Effect of layer-by-layer antimicrobial edible coating of alginate and chitosan with grapefruit seed extract for shelf-life extension of shrimp (Litopenaeus vannamei) stored at 4 °C

The effect of a layer-by-layer (LbL) electrostatic deposition coating of alginate and chitosan with grapefruit seed extract was investigated on the shelf life of shrimp (Litopenaeus vannamei) stored for 15 days under refrigeration (4 °C). The shrimp were periodically analyzed for changes in microbiological parameters (total aerobic mesophilic bacteria and total aerobic psychrotrophic bacteria counts), chemical parameters, melanosis, and sensory characteristics. The chitosan-alginate coating had the advantage of reducing the bacterial count by 2 log CFU in combination with the antimicrobial activity of the grapefruit seed extract. The bilayer coating reduced the off-flavor of shrimp during the storage period by preventing the odor of acetic acid that was used to dissolve chitosan. In conclusion, chitosan and chitosan-alginate treatments could prolong the shelf life of shrimp.