Natural blue swirl
Alan Houghton & Andrew Davis, John Innes Centre
Tubes containing extract of anthocyanins from butterfly pea (Clitoria ternatea). Anthocyanins are pigments that give many flowers and fruits their red, purple or blue colours. In plants, this helps to attract pollinators and seed dispersers but when eaten by us, dietary anthocyanins are associated with protection against certain cancers, cardiovascular diseases and other chronic human disorders. The colour of anthocyanins is dependant on pH, in acidic environments they are red and in neutral pH, they appear blue. However anthocyanins are typically unstable at neutral pH and are quickly degraded, becoming colourless within hours. The anthocyanins of butterfly pea are different in that they are covered in carbohydrates and associate with other groups (i.e, are heavily glycosylated and aromatically acylated) giving them greatly enhanced colour stability even at neutral pH. Scientists at the John Innes Centre are researching anthocyanins from different species and assessing their potential health benefits.