The parameters of hygienic quality of four most common types of fish in Serbian market

Abstract

The aim of this study was to show the comparative results of chemical and microbiological investigation of two freshwater fish species, pangasius, which, in recent years, occupies a leading position on the market, and carp, as the most common fish in the national aquaculture and two species of marine fish, hake and mackerel. Microbiological testing included Salmonella species, coagulase-positive staphylococci, sulphite-reducing clostridia, E. coli and total aerobic mesophilic bacteria. Of chemical contaminants, the presence of the following organochlorine pesticides (OClP) was investigated: gamma-hexachlorocyclohexane (gamma- HCH), i.e. lindane, alpha-HCH, beta-HCH, aldrin, dieldrin, heptachlor, cis-and trans-heptachlor epoxide, p, p'-DDT (dichloro diphenyl trichloroethane), pp'-DDE (dichlorodiphenyl dichloroethane), pp'-DDD dichlorodiphenyl dichloroethane), endrin, hexachlorobenzene (HCB), alpha-and gamma-chlordane. In the same samples congeners of polychlorinated biphenyls (PCBs), IUPAK no. 28, 52, 101, 118, 138, 153, 180, were determined as well and the heavy metals lead, cadmium and mercury. The presence of coagulase-positive staphylococci, sulphite reducing clostridia, Salmonella spp. and E. coli was not established in the tested samples. The total count of aerobic bacteria was the highest in carp samples (3.40 } 0.57), but did not exceed the recommended limit of acceptability of 5.69 log cfu/g. Amounts of dieldrin, HCH, HCB and chlordane were lower than the detection limit (0.001 mg/kg) in samples of all four fish species. For pangasius samples, the total amount of DDT ranged from detection limit (0.001 mg/kg) to 0,005 mg/kg, while the values of pesticides in samples of mackerel were in the range of the detection limit (0.001 mg kg) to 0.019 mg/kg. The sum of heptachlor quantities and heptachlorepoxide in samples of pangasius ranged from the detection limit to 0.009 mg/kg, and in samples of carp from the detection limit to 0.019 mg/kg. In samples of pangasius, mackerel and hake the content of lindane was below the detection limit (0.001 mg/kg), while in the carp samples ranged from the detection limit to 0.017 mg/kg. The content of polychlorinated biphenyls ranged from the detection limit (0.001 mg/kg) to 0.030 mg/ kg, for the samples of pangasius and to 0.089 mg/kg for carp samples. In samples of mackerel, sum of aldrin and dieldrin ranged from the detection limit to 0.010 mg/kg, while in samples of pangasius, carp and hake its value was below the detection limit (0.001 mg / kg). Amounts of heavy metals (Hg, Pb and Cd) were also below the maximum residue limits (MRL). Lead content was the highest in pangasius samples, 0.21 mg/kg, while the highest content of cadmium, 0.049 mg/kg, was detected in samples of hake. Samples of mackerel had the highest mercury content, which amounted to 0.162 mg / kg. In respect to food safety, samples of fish were of good quality, with the concentration of chemical contaminants below the maximum residue limits and with no increase in the number of microorganisms.