This week molecule will be putrescine, a biogenic amine related, together with cadaverine, to the bad smell of putrefying flesh.
The presence of this molecule in food is due to bacterial metabolism and it is potentially carcinogenic.
Would you have ever said that such a small molecule could be so dangerous?
Want to read more about this? Have a look at this article: http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12099/abstract