Multiple color and pH stability of floral anthocyanin extract: Clitoria ternatea

Clitoria ternatea, commonly known as butterfly pea is found in great abundance in Malaysia. The color of Clitoria ternatea anthocyanin extract (CTAE) varied with changes in pH. The anthocyanin pigment gave intense red, violet, blue, blue green, green and yellow at pH 0.05 – 12.0. Such variation in color has been attributed to structural transformation of anthocyanin in response to changes in pH. It was noted that there was no discoloration in the pH range 4–6 and no brown precipitate formation at the pH range studied at all temperatures. Acidic solutions of CTAE showed higher storage stabilities than alkaline pHs. The red CTAE retained 70–80% of its color on day 60 at 27 and 37 °C. The red, violet and blue CTAE were stable for at least a year at 7 °C which is the best storage condition for these colors. The red, violet and blue CTAE have potential applications in food, cosmetic, and pharmaceutical products.