Natural antioxidants derived from macroalgae have great potential for improving oxidative stability of food products. Fucus spiralis (F. spiralis) is a brown macroalgae rich in bioactive compounds, including phlorotannins that are polyphenols derived from phloroglucinol with important antioxidant properties.
A F. spiralis phlorotannin-enriched ethyl acetate extract was evaluated as natural antioxidant to extend the shelf-life of salmon homogenates, while comparing it to artificial antioxidant BHT. The extract was obtained by submitting F. spiralis biomass collected in summer to an extraction with ethanol:water, followed by a liquid-liquid fractionation with organic solvents (Almeida et al., 2021).
Atlantic salmon (Salmo salar) fillets were ground, and the minced salmon was divided into three equally distributed groups: G1 with the incorporation of 0.01% F. spiralis extract; G2 with the incorporation of 0.01% synthetic antioxidant BHT; and G3 as control group. The extract and BHT were dissolved in food grade ethanol/water mixture (80:20 v/v) and the same amount of solvent was added to the control group. For each treatment, salmon patties were shaped, wrapped with polyethylene film paper, and stored at 4 °C. Moisture, pH, colour, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) were analysed at days 0, 3, 7, 11, 15, and 21 of storage.
The addition of the algal extract did not show significant differences in the maintenance of pH and humidity of the samples throughout testing time (21 days) when compared to the samples with artificial antioxidant BHT and the control. However, the extract had a similar behavior to the artificial antioxidant BHT regarding the diminishing of deterioration compounds in fish (decrease of thiobarbituric acid reactive species TBARs) on the first days of the study (until day 11) when compared to the control. Relative to color alteration, none of the antioxidants decreased color loss, as no significant changes were observed in the measured parameters. Regarding the quantification of total volatile basic nitrogen (TVB-N), no significant difference was observed among treatments.
References:
Almeida, B, Barroso, S., Ferreira, A. S. D., Adão, P., Mendes, S., Gil, M. M. (2021). Seasonal Evaluation of Phlorotannin-Enriched Extracts from Brown Macroalgae Fucus spiralis, Molecules, 26, 4287.
