Sustainable Synthesis of Omega-3 Fatty Acid Ethyl Esters from Monkfish Liver Oil

Abstract

The search for economic and sustainable sources of polyunsaturated fatty acids (PUFAs) within the framework of the circular economy is encouraged by their proven beneficial effects on health. The extraction of monkfish liver oil (MLO) for the synthesis of omega-3 ethyl esters was performed to evaluate two blending systems and four green solvents in this work. Moreover, the potential solubility of the MLO in green solvents was studied using the predictive simulation software COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS). The production of ethyl esters was performed by one or two-step reactions. Novozym 435, two resting cells (Aspergillus flavus and Rhizopus oryzae) obtained in our laboratory and a mix of them were used as biocatalysts in a solvent-free system. The yields for Novozym 435, R. oryzae and A. flavus in the one-step esterification were 63, 61 and 46%, respectively. The hydrolysis step in the two-step reaction led to 83, 88 and 93% of free fatty acids (FFA) for Novozym 435, R. oryzae and A. flavus, respectively. However, Novozym 435 showed the highest yield in the esterification step (85%), followed by R. oryzae (65%) and A. flavus (41%). Moreover, selectivity of polyunsaturated fatty acids of R. oryzae lipase was evidenced as it slightly esterified docosahexaenoic acid (DHA) in all the esterification reactions tested.

Efficient Expression and Application of a Modified Rhizomucor miehei Lipase for Simultaneous Production of Biodiesel and Eicosapentaenoic Acid Ethyl Ester from Nannochloropsis Oil

“…High-purity EPA-EE is more effective than mixed omega-3 PUFA in treating conditions such as high cholesterol, heart disease, and major depression . Currently, EPA-EE is primarily obtained by esterifying omega-3 PUFA-rich marine fish through chemical methods. , Only a few enzymes can act on EPA, but the catalytic efficiency or rate is low because of the substrate specificity. ,, Given the suboptimal results of directly enzymatically esterifying EPA, most studies exploit the characteristic that enzymes do not act on EPA to enrich it from fish or microalgae oil. , However, the enriched EPA must still undergo chemical processes to produce EPA-EE. As the market demand for EPA-EE expands and environmental protection requirements increase, new and green preparation processes for EPA-EE are required.…”

“…Subsequently, these free fatty acids are enzymatically converted into FAEEs through ethanolysis . Furthermore, using Novozym 435 for ethyl esterification of monkfish liver oil into EPA-EE took 72 h for full EPA conversion with a low total ester conversion rate of only 63% . Immobilized Thermomyces lanuginosa lipase converted fish oil to EPA-EE with a conversion rate of only 80% …”

Highly Valuable Fish Oil: Formation Process, Enrichment, Subsequent Utilization, and Storage of Eicosapentaenoic Acid Ethyl Esters

“…In comparison, Novozym 435 showed the highest yield in the esterification step (85%), followed by Rhizopus oryzae (65%) and Aspergillus flavus (41%). Therefore, it is evident that filamentous fungal resting cells can also be a powerful tool for the esterification enrichment of omega-3 PUFAs, with a lower cost than commercial immobilized enzymes [ 117 ].…”

Influence of Selected Compositions of Wall Materials and Drying Techniques Used for Encapsulation of Linseed Oil and Its Ethyl Esters

“…ALA sources in diets can be real oils (linseed, chia, hemp, etc.) or their preparations like ethyl esters [19][20][21]. Data on the encapsulation of linseed oil is relatively easily accessible.…”