Valorization of Black Carrot Industrial Residues for the Anthocyanin Pigment Production

Industrial residues from black carrot were valorized for using them as a raw material to produce anthocyanin pigments, which were obtained as concentrated extracts and microcapsules.

The anthocyanins were extracted by citric, tartaric, and lactic acids to prevent degradation. Concentrated extracts were obtained by 80% of water reduction, whereas microcapsules were prepared by spray drying using gum arabic as a carrier agent.

The effect of pH and temperature on the anthocyanin content and coloration was assessed. In addition, the shelf-life of pigment products was determined for 360 days of storage at 4 and 20 °C, measuring anthocyanins concentration, color, and total phenolic retention.

Black carrot residues resulted in an excellent material for pigments products preparation. Concentrated extracts reached up to 7000 mg/L of anthocyanins, high antioxidant activity, and dark red color. The obtained products showed high color stability at 2–7 pH range and temperature stress from 20 to 90 °C. Furthermore, the concentrated extract showed 80% of anthocyanins preservation and 90% of color retention after storage for 360 days at 4 °C. Anthocyanin microcapsules exhibited 280 mg/L of anthocyanins with pink, red coloration, maintaining 50% of anthocyanins after storage for 180 days at 20 °C.