Fruits, vegetables, spices, and herbs are a potential source of phenolic acids and polyphenols. These compounds are known as natural by-products or secondary metabolites of plants, which are present in the daily diet and provide important benefits to the human body such as antioxidant, anti-inflammatory, anticancer, anti-allergic, antihypertensive and antiviral properties, among others. Plentiful evidence has been provided on the great potential of polyphenols against different viruses that cause widespread health problems. As a result, this review focuses on the potential antiviral properties of some polyphenols and their action mechanism against various types of viruses such as coronaviruses, influenza, herpes simplex, dengue fever, and rotavirus, among others. Also, it is important to highlight the relationship between antiviral and antioxidant activities that can contribute to the protection of cells and tissues of the human body. The wide variety of action mechanisms of antiviral agents, such as polyphenols, against viral infections could be applied as a treatment or prevention strategy; but at the same time, antiviral polyphenols could be used to produce natural antiviral drugs. A recent example of an antiviral polyphenol application deals with the use of hesperidin extracted from Citrus sinensis. The action mechanism of hesperidin relies on its binding to the key entry or spike protein of SARS-CoV-2. Finally, the extraction, purification and recovery of polyphenols with potential antiviral activity, which are essential for virus replication and infection without side-effects, have been critically reviewed.

The production of olive oil and wine are two of the main agri-food economic activities in Southern Europe. They generate large amounts of solid and liquid wastes (e.g., olive pomace, olive mill wastewater, grape pomace, grape stems, wine lees, and wine processing wastewater) that represent a major environmental problem. Consequently, the management of these residues has become a big challenge for these industries, since they are harmful to the environment but rich in bioactive compounds, such as polyphenols. In recent years, the recovery of phenolic compounds has been proposed as a smart strategy for the valorization of these by-products, from a circular economy perspective. This review aims to provide a comprehensive description of the state of the art of techniques available for the analysis, extraction, and purification of polyphenols from the olive mill and winery residues. Thus, the integration and implementation of these techniques could provide a sustainable solution to the olive oil and winery sectors.

Nanofiltration (NF), as a selective Mg(II) and Ca(II) separation and concentration treatment, and electrodialysis with bipolar membranes (EDBM) were evaluated for the valorization of seawater desalination reverse osmosis brines (60 NaCl/L) to produce both rich Mg(II) and Ca(II) brines for phosphate recovery and HCl and NaOH as chemicals for desalination treatments. A NF pilot plant, using NF270 membranes at 20 bar, provided a rich Mg(II) (8.3 g Mg(II)/L) and Ca(II) (2.1 g Ca(II)/L) brine on the concentrated stream with enrichment factors of 3.2 for Mg(II) and 2.5 for Ca(II). The NF permeate stream containing 50 ± 2 g NaCl/L was treated to remove residual Mg(II) (760 mg/L) and Ca(II) (415 mg/L) by chemical precipitation with Na2CO3 and NaOH before the EDBM unit. Divalent cations free brine containing NaCl (50 g NaCl/L) were fed into the EDBM stack in order to produce NaOH and HCl under recirculation configuration. Constant voltage and acid and base concentrations at different initial conditions were evaluated to obtain the maximum acid and base concentration (approximately 1 M NaOH/HCl) at 9 V. No substantial effect of initial acid and base concentrations on the overall performance was observed. An energy consumption of 2.6 kWh/kg NaOH and current efficiency of 77 ± 3% were calculatedPostprint (author's final draft

The use of treatments of segregated process streams as a water source, as well as technical fluid reuse as a source of value-added recovery products, is an emerging direction of resource recovery in several applications. Apart from the desired final product obtained in agro-food industries, one of the challenges is the recovery or separation of intermediate and/or secondary metabolites with high-added-value compounds (e.g., whey protein). In this way, processes based on membranes, such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), could be integrated to treat these agro-industrial streams, such as milk and cheese whey. Therefore, the industrial application of membrane technologies in some processing stages could be a solution, replacing traditional processes or adding them into existing treatments. Therefore, greater efficiency, yield enhancement, energy or capital expenditure reduction or even an increase in sustainability by producing less waste, as well as by-product recovery and valorization opportunities, could be possible, in line with industrial symbiosis and circular economy principles. The maturity of membrane technologies in the dairy industry was analyzed for the possible integration options of membrane processes in their filtration treatment. The reported studies and developments showed a wide window of possible applications for membrane technologies in dairy industry treatments. Therefore, the integration of membrane processes into traditional processing schemes is presented in this work. Overall, it could be highlighted that membrane providers and agro-industries will continue with a gradual implementation of membrane technology integration in the production processes, referring to the progress reported on both the scientific literature and industrial solutions commercialized.

Water scarcity in the Mediterranean basin has been solved by using seawater desalination reverse osmosis technology (SWD-RO). This technology produces brine which is discharged back into the sea resulting in an environmental impact on marine ecosystems. Under the circular economy approach, the aim of this work is to recover resources from NaCl-rich brine (~60-70 g/L), e.g. in the form of NaOH and HCl, by integration of two ion exchange-based membrane technologies and quantify the electrical energy consumption. Electrodialysis (ED) incorporating monovalent selective cation exchange membranes as divalent ions purification and concentration of the NaCl present in the SWD-RO brine, was integrated with bipolar membrane ED (EDBM) to produce NaOH and HCl. Current densities of 0.30–0.40 kA/m2 at two temperature ranges simulating different seawater temperature regimes (15-18 ºC and 22-28ºC) were tested and a pure NaCl solution was used as starting concentrate stream. NaCl-rich brines with 100 or 200 gNaCl/L were obtained by ED and then introduced in the EDBM stack producing HCl and NaOH up to 2 M, depending on the initial concentrations. A minimum energy consumption of 1.7 kWh/kgNaOH was calculated when working by EDBM with initial concentrations of 104 g NaCl/L and 0.24 M HCl and NaOH.Peer ReviewedPostprint (author's final draft