Effects of seaweed extracts on the quality and shelf life of Nile tilapia (Oreochromis niloticus) fillets during frozen storage
Farhat Afrin, M.M. Islam, Md. Golam Rasul, Md. Shirajul Islam Sarkar, Chunhong Yuan, A.K.M. Azad Shah
Abstract
This study investigated the effects of seaweed (Padina tetrastromatica, Sargassum muticum, and Spatoglossum asperum) extracts on the quality and shelf life of Nile tilapia (Oreochromis niloticus) fillets during frozen storage for a period of 20 weeks. Each of the seaweed ethanolic extracts solution (2%, w/v) were used for dipping the tilapia fillets for 10 min at 4°C. The control and seaweed extracts-treated fillets were stored at -18±1°C, and chemical, microbiological and sensory attributes were evaluated periodically. Results showed that P. tetrastromatica extract-treated fillets significantly (P < 0.05) delayed the increment of pH, total volatile basic-nitrogen, peroxide value, and thiobarbituric acid reactive substances in Nile tilapia fillets than other seaweed extracts-treated and control fillets. The aerobic plate count of fish fillets was within acceptable range during the storage period. Moreover, P. tetrastromatica extract-treated fillets displayed comparatively better sensory attributes than other seaweed extracts-treated fillets as well as control fillets. Results of this study indicated that ethanolic extract of P. tetrastromatica retains the quality and extends the shelf-life of frozen Nile tilapia fillets for 8 weeks longer than control fillets. Thus, it can be concluded that P. tetrastromatica extracts can be used as a natural preservative for Nile tilapia fillets.