Electrostatic adsorption and removal mechanism of ochratoxin A in wine via a positively charged nano-MgO microporous ceramic membrane

Ochratoxin A (OTA) is a very important mycotoxin. However, there are few studies on the removal of OTA in wine because of the great influence on product quality and difficulty in practical application. A nano-MgO-modified diatomite ceramic membrane (MCM) with a high positive charge was prepared and applied to remove OTA in wine. The isotherm adsorption between the positively charged membrane and OTA was in accordance with the Langmuir model, with a maximum adsorption capacity of 806 ng/g at 25 degrees C. All of the changes in adsorption enthalpy (Delta H), adsorption free energy (Delta G) and adsorption entropy (Delta S) were negative, which indicated that the combination of nano-MgO MCM and OTA was a spontaneous exothermic and nonspecific physical adsorption process. The concentrations of OTA in adsorption-treated wines were lower than 2 mu g/kg, and the removal rates exceeded 92%. After OTA removal, the composition of wines was preserved to some extent.

Automated summary

Research on the removal of OTA in wine is crucial, and nano-MgO MCM has proven to be an effective method with high adsorption capacity, removal rates exceeding 92%, and an adsorption process that is spontaneous, exothermic, and non-specific.