Beata Paszczyk

Fatty acid profiles in marine and freshwater fish from fish markets in northeastern Poland

Abstract The fatty acid compositions were studied in eight commercially important fish from fish markets: salmon, Salmo salar L.; cod, Gadus morhua L.; common sole, Solea solea (L.); European flounder, Platichthys flesus (L.); catfish, Clarias gariepinus (Burchell); rainbow trout, Oncorhynchus mykiss (Walb.); Nile tilapia, Oreochromis niloticus (L.); and pangasius, Pangasianodon hypophthalmus (Sauvage). The freshwater fish contained 25.69-42.18% saturated, 34.90-43.79% monounsaturated, 8.46-16.32% n-6 polyunsaturated, and 5.01-20.43% n-3 polyunsaturated acid, while marine fish contained 18.53-32.77% saturated, 17.95-49.89% monounsaturated, 3.40-11.51% n-6 polyunsaturated, and 18.74-45.42% n-3 polyunsaturated acid. Marine fish contained significantly more Ʃn-3 PUFA (29.79%), EPA (12.26%), DHA (13.20%), and a higher n-3/n-6 (6.95) ratio than freshwater fish (13.13, 2.47, 7.14, 1.29%) (P≤ 0.05). There were statistically significant differences in the n-3/n-6 ratio among fish species (cod (13.40) > sole (8.47) > flounder (4.30) > rainbow trout (2.41) > catfish (1.83) ≈ salmon (1.63) > tilapia (0.57) ≈ pangasius (0.36) (P ≤0.05)).

Fatty Acid Profile of Muscles of Freshwater Fish from Olsztyn Markets

Fatty Acid Profile of Muscles of Freshwater Fish from Olsztyn Markets The aim of the present study was to determine the profile of fatty acids in muscle lipids of freshwater fish: carp (Cyprinus carpio L.), rainbow trout (Oncorhynchus mykiss Walb.), bream (Abramis brama L.) and tench (Tinca tinca L.) from markets of Olsztyn (north-eastern Poland). Separation and identification of fatty acids were made using gas chromatography. The content of some fatty acids varied among species. Generally, palmitic acid (15.6%-19.5%) was the most abundant saturated fatty acid (SFA). The main monounsaturated fatty acid (MUFA) was oleic acid (20.7%-42.7%). Linoleic (4.6%-8.0%), arachidonic (AA) (0.8%-6.6%), docosahexaenoic (DHA) (1.7%-15.9%) and eicosapentaenoic (EPA) (1.2%-8.8%) acids were the predominant polyunsaturated fatty acids (PUFA). There were no significant differences (p>0.05) in the content of SFA (24.3%-28.7%) among the fish species. The content of MUFA in muscle lipids of carp (55.0%) was significantly higher (p≤0.01) than in the lipids of the other fish examined (35.8%-38.3%). Bream and rainbow trout (26.6% and 27.7%, respectively) contained significant more n-3 PUFA than carp (4.7%) and tench (20.5%) (p≤0.01). Total n-6 PUFA ranged between 8.4% (rainbow trout) and 12.9% (tench). Significant differences in n-6 PUFA content were only observed in the case of these fish (p≤0.01). The differences in the n-3/n-6 ratio (rainbow trout (3.3) > bream (2.6) > tench (1.6) > carp (0.4)) were statistically significant (p≤0.01).

Fish as a bioindicator of heavy metals pollution in aquatic ecosystem of Pluszne Lake, Poland, and risk assessment for consumer's health

Heavy metals content (Zn, Cu and Hg) were measured in gills, liver, gonads and muscles of perch, Perca fluviatilis (L.) and roach, Rutilus rutilus (L.) from Lake Pluszne (north-eastern Poland). Correlations between heavy metals levels and total length, weight, HSI, GSI and FCF were examined. As expected, muscles contained the significantly highest values of Hg (P ≤ .05). The concentrations of Zn were significantly higher in gills of roach and gonads of perch (P ≤ .05), while the liver of fish accumulated significantly more Cu than other organs (P ≤ .05). In all organs of perch the higher content of mercury was found (P ≤ .05). The value of Zn and Cu was highest in organs of roach (P ≤ .05) (with the exception of Zn in muscles P > .05). Sequence of metals in both species was Zn > Cu > Hg. Only in muscle tissue, Hg was significantly positive correlated with weight of roach (r = 0.811, P = .045) and perch (r = 0.652, P = .041), and total length of roach (r = 0.806, P = .005). A positive relationship was also observed between Zn concentration in gills of perch and their weight (r = 0.634, P = .049). In contrary, Zn in gills of roach decreased with weight (r = -0.693, P = .026)) and length (r = -0.668, P = .035). Cu concentration in liver of perch was statistically positively correlated with HSI (r = 0.717, P = .020), whereas Hg content in muscle tissue of roach with FCF (r = 0.643, P = .045). There was negative relationship between Hg in perch gonads and GSI (r = -0.808, P = .005). Metal pollution index (MPI) in gills, liver, gonads and muscles of roach was 7.68, 7.24, 6.77 and 3.13, respectively, whereas in these organs of perch was 3.25 (gills), 4.75 (liver), 5.84 (gonads) and 4.44 (muscles), therefore the contamination of each tissue ranged from very low contamination to low contamination. The concentration of mercury was lower than the maximum acceptable limit estimated by the Commission Regulation (EC) No 629/2008 of 2 July 2008. The values of HI and THQ were below 1, which means that consumption of these fish is not hazardous to the consumer.

Concentration of mercury in muscles of predatory and non-predatory fish from lake Pluszne (Poland)

Abstract Introduction: The study examined the concentration of total mercury and correlation coefficients between fish size or FCF (condition factor) and the content of Hg in muscle tissue of six freshwater fish: bream (Abramis brama L.), roach (Rutilus rutilus L.), whitefish (Coregonus lavaretus L.), vendace (Coregonus albula L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.). Material and Methods: The fish were caught from the Lake Pluszne located in the Olsztyn Lake District (Poland). Mercury was analysed by atomic absorption spectrometry using Milestone DMA-80 (with dual-cell). Results: The content of the element in the muscles of the examined fish was as follows: pike (0.197 mg/kg) ≈ perch (0.173 mg/kg) > vendace (0.114 mg/kg) ≈ roach (0.095 mg/kg) and roach ≈ whitefish (0.065 mg/kg), and whitefish ≈ bream (0.042 mg/kg) (p ≤ 0.05). In all cases, the content of mercury correlated positively with the body weight and total length of the fish. Only the correlation coefficients between mercury concentration and weight or length of bream were slightly higher (0.979 and 0.977 respectively, p ≤ 0.001). The length and weight relationship of the fish was also determined. Conclusion: The results showed that the levels of mercury were lower than the maximum acceptable limit established by the Commission Regulation (EC) No 629/2008 of 2 July 2008. Thus, they are safe from consumer health point of view.

Mercury, Fatty Acids Content and Lipid Quality Indexes in Muscles of Freshwater and Marine Fish on the Polish Market. Risk Assessment of Fish Consumption

Mercury content and fatty acids in muscles of Perca fluviatilis L. (European perch), Leuciscus idus L. (ide), Cyprinus carpio L. (European or common carp), Oncorhynchus mykiss Walb. (rainbow trout), Platichthys flesus L. (European flounder). and Clupea harengus L. (bream) from the Polish market were investigated. The total mercury was processed with AAS. The fatty acids were analyzed by gas chromatography. The concentration of mercury in muscles varied from 0.006 to 0.138 mg/kg and decreased as follows: perch ≈ ide > flounder > herring ≈ bream ≈ rainbow trout > carp (p ≤ 0.05). There were only significant positive correlations between body weight and mercury content in muscle tissue of carp (r = 0.878), flounder (r = 0.925) and herring (r = 0.982) (p ≤ 0.05). The atherogenic index (AI), thrombogenicity index (TI) and flesh-lipid quality index (FLQ) were calculated as follows 0.33–0.70 (IA), 0.16–0.31 (IT) and 13.01–33.22 (FLQ). Hypocholesterolemic (OFA) and hypercholesterolemic fatty acids (DFA) in muscles of fish ranged from 18.26 to 23.01 and from 73.91 to 78.46, respectively. In most cases, there were not significant correlations between size (body weight and total length) and fatty acids in the muscles of the examined fish (p > 0.05). The Target Hazard Quotient (THQ) values were below 1, which shows that there is no non-carcinogenic health risk to the consumer by consuming the examined fish.

Fatty acids composition and trans isomers in cheeses and cheese-like products

Background. Cheeses are a very important component of our diet. The assortment of cheeses on the Polish market is very large. Besides commercial cheeses, cheeses from individual farms are available, as well as cheese-like products, which are more likely to be bought by consumers for their lower prices. The aim of the study was to evaluate the fatty acid composition, with particular focus on cis9trans11 C18:2 (CLA), trans isomers of C18:1 and C18:2 fatty acid content, in commercial cheeses, cheeses made by farmers, and cheese-like products. Material and methods. The study evaluated commercial rennet ripening cheese from different manufacturers (8 products), cheese-like products from different manufacturers (8 products) and ranching rennet ripening cheese derived from individual producers (8 products). Determination of the fatty acid composition was performed by GC-FIDupe in 100 m capillary column with CP Sil 88 phase. Reference milk fat and fatty acid methyl esters standards from Sigma and Supelco were used for identification of fatty acids. Results. The study showed that the tested commercial cheese, cheese made by farmers and cheese-like products were characterized by varying fat content, as well as a diverse composition of individual groups of fatty acids. Within a single group of products the biggest difference in the content of individual groups of fatty acids was observed in the cheese made by farmers. Conclusions. Based on extensive studies it can be concluded that the commercial cheese and cheese made by farmers are characterized by a higher content of saturated and short-chain fatty acids than in cheese-like products and a lower content of monoenoic and polyenoic acids than in cheese-like products. Cheeses are a better source of conjugated linoleic acid in our diet than are cheese-like products.