Oleuropein Aglycone Production and Formulation by Integrated Membrane Process

In this work, for the first time, the integration of a biocatalytic membrane reactor (BMR) and a membrane emulsification (ME) process, has been studied. The production and formulation of an important antioxidant compound (oleuropein aglycone (OA)) has been used as case study. Two different configurations of integrated membrane processes were studied. In the first one, a BMR unit was combined with two ME units (one for extraction of OA and one for its formulation) obtaining OA encapsulation in a hydrophobic matrix based on solid-lipid particles (SLPs). Instead in the other configuration, BMR was combined with one ME unit and OA-loaded poly(vinyl alcohol) (PVA) particles were produced. The noncommercially available OA was produced in the BMR, starting from olive leaves (which contained the substrate of this reaction, oleuropein) with a conversion of 40% at each passage of the substrate through the system. OA encapsulation efficiency (EE) of 90% and 98% was obtained for SLPs and PVA particles, respectively. Energy consumption and environmental impact of the two integrated membrane processes have been also evaluated with the aim to demonstrate the sustainability of MBR/ME integration. The analysis demonstrated that the use of ME instead of conventional methods (for both extraction and/or formulation) allowed decreasing the energy consumption of about 3 orders of magnitude. Water is the most used compound among the raw materials, solvents, and products contributing to process sustainability increase. Thanks to membrane processes versatility, the proposed approach could be easily extended to other applications in which bioconversion and formulation are combined to develop a sustainable and continuous process for the production and formulation of a molecule of interest.