Effects of microencapsulated eugenol emulsions on microbiological, chemical and organoleptic qualities of farmed Japanese sea bass (Lateolabrax japonicus) during cold storage

The objective of this study was to investigate the effect of sodium alginate (SA) and flaxseed gum (FG) active coatings containing microencapsulated eugenol emulsions on microbiological, physicochemical, flavor and organoleptic evaluation of farmed Japanese sea bass samples during 16 days storage at 4 degrees C. Results showed that SA-FG coatings combining with 0.15% eugenol emulsions could significantly lower total viable count (TVC), Pseudomonas spp., H2S-producing bacteria and psychrophilic counts, and reduce the productions of off-flavor compounds including the trimethylamine (TMA), total volatile basic nitrogen (TVB-N) and ATP-related compounds, and accumulation of free amino acids (FAAs). 29 volatile compounds were identified by SPME-GC/MS during cold storage and the coating treated sea bass samples significantly lowered the relative content of fishy flavor compounds, such as 1-octen-3-ol, 1-penten-3-ol, hexanal, heptanal, nonanal, decanal, (E)-2-octenal and 2, 3-pentanedione. Further, SA-FG coatings containing eugenol could more efficiently retard the water migration by magnetic resonance imaging (MRI) results, and maintained quality of sea bass during storage at 4 degrees C according to organoleptic evaluation results.