Gareth at the Ymddiriedolaeth GIG Bro Morgannwg asks:

>>Can anyone help me with this project question.

The use of foodstuffs/juices (i.e beetroot, carrot) as a histological dye.

Are there any papers/articles.<<

Carmine (cochineal): The natural product is I believe still used to prepare 
Mayer's mucicarmine, still in at least occasional use by surgical 
pathologists. Its use as a red food dye is limited by its occasional 
contamination with salmonella, but I don't believe it's been entirely banned 
- I've seen it most recently in "organic" fruit juice preparations.

Saffron: Still used in the hematoxylin-phloxin-saffron variant of the Masson 
stain. Still indispensable in paella. No synthetic substitute for either 
purpose.

Logwood: Hematoxylin is of course well known. I have never heard of logwood 
being used to color food, but I'm sure the Elizabethans tried it.

Beetroot: The complex subject of anthocyanins - widespread red and blue plant 
pigments - as histologic stains is covered in Conn 9th ed.

The reference I'd recommend for these and some more obscure materials is H.J. 
Conn's Biological Stains, edited by Ralph D. Lillie, 9th ed. 1977. Seven 
pages on anthocyanins alone.

Bob Richmond
Samurai Pathologist
Knoxville TN