Antioxidant effect of ascorbic acid on the quality of cobia (Rachycentron canadum) fillets during frozen storage

The effect of aqueous solutions of ascorbic acid (AA) on the rancidity development in Cobia (Rachycentron canadum) fillets during frozen storage was studied. Cobia fillets were treated with ascorbic acid (AA 0.25% and AA 0.5%) then stored at -18°C up to 6 months. Rancidity development was measured by several biochemical indices including free fatty acids (FFA), peroxide value (PV), and thiobarbituric acid (TBA) and complemented by the sensory analysis (odor, consistency and appearance). In addition, pH and expressible moisture (EM) were measured during 6 months storage. Proximate composition was also determined in the first day. TBA, PV and FFA levels increased on all treatments due to lipid oxidation. Ascorbic acid showed antioxidative effect on Cobia fillets during frozen storage as indicated by TBA, PV and FFA levels. Results showed that free fatty acid, primary and secondary oxidation products, EM and pH value of AA-treated samples were significantly lower than those of the control samples (P<0.05). A gradual decrease (P<0.05) in sensory analysis were observed as the storage time increased. Results of our investigation revealed that ascorbic acid retarded oxidative changes in frozen Cobia fillets whereas AA 0.25% was not as effective as AA 0.5% on oxidative stability. Best oxidation inhibition results on fish fillets were obtained when employing a 0.5% AA solution

Changes of fatty acid profiles in fillets of Cobia (Rachycentron canadum) during frozen storage

In this study changes in fatty acids profile during frozen storage at -18°C of Cobia (Rachycentron canadum), caught from the Persian Gulf (Bandar Abbas) were studied. Changes in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), EPA+DHA/C16, n-3 PUFA/n-6 PUFA (n-3/n-6) and polyunsaturated fatty acids /saturated fatty acids (PUFA/SFA) were investigated during a six- month storage at -18°C. Eighteen fatty acids were found in Cobia, with higher percentage of saturated fatty acids (46.07%), monounsaturated fatty acids (33.72%) and polyunsaturated fatty acids (15.44%). The MUFAs and PUFAs reduced from 33.72 to 26.26% and 15.44 to 10.78%, respectively. Palmitic acid (C16:0, 27.42% of total fatty acids) and stearic acid (C18:0, 12.62%) were the dominant saturated fatty acids. The major unsaturated fatty acids were determined as docosahexaenoic acid (C22:6n3, 5.76%), oleic acid (C18:1n9, 25.76%) and linoleic acid (C18:2n6, 4.38%). As a result of the frozen storage (up to 6 months), marked content decreases were found in fatty acid groups such as monounsaturated, polyunsaturated and n-3 polyunsaturated, as well as in the n-3/n-6 ratio and it means that the nutritional value of Cobia has decreased

Predictive models for evaluation of mesophilic and psychrophilic bacterial loads in muscles of fresh ice-stored silver pomfret by impediometric technique

Current microbial methodologies to determine fish quality are laborious and have long time required to obtain results. The impediometric technique as a rapid sensitive method was used to determine the correlation between impedance detection times (IDTs) and conventional reference psychrophilic and mesophilic plate counts of fish in order to develop models for predicting the microbial quality and determining fish shelf-life. The changes in sensorial factors, psychrophilic and mesophilic bacterial loads of ice stored fresh silver pomfret (Pampus argenteus) were measured by two different methods including conventional reference plating techniques and also impediometric monitoring method at 0, 3, 6, 9, 12, 15, 18, 21, 24 and 27 days of storage. The primary psychrophilic (3.44 ± 0.69 logCFU/g) and mesophilic (3.64 ± 1.08 logCFU/g) bacterial loads increased to more than acceptable limit (6 logCFU/g) on days 12 and 21, respectively. The calibration curves for the two methods and their equations were designed with linear regression models. IDTs were highly correlated with psychrophilic (r=-0.9614) and mesophilic (r=-0.9547) bacterial loads. This study suggests that impediometric technique can be used as a rapid and reliable method to accurate estimation of silver pomfret bacterial loads and determine its shelf-life as seafood. According to results, the sensorial data were correlated with psychrophic bacterial load. The shelf-life of ice stored silver pomfret determined 9-12 days based on sensorial data and psychrophic bacterial load

Efecto de un tratamiento previo con ácido ascórbico sobre el perfil de ácidos grasos de filetes de cobia (Rachycentron canadum) conservada en congelación.

[EN] The present research focuses on the nutritional value of the lipid retention associated with frozen cobia (Rachycentron canadum). The effect of a previous soaking in an aqueous ascorbic acid (AA) solution on the fatty acid profile of fish fillets during a further frozen storage period (–18 °C) was investigated. Two different AA concentrations were tested (0.25% and 0.50%) and compared to control conditions. As a result of the frozen storage period (up to 6 months), marked decreases were found in the contents of fatty acid groups such as monounsaturated, polyunsaturated and n-3 polyunsaturated, as well as in the n-3/n-6 ratio. However, a preserving effect on such fatty acid parameters could be observed resulting from the previous AA treatment, which was greater when applying the 0.50% AA concentration. Assessment of the polyene index indicated an increased lipid oxidation development during the frozen storage time; this increase was partially inhibited by the previous AA soaking.[ES] Este estudio se centra en el valor nutricional lipídico de cobia (Rachycentron canadum) congelada. Para ello, se investiga el efecto que un tratamiento previo con ácido ascórbico (AA) puede tener sobre el perfil de ácidos grasos de filete de pescado durante su conservación en congelación (–18 °C; seis meses). Se aplicaron dos concentraciones de AA (0.25% y 0.50%) que fueron comparadas con muestras control. Como resultado de la conservación en congelación, se observó un descenso importante en grupos de ácidos grasos monoinsaturados, poliinsaturados y poliinsaturados de las serie n-3, así como en la relación n-3/n-6. Sin embargo, el tratamiento previo con AA produjo un efecto protector en estos parámetros, siendo mayor al aplicar AA en la concentración superior. La medida del índice de polienos reflejó un incremento de la oxidación lipídica durante la conservación en congelación; este incremento fue parcialmente inhibido como resultado del tratamiento previo con AA.Peer reviewe

Determination the Amount of Illegal Furazolidone Residues in Broilers in Ahvaz Abattoir by HPLC Method

Background & aim: due to the risks to human health, particularly in terms of carcinogenicity, the application of Furazolidone in animals which their products are consumed by human population is strongly prohibited. The purpose of this study was to determine the amount of unauthorized furazolidone in broiler chickens slaughtered in Ahvaz by using HPLC. Methods: In the present cross-sectional study which was conducted within six months, 100 broiler carcasses were randomly collected from Ahvaz slaughterhouses. Then by using ice, the carcasses were transported to the laboratory in less than 24 hours inorder to illicit the amount of furazolidone drug by the HPLC method. After extraction and degrading processes, using Ethyl-acetate and related protocols for isolation of Furazolidone from muscles, and also calibrating HPLC system to obtain standard curves, the amount of 20 microliters of each sample was injected to the HPLC device and the amounts of Furazolidone were determined in the mixture of pectoral and femoral muscles. Finally the obtained results were statistically analysed by using one sample t-test in the SPSS software. Results: The mean Furazolidone concentration in the mixture of femoral and thorasic muscles was 28.15±2.37 mg/kg. Thirty-nine percent of the samples were positive for containing illegal Furazolidone residue. Conclusion: According to the results of the current study, more attention is seriously recommended by authorized responsibilities to prevent the antibiotic residues such as furazolidone in poultry meat