Enhancing the shelf life of white leg shrimp (Litopenaeus vannamei) coated with alginate/gelatin incorporated with zinc oxide nanoparticles during refrigerator storage

This study aimed to investigate the effect of zinc oxide nanoparticles in combination with a composite (gelatin/alginate) on the shelf life of white leg shrimp (Litopenaeus vannamei) during 10 days of refrigerated storage. Shrimp were prepared in 5 treatments, including: control (shrimp treated in distilled water), SMS (shrimp treated with sodium metabisulfite solution), composite (shrimp treated in an alginate/gelatin coating), ZnO2.5 [shrimp treated in a composite containing 2.5% ZnO nanoparticles (w/w)], and ZnO5 [shrimp treated in a composite containing 5% ZnO nanoparticles (w/w)]. The results showed that the number of mesophilic aerobic bacteria, Pseudomonas, and lactic acid bacteria in the control sample increased significantly until the end of the storage period, while the samples containing ZnO nanoparticles had significantly lower levels of bacteria. In addition, total volatile base nitrogen, trimethylamine, thiobarbituric acid species, and pH levels in shrimp treated with the nanoparticles were significantly lower than those in the control group (P < 0.05). The highest and lowest changes in texture (springiness and cohesiveness) were observed in the control and treatments containing ZnO, respectively (P < 0.05). The sensory evaluation, texture, and color results were consistent with those of other reported data. However, using an alginate/gelatin coating significantly delays shrimp spoilage during refrigerated storage, and the use of zinc oxide nanoparticles significantly reduces microbiological and chemical spoilage and increases the shelf life of shrimp.