Johannes Siemensmeyer

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Peter Heckwolf

Summer semester 2017

Faculty:
Art and Design

Degree programme:
Visual Communication (Bachelor of Arts (B.A.))

Free project

All colors are created with red cabbage.
https://en.wikipedia.org/wiki/Anthocyanin#pH

Anthocyanins generally are degraded at higher pH, however, some anthocyanins, such as petanin (petunidin 3-[6-O-(4-O-(E)-p-coumaroyl-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside]-5-O-β-D-glucopyranoside), are resistant to degradation at pH 8 and may be used effectively as a food colorant.

Anthocyanins may be used as pH indicators because their color changes with pH; they are red or pink in acidic solutions (pH < 7), purple in neutral solutions (pH ~ 7), greenish-yellow in alkaline solutions (pH > 7), and colorless in very alkaline solutions, where the pigment is completely reduced.