Nile tilapia (Oreochromis niloticus) is a widely consumed freshwater fish globally, known for its mild flavor and culinary versatility. However, like any fresh food product, Nile tilapia is susceptible to deterioration and quality loss over time, posing challenges for the aquaculture industry and consumers alike.
A recent study conducted by researchers at Bangabandhu Sheikh Mujibur Rahman Agricultural University has shed light on a promising solution involving ethanolic extracts from seaweed (Padina tetrastromatica, Sargassum natans, and Sargassum fluitans) to extend the shelf life and enhance the quality of Nile tilapia fillets.
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Why is Prolonging the Shelf Life of Aquaculture Products Important?
The fishing and aquaculture industry plays a crucial role in global food supply, providing a significant source of protein for millions of people. However, ensuring that these products reach consumers in optimal condition is an ongoing challenge. Deterioration of aquaculture products not only reduces quality and nutritional value but can also result in significant economic losses for producers and the supply chain.
Fish is highly perishable due to endogenous enzymatic and microbial activity in the postmortem state, leading to the production of undesirable metabolites that limit shelf life and cause quality deterioration. To prevent fish deterioration, various methods such as refrigeration, cooling, glazing, and more are employed to lower temperature. Synthetic phenolic compounds are also used as antioxidants and antimicrobial agents to increase the shelf life and quality of fish and seafood.
The Use of Seaweed Extracts
Seaweed extracts are emerging as a viable and abundant source of natural antioxidants, and various classes of bioactive compounds with promising properties. In the study, scientists investigated the effects of ethanolic extracts from three types of seaweed: Padina tetrastromatica, Sargassum natans, and Sargassum fluitans. These extracts were used to immerse Nile tilapia fillets for 10 minutes at 4°C before storing them in airtight polyethylene bags at 4±1°C for a period of 20 days. Chemical, bacteriological, and sensory evaluations were conducted at 4-day intervals.
The study’s findings are encouraging. The Padina tetrastromatica extract proved to be particularly effective in preserving Nile tilapia fillets. A significant reduction in pH variation, peroxide value, thiobarbituric acid reactive substances, and total volatile basic nitrogen values was observed compared to fillets treated with extracts from other seaweeds or untreated fillets.
In terms of bacterial quality, fillets treated with seaweed extracts also exhibited lower bacterial counts compared to untreated fillets, which is essential for ensuring food safety.
The sensory quality of fillets treated with Padina tetrastromatica extract remained superior throughout the storage period compared to other groups of fillets. This suggests that treated fillets maintained a more pleasant taste and texture for a longer duration.
This study offers a promising insight into how seaweed extracts can extend the shelf life and improve the quality of Nile tilapia fillets. Ethanolic extracts of Padina tetrastromatica, in particular, proved effective in preserving fillets for an additional 12 days under refrigeration compared to untreated fillets.
These findings are relevant for both the fishing industry and consumers. Extending the shelf life of aquaculture products not only reduces food waste but also ensures that consumers can enjoy fresh and safe products for a longer period. Additionally, the use of seaweed extracts could be a sustainable and natural alternative to other preservation methods.
In summary, ongoing research continues to provide innovative solutions to enhance food safety and quality, and the use of seaweed extracts is a notable example of how nature can help us keep our food fresh and flavorful for longer.
The study was funded by the Ministry of Education of the Government of the People’s Republic of Bangladesh.
A. K. M. Azad Shah
Department of Fisheries Technology
Bangabandhu Sheikh Mujibur Rahman Agricultural University
Gazipur 1706, Bangladesh.
Reference (Open Access)
Shahrier, J., Rasul, G., Afrin, F., Islam, R., & Shah, A. K. M. A. (2023). Extension of shelf life of Nile tilapia (Oreochromis niloticus) fillets using seaweed extracts during refrigerated storage. Food Science & Nutrition, 00, 1–11. https://doi.org/10.1002/fsn3.3673