The mineral elements in processed food of marine origin

Praca przedstawia makro- i mikroelementy oraz metale toksyczne występujące w konserwach ze śledzi. Badaniami objęto konserwy ze śledzi i filetów śledziowych w oleju i w pomidorach. Wykonano analizy zawartości wapnia, fosforu, magnezu, potasu, miedzi, cynku, żelaza, manganu, chromu, selenu, fluoru, jodu, kadmu, ołowiu, rtęci i arsenu. Konserwy ze śledzi są źródłem wapnia, fosforu, selenu, fluoru i jodu, w mniejszych ilościach występuje w nich cynk i żelazo. Pozostałe mikroelementy (miedź, chrom, mangan) występują w badanych konserwach w niewielkich ilościach i nie wpływają znacząco na ich wartość odżywczą. Na podstawie średnich zawartości poszczególnych pierwiastków oszacowano, że jedna konserwa ze śledzi (o wadze 170 g) może dostarczyć do organizmu konsumenta ponad 50% dziennego zapotrzebowania na wapń i fosfor, 50% wymaganego jodu, do 40% potrzebnego selenu i całkowicie spełnia oczekiwania organizmu na fluor. Ponadto pokrywa w około 20% dzienne zapotrzebowanie na magnez, potas, cynk i żelazo. Metale toksyczne (kadm, ołów, rtęć i arsen) występują na niskim poziomie i nie stwarzają zagrożenia dla zdrowia ludzi.The work discusses contents of macro- and microelements and toxic metals in tinned herrings. The tests covered tinned herring and herring fillets in oil and tomato sauce. The analyses of calcium, phosphorus, magnesium, potassium, copper, zinc, iron, manganese, chromium, selenium, fluorine, iodine, cadmium, lead, mercury and arsenic content were conducted. A technological processing did not free these products from mineral elements. The tinned herring the significant amount of calcium, phosphorus, selenium, fluorine and iodine, and zinc and iron in lesser amounts. Other microelements (copper, chromium, manganese) occur in the tested tinned food in little amounts and do not have any significant effect on their nutritive value. On the basis of average contents of individual elements it was estimated that one tinned herring (with a weight of 170g) could provide to the consumer's organism more than 50% of daily demand for calcium and phosphorus, 50% of required iodine, up to 40% of required selenium and fully meet the organism demand for fluorine. Furthermore it provides in approx. 20% of daily demand for magnesium, potassium, zinc and iron. It was found out that all analyzed tinned sprat products contained low level of cadmium, lead, mercury, and arsenic, and did not pose any threat to human health

Effects of processing methods on the content of minerals in fish products

Effects of salting, pickling and smoking processing methods on the mineral composition in fish products were investigated. The concentrations of Ca, P, Mg, K, Na, Cu, Fe, Zn, Mn and Se in fish products were determined during subsequent stages of processing in raw fish, semi-processed products and ready products. Fresh fish contained macro-elements in the following order: K > P > Na > Ca > Mg. The tendency was similar in semi-processed and ready products, except for the dominance of sodium. The sodium content in marinated products was three-fold higher than in fresh fish and twelve-fold higher in salted herring and cold-smoked fish. The sodium content in a 100 g portion of salted herring exceeded by six-fold the recommended daily allowance and by two-fold the tolerated amount. The content of K, Mg and P in marinated and salted herring tended to decrease throughout processing. No significant differences were observed in concentrations of Ca. The order of the concentrations of microelements was as follows: Zn > Fe > Cu > Se > Mn. The content of these elements in fish products was similar to their levels in fresh fish and corresponded to the following shares of the recommended allowances: Se up to 20%; Cu up to 11%; Zn up to 6%; Mn up to 1%; Fe up to 10%. Disadvantageous changes in the mineral composition in fish during processing result from water losses during technological processes, but the primary cause of mineral loss was leaching when the products were soaked in brine solutions with a high sodium content. Significant changes in the content of minerals in salted and pickled herring decreased the nutritional value of these products. Smaller mineral losses that occurred during smoking meant that these products were more valuable nutritionally in relation to minerals

Toxic metals (Cd, Pb) in flatfish, mollusc Macoma balthica, water and sediments from the southern Baltic Sea

Environmental pollution is a worldwide problem, with toxic metals being among the most noxious pollutants. Aquatic organisms can accumulate toxic elements from their environment through different pathways, including water, diet and sediments. The aim of the study was to determine the distribution of toxic metals (Cd and Pb) in tissues of three species of flatfish (Platichthys flesus, Pleuronectes platessa, Scophthalmus maximus), and in their environment (water, sediment and their prey mollusc Macoma balthica) in four regions of the southern Baltic Sea, in order to identify the most important pathways of metal uptake in these fish. The concentrations of toxic metal were measured in a graphite furnace by atomic absorption spectrometry. Toxic metal concentrations in flatfish liver were significantly higher than in the muscle tissue. The liver was the target organ for Cd and Pb accumulation. The flatfish liver, M. balthica, sediment, and water from the Gulf of Gdansk contained higher level of Pb than did the samples from the central Baltic Sea coast. The Pb concentrations in the liver of P. flesus and P. platessa showed positive correlations with Pb in the soft tissue of M. balthica, sediment and sea water. The high correlation coefficient values for Pb suggest that flatfish took up this metal through the food chain from molluscs. In turn, M. balthica took up Pb and Cd from sediment and water, which was confirmed by the high correlation coefficients for these metals between this mollusc and sediment and water. The positive correlations for concentrations Pb and Cd in sediment and in water indicate the next stage of the pathway along which the metals travel in the Baltic Sea environment

Mineral elements content in smoked fish

Zbadano zawartość makroelementów: wapnia, fosforu, potasu, sodu i magnezu, mikroelementów: miedzi, cynku, żelaza, manganu, chromu, selenu i jodu w następujących rybach wędzonych: szprot, makrela, pikling, łosoś bałtycki i norweski oraz pstrąg. Najwięcej wapnia, fosforu żelaza, cynku, miedzi i manganu zawierały wędzone szproty. Zawartość wapnia w pozostałych gatunkach ryb była znacznie niższa, a zawartość fosforu zbliżona do jego zawartości w szprocie. Selen i fluor stwierdzano na zbliżonym wysokim poziomie we wszystkich badanych rybach, natomiast zawartość jodu była wysoka, choć zróżnicowana. Najwięcej jodu zawierały wędzone łososie i pstrągi, natomiast najmniej pikling, szprot i makrela. Oszacowano udział ryb w zalecanym dziennym spożyciu składników mineralnych w odniesieniu do zalecanego dziennego pobrania.The content of macroelements (phosphorus, calcium, magnesium potassium and sodium) and microelements (copper, zinc, iron, manganese, chromium, selenium, fluorine and iodine) in the following smoked fish: sprat, mackerel, salmon, smoked herring and trout were determined. The most of calcium, phosphorus, iron, zinc, copper and manganese contain smoked sprat. The amount of calcium in fish's remaining species is considerably lower, and phosphorus approximated to his content in sprat. The selenium and the fluorine occur on approximate level in all examined fish, however the amount of iodine was diverse but high. Smoked salmon and trout contain the most iodine, and the least smoked herring, sprat and mackerel. Contribution of fish in the recommended daily intake for mineral elements was estimated

Toxic metals (Cd, Pb) in flatfish, mollusc Macoma balthica, water and sediments from the southern Baltic Sea

Environmental pollution is a worldwide problem, with toxic metals being among the most noxious pollutants. Aquatic organisms can accumulate toxic elements from their environment through different pathways, including water, diet and sediments. The aim of the study was to determine the distribution of toxic metals (Cd and Pb) in tissues of three species of flatfish (Platichthys flesus, Pleuronectes platessa, Scophthalmus maximus), and in their environment (water, sediment and their prey mollusc Macoma balthica) in four regions of the southern Baltic Sea, in order to identify the most important pathways of metal uptake in these fish. The concentrations of toxic metal were measured in a graphite furnace by atomic absorption spectrometry. Toxic metal concentrations in flatfish liver were significantly higher than in the muscle tissue. The liver was the target organ for Cd and Pb accumulation. The flatfish liver, M. balthica, sediment, and water from the Gulf of Gdansk contained higher level of Pb than did the samples from the central Baltic Sea coast. The Pb concentrations in the liver of P. flesus and P. platessa showed positive correlations with Pb in the soft tissue of M. balthica, sediment and sea water. The high correlation coefficient values for Pb suggest that flatfish took up this metal through the food chain from molluscs. In turn, M. balthica took up Pb and Cd from sediment and water, which was confirmed by the high correlation coefficients for these metals between this mollusc and sediment and water. The positive correlations for concentrations Pb and Cd in sediment and in water indicate the next stage of the pathway along which the metals travel in the Baltic Sea environment

Macro- and microelements in eel (Anguilla anguilla) from the northern regions of Poland

The abundance of the eel (Anguilla anguilla) in Europe has been on the decline in recent years, to the extent that this fish species is now considered to be threatened with extinction. Hence, the current implementation of the Eel Management Plan in Poland, whose aim is to restore w stocks of this fish. The main natural habitats of eel are the transitional waters of the Vistula and Szczecin lagoons and lakes in northern Poland. The eel is highly valued by many consumers for the taste and texture of its meat. The aim of the study was to determine differences in concentrations of macro- and microelements and toxic metals in muscles of the eel as a function of each specimen’s length, mass and the origin. The results of the study also served an evaluation of the health benefits and risks to consumers of eel meat with regard to the content of macro- and microelements and toxic metals. Specimens of the eel (Anguilla anguilla) were caught in 2011-2013, in five regions of Poland: the southern Baltic, inland lakes in northeast Poland, the Vistula and Szczecin lagoons, and in the Vistula River. The concentrations of Ca, P, Mg, Na, K, Fe, Sr, Zn and As were determined with optical emission spectrometry. The flameless atomic absorption spectrometry method was used to measure concentrations of Cu, Cd and Pb. The content of Hg and Se were determined with atomic absorption, those of mercury with cold vapour, and of selenium with hydride generation. The concentrations of macro- and microelements in most instances, with the exception of P and Zn, were negatively correlated with the eel’s length and mass, which indicated that small fish contained more minerals than large specimens. The eel is a rich source of phosphorus, zinc, selenium and iron, and it can supply significant quantities of the daily requirements of human consumers for these minerals. The other minerals occurred in eel muscle at levels that ranged from 2 to 6% of human daily requirements. Among the toxic metals, mercury was the cause for concern, while cadmium and lead occurred at low levels in all of the specimens examined regardless of their size. The mean concentration of mercury ranged from 0.147 to 0.273 mg kg-1 and was positively correlated with specimen length and mass. The content of mercury in large eel exceeded 0.500 mg kg-1, while small eel (up to 70 cm) contained lower levels of mercury. Large eel exceeding 70 cm can pose a threat to the consumer’s health because of mercury, and especially its organic from of methylmercury. This is why consumers should limit long-term consumption of larger eel, while it is safe to consume smaller specimens since they contain less mercury and more minerals than do large eel

Quality and amino acid composition of protein of fish from the Vistula Lagoon

Celem pracy była ocena ilości i jakości białka oraz aminokwasów zawartych w rybach z Zalewu Wiślanego. Badaniami objęto gatunki ryb (węgorz, śledź, leszcz, sandacz, płoć i okoń) najliczniej poławianych w tym akwenie. Określono podstawowy skład chemiczny mięsa ryb (zawartość białka, tłuszczu, wody), strawność białka i skład aminokwasów. Badane ryby były rybami chudymi i średnio tłustymi (z wyjątkiem węgorza) i zawierały od 14,4 do 19,5 g/100 g białka wysoko strawnego (98,3 – 98,8 %). Białko badanych ryb, a szczególnie sandacza zawierało dużo aminokwasów egzogennych. W 100 g mięśni znajdowało się od 5,79 do 8,85 g tych niezbędnych dla organizmu związków. Wyniki badań wskazują, że 100 g mięsa każdego gatunku ryb z Zalewu Wiślanego pokrywa z nadmiarem dzienne zapotrzebowanie dorosłego człowieka na białko. Zawartość aminokwasów egzogennych występujących w mięsie ryb z Zalewu Wiślanego przewyższa ich ilość w białku wzorcowym. Świadczy to o wysokiej jakość białka ryb. W białku dominują aminokwasy; metionina i cysteina, lizyna, izoleucyna oraz histydyna. Ich zawartość w stosunku do białka wzorcowego wynosiła od 145,2 do 239,5 %.The objective of the research was to assess the quantity and quality of protein and amino acids contained in fish from the Vistula Lagoon. The research covered the fish species (eel, herring, bream, pike- perch, roach, and perch) most frequently caught in this water basin. The basic chemical composition of fish meat (content of protein, lipids, and water) was determined as were the digestibility of protein and the composition of amino acids. The fish examined were lean and medium-fat (except for eel) and contained 14.4 to 19.5 g/100 g of highly digestible proteins (98.3 - 98.8 %). The protein of the fish tested, especially that of pikeperch, contained high amounts of exogenous amino acids. In 100 g of meat, there was 5.79 to 8.85 g of those elements appearing essential for organism. The research results show that 100 g of meat of each fish species from the Vistula Lagoon covers with excess the daily protein demand of the adults. The content of exogenous amino acids in the meat of fish from the Vistula Lagoon exceeds their quantity in the standard protein. This proves the high quality of fish protein. The predominant amino acids in the protein are methionine and cysteine, lysine, isoleucine, as well as histidine. Their content ranged from 145.2 to 239.5 % compared to the standard protein