Effects of Herbal Essential Oils Used To Extend the Shelf Life of Freshwater-Reared Asian Sea Bass Fish (Lates calcarifer)

Abstract

Sensory and microbiological characteristics of Asian sea bass (Lates calcarifer) fish raised in a freshwater pond were evaluated during cold storage for 33 days. Whole fish (averaging 400 g each) were stored in a cold storage room at 0 to 2 degrees C. Essential oils of herbs--thyme (Thymus vulgaris) and oregano (Origanum vulgare)--added at 0.05% (vol/vol) were used as preservatives. On the basis of the sensory test results as well as the bacteriological tests, the addition of oregano and thyme essential oils can considerably slow the process of spoilage. The fish treated with these oils were still fit for human consumption after 33 days of storage. The results obtained through sensory tests are corroborated to a great extent by the chemical (hypoxanthine) tests and to a lesser extent by the physical (Cosmos units) tests. The initial total bacteriological counts were 1.7 x 10(3) CFU/cm2 on the fish surface and <10(2) CFU/g in the fish flesh, and in the control treatment (without preservatives), these counts rose continuously, reaching around 10(7) CFU/cm2 on the fish surface and 10(3) CFU/g in the flesh after 33 days of storage at 0 to 2 degrees C. The use of herbal essential oils as preservatives, on the other hand, resulted in a maximal count of 10(5) CFU/cm2 on the fish surface, while the bacterial count in the flesh remained <10(2) CFU/g by the end of the 33-day storage period at 0 to 2 degrees C.

Effect of chitosan on shelf life of restructured fish products from pangasius (pangasianodon hypophthalmus) surimi during chilled storage

“…TVB-N increase is related to the activity of spoilage bacteria and endogenous enzymes because enzymes are still active. A TVB-N level of 30 mg/100 g is considered as the upper limit above which fishery products are considered spoiled and unfit for human consumption (Harpaz et al 2003). In the present study, none of the samples reached the rejection limit during chilled storage.…”

Sensitivity of spoiling and pathogen food-related bacteria to Origanum vulgare L. (Lamiaceae) essential oil

“…Essential oil addition was able to cause The number of researches regarding the antimicrobial activity of spices and derivatives in food matrix still could be considered small when compared to the number of researches using laboratorial media (3,16). Inhibitory effectiveness of O. vulgare essential oil in foods has been noted in minced beef (28), beef fillets (32), Asia sea bass (12) and eggplant salad (27).…”

Combining ozone and slurry ice to maximize shelf-life and quality of bighead croaker (Collichthys niveatus)

“…At the end of the storage period, TVB-N value raised to 60.21 ± 5.87 mg/100 g, whereas counterpart batches stored in slurry and ozonised slurry ice displayed noticeably lower TVB-N contents of 11.02 ± 1.11 and 9.56 ± 1.02 mg/100 g, respectively. A level of 30 mg N/ 100 g TVB-N has been regarded as the acceptable limit for fishery products, above which they are considered spoiled and unfit for human consumption (Harpaz et al 2003). TVB-N reached spoilage limit by day 9 for the flake ice group, while this parameter remained below the acceptable limit throughout the period for the other two groups, implying that slurry ice could effectively retard TVB-N formation.…”