Towards a green process for recovering phenolic compounds from fennel wastes (Foeniculum vulgare Mill.): Identifying target molecules and assessing membrane nanofiltration for their separation
Carmela Conidi, Rosanna Morelli, Antonio Elia, Alfredo Cassano
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引用次数: 0
Abstract
Fennel (Foeniculum vulgare Mill.) wastes represent a source of phenolic compounds with multiple healthy properties. This study reports, for the first time, a green biorefinery strategy, based on an eco-friendly extraction of fennel wastes followed by sequential microfiltration (MF) and nanofiltration (NF) processes, to purify and concentrate low molecular weight phenolic compounds (caffeic, chlorogenic and ellagic acids, catechin) from a fennel waste extract. A detailed investigation of the effects of operating conditions, such as transmembrane pressure (TMP) and cross flow velocity (CFV), on permeate flux and separation efficiency of the NF membrane for target molecules, was undertaken. The MF process enabled the complete recovery of phenolic compounds in the clarified extract and their purification from suspended solids particles. An increase of both TMP and CFV, resulted in higher permeate fluxes, as well as in higher rejection values and separation efficiency of the NF membrane towards all analyzed compounds. Specifically, at a TMP of 20 bar and CFV of 4.43 m/s, the separation factor between caffeic acid and chlorogenic acid, ellagic acid and catechin was close to 280, and much lower (11–15) with respect to other compounds such as carbohydrates and total polyphenols. The concentrated fraction resulted enriched in chlorogenic acid (148.2 mg/L), ellagic acid (73.6 m/L), catechin (2.56 mg/L) and flavonoids (722.6 mg/L) exhibiting a total content of polyphenols of about 5000 mg GAE/L. On the other hand, about 60 % of caffeic acid was recovered in the NF permeate. The investigated process can be considered a promising approach for an environmentally sustainable valorization of fennel wastes and could be recommended for large-scale industrial applications.
期刊介绍:
Separation and Purification Technology is a premier journal committed to sharing innovative methods for separation and purification in chemical and environmental engineering, encompassing both homogeneous solutions and heterogeneous mixtures. Our scope includes the separation and/or purification of liquids, vapors, and gases, as well as carbon capture and separation techniques. However, it's important to note that methods solely intended for analytical purposes are not within the scope of the journal. Additionally, disciplines such as soil science, polymer science, and metallurgy fall outside the purview of Separation and Purification Technology. Join us in advancing the field of separation and purification methods for sustainable solutions in chemical and environmental engineering.