Methanol and starch reaction

[deleted-332158]

Why does the methyl alcohol dye the starch in a potato light pink?
Could it be the same principle as the iodine reaction?

[norman40]

Hi Coalpowered,

I’m not sure that methanol will react with starch under ordinary conditions. But potatoes will turn pink after exposure to air due to oxidation of some of the phenolic compounds present. Could this be the same as the pink coloration you’ve observed?

There is a well-known reaction of iodine with starch that yields a deep blue color. In this case, iodine forms a complex with the starch structure. More detail about the starch/iodine reaction is at this site:

http://chemwiki.ucdavis.edu/Biological_ ... and_Iodine

I hope this help. Please post again if you have more questions.

A. Norman