Studying the impact of phycoerythrin on antioxidant and antimicrobial activity of the fresh rainbow trout fillets

Abstract

Marine cyanobacteria present a significant potential source of new bioactive compounds with vast structural diversity and relevant antimicrobial and antioxidant activities. Phycobiliproteins (PBPs) like phycocyanin (PC), phycoerythrin (PE), and water-soluble cyanobacterial photosynthetic pigments, have exhibited strong pharmacological activities and been used as natural food additives. In this study, phycoerythrin (PE) isolated from a marine strain of cyanobacterium Nostoc sp. Ft salt, was applied for the first time as a natural antimicrobial as well as an antioxidant to increase the shelf life of fresh rainbow trout i.e., (Oncorhynchus mykiss) fillets. Fresh trout fillets were marinated in analytical grade PE (3.9 μg/mL) prepared in citric acid (4 mg/mL), and stored at 4 °C and 8 °C for 21 days. Microbiological analysis, antioxidant activity and organoleptic evaluation of both control and treated fish fillets were then statistically compared. The results demonstrated noticeable (P < 0.05) differences in the microbial counts, antioxidant activity, and organoleptic characteristic values between PE-treated and non-treated groups. In addition, we observed that treating fresh fish fillets with a PE solution leads to a significant increase in shelf life by at least 14 days. Consequently, PE could be an alternative to synthetic chemical additives since it does not contain the potentially dangerous residues of the synthetic chemical additives and is thus healthier to the consumers.

The synergistic effect of dielectric barrier discharge plasma and phycocyanin on shelf life of Oncorhynchus mykiss rainbow fillets

“…In comparison to previous studies 53 , the combined effect of PC and DBD treatment significantly reduces DPPH and ABTS levels, with P 80:5 +PC exhibiting the lowest levels across all days. This observation aligns with previous research on DBD and PC treatments 5 , 54 , 55 . Notably, ascorbic acid oxidation likely contributes to the notable decrease in DPPH observed in all fillets treated at 80 kV starting on the sixth day of storage compared to the control 56 .…”

“…Extraction involved mixing freeze-dried biomass with sodium phosphate buffer, followed by freezing, thawing, and centrifugation. The PC content was collected, freeze-dried, and stored at − 20 °C 5 . To assess stability, citric acid preservative was added to the PC solution.…”

“…Extending shelf life becomes imperative for consumer satisfaction, involving the inhibition of microbial growth, reduction of spoilage risks, and minimization of bacterial contamination. Utilizing modern methods like non-thermal plasma treatment and pigment incorporation, as opposed to traditional preservation approaches, offers substantial advantages in this regard 4 , 5 .…”

“…This utilization aligns with regulatory requirements, emphasizing the industry's commitment to providing safe, high-quality, and naturally preserved food products 11 . According to Nowruzi et al 5 , PC has been shown to extend the shelf life of rainbow trout.…”