The Potential of Acorn Extract Treatment on PUFAs Oxidative Stability: A Case Study on Fish Cooking Wastewater.

Fish byproducts are valuable sources of Ω-3 polyunsaturated fatty acids (PUFAs). Their valorization potentially alleviates pressure on this sector. This study uses a circular economy approach to investigate the oil fraction from sardine cooking wastewater (SCW). Analysis of its fatty acid (FA) profile revealed promising PUFA levels. However, PUFAs are highly susceptible to oxidation, prompting the exploration of effective and natural strategies to replace synthetic antioxidants and mitigate their associated risks and concerns. An antioxidant extract from acorn shells was developed and evaluated for its efficacy in preventing oxidative degradation. The extract exhibited significant levels of total phenolic compounds (TPC: 49.94 and 22.99 mg TAE or GAE/g DW) and antioxidant activities (ABTS: 72.46; ORAC: 59.60; DPPH: 248.24 mg TE/g DW), with tannins comprising a significant portion of phenolics (20.61 mg TAE/g DW). LC-ESI-UHR-QqTOF-MS identified ellagic acid, epicatechin, procyanidin B2 and azelaic acid as the predominant phenolic compounds. The extract demonstrated the ability to significantly reduce the peroxide index and inhibit PUFA oxidation, including linoleic acid (LA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA). This approach holds promise for developing stable, functional ingredients rich in PUFAs. Future research will focus on refining oil extraction procedures and conducting stability tests towards the development of specific applications.

Membrane fractionation of Cynara cardunculus swine blood hydrolysate: Ingredients of high nutritional and nutraceutical value.

This work proposes an innovative approach to valorise swine blood based on enzymatic hydrolysis and membrane fractionations. Hydrolysis with Cynara cardunculus enzymes, followed by microfiltration and double nanofiltration generated three high protein fractions, retentate of microfiltration (RMF; >0.5 µm) and retentate of nanofiltration (RNF; >3 kDa) with approximately 90% of protein on a dry basis and filtrate of nanofiltrate (FNF; <3 kDa) with 65%. FNF, rich in low molecular weight peptides, showed excellent antioxidants (ABTS and ORAC of 911.81 and 532.82 µmol TE g-1 DB, respectively) and antihypertensive (IC50 of 28.51 µg mL-1) potential. By peptidomics and in silico analysis, 43 unique sequences of interest were found, among which LVV-Hemorphin-7 was identified. This hemorphin was demonstrated as the main responsible for the observed bioactivity. Complementary results showed a prebiotic effect mainly for the growth of Bifidobacterium animalis Bo, as well as interesting free amino acids (mainly glutamic acid, leucine, alanine, phenylalanine and aspartic acid) and mineral (e.g., Ca, Mg, P, K and Na) profiles. No antibacterial effect was verified for the seven pathogenic bacteria tested. This study allowed obtaining new ingredient of high nutritional and nutraceutical value for human consumption, with a perspective of sustainability and industrial viability.

Integrated ultrafiltration, nanofiltration, and reverse osmosis pilot process to produce bioactive protein/peptide fractions from sardine cooking effluent.

Sardine cooking effluents contain a high level of organic matter, such as proteins and lipids, which allows them to be forward into a chain exploiting high added-value compounds attained from these effluents, increasing their economic value while reducing their environmental effect. Thus, the purpose of this work was to develop an innovative pilot-scale integrated membrane process, with or without enzymatic hydrolysis, to obtain fractions with high protein/peptide and low NaCl contents, as well as optimized bioactive properties. The research strategy followed involved the use of ultrafiltration (UF) and nanofiltration (NF) technologies of the pretreated sardine cooking effluent followed by reverse osmosis (RO) at a pilot scale levels. Moreover, it allowed for the attainment of fractions rich in protein/peptides that might be used in the food, pharmaceutical, or cosmetic industries, particularly after RO, as they present a lower NaCl content. The RO retentate (hydrolyzed sample) coupled with UF and NF resulted in the fractions with the best bioactive properties (higher antioxidant capacity and antimicrobial activity) of all the analyzed samples. Overall, the current work demonstrated the feasibility of exploiting liquid by-products as a source of functional components as well as reinforcing this strategy's potential relevance in future effective management strategies for this type of effluents.