Previously I discovered that you can get pleasingly blue food by mixing red cabbage with egg. I now understand that all the egg is doing to the red cabbage is raising its pH. The same effect can be achieved by adding a little baking soda to minced red cabbage. However, the colour doesn't seem to be very stable - cooking or drying the mixture seems to alter the colour from blue to a paler, sea-green shade.
Similar pH sensitive pigments exist in raspberries, red wine and perhaps blueberries... more experiments ahoy! http://wiki.chemprime.chemeddl.org/index.php/PH_and_pOH_in_Food_Color
I mixed my blue minced cabbage to a standard dough (strong white flour, salt, water) and used it to make udon noodles - they went a bit green while being boiled in the soup, but still tasty!
|Chapatis - one with baking soda - turning the red cabbage blue green, the other without.|
I added a little aniseed to my bread mix - synesthetically speaking, it is one of the bluest of flavours!