Nutritional value and sensory properties of common carp (Cyprinus carpio L.) fillets enriched with sustainable and natural feed ingredients

Declines across global fishery stocks forced aquaculture feed manufacturers to search for new and sustainable components. Therefore, the aim of study was assessing nutritional value and sensory properties of meat of common carp (Cyprinus carpio L.) fed for 116 days with two blends. The control feed contained 5% of fishmeal and vegetable oils (rapeseed and soybean) as sole fat sources. While in the experimental diet half of the fishmeal was replaced with a blend of microalgae (Spirulina sp., Chlorella sp.), macroalgae (Laminaria digitata) and vegetable oil was replaced with salmon oil. Proximate composition, energy value, fatty acid profile of meat, nutritional characteristics of fat and protein as well as culinary properties of fillets were assessed. Fillets of carp fed experimental diet had a higher level of protein, lower level of fat and energy value. Intramuscular fat of fish fed with the experimental diet had a better parameters of quality. Protein in the meat of fish from both groups was characterized by a high quality comparing to the protein standard. Our study showed that meat of carp fed with experimental feed enriched with sustainable and natural feed ingredients can be a sensorily attractive source of nutritious ingredients in the human diet.

Effects of steaming on health-valuable nutrients from fortified farmed fish: Gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio) as case studies

Fish fortification with iodine-rich macroalgae (Laminaria digitata) and Selenium-rich yeast is expected to promote nutritional added value of this crucial food item, contributing to a healthy and balanced diet for consumers. However, it is not known if steaming can affect these nutrient levels in fortified fish. The present study evaluates the effect of steaming on nutrients contents in fortified farmed gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio). Fortified seabream presented enhanced I, Se and Fe contents, whereas fortified carp presented enhanced I, Se and Zn contents. Steaming resulted in increased I and Se contents in fortified seabream, and increased Fe and Zn levels in fortified carp, with higher elements true retention values (TRVs >90%). The consumption of 150 g of steamed fortified seabream contributes to a significant daily intake (DI) of I (up to 12%) and Se (up to >100%). On the other hand, steamed fortified carp contributes to 19-23% of I DI and 30%-71% of Se DI. These results demonstrate that steaming is a healthy cooking method, maintaining the enhanced nutritional quality of fortified fish. Moreover, the present fortification strategy is a promising solution to develop high-quality farmed fish products to overcome nutritional deficiencies.

Structural and molecular indices in common carp (Cyprinus carpio L.) fed n-3 PUFA enriched diet

Sustainable freshwater aquaculture has been recently gaining attention owing to the potential of nourishing the world. The study aimed to evaluate the influence of finishing diets on the activity of 21 genes involved in hepatic lipid metabolism and intestinal homeostasis, liver and intestine histology, and the level of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in common carp fillets. We compared two experimental diets: control diet mimicking a commercial feed (CTRL) and a test diet (CB) fortified with EPA and DHA retrieved from salmon by-products. An additional control (eCTRL) from extensively cultured carps was investigated. The study revealed that the expression of seven hepatic genes, e.g., lipoprotein lipase and fatty acid synthase, and six intestinal genes e.g., claudin-3c and γ-glutamyl transpeptidase, was influenced specifically by the experimental diets and farming type. Fish from the eCTRL group had the smallest hepatocytes and the largest nuclei compared with CTRL and CB. No pathological signs were found in intestine samples. Additionally, the levels of EPA and DHA in fillets were significantly higher in fish receiving CB compared with CTRL and eCTRL. The use of fortified diets is a promising solution to produce freshwater species with enhanced nutritional value without compromising the safety of fillets.

A comparison of the concentrations of heavy metals in modern and medieval shells of swollen river mussels (Unio tumidus) from the Szczecin Lagoon, SW Baltic basin

The shells of mussels, live-collected bivalves or during archaeological excavations, can be used as bioindicators of current and historical levels of heavy metal contamination. In this study, we examined the shells of Unio tumidus, commonly found in the Baltic Sea region, and determined the concentrations of Zn, Cu, Fe, Pb, Ni, and Cd in samples from the 10th, 11th, and 21st century from the area of the Szczecin Lagoon. The average levels of heavy metals (in μg g^-1 dry weight) in the shells from the Middle Ages were: 137.5 (Fe), 3.87 (Zn), 0.789 (Cu), 0.012 (Pb), 0.047 (Ni), and 0.0009 (Cd). Shells from the 21st century were significantly (P<0.05) more abundant in Fe, Cu, Ni, Pb, and Cd (rates of increase: 1.96×, 3.54×, 2.71×, 2.08×, and 3.55×, respectively) than shells from the Middle Ages. These results reflect contemporary anthropogenic pollution of the environment with heavy metals and confirm the possibility of using U. tumidus shells in the assessment of heavy metal pollution levels.

Macroelements and Trace Elements in Invasive Signal Crayfish (Pacifastacus leniusculus) from the Wieprza River (Southern Baltic): Human Health Implications

Signal crayfish (Pacifastacus leniusculus) is an invasive species displacing native European crayfish from their natural habitats. The elemental composition of the population from the southern Baltic coastal river and the potential health hazards are not known. The aim of the conducted research was to assess the quantitative content of Al, As, Ca, Cd, Cu, Fe, K, Mg, Na, Ni, Pb, Se, and Zn in meat, hepatopancreas, and exoskeleton in a population from Wieprza River (Poland) and compare the results with the recommendations of daily human consumption. Analysis also involved the composition of water and sediments. The concentrations of elements were analyzed using an Atomic Absorption Spectrometer. The bioconcentration factor (BCF) of elements in the signal crayfish was much higher from water than from sediments. Bioaccumulation of elements differed between the particular parts of the body of crayfish, e.g., Ca showed extreme predominance in the exoskeleton, while in meat exhibited a predominance of K, Na, Ca, and Mg. Among trace elements, crayfish meat was the richest in Zn, Cu, and Fe. The concentrations of non-essential Cd, Pb, and As were low compared to other determined elements. The highest concentrations of As, Cd, Cu, Fe, Ni, and Se were found in the hepatopancreas, while the highest levels of Al and Pb were found in the exoskeleton. Generally, it was found that the meat of P. leniusculus can be a perfect supplement to the human diet, and the consumption of 100 g of meat per day did not exceed the dietary reference values for essential elements and also for Al, As, Cd, Ni, and Pb.

Microelements and macroelements in the body of the invasive Harris mud crab (Rhithropanopeus harrisii, Maitland, 1874) from the central coast of the South Baltic Sea

In this study, we determined the levels of essential and non-essential elements in the Harris mud crab (Rhithropanopeus harrisii, Maitland, 1874) from the southern Baltic Sea. Results revealed high levels of Ca (246,000 ppm), Mg (11,000 ppm), Na (8160 ppm), K (3,780 ppm), and Fe (1830 ppm). The concentrations of essential metals such as Zn (62.5 ppm) and Cu (25 ppm) were similar to those recorded in other crab species. The concentrations of non-essential metals such as Pb (0.140 ppm), Cd (0.0017 ppm), and As (0.288 ppm) were well below the International Standards for Maximum Levels for Food. In view of the above, the Harris mud crab from the southern Baltic is safe to be used as a component of well-balanced feeds for terrestrial and aquatic animals.

Concentrations of heavy metals (Mn, Co, Ni, Cr, Ag, Pb) in coffee

Technologies involved in roasting coffee beans, as well as the methods used to prepare infusions, vary according to culture, and contribute to differences in the concentration of elements in the drink. Concentrations of six elements: manganese (Mn), cobalt (Co), nickel (Ni), chrome (Cr), silver (Ag) and lead (Pb) were investigated in coffee infusions from eleven samples of coffee, roasted and purchased in four countries: Bosnia and Herzegovina, Brazil, Lebanon and Poland. Metal concentrations were determined using an induction coupled plasma technique in combination with mass spectrometry (ICP-MS, Perkin Elmer) which measures total metal (ionic and non-ionic) content. Metal intake estimated for individual countries (in the respective order; mean consumption per person per year) was as follows: Mn: 26.8-33.1, 28.3-29.5, 29.7, 12.6-18.9 mg; Co: 0.33-0.48, 0.42-0.35, 0.32, 0.12-0.17 mg; Ni: 3.83-5.68, 4.85-5.51, 4.04, 2.06-2.24 mg; Cr: 0.17-0.41, 0.21-0.47, 0.17, 0.09-0.28 mg; Ag: 0.16-1.13, 0.26-0.70, 0.61, 0.33-1.54 mg, Pb: 4.76-7.56, 3.59-5.13, 3.33, 1.48-2.43 mg. This finding gives new data for Mn, Co, Ni, Cr, and Ag intake from coffee , and suggests that the amounts are negligible. However, the data for Pb consumption in heavy drinkers, for example in Bosnia and Herzegovina, indicate that Pb intake from coffee may contribute to the disease burden. The high lead level in some coffees suggests the need for a more precise control of coffee contamination.

Concentrations of heavy metals (Mn, Co, Ni, Cr, Ag, Pb) in coffee

AIM

Technologies involved in roasting coffee beans, as well as the methods used to prepare infusions, vary according to culture, and contribute to differences in the concentration of elements in the drink.

MATERIALS AND METHODS

Concentrations of six elements: manganese (Mn), cobalt (Co), nickel (Ni), chrome (Cr), silver (Ag) and lead (Pb) were investigated in coffee infusions from eleven samples of coffee, roasted and purchased in four countries: Bosnia and Herzegovina, Brazil, Lebanon and Poland. Metal concentrations were determined using an induction coupled plasma technique in combination with mass spectrometry (ICP-MS, Perkin Elmer) which measures total metal (ionic and non-ionic) content.

RESULTS

Metal intake estimated for individual countries (in the respective order; mean consumption per person per year) was as follows: Mn: 26.8-33.1, 28.3-29.5, 29.7, 12.6-18.9 mg; Co: 0.33-0.48, 0.42-0.35, 0.32, 0.12-0.17 mg; Ni: 3.83-5.68, 4.85-5.51, 4.04, 2.06-2.24 mg; Cr: 0.17-0.41, 0.21-0.47, 0.17, 0.09-0.28 mg; Ag: 0.16-1.13, 0.26-0.70, 0.61, 0.33-1.54 mg, Pb: 4.76-7.56, 3.59-5.13, 3.33, 1.48-2.43 mg.

CONCLUSIONS

This finding gives new data for Mn, Co, Ni, Cr, and Ag intake from coffee , and suggests that the amounts are negligible. However, the data for Pb consumption in heavy drinkers, for example in Bosnia and Herzegovina, indicate that Pb intake from coffee may contribute to the disease burden. The high lead level in some coffees suggests the need for a more precise control of coffee contamination.