The Impact of Glazing with Natural Preservatives on Some Qualitative Characteristics of Frozen-Stored Japanese Threadfin Bream Nemipterus japonicas

The current study was conducted to determine the impact of immersion using garlic, sumac, and citric acid on certain qualitative characteristics of Japanese threadfin bream (Nemipterus japonicus) during frozen storage. Fish were immersed with 1% addition of each natural substance and stored at -18 ^ͦC for 150 days. The results revealed that immersion with garlic, sumac, and citric acid prevented lipid oxidation and reduced the production of free fatty acids (FFA), volatile nitrogen bases (TVN), and thiobarbituric acid (TBA) in the groups treated with natural substances compared to untreated and water-immersed groups. The lowest pH value was 6.11 at day zero for the frozen fish, which increased to 6.98 at the end of storage for the same treatment. The lowest TVN, FFA, and TBA values were observed in the garlic-treated fish at day zero: 4.2mg nitrogen/ 100g fish, 0.12%, and 0.27mg malondialdehyde/ 100g fish, respectively. These values increased significantly during the final storage period to 29.4mg nitrogen/ 100g fish, 0.88%, and 5.41mg malondialdehyde/ 100g fish for the frozen fish only at 150 days of storage, with significant differences among treatments and storage periods (P<0.05). The lowest percentage of lost fluids was 2.33% for the garlic immersion treatment at day zero, while the highest value was 5.49% for the frozen fish only at 150 days. In conclusion, the study demonstrated the potential use of these substances in immersion as natural antioxidants and inhibitors of enzymatic, microbial, and quality loss.