Oleuropein Aglycone Production and Formulation by Integrated Membrane Process

Abstract

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.

Production of Plant-Derived Oleuropein Aglycone by a Combined Membrane Process and Evaluation of Its Breast Anticancer Properties

“…Owing to this process, OLA is extracted into the organic phase at the water-ethyl acetate interface. Due to the non-stabilized droplets of the formed emulsion ( Piacentini et al, 2019 ), fast separation of the two phases was promoted, which guaranteed an easy recovery of the phase of interest. Dry OLA was produced at the end of the process by ethyl acetate evaporation.…”

“…The optimized MBR was then integrated with a ME process to achieve the extraction of OLA in the ethyl acetate as reported in Piacentini et al (2019). When the dispersed phase, containing OLA coming from the MBR permeated through the membrane of the ME system, water droplets are generated at the membrane pore level that quickly separated from the continuous organic phases.…”

“…OLA is a vegetal product with many therapeutic applications due to its antihyperglycemic, anti-Alzheimer disease, anti-inflammatory, antioxidant, and other properties ( Galiano and Villalain, 2015 ). In particular, it was produced by the enzymatic (β-glucosidase) hydrolysis of oleuropein (OLE) extracted from olive leaves ( Mazzei et al, 2010b , 2012 ; Ranieri et al, 2018 ; Piacentini et al, 2019 ). In the above-mentioned MBRs, the enzyme was immobilized within the membrane and the maximum conversion achieved was 60%.…”

Oleuropein: Methods for extraction, purifying and applying

“…In recent years, membrane technologies for the separation, purification and concentration of bioactive compounds from aqueous solutions have gained great attention and have showed an increasing potential for application (Khemakhem et al, 2017;Ranieri et al, 2018;Piacentini et al, 2019). This technique is based on the principle of selective permeation of solute molecules by means of a semipermeable polymer or inorganic support, namely, membranes.…”

A comparative assessment for efficient oleuropein extraction from olive leaf (Olea europaea L. folium)

“…Consumers are increasingly seeking natural goods or products that incorporate natural chemicals in their composition, pushing researchers in the food and cosmetic fields to investigate replacing synthetic antioxidants with those derived from plants [12,13]. Phenolic ingredients can be extracted by several methods including the use of cold solvents [14], filtration [15], microwave [16], microfluidic system [17], pressurized fluid [18], Soxhlet [19,20], supercritical fluids [21], and ultrasound [22,23]. Soxhlet extraction is well known and preferred as an extraction method that offers much higher efficiency than other methods in obtaining the desired target compounds (antioxidant and phenolic compounds) [24].…”