Suhendan Mol

Determination of trace metals in canned anchovies and canned rainbow trouts

Trace metal (Fe, Zn, Cu, Cd, Sn, Hg and Pb) concentrations of canned anchovies (Engraulis encrasicolus Linnaeus, 1758) and canned rainbow trouts (Oncorhynchus mykiss Walbaum, 1792), commercialized in Turkey, were determined using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). The average contents of trace metals in canned anchovies and canned rainbow trouts were found as 50.708 and 6.980 mg/kg for iron, 22.467 and 11.605 mg/kg for zinc, 1.145 and 0.541 mg/kg for copper, 0.019 and 0.001 mg/kg for cadmium, 0.140 and 0.023 mg/kg for tin, 0.041 and 0.026 mg/kg for mercury, and 0.188 and 0.167 mg/kg for lead, respectively. Although these products pose no risk with respect to the concentrations of zinc, copper, cadmium, tin and mercury, some of the samples had higher contents of lead and iron than the permissible limits. Comprehensive and periodic controls of trace metals in canned fish are needed to assess the safety of these products with respect to human health.

Comparison of Proximate, Fatty Acid and Amino Acid Compositions of Various Types of Fish Roes

Proximate compositions, amino acid compositions and fatty acid compositions of fish roe have been measured and compared. Glutamic acid, aspartic acid, lysine, and serine have been the major amino acids. However, Imperial-type caviar has also included higher amounts of tryptophan (p < 0.05). Essential /Nonessential (E/NE) ratio has been found to be between 0.93 - 1.23, and n3/n6 ratio has been found to be 2.56–8.06. Major fatty acids were C16:0, C18:1 n9c, C16:1 n7, C20:5n3, and C22:6 n3. Fish roes contain high amount of lipids and energy, however, they are also rich sources of unsaturated fatty acids, proteins and amino acids.

Survival of Salmonella Enteritidis during salting and drying of horse mackerel (Trachurus trachurus) fillets

Survival of Salmonella Enteritidis inoculated (5-6 log cfu/g) on horse mackerel fillets was studied during salting and/or drying processes at 4 degrees C for up to 70days. Sample groups were as follows: group A (salt/fish=80/100), group B (salt/fish=30/100), group C (salted as group A and dried after 15days), group D (salted as group B and dried after 15days), and group E (dried without salting). The salt content increased in all groups with a maximum level of 29.36%. Final salt contents (%) were higher (P<0.05) in salted-dried groups (C and D) than the salted groups (A and B). Total reductions in a(w) values were found as group E>group D>group C>groups A and B (P<0.05). Salmonella survived 60days in group A, 65days in group B, 35days in group C, 45days in group D and 20days in group E. Drying process following salting accelerated the elimination of this pathogen. Salmonella survived longer in salted samples than in salted-dried and dried samples. This work demonstrated that Salmonella may be inhibited by one of salting, drying and salting-drying techniques; however, processing periods should be long enough to reduce a(w) sufficient to inhibit this pathogen.

The Effect of Ascorbic Acid, Citric Acid and Salt on the Quality of Spiny Dogfish (Squalus acanthias) Fillet

ABSTRACT In this study, spiny dogfish fillets were soaked in 10% brine (1:2 w fillet/v solution) for 30 min. Then they were dipped in a solution containing 0.1% ascorbic acid and 1.0% citric acid (1:2 w/v) for 5 min. All samples were covered with ice and stored at 3 ± 1°C for 12 days. Sensory, chemical, and bacteriological analyses were done in every 3 days. Sensory values were 3 and 5; pH values were 7.03 and 6.87; mesophilic aerobic bacteria counts were 5.77 and 5.56 for the control and treated samples, respectively, at the 12th day and these values were significantly (p < 0.05) different. Control samples were marketable on the 9th day and spoiled on the 12th day of storage while the treated samples were still marketable. It was seen that treatment of the spiny dogfish fillet with salt, ascorbic acid, citric acid increased the shelf life.

Determination of irradiation dose and distinguishing between irradiated and non irradiated fish meat by real-time PCR.

In this study, the effects of gamma irradiation on the DNA of fish (Oncorhynchus mykiss) by real-time PCR were studied. Fish (O. mykiss) were exposed to radiation doses of 0.250, 0.500, 1, 3, 5, 7, and 9 kGy in a gamma cell. Primers were designed for regions with different lengths of both nuclear and mitochondrial DNA, and each primer was used to amplify the DNA from irradiated samples. The amplicon curves for mitochondrial and nuclear DNA, and the correlations among the curves, were obtained. The Ct values for a 519 bp region of the 18S RNA gene on nuclear DNA correlated appropriately. Radiation doses applied to the fillets were estimated using the standard curve data obtained from the correlation values, and the DNA damage caused by each dose was calculated. As a consequence, a molecular methodology to analyze irradiated fish meat qualitatively and also for the estimation of administered dose was developed. This method allowed analysis of irradiated fish, which had been stored for up to 3 months with a dose limit of approximately 0.5 kGy.

Potential health risks due to heavy metal uptake via consumption of Thunnus thynnus from the northern Levantine Sea

Abstract The potential human health risks of copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) in Thunnus thynnus from the northern Levantine Sea were assessed. The mean concentrations (mg/kg) of metals were found as 0.819 for Cu, 8.344 for Zn, 2.102 for As, 0.002 for Cd, 0.001 for Hg and 0.115 for Pb. Even though these values were below the permitted levels, 11% of the samples contained Pb above the limits. Estimated weekly intakes were conspicuously lower than the PTWI values. The target hazard quotients (THQs) of each metal and total THQ of combined metals remained well below 1, showing no public health risk for an average consumer.

Levels of Selected Metals in Albacore (Thunnus alalunga, Bonnaterre, 1788) from the Eastern Mediterranean

Albacore has been exported mainly to Europe from Turkey. To evaluate the possible health risks and provide information for surveillance programs, concentrations of cadmium, mercury, and lead were determined in albacore from the Eastern Mediterranean Sea. Of the 34 individuals, 25 contained mercury and 9 contained cadmium above the permissible limits set by the European Union (1 mg/kg and 0.1 mg/kg, respectively). None of the samples contained lead above the limit (0.3 mg/kg). It was concluded that concentrations of trace metals in albacore, especially mercury, must be controlled comprehensively and periodically with respect to consumer health.