Preservation and Bacteriostasis Effects of Citral Nanoemulsion on Golden Pomfret (Trachinotus ovatus) During Refrigeration

The objective of this study was to validate the preservation and bacteriostasis effects of a citral nanoemulsion on golden pomfret (Trachinotus ovatus) stored at 4°C, in comparison with sterile saline and blank nanoemulsion without citral addition, aiming at keeping the freshness of T. ovatus and enhancing the quality maintenance technology for aquatic products. The analysis of microbial composition revealed that Shewanella spp. and Pseudomonas spp. were predominant spoilage organisms in T. ovatus (accounting for more than 90% of the total proportion during most storage time), when the citral nanoemulsion treatment led to an abundance decrease of Shewanella spp. and an increase of Pseudomonas spp. The total viable count (TVC) of fish samples treated with citral nanoemulsion consistently exhibited the lowest TVC values, surpassing the limit (7.0 log CFU/g) on Day 10, which was observed with a delay of 2–4 days compared to the other two groups. Meanwhile, the fish samples of the citral nanoemulsion group exhibited significantly reduced levels in total volatile base nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and K value, with better attributes in texture and sensory evaluation. Furthermore, the Pearson analysis revealed highly significant correlations between TVC and these quality indices (correlation coefficients exceeding 0.9), underscoring the importance of microbial control in T. ovatus. These findings highlighted the potential application of citral nanoemulsion on the preservation and bacteriostasis of T. ovatus during refrigeration.