Enzyme membrane reactor with heterogenized β-glucosidase to obtain phytotherapic compound: Optimization study

► Optimization of biocatalytic membrane reactor. ► Production of not commercially available compounds from olive mill waste. ► Optimization of process parameters (T, pH, immobilized enzyme amount, residence time). ► Improvement of the conversion and stability of biocatalytic membrane reactor. ► Production of natural antioxidants on prototype scale (oleuropein aglycon production 9.0 (±0.2) g/m2 h).