Lipid Composition and Antioxidant Capacity Evaluation in Tilapia Fillets Supplemented with a Blend of Oils and Vitamin E

Abstract

Since the nutritional value of farm‐raised fish fillets is directly related to the diet provided, we supplemented the diet of Tilapia (Oreochromis niloticus) with a blend of chia (Salvia hispanica L.) oil, tung (Aleurites fordii) oil, and conjugated linoleic acid (CLA) to evaluate the effects on the fatty acid composition. Vitamin E was also added to the diet to improve the antioxidant capacity of tilapia fillets. We observed an increase in α‐linolenic acid content (from 6.56 to 19.03 mg g−1 of total lipids), as well as the incorporation of CLA and conjugated linolenic acid (CLnA) isomers in the fillets. The addition of vitamin E resulted in the antioxidant capacity improvement of the fillets and higher values were found after 15 feeding days (39.25 µmol TE g−1 in the Ferric Reducing Ability Power assay). Supplementation proved to be an excellent tool to improve the nutritional value of fish fillets.

Effects of a Diet Supplemented with Japanese Grape (Hovenia dulcis) Seed Oil on the Omega-3 and Nutritional Lipid Quality in Nile Tilapia (Oreochromis niloticus)

“…The decrease of the n-6/n-3 ratio for the fish fillets was not in the same proportion as that for the prepared diets due to the influence of metabolic factors, including digestibility and preferential fatty acid catabolism, which may affect the FA composition in the fish fillets. [51][52][53] Even so, the n-6/n-3 ratio for the fish fillets from TII (30) was significantly closer to the values suggested by Simopoulos,4 i.e., the closer the n-6/n-3 ratio to 1:1, the better it will be for the prevention of many diseases, such as diabetes, cancer, obesity, and cardiovascular and autoimmune diseases. Table 4 shows the nutritional profile of the lipid fraction of the Nile tilapia fillets fed with the prepared diets.…”

“…It can also be noted in Figure 1 that the total lipids incorporated in the fish muscle tissues during the feeding time increased around 33% from T (0) (initial sample) to TI (30) and TII (30) (samples of treatments I and II, respectively, during 30 days of feeding). However, although there was no significant difference between the TL values of the two treatments after 30 days, the Nile tilapias fed with the supplemented diet (TII) grew more and gained more weight to those fed with the control diet (TI).…”

“…For the PCA analysis, three PCs were used to explain 98.97% of the total variance of the data. (15) and TI (30) : samples of treatment I during 15 and 30 days of feeding, respectively; e TII (15) and TII (30) : samples of treatment II during 15 and 30 days of feeding, respectively; f PUFA: total of polyunsaturated FA; g MUFA: total of monounsaturated FA; h SFA: total of saturated FA; i S n-6: total n-6 FA; j S n-3: total n-3 FA.…”

“…50 By the comparison of the results from TL (Figure 1) and the FA composition of the fish fillets (Table 3), it can be observed that for both treatments (TI (30) and TII (30) ) the TL increased significantly during the feeding time. However, the fish fillets from TII (30) incorporated significantly higher amounts of n-3 FAs, raising the nutritional lipid quality of the freshwater fish fed with the supplemented diet with JGSO. Moreover, the n-6/n-3 ratio decreased 2.8 times in the fish fillets, especially with the increase of LNA, as was already described for the prepared diets.…”

“…28,29 Additionally, recently published studies involving Nile tilapia fed a diet supplemented with different seed oils showed an expressive increase of n-3 PUFAs in their fillets and a decrease in the n-6/n-3 ratio. 30,31 In the present study, we evaluated the incorporation of LNA, the effect on EPA and DHA levels and lipid nutritional quality indexes in the fillets of Nile tilapia fed a diet supplemented with Japanese grape seed oil (JGSO). …”