Effect of the Combination of Vanillin and Chitosan Coating on the Microbial Diversity and Shelf-Life of Refrigerated Turbot (Scophthalmus maximus) Filets.

Tingting Li,Xiaojia Sun,Haitao Chen,Yongchao Mei,Binbin He,Jianrong Li,Dangfeng Wang

doi:10.3389/fmicb.2020.00462

Abstract

The effect of the combination of vanillin and chitosan (VC) coating on the microbiota composition and shelf-life of turbot (Scophthalmus maximus) filets during a 15-day storage period at 4 ± 1°day was investigated in this study. The control and coated fish samples were analyzed periodically for sensory and chemical attributes [total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and pH] and the presence of dominant spoilage microbiota. The results suggested that the sensory and the chemical quality of turbot filets effectively improved after treatment with vanillin (final concentration 2 mg/ml) combined with 1% chitosan, and the shelf-life was prolonged for 6 to 7 days compared with the control group. Furthermore, high-throughput sequencing showed that Proteobacteria (52.2%) and Firmicutes (29.8%) were the dominant bacteria at the phylum level in fresh turbot filets, while Pseudomonadaceae (40.2%) and Lactobacillaceae (39.4%) were the dominant bacteria at the family level in deteriorated turbot filets. However, after VC treatment, the relative abundance of Pseudomonadaceae and Lactobacillaceae decreased significantly due to the growth inhibition of potential bacteria, specifically spoilage bacteria, along with the rich bacterial diversity at the end of storage. Therefore, our data indicated that VC treatment might be effective in decreasing bacteria-induced quality deterioration and in extending the shelf-life of refrigerated turbot filets.

Highlights

Turbot (Scophthalmus maximus) is a highly nutritious, economically important fish species
These results demonstrated that the decrease in sensory quality loss might be related to the inhibition of microbial growth and lipid oxidation by vanillin and chitosan (VC) coating, thereby prolonging the shelf-life of turbot filets during refrigeration
This observation was similar to that of Yu et al (2018b), who observed that the sensory quality of grass carp filets treated with chitosan composite coatings was improved during refrigerated storage and had significantly extended shelf-life compared with the control group

Summary

Introduction

Turbot (Scophthalmus maximus) is a highly nutritious, economically important fish species. The sensory properties of fish deteriorate with storage, processing, and distribution, owing to chemical and biological changes (Özogul et al, 2006). The annual damage rate of aquatic product harvests is estimated to be 10% (Kulawik et al, 2013). Microorganisms are considered to play a key role in the fish spoilage process (Remenant et al, 2015). Effect of Vanillin and Chitosan Coating on Turbot. From the perspective of sensory rejection, the most active microorganisms producing enough metabolites were considered as specific spoilage organisms (SSOs), which involved more than one microbial group, genus, or species in most cases (Don et al, 2018). Controlling the existence and storage conditions of microorganisms is an important factor for determining the fresh fish quality and shelf-life

Methods

Results

Conclusion