Edible Coating for Extending Prawn Shelf Life Using Synergistic Antimicrobial Combination of K-Casein, Chlorella, and Carvacrol

Seafood consumption is rising rapidly due to its high protein content, but its perishable nature necessitates novel preservation methods. This study investigates a biopolymer-based edible coating to extend the prawn shelf life. Bacteria isolated from prawns were identified using 16S rRNA sequencing, revealing strains of Staphylococcus aureus, Aeromonas hydrophila, Aeromonas veronii, and Vibrio parahaemolyticus. Among 12 tested biopolymer combinations, Combo 1 inhibited all bacterial strains in the MTT assay and was selected for further analysis. Coated prawns showed significant bacterial reduction on TCBS and Zobell agar at 28 and 4 °C from day 1 to day 7. This correlated with increased radical scavenging activity, rising from ∼40% to 50%, and notable lipid peroxidation inhibition. SEM analysis showed that treated samples maintained their structure. The results indicate the coating extends prawn shelf life up to 7 days and works as a natural preservative with antimicrobial and antioxidant benefits.