A ratiometric fluorescent probe for hypoxanthine detection in aquatic products based on the enzyme mimics and fluorescence of cobalt-doped carbon nitride

A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.

A Critical Review on Superchilling Preservation Technology in Aquatic Product

aquatic product, known as one of the good resources for white meat, has been widely accepted by the consumers due to its high protein, low fat, especially low cholesterol. With the fast development of living standards around the world, the consumer demands for high quality, nutrition, safety and freshness of ifshery food are increasing. Thus, high efifcient preservation technologies for aquatic products become particularly important. Superchilling is one of the controlled-temperature preservation technologies for seafood. Aquatic products can be kept in better quality under superchilling conditions. This review introduced the principle and development of superchilling process, mainly focusing on research progresses and technical dififculties of superchilling. The growth mechanism of ice crystals and the feasibility of application of computational lfuid dynamics in analyzing the temperatures variation and ice crystals during superchilling progress were also discussed, which will provide theoretical foundation for its improvement and application.

Issues and Development Opportunities of Aquatic Product Industry in China

China is the largest producer and trader of aquatic products in the world, but does not mean that it belongs to the strongest power group of aquatic production and trade. This paper objectively analyzed the main problems existing in the highspeed development of China＇s aquatic product industry by empirical analysis. For example, the situation of quality and safety of aquatic products is serious now; the basic conditions of aquaculture lag behind the production development; aquatic industry is still in a low level of development and organization; and the quality and safety of aquatic products is the most main problem. This paper also revealed that fish would be the main source of animal-derived food, and the demand of characteristic aquatic products would continuously go up. Aquatic processing has initially formed a standard system. It drew a conclusion that it would be a good opportunity for China＇s aquatic processing industry in the future

Determination of Selenium in Marine Aquatic Products by Hydride Generation-atomic Fluorescence Spectrometry (HG-AFS)

A method for the analysis of selenium in marine aquatic products by HG-AFS has been investigated. The method is based on the reduction of inorganic selenium to volatile SeH2 which is bubbled out by carrier gas of pure argon, and then swept to Ar-H2 flame quarts atomizer to measure its fluorescence intensity. The hydride generation, transportation, atomization and some instrumental parameters were studied by a kind of orthogonal design. The optimum conditions selected are as follows： reactive acidity, 20% HC1; the amount of NaBH4, 4.9mL; gas flow of argon, 600mLmin^-1; atomizing temperature, 200 ℃ ; negative high voltage, - 300V; light current, 100 mA; integral time, 7s. The detection limit of the presented method is 0.072μgL^-1 for selenium. The calibration curve shows a satisfactory line inthe concentration range from 0.000 to 1.000μgL^-1 Se. The recovery is 95.8%-102.2%.

Accumulation Characteristics and Safety Evaluation of Heavy Metals in Four Kinds of Aquatic Products from Lake Taihu

In order to investigate the current status of heavy metals pollution and food safety of aquatic products from Lake Taihu,atomic absorption spectrophotometry( AAS) was used to determine the contents of Pb,Cd,Cu,and Zn in the head,muscle and viscera of farmed and wild aquatic products. The results showed that the distribution patterns of heavy metals in different parts of aquatic products were quite different. Heavy metals were mainly distributed in the head and viscera of all investigated aquatic products except wild Carassius auratus. The contents of heavy metals in each part of aquatic products generally decreased in the following order: Zn > Cu > Pb > Cd. The levels of heavy metals pollution in the muscle tissue of farmed and wild aquatic products were different,with higher levels being found in the muscle tissue of wild aquatic products. Furthermore,the content of each heavy metal in muscle tissue was also different among different kinds of aquatic products,with both farmed and wild Metapenaeus ensis having the strongest Cu accumulation capacity while wild C. auratus having the strongest Zn accumulation capacity. The heavy metals pollution in the muscle tissue of aquatic products from Lake Taihu was generally at unpolluted to minor pollution level,and only a few of them were seriously polluted with heavy metals. The main pollution factors were Pb and Zn.

Hunan Yahua Aquatic Product Co., Ltd.

Hunan Yahua Aquatic Product Co., Ltd. is a professional aquatic product processing enterprise, an independence legal person under the listed company - Hunan Yahua Seeds Share Holding Co., Ltd.. Conveniently located at Yiyang City of Hunan Province, the company is by the Dongting Lake, in the north of Shichang Railway, in the east of Changchang High Way and in the

Study on the Influencing Factors of the Aquatic Products Consumption in China

In this paper, an econometric model for the aquatic products consumption of urban residents was established, aiming at investigating the different effects of seven factors （urban residents＇ annual disposable income, annual consumption quantity of pork and poultry and related byproducts, family structure, aging level, educational background, having meals out of home, and the number of retail chains stores） on the aquatic products consumption quantity of urban residents. The result of the model showed urban residents＇ annual disposable income and having meals out of home play the greatest effect on the consumption of aquatic products, followed by the number of retail chains stores; family structure plays a negative effect on the consumption of aquatic products. Also, the analysis shows not only the prices of the aquatic products as well as substitutes should be considered and also the quantity of the meals consumed by residents out of home and the number of retail chains stores should be used as important associated factors in studying the change trend of aquatic products consumption, and simultaneously the effect of family structure on the consumption quantity of aquatic products should be taken seriously, so that the aquatic products consumption of Chinese residents should be further promoted and also the aquatic products market can attain a development.

High Efficient Extraction of Phthalates in Aquatic Products by a Modified QuEChERS Method

A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-MS）. When this method was adopted, samples were pretreated by modified QuEChERS（quick, easy, cheap, effective, rugged and safe） method. An environmentally friendly extractant（ethanol aqueous solution） replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin（BSA） with phthalates show that there was a high-affinity interaction between phthalate and protein, de- creasing the extraction efficiency of phthalates from fish samples. However, in the 80%（volume fraction, ~） ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in ^（ethanol） 80% aqueous solution than in either ~p（ethanol） 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the puri- fication steps were greatly simplified. Overall recoveries were 81.77%--90.5% with limits of detection between 2.53 and 9.61 ~tg/L, and relative standard deviation values at 1.15%---4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.

Multiresidue determination and potential risks of emerging pesticides in aquatic products from Northeast China by LC-MS/MS

A simple method for determining 33 pesticides with a wide polarity range（log Kow0.6-4.5） in aquatic products was developed based on LC–MS/MS. The target analytes included three types of widely used pesticides： insecticides, fungicides and herbicides. Based on the optimization of ultrasonic assisted extraction and GPC clean-up procedures, the matrix effect, extraction recoveries and LOD were improved distinctively. LOQ of this method was below 0.5 ng/g for all pesticides, which is superior to values in the literature, and the matrix effect was reduced effectively（-14.7% to 7.5%）. The method was successfully applied to investigate the pesticide residue levels of twenty-five samples including seven common kinds of fishes from Northeast China. The results showed that all targeted pesticides were present in the fish samples; however, their levels were low, except for atrazine, linuron,ethoprophos, tetrachlorvinphos, acetochlor and fenthion. Atrazine and linuron caught our attention because the concentrations of atrazine in fish samples from Liaoning province were in the range of 0.5-8 ng/g（w/w） with mean concentration of 2.3 ng/g, which were far above those of other pesticides. The levels of linuron were in the range of 0.6-6 ng/g（mean concentration 2.8 ng/g）, which were the highest among all targeted pesticides in the Inner Mongolia. This is the first systematic investigation on the characteristics and levels of these pesticides in aquatic products from northeast China. Considering their toxicity and bioaccumulation, the potential risk of atrazine and linuron from consuming aquatic products should be paid more attention.

Research on ＂Intemet ＋ Fishery＂ Drop-shipping Model

The development ofinternet technology makes the aquatic products retailers change their traditional intermediary function in succession, and improve the information flow in the market relying on internet technology. This text aims to discuss the feasibility of adoption of drop-shipping model by the aquatic products e-retailers under ＂Internet ＋＂ and its influence factors, and provide the aquatic products e-retailers with relevant advices and suggestions on adoption of drop-shipping model.

A statistical analysis of China's fisheries in the 12th five-year period

This paper reviews the status and development of China's fisheries in the 12th five-year period using data from FAO,China Fishery Statistics Yearbooks,China Statistical Yearbooks and other sources.The main observations are as follows:in the 12th five-year period,China's aquatic products accounted for more than 35%of global aquatic production;China's aquaculture products accounted for more than 60%of global aquaculture production;in freshwater aquaculture,pond aquaculture accounted for about 70%of the national freshwater aquaculture production,and fish products were proportionally higher than others;in mariculture,bottom sowing and raft culturing products accounted for more than 50%of total marine aquaculture production and shellfish production was proportionally higher than others.There has been only a slow rise in capture production of wild fish over the same period.The freshwater catches from four provinces including Jiangsu accounted for half of the country's total freshwater catches,in which fish catches accounted for more than 70%.Marine capture production from four provinces including Zhejiang accounted for about 80%of the country's marine catches,in which fish catches accounted for more than 70%.There was an overall growth in production of processed aquatic products,particularly frozen aquatic products,surimi-based products and dry-cured products which together accounted for more than 80%processed seafood products.The average annual net income of fishermen per capita witnessed a growth of 11.71%,outpacing the GDP growth over the same period.With the rapid development of China's fisheries,there are also challenges such as overcapacity,low aquaculture product quality,resource overexploitation,as well as environmental problems.A change in approach,transformation and structure adjustment are suggested to reshape China's fisheries development model and to achieve the goal of sustainable development.

A review on source,occurrence,and impacts of microplastics in freshwater aquaculture systems in China

Microplastic pollution has become an increasingly important environmental issue worldwide in recent years because of its ubiquitous presence in different environmental media and its potential to affect the health of organisms and ecosystems.Aquaculture contributes significantly to the world's food production and nutritional supply,especially in developing countries.Widespread occurrence of microplastics in aquaculture systems has raised great concern regarding aquaculture production and food safety issues of aquaculture products.China is a world leader in aquaculture production,with freshwater aquaculture accounting for 59.1%of total aquaculture production of the world in 2020.Therefore,this review mainly focuses on recent research progress related to microplastic pollution in freshwater aquaculture systems in China.Results from the literature show that microplastics are present in freshwater aquaculture systems at abundances comparable to natural waterbodies in China.Microplastics can be ingested and remain in the body of aquaculture products.Exposure to microplastics can adversely affect the health of aquatic organisms and aquatic ecosystem functions.However,risks of microplastics in real world environment remain uncertain.Consumption of freshwater aquaculture products is not a major pathway for human exposure to microplastics.To provide scientific guidance for governmental decision-making and pollution control,future work should focus on progress in toxicological methodology and understanding the impacts of microplastics at community and ecosystem levels.