Delivering a Nutritionally Enhanced Tilapia Fillet Using a Pre‐Harvest Phase Omega‐3 Thraustochytrids Protist Enriched Diet

Abstract

AbstractNile tilapia (Oreochromis niloticus) offers an affordable food source to many low‐income consumers. However, farmed tilapia has drawn much criticism over the low omega‐3 (n‐3) and high omega‐6 (n‐6) lipid levels. Subsequently, it has been questioned whether it is truly healthy food. This study fed tilapia with a specialized “finishing” diet with the inclusion of commercial Thraustochytrids protist biomass and oil before the harvestable fish size. The fish are fed with two different dietary regimes over 6 weeks. One is a commercially available tilapia feed used as a reference. The second diet is composed of an exclusive oil source from Thraustochytrids protist (HI‐n3). The results show that HI‐ n3 has significantly increased the fillet n‐3 content by 400% in comparison to commercial diet (COM) after Week 6 of feeding. Specifically, docosahexaenoic acid (DHA, n‐3) content is the attributing fatty acid for the n‐3 increase. This is particularly evident when DHA is expressed as a percentage of total lipid content. The n‐3:n‐6 ratio increased in tilapia fed with the HI‐n3 diet attributed to the DHA accumulation. The investigation shows that it is possible to favorably “lipid tailor” tilapia before harvest.Practical applications: The practical application of this technique is to enrich farmed tilapia with a high dietary omega‐3 (n‐3) Thraustochytrids protist oil source for a short‐term period before harvesting. It is an objective that the fillet product would be more functional in its nutritional content by supplying more than just high‐quality protein for consumers. This would have paramount implications for low‐income consumers, where high n‐3 oil foods are not readily available or affordable (e.g., landlocked nations). Furthermore, tilapia is widely consumed in China and Southeast Asian countries but is also promoted as a high nutritional value food source in the western hemisphere. This investigation advocates the ability to change the image of this fish species by a simple dietary manipulation. In an era of elevated intake of omega 6 (n‐6) fatty acids food sources, n‐3 rich fish is a vital balance to counter this negative trend in human health.