The anthocyanin dissolved in water is unstable. and will disappear
fairly quickly, as you have seen.
The only way to tell if you had some of the yellow water soluble
flavanoid pigment to start with is to separate them initially.
One way to do this is to get a hold of blotter paper, or something
similar. Crush a spot about 1/8 to 1.4" about 3/8" from one edge. then
place paper into a container with water in the bottom, below the sample
spot. The water and pigments will travel up the paper, and the
different pigments will separate out. Stop this experiment when the
water front is almost at top of paper. If you have a yellow water
soluble pigment at start, it will show.
The delphinidin pigments are a group of pigments. And each one will
break down differently, into different groups and at different rates.
From: Linda Mann <email@example.com>
To: iris-photos <firstname.lastname@example.org>
Sent: Tue, May 1, 2012 10:12 am
Subject: [iris-photos] Re: HYB: pigments - wash water
After letting the hot water wash sit for a day or so, all of the blue
pigment is gone from the jar that contained SULTRY MOOD (far left).
What's left is quite yellow. Chuck, do you know if that is likely a
conversion product from the anthocyanin or water soluble yellow pigment?
The middle one is from STAR GATE - - the blue is partly gone (paler
it was initially) but no obvious yellow showing.
The one on the far right is from a seedling from ROM EVE. It has the
most blue pigment left, but also is starting to show some yellow (i.e.,
looks green, esp compared to the STAR GATE jar).