Seaweed extracts show positive effects on fillet preservation
A study in Spain has concluded that four extracts from different macro and microalgae had antioxidant and antimicrobial effects that extended the shelf life of rainbow trout fillets.
The high content of polyunsaturated fatty acids in salmon fillets contributes to a greater susceptibility to oxidative processes, presenting a challenge to control their organoleptic characteristics (how they taste, look, smell and feel) and shelf life.
Macro and microalgae are recognised for being rich in a wide variety of bioactive compounds, such as polyphenols and carotenoids, linked to remarkable antioxidant and antimicrobial activities.
For this reason, scientists from the University of Almería, Spain, decided to evaluate the potential preservative effects of four species of algae (Crassiphycus corneus (Cc), Ulva ohnoi (Uo), Arthrospira platensis (Ap) and Haematococcus pluvialis (Ep) on the shelf life and quality attributes of chilled rainbow trout (Oncorhynchus mykiss) fillets.
Antimicrobial effects
Extracts were prepared at a concentration of 0.3% and the researchers studied the changes in the fillets at 1, 4, 6, 8 and 12 days. Changes in antioxidant activity, microbial counts, pH and water retention capacity (WHC), lipid oxidation (TBARS), texture profile analysis (TPA), and fillet colour were determined.
Among their results, the researchers showed that all the algae species analysed showed antioxidant and antimicrobial effects and improved the texture parameters, extending the useful life of the fillets compared to the untreated controls.
“Outstanding activities of FRAP and DPPH were found in the aqueous extract of Ap, in agreement with the highest phenolic content. Furthermore, algae extracts with higher carotenoid contents produced the highest antioxidant capacity (Cc and Uo)”, wrote the researchers.
Natural additives
In terms of impact on fillet colour, Hp outperformed the other macro and microalgae.
“In view of the results, the extracts of the algae species analysed could represent valuable alternative sources of natural additives with notable effects on the quality parameters of fresh fish,” the study authors concluded.
Read the full study, “Assessing the Potential of Algae Extracts for Extending the Shelf Life of Rainbow Trout (Oncorhynchus mykiss) Fillets,” here.
