Green synthesis of Hesperitin dihydrochalcone glucoside by immobilized α-l-rhamnosidase biocatalysis based on Fe3O4/MIL-101(Cr) metal-organic framework

In this study, α- l -rhamnosidase was immobilized on magnetic Fe 3 O 4 /MIL-101 (Cr) nanoparticles using MIL-101(Cr) as precursor by crosslinking method. The crosslinking agent concentration ratio and crosslinking time were EDC/NHS 1:1 and 2 h, respectively. The immobilized materials were characterized by FT-IR, XRD, SEM and VSM. The saturation magnetization of the prepared magnetic nanoparticles was 46.2 emu/g. The optimum pH and temperature of immobilized enzyme were 6 and 60 °C. The application of immobilized enzyme in the preparation of hesperidin dihydrochalcone glucoside (HMGDC) by hydrolysis of hesperidin dihydrochalcone (HSDDC) was studied. The results showed that immobilized enzyme had better temperature resistance, repeatability and stability than free enzyme. The immobilized enzyme activity was 293.55 U/g, and the recovery was 116.03%. After treatment at 60 °C for 4 days, the enzyme activity remained at 24.6%. The conversion rate of HSDDC reached 93.1%.