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

Abstract

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.