Black Carrot (Daucus carota ssp.) and Black Soybean (Glycine max (L.) Merr.) Anthocyanin Extract: A Remedy to Enhance Stability and Functionality of Fruit Juices by Copigmentation

Application of extracted black carrot anthocyanins (BCA) and black soybean anthocyanins (BSA) as colour enhancers was demonstrated by copigmenting with heat sensitive anthocyanins from plum, pomegranate, strawberry and jamun. Improved pigment stability was confirmed by thermal stability, chromacity studies and hyperchromic and bathochromic shifts. BCA (2%, 500 mg/L) caused largest hyperchromic shift in plum whereas maximum bathochromic shift (18-20 nm) was observed in strawberry. BSA (2%, 500 mg/L) caused largest hyperchromic shift in pomegranate whereas maximum bathochromic shift (22 nm) was observed in plum. Copigmented plum, jamun, strawberry and pomegranate juices copigmented with BCA achieved high half-life (t(1/2)) and lower rate constant (k) values. Copigmenting anthocyanins with other juice is an effective strategy to impart high thermal stability, improve colour retention and antioxidant activity.