Effects of different pH, temperature, and pressurisation time on the stability of chlorophylls treated with Zn2+ and high hydrostatic pressure

Summary This study provides an effective method to improve the stability of chlorophylls. The effects of different pH, temperature, and pressurisation time on the colour, antioxidant activity, Zn 2+ replacement ratio, structure, and thermal stability of chlorophylls treated with Zn 2+ (10 mg 100 mL −1 ) and high hydrostatic pressure (500 MPa) were investigated. The electronic eye, ultraviolet spectrophotometer, high‐performance liquid chromatography, Fourier transform infrared, and high hydrostatic pressure (HHP) online monitor cooperated with fluorescence spectrophotometer were used to investigate the effects of different pH values, water bath temperatures, and pressurisation time on the colour, antioxidant activity, Zn 2+ replacement ratio, and structure of chlorophylls. The highest − a * (6.92), antioxidant activity (ABTS 41.01 g ACE 100 g −1 , DPPH 52.86 g ACE 100 g −1 , FRAP 35.72 g TE 100 g −1 DW), and Zn 2+ replacement ratio (47.32%) were obtained at 50 °C, pH = 7.0, and 20 min. It is hoped that this study will provide a new idea for the protection of natural pigments.