A novel process for asparagus polyphenols utilization by ultrasound assisted adsorption and desorption using resins.

The ultrasound assisted purification of asparagus polyphenols by adsorption and desorption on the macroporous resins was investigated. The ultrasound within the selected intensities (12-120 W) and temperatures (25-35 °C) increased the adsorption and desorption capacities of asparagus polyphenols on D101 resins. Higher ultrasound intensity (120 W) and lower temperature (25 °C) benefited the adsorption process and the adsorption capacity of total polyphenols after ultrasound was 3.95 mg/g, which was 2 times than that obtained after shaking at 120 rpm. Meanwhile, ultrasound can significantly shorten the equilibrium time and the adsorption process of asparagus polyphenols could be well described by Pseudo-second order model and Freundlich model. Stereoscopic microscope was first used to investigate the microstructure characterization of resins, indicating that ultrasound mainly enhanced the surface roughness of resins. Interestingly, rutin possessed the highest adsorption capacities and ferulic acid had the highest the desorption capacities among the studied individual polyphenols. The obtained results evidenced on a progressive insight of application of ultrasound assisted resins for purification of asparagus polyphenols.