Blend of renewable bio-based polymers for oil encapsulation: Control of the emulsion stability and scaffolds of the microcapsule by the gummy exudate of Prosopis nigra

Comparative oil extraction from mutt (Myliobatis goodei) liver by enzymatic hydrolysis: free versus immobilized biocatalyst

BACKGROUND

The development and fine-tuning of biotechnological processes for fish oil extraction constitute a very important focus to contribute to the development of a food industry based on fish consumption. This work lies in a comparative analysis of the oil extraction yield of Myliobatis goodei livers using free and immobilized enzymes.

RESULTS

An immobilized biocatalyst was designed from the cell-free extract of a Bacillus sp. Mcn4. A complete factorial design was used to study the components of the bacterial culture medium and select the condition with the highest titers of extracellular enzymatic activities. Wheat bran had a significant effect on the culture medium composition for enzymatic production. The immobilized biocatalyst was designed by covalent binding of the proteins present in the cocktail retaining a percentage of different types of enzymatic activities (Mult.Enz@MgFe2 O4 ). Among the biocatalyst used, Alcalase® 2.4 L and Purazyme® AS 60 L (free commercial proteases) showed extraction yields of 87.39% and 84.25%, respectively, while Mult.Enz@MgFe2 O4 achieved a better one of 89.97%. The oils obtained did not show significant differences in their physical-chemical properties while regarding the fatty acid content, the oil extracted with Purazyme® AS 60 L showed a comparatively lower proportion of polyunsaturated fatty acids.

CONCLUSIONS

Our results suggest that the use of by-products of M. goodei is a valid alternative and encourages the use of immobilized multienzyme biocatalysts for the treatment of complex substrates in the fishing industry. © 2023 Society of Chemical Industry.

Tuning surface interactions on MgFe2O4 nanoparticles to induce interfacial hyperactivation in Candida rugosa lipase immobilization

Lipase adsorption on solid supports can be mediated by a precise balance of electrostatic and hydrophobic interactions. A suitable fine-tuning could allow the immobilized enzyme to display high catalytic activity. The objective of this work was to investigate how pH and ionic strength fluctuations affected protein-support interactions during immobilization via physical adsorption of a Candida rugosa lipase (CRL) on MgFe2O5. The highest amount of immobilized protein (IP) was measured at pH 4, and an ionic strength of 90 mM. However, these immobilization conditions did not register the highest hydrolytic activity (HA) in the biocatalyst (CRLa@MgFe2O4), finding the best values also at acidic pH but with a slight shift towards higher values of ionic strength around 110 mM. These findings were confirmed when the adsorption isotherms were examined under different immobilization conditions so that the maximum measurements of IP did not coincide with that of HA. Furthermore, when the recovered activity was examined, a strong interfacial hyperactivation of the lipase was detected towards acidic pH and highly charged surrounding environments. Spectroscopic studies, as well as in silico molecular docking analyses, revealed a considerable involvement of surface hydrophobic protein-carrier interactions, with aromatic aminoacids, especially phenylalanine residues, playing an important role. In light of these findings, this study significantly contributes to the body of knowledge and a better understanding of the factors that influence the lipase immobilization process on magnetic inorganic oxide nanoparticle surfaces.

Stabilization of the Antioxidant Properties in Spray-Dried Microcapsules of Fish and Chia Oil Blends

Even with healthy foods, there is still a need to protect the functionality during processing. The stabilization and enrichment of fish oil (FO) extracted from fish fillets using solvent extraction might make this healthy oil more available. FO was stabilized by mixing it with chia seed oil (CSO) at 50:50 at room temperature. The antioxidant properties of the blends were evaluated using the total phenolic content (TPC), free radical scavenging activity (DPPH), ferric reducing antioxidant potential (FRAP), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) activities with FO and CSO as controls. The blends of FO and CSO increased the oxidative stability, while FO was the most susceptible to degradation. The stability and bioactivity of antioxidants against environmental factors were improved by using encapsulation. Response surface methodology (RSM) was used to optimize spray-drying operating conditions for spray-dried microcapsules (SDMs). The independent variables were the inlet air temperature (IAT), which varied from 125 to 185 °C; wall material (WM) concentration, which varied from 5 to 25%; pump speed (PS), which varied from 3 to 7 mL/min; and needle speed (NS), which varied from 3 to 11 s. The results indicated that the maximum antioxidant activity of SDM was obtained at 140 °C IAT, 10% WM, 4 mL/min PS, and 5 s NS, while the minimum value was obtained at 170 °C IAT, 20% WM, 6 mL/min PS, and 9 s NS. The IAT had a significant effect on the antioxidant activities, and the stability of SDMs was increased. These SDMs can be used in the formulation of food matrices due to their therapeutic and nutritional properties.