Dietary Vitamin A Improved the Flesh Quality of Grass Carp (Ctenopharyngodon idella) in Relation to the Enhanced Antioxidant Capacity through Nrf2/Keap 1a Signaling Pathway

Fish is an important animal-source food for humans. However, the oxidative stress-induced by intensive aquaculture usually causes deterioration of fish meat quality. The nutritional way has been considered to be a useful method for improving fish flesh quality. This study using the same growth experiment as our previous study was conducted to investigate whether vitamin A could improve flesh quality by enhancing antioxidative ability via Nrf2/Keap1 signaling in fish muscle. Six diets with different levels of vitamin A were fed to grass carp (Ctenopharyngodon idella) (262.02 ± 0.45 g) for 10 weeks. Dietary vitamin A significantly improved flesh sensory appeal and nutritional value, as evident by higher pH24h value, water-holding capacity, shear force, contents of protein, lipid, four indispensable amino acids (lysine, methionine, threonine, and arginine) and total polyunsaturated fatty acid in the muscle. Furthermore, dietary vitamin A reduced oxidative damage, as evident by decreased levels of muscle reactive oxygen species, malondialdehyde, and protein carbonyl, enhanced activities of antioxidative enzyme (catalase, copper/zinc superoxide dismutase (CuZnSOD), MnSOD, glutathione peroxidase, and glutathione reductase), as well as increased content of glutathione, which was probably in relation to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. These findings demonstrated that dietary vitamin A improved flesh quality probably by enhancing antioxidant ability through Nrf2/Keap 1a signaling in fish.

A review of microplastic pollution in commercial fish for human consumption

Today microplastics (MPs) have received worldwide attention as an emerging environmental pollution which is one of the four major global environmental threat and health hazard to human as well. Unfortunately, MPs have been founded in the all environments and media include air, water resources, sediments, and soil. It should not be forgotten MPs have also been detected in food and processing products like tuna. MPs can be ingested by marine organisms such as zooplankton, fish and birds. Accumulation and distribution of MPs by commercially important aquatic organisms is expected to lead to greater exposure risk for human populations with possible adverse effects over time. The aim of this work was to review the published literature regarding the contamination of commercial fish muscle for human consumption. Furthermore, a short revision of the environmental contamination and human health effects by MPs are included. We also estimated human daily intake considering the worldwide contamination of commercial fish muscle ranged from 0.016 items/g muscle of fish to 6.06 items/g muscle of fish. MPs have been found in 56.5% of the commercial fish samples analysed here. As fish is used in human food table across the word, they constitute a long-term exposure route for all humans and raise the concern about the potential public health risk.

Studying sanitary and hygienic conditions of bream and water in its habitat

The article highlights the data on microbiological monitoring of fish raw materials and water of the Volga-Caspian fishing channel in 2020-2021. The most indicative organisms for assessing the quality of the aquatic environment are benthos-eating fish. Bream Abramis brama (Linnaeus, 1758) is one of the valuable objects of fishing in the Astrakhan region. As a commercial object of river coastal fishing, bream has a higher bacterial contamination than fish caught in the sea. In this regard, studying the conditions for bacteriocenosis of fish raw materials, as well as the factors that determine the pathogenicity of its microflora and sanitary and epizootic monitoring by the microbiological tests remain the most relevant research of aquatic organisms. Quantitative and qualitative indicators of the bream microflora were estimated, according to the analysis of 180 species. The indicators of the water microflora were analyzed using the results of studies of 90 samples. The species identification of the isolated microflora was carried out according to the Bergey identification keys. In the samples of bream muscles there was determined the total number of facultative anaerobic microorganisms and aerobic mesophylls, presence of coliform microorganisms, as well as a causative agent of Staphylococcus aureus, pathogenic bacteria Salmonella and Listeria, and parahemolytic vibrios Vibrio. The study results were processed, according to the methods of biological statistics in the Microsoft Excel 2010 software. The results are presented as mean values and standard errors (M ± m). The general microbiological analysis of the fish muscle tissue confirmed the satisfactory sanitary state of bream Abramis brama (L., 1758) caught in the fishing area of the Volga-Caspian Canal during the study period. Pathogenic microflora in the form of E. coli bacteria, bacteria Salmonella, L. monocytogenes and St. aureus were not found

High-technology methods of processing fish raw materials farmed in Astrakhan region

The modern level of development of fish processing technology is analyzed. A number of high-tech processes related to deep processing of aquaculture objects (paddlefish, clary catfish and tilapia), grown in the Astrakhan region, in closed water supply installations, have been proposed for implementation. The chemical composition of fish muscle tissue has been studied. A method has been developed to reduce the microbial contamination of raw materials using a low-frequency electromagnetic field. Methods of electrophysical and gas-liquid processing of raw materials have been adapted to real production conditions. Methods for processing secondary fish resources into edible fish meal and fish oil have been tested using gas-liquid technologies. Methods for processing water and muscle tissue of fish raw materials by electromagnetic and gas-liquid methods are proposed. The chemical composition of fish pates enriched with CO2-extracts was investigated.

Detection of contamination by some trace elements in the muscles of Carassius auratus (Linnaeus) collected from the Euphrates River / Central Iraq

The study involved measuring the concentration of seven trace elements (Cd , Pb , Zn , Fe , Mn , Se and Ni) In edible tissues of three classes of different weight and height of Carassius auratus (Linnaeus) collected from three sites of the Euphrates River, which Al- Hindiya barrage (first site) and Touirij (second location) and the Kifil (third site), for the period from Spring 2015 to Winter 2016 , and included also The study also estimated the concentrations of the trace elements studied in river water, in both dissolved and particular form , as well as exiamining of some physio- chemical properties of water river , which variations depended on the different both sites and seasons The Findings of the present study indicated seasonal changes in the concentration of trace elements studied in both water forms (dissolved and particular form) and in fish muscle in the three locations of the current study. These were noticed that the level of trace elements in the third group, the contrast of the first and second categories was strong, and the finding found a clear link between the length and weight of the fish and the concentration of the fish as elements of concentration increases with increasing length and weight . The results founded that the concentrations of trace elements studied the particular form of higher compared to dissolved form as well as to the effective of certain physical and chemical properties of water such as Temperature, pH, Electrical conductivity and salinity on the concentration of these trace elements.

Determination of Heavy Metal Concentration in Two Bony Fish (Catfish and Tilapia) from Orashi River in Rivers State, Nigeria

The research was intended to study the influence of human and industrial activities on the Orashi River and two bony fish (Clarias gariepinus and Tilapia nilotica). Three groups are observed to have impacted the environment – Oil/gas industries, tyre burning from abattoir, untreated human and animal waste from settlers and the abattoir. The study was carried out from September 2019 to August 2020. The mean concentrations of the parameters studied in some samples were close to or exceeded World Health Organization (WHO) and Federal Ministry of Environment (FMEnv) recommended limits for drinking water and seafood. The results from this study have provided information on the heavy metals profile on the fish of the river. The level of heavy metals in the muscle of Catfish and Tilapia showed a range of Cadmium in Catfish (1-3.9mg/kg and Tilapia (0.1-4.2mg/kg) with the highest level occurring in station 2 (3.47mg/kg for Catfish and 3.39mg/kg for Tilapia) which is high with regard to FAO 19835, FAO/WHO 10896, EEC 20054 permissible limit of 0.01mg/l and USEPA SQG (1mg/kg) level in seafood. The levels of essential heavy metals in fish muscle were Copper (Catfish-10.9-33mg/kg, Tilapia -17.3-40.6mg/kg), Iron (Catfish-1.0-2.5mg/kg, Tilapia -0.1-5.6mg/kg) were within the FAO 1983 permissible limit while Zinc (Catfish-22-213.2mg/kg) and Tilapia (30.1-196mg/kg) exceeds the limit in some stations. Catfish muscles recorded higher mean value (127.12mg/kg) for all heavy metals than tilapia (44.03mg/kg) and the sequence is Copper > Zinc > Iron > Cadmium. The concentration of heavy metals in Orashi River is in the sequence: Sediment > Catfish > Tilapia >Water. The Total Heavy metal concentration in muscle of Catfish (0.5-1.8mg/kg) and Tilapia (0.1-3.8mg/kg) were within permissible limit.

A Food-Safety Risk Assessment of Mercury, Lead and Cadmium in Fish Recreationally Caught from Three Lakes in Poland

Heavy metals are introduced into water due to anthropogenic activities and can significantly affect an entire ecosystem. Due to their close integration with the water environment, fish are a sensitive indicator of contamination. In addition, fish is an important element in human diets, therefore, monitoring the concentrations of metallic contaminants in their meat is particularly important for food safety. This study aimed to assess the pollution of water ecosystems with selected toxic heavy metals in lakes Dratów, Czarne Sosnowickie, and Syczyńskie. The concentration of Pb, Cd, and Hg in water, sediment, and freshwater fish muscle tissue was determined, and a food safety assessment was performed. The analysis of water and sediments showed that the sediments were characterised by a significantly higher concentration of heavy metals. Presumably, this ecosystem element plays an important role in the uptake of heavy metal contaminants by fish whose levels were higher in planktonophagous and benthophagous fish species as compared to predatory fish. The food safety assessment showed that amounts of heavy metals in the muscle tissue posed no threat to the health of consumers ingesting that fish species, neither individually (THQ) nor collectively (TTHQ).

Concentration of Metals in Native and Invasive Species of Fish in the Fluvial-Lagoon-Deltaic System of the Palizada River, Campeche

Aquatic organisms, such as fish, are important indicators of the bioavailability of metals in coastal environments, demonstrating the capacity of different species to bioaccumulate these metallic elements. The fluvial-lagoon system of the Palizada River is an important ecosystem for its terrestrial and aquatic biological diversity where fishing is an important productive activity in this system. The objective of this research was to evaluate the concentration of Pb and Cd in the muscle tissue of native and invasive fish species in this area. For this, the digestion of fish muscle samples was carried out with a CEM MARS 5 Digestion Microwave System, while the quantification of metals was performed with an atomic absorption equipment. All analysis muscle samples from native and invasive fish showed Pb and Cd in their content. By sampling site there was a statistically significant difference (p < 0.05), with a maximum Pb concentration of 7.760 µg g−1 at the LLAR site (Laguna Larga). In terms of species, the maximum Cd concentration was obtained in the Cyprinus carpio with 6.630 ± 0.127 and in Pterygoplichthus pardalis with 6.547 ± 0.873 µg g−1 (dry weight). The presence of metals such as Pb and Cd in muscle tissue of native and invasive fish species represents an important bioindicator of environmental exposure in the study area and a potential risk to public health, as these species are commonly consumed.