Removal of ginkgotoxins from the Ginkgo biloba seed powder by enzymatic degradation with the laccase-syringaldehyde system

Ginkgo seeds are rich in nutrients and bioactive compounds, but they cause poisoning after excessive consumption, thus limiting their application. In this work, enzymatic degradation technology was employed to remove ginkgotoxins presented in ginkgo seeds, including 4’-O-methylpyridoxine (MPN) and MPN-5’-glucoside (MPNG). Through the screening of four oxidases and ten reaction mediators, the laccase-syringaldehyde system was successfully established. After optimizing the reaction conditions using response surface methodology (RSM), ginkgotoxins in both raw and boiled ginkgo seed powder was completely degraded at a temperature of 40 °C and a solvent to solid ratio (60 mL/g) of the ginkgo seed powder suspension within 3 h. Furthermore, the main nutritional components of detoxified ginkgo seed powder did not exhibit significant changes, but there was inevitably a decrease in the content of bioactive compounds. Finally, an acute oral toxicity assessment demonstrated that the detoxified ginkgo seed powder was virtually non-toxic. Therefore, enzymatic degradation using the laccase-syringaldehyde system has the potential to be a simple and effective approach for removing ginkgotoxins from ginkgo seed powder, thereby meeting the safety requirements for ginkgo products.