Work

Evaluation of shelf-life of sardines (Sardina pilchardus) and gilthead seabream (Sparus aurata) treated with rosemary and sea fennel leaf aqueous extract

Year: 2026

Type: article

Abstract: The aim of this study was to investigate the effect of rosemary ( Rosmarinus officinalis ) and sea fennel ( Crithmum maritimum L.) aqueous extract on the quality of sardines and gilthead seabream during the storage. Fishes were immersed in plant extracts and stored at 4°C in the fridge. On each sampling day, quality was evaluated by performing sensory and microbiology analysis, as well as determining thiobarbituric acid reactive substances (TBARS), proteolytic index and total volatile basic nitrogen (TVB-N). During the fish storage, the TBARS values for all treatments and for both fish samples are increasing. The final TBARS values for sardines are 5.50 and 5.32 mg MDA/kg for the treatments with rosemary and sea fennel leaf extract, comparing to the control, that is a bit lower, 4.86 mg MDA/kg. Considering the experiment with gilthead seabream, the treatment with rosemary extract resulted with the lowest TBARS value, 0.05 mgMDA/kg comparing to the control which was 0.29 mg MDA/kg. Inhibition of lipid oxidation in fish is attributed to phenolic compounds present in the extracts. The plant extracts applied on the sardines did not affect positively on the proteolytic index, while in gilthead seabream, the treatment with sea fennel led to a decrease of 12%. Detailed statistical analysis indicate that in sardines the spoilage was mostly caused by protein degradation, so proteolytic index and TVB-N could be considered as reliable indicators. In parallel, in gilthead seabream spoilage was dominated by lipid oxidation, making TBARS the best indicator. Microbiological analysis showed the absence of Salmonella spp., Listeria monocytogenes and sulphite-reducing bacteria in all fish samples, while the Enterobacteriaceae were observed just in control samples during the sardine storage. The decrease in aerobic mesophilic bacteria after 4 days of storage was noticed in batches treated with rosemary extract, indicating the antimicrobial potential of rosemary. Considering the sensory evaluation, the application of plant extracts prolonged the fish shelf life for 1 day for sardines, and 2-3 days for gilthead seabream. Therefore, the results presented in this study confirmed high potential of implementation of plant extracts as functional components in convenience fish products, and may contribute to extending fish shelf life during refrigerated storage.

Source: Applied Food Research

DOI: 10.1016/j.afres.2026.102478