Tomato is a perishable fruit and can be contaminated by microorganisms mainly during storage.

This is due to the high storage temperatures, increase in relative humidity, and increase in contact with fruit contaminated with microorganisms.
The fungi Alternaria alternata, Rhizopus stolonifer, Colletotrichum gloeosporioides, and Aspergillus flavus can contaminate tomatoes during storage, causing physical damage to the fruit.

Aspergillus flavus, in addition to causing physical damage to the fruit, also produces toxic secondary metabolites for the human body called aflatoxins [1].
The consumption of aflatoxins has been confirmed to have carcinogenic, toxic, and mutagenic activity in humans and animals.