does phycocyanin have an antimicrobial effect on shrimp shelf life?

The phycocyanin (blue), phycoerythrin (red), phycoerythrocyanin (orange), and allophycocyanin (blue-green) pigments are found in algae only, and phycocyanin is the most important from a commercial point of view. phycocyanin is a nontoxic water-soluble natural pigment, belonging to the group of phycobilin proteins and derived from spirulina algae. owing to its antioxidant, inhibiting the oxidation of lipids, and anti-inflammatory properties, it is mainly used for dairy products, ice cream, beverages, candy, and cosmetics. this study aims to investigate the effect of phycocyanin in combination with the increase in the shelf life of litopenaeus vannamei. four treatments were considered: shrimps in sodium metabisulfite solution؛ shrimps in a coated solution of sodium alginate and gelatin؛ and shrimps treated in a coating solution with 10% and 20% phycocyanin. microbial spoilage quickly changes the texture, taste, and smell of meat, and it is the main cause of spoilage in non-frozen seafood. during 10 days, the number of aerobic mesophilic bacteria increased from 3.3 log cfu/g in all treatments, whereas in the group containing 20% phycocyanin, this number remained lower than in other treatments (p<0.05). at the end of the maintenance period, the number of tvc in the %10 phycocyanin reached 5 log cfu/g. the growth rate of pseudomonas increased during the period (p<0.05). the highest level of bacterial growth was related to control and sms treatments (p<0.05). at the end of the maintenance period, lab was shown at the highest level in the control and sms treatments, and the lowest level was observed in the treatment containing 10% phycocyanin (p<0.05). various studies showed a reduction in the growth of different bacteria, including psychrophilic bacteria, by using antioxidants. moreover, the antimicrobial properties of phycocyanin can be attributed to antimicrobial peptides that cause permeability of the cytoplasmic membrane.