Valorization of Agri-Food By-Products from Plant Sources Using Pressure-Driven Membrane Processes to Recover Value-Added Compounds: Opportunities and Challenges

Agri-food by-products are defined as secondary products derived from food manufacturing processes. They can be of plant or animal origin. When agri-food by-products are not valorized, they regularly end up in landfills or rivers and create pollution problems. However, many of these by-products contain high value-added compounds, including carbohydrates, oligosaccharides, proteins, peptides, fibers, phenolic compounds, and isoflavones, which can be recovered. In this context, membrane processes such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis are of interest for the valorization of agri-food by-products. In this review, the advantages and limitations of membrane processes for the valorization of agrifood by-products from plant sources are discussed as well as some research avenues to reduce membrane fouling, which remains the main limitation for large-scale industrial applications.