For mycotoxin detection you need some analytical equipment.

In worse sensitivity cases TLC equipment,

In middle HPLC with fluorescence detection with post column derivatization unit.

In high sensitivity triple quadrupole or orbitrap HPLC/MS/MS.

So, most preferable method depends from your analytical facilities.

Adding to the above mentioned methods, there are also highly sensitive ELISA kits for detection of mycotoxins in food such as Veratox HS.

As for the assessment of fungal population, standard agar plate count on media specific for dry condition tolerant mycotoxigenic fungal species e.g. Aspergillus and Penicillium spp. can useful. You may check this publication for the method:

Mannaa, M., Oh, J. Y., & Kim, K. D. (2017). Microbe‐mediated control of Aspergillus flavus in stored rice grains with a focus on aflatoxin inhibition and biodegradation. Annals of applied biology, 171(3), 376-392.

Regards

Article Mycotoxins in fruits and their processed products: Analysis,...

Hi Nurudeen

You can read this reference may be useful for you

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjujoWD8MHfAhVQMewKHWx9DUQQFjAAegQIABAC&url=http%3A%2F%2Fwww.journalrepository.org%2Fmedia%2Fjournals%2FARRB_32%2F2017%2FOct%2FHegazy1762017ARRB35571.pdf&usg=AOvVaw3rXRdyB-u4S6u0EUGbP9nO

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=2ahUKEwjujoWD8MHfAhVQMewKHWx9DUQQFjACegQIBBAC&url=http%3A%2F%2Fwww.aascit.org%2Fauthor%2Fdownload%3FpaperId%3D6045%26stateId%3D8000%26fileType%3D3&usg=AOvVaw1mHTFRC07XtbTmlxMqiTFD