Abstract:

The ultrasonic-aided extraction of blueberry pigments was optimized by single-factor and central composite design methods. Besides, the stability of blueberry pigments under different environmental conditions was also measured. The optimal conditions for the extraction of blueberry pigments were found to be: extraction solvent, 45% alcohol; ultrasonic power, 450 W; material/liquid ratio, 1:13, extraction temperature, 55 ℃, extraction duration, 50 min; and pH 4.5. The extraction rate of blueberry pigments was 3.26% under these optimal conditions. Blueberry pigments were thermostable. The stability of blueberry pigments was good in the respective presence of K+, Na+ and Mg2+ and potassium sorbate, while Zn2+, Fe2+, Fe3+, Ca2+ and alkaline condition could damage their stability.

Key words: blueberry, ultrasonic-aided extraction, natural pigment, stability, central composite design