The Function of Emulsions on the Biogenic Amine Formation and their Indices of Sea Bass Fillets (Dicentrarchus Labrax) Stored in Vacuum Packaging.

The impacts of emulsions based on commercial oils on the biogenic amine formation and their indices of vacuumed packed sea bass fillets were investigated. The results showed that among biogenic amines, cadaverine, putrescine, spermidine, spermine, serotonin, dopamine, and agmatine were predominant amines in sea bass fillets stored under vacuum packaging. Significant differences (P < 0.05) in biogenic amines concentrations of vacuumed packed sea bass treated with emulsions were observed. All groups contained histamine lower than 5.0 mg/100 g, regarded as the allowable limit by the U.S. Food and Drug Administration. Polyamine levels were not affected by application of emulsion. Quality index (QI) showed an increase and after 14 d of storage it decreased in all groups. The control generally seemed to higher QI value than those of treatment groups except at 14 and 18 days while soybean and corn gave lower QI among treatment groups. Only biogenic amine index correlated with sensory acceptability of vacuumed packed sea bass, indicating that this index can be used for determination of the degree of spoilage of vacuumed packed sea bass. Emulsions extended the shelf-life (approximately 2 to 4 d) of vacuumed packed sea bass fillets by inhibiting microbial growth compared to the control. PRACTICAL APPLICATION: Emulsions have become popular since they are regarded as ideal carrier for the delivery of lipophilic substances due to the ease of preparation, small particle size, their enhanced bioavailability, and long term kinetic stability. They have been proven to be self-preserving antimicrobials due to bound water in their structure and thus no available water to microorganisms. Antimicrobial emulsions have potential applications in many fields because they are inexpensive, stable, and nontoxic agents.

Fatty acid composition and biogenic amines in acidified and fermented fish silage: a comparison study.

In the presented study, ensiling of discard fish by acidification or fermentation was evaluated. Klunzinger's ponyfish which is a discard fish was used for the production of fish silage by acidification (3% formic acid for Method FA; 1.5% formic and 1.5% sulphuric acid for Method FASA) and fermentation (Lactobacillus plantarum for Method LP and Streptococcus thermophilus for Method ST). The chemical, microbiological and nutritional properties of the differently preserved fish silages were estimated during a storage period of 60 d at ambient temperature. Compared to the raw material, a slight increase in saturated fatty acids and a slight decrease in polyunsaturated fatty acids were observed in all silages. At the end of the storage period, the aerobic bacteria counts after applying Methods FA, FASA, LP and ST amounted to 2.35, 2.39, 5.77 and 5.43 log cfu/g, respectively. The analysis of thiobarbituric acid revealed that acidification of silages accelerated the lipid oxidation. Nine biogenic amines were found in raw fish and different silages. The initial histamine concentration in raw fish was 0.17 mg/100 g and in all silages it remained at low levels during the storage period. The initial tyramine content was found to be 1.56 mg/100 g in raw fish and increased significantly in all silages. The increase of the tyramine content in fermented silages was considerably higher than in acidified silages (23-48 mg/100 g and 5-10 mg/100 g, respectively). It can be concluded that acidified or fermented fish silage should be considered as potential feed component for animals because of its high nutritional value and appropriate microbiological and chemical quality.