potato phenolics question

[Marek Nelke]

Dear netters!

I am a post-doc who was asked  to start project dealing with 
elimination of after cooking darkening of proccessed potato using 
molecular biology techniques. I have problem with  it from the start. 
After quite intensive studies of literature in the field my 
understanding is that after-cooking darkening in potato is 
non-enzymatic chain of chemical reactions. Am I wrong? So there is no 
genes involved in darkening, just during the cooling of boiled potato 
air oxygen oxidases chlorogenic acid to quinones which are 
transformed into melanins. Are any enzymes involved in pigment 
formation from quinones? I can not knock out polyphenol oxidase by 
antisense RNA for example because after-cooking darkening is 
non-enzymatic reaction. Is it something wrong with me or elimination 
of after-cooking darkening proccessed potato can not be achieve by 
molecular biology approach? I would really appreciate your response 
and maybe some advice because I am really lost.
Please, respond  to my E-mail address ( MNelke at IMail.nsac.ns.ca )

							Cheers,  Marek
Marek Nelke
Nova Scotia Agricultural College
Department of Plant Science
Truro, Nova Scotia
B2N5E3
E-mail: MNelke at IMail.nsac.ns.ca
Tel: (902) 893-7812
Fax: (902) 897-9762