepared from ground caramalt kernels followed by identification experiments revealed 3-methylbutanal (malty), 1-octen-3-one (mushroom-like), methional (cooked potato), (E,E)-2,4-decadienal (fatty, waxy), vanillin (vanilla-like), 2- and 3-methylbutanoic acid (sweaty) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like) as the most odor-active compounds. Using static headspace/olfactometry, the very volatile odorants dimethyl sulfide (cooked vegetable-like) and 2-methylpropanal (malty) were identified as additional odorants contributing to the overall rye-bread crust-like odor of the caramalt
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