Edible Coating Chitosan‐Acerola to Replace the Sulfites as Preservatives of Fresh Shrimps ( Litopenaeus vannamei )

Melanosis is a chemical reaction based on lipid oxidation, which reduces shrimp shelf‐life. This research is aimed at applying chitosan‐based coating solutions incorporated with a natural antioxidant (acerola extract) as an antimelanotic material for shrimp preservation. Antimicrobial activity, ascorbic acid content, and pH of coating solutions were investigated, as well as their impact on pH, total volatile nitrogen bases (TVB‐N), color, texture, microbial growth, dark spot index, and quality index (QI) of shrimps during their storage at 4°C. Chitosan coatings with and without acerola displayed antimicrobial activity against Salmonella spp., Staphylococcus aureus , Pseudomonas aeruginosa , and Escherichia coli. Shrimp coated with a chitosan‐acerola (1% w/v) showed an acceptable pH until the 6th day of storage, and TVB‐N values until the 9th day. The dark spot index of shrimps with bioactive coatings remained stable for 9 days, suggesting the effective action of bioactive compounds from acerola. Similarly, coated shrimps had better QI values and lower psychrotrophic counts. These results indicated that chitosan‐acerola coatings (1%) can be considered as a potential material for extending the shrimp shelf‐life.