Incorporation of conjugated fatty acids into Nile tilapia (Oreochromis niloticus)

BACKGROUND

The aim of this work was to improve the nutritional quality of Nile tilapia meat through enriched diets with conjugated isomers of linolenic acid from tung oil. The transfer process of conjugated fatty acids (CFAs) into fish muscle tissue was evaluated by gas chromatography-flame ionization detection (GC-FID) and easy ambient sonic-spray ionization mass spectrometry (EASI-MS).

RESULTS

The results showed that conjugated fatty acids were transferred from enriched diet for muscle tissue of Nile tilapia. Conjugated linoleic acids biosynthesis from conjugated linolenic acids was also observed after 10 days. Other important fatty acids such as docosahexaenoic (DHA), eicosapentaenoic (EPA) and arachidonic (AA) acids were also identified over time; however, DHA showed the highest concentration when compared with EPA and AA compounds.

CONCLUSION

Therefore, the nutritional quality of Nile tilapia was improved through feeding with enriched diets. The ingestion of these fish may contribute to reaching adequate levels of daily CFA consumption. Furthermore, other important substances which play an important role in human metabolism, such as EPA, DHA and AA, can also be ingested together with CFA. © 2016 Society of Chemical Industry.

Polyelectrolyte complexes based on alginate/tanfloc: Optimization, characterization and medical application

Hydrogels based on alginate and tanfloc (a cationic biopolymer obtained from natural condensed tannins) were successfully prepared. Tanfloc (TN) presents high aqueous solubility at pHs lower than 10; it contains substituted amino sites and molar weight of ca. 600,000gmol^-1. A factorial design (2²) was used to optimize the yield of alginate/tanfloc polyelectrolyte complexes (PECs). Dialysis recovered the overplus of alginate (AG) no complexed with TN. These materials were characterized by thermal analyses (TGA/DTG and DSC), zeta potential, and FTIR, while SEM technique depicted a rough surface on AG/TN complex, containing non-homogeneous pores. Indeed, the AG and TN were tailored to elicit scaffold materials with outstanding cytocompatibility, mainly upon mouse preosteoblastic cells because of reconstruction of bone tissues (119% at 10days). The AG/TN complex also displayed antioxidant and bactericidal activities against Staphylococcus aureus (S. aureus). Besides, the pristine TN fostered bacteriostatic and bactericidal performances towards S. aureus and Escherichia coli. However, for our best knowledge, no studies were still carried out on TN and TN-based materials for medical purpose.