Aquatic Products Research Articles

Perchlorate and chlorate in aquatic products from Shenzhen, China, and their implications for human exposure

Perchlorate and chlorate are chemically stable species with high solubility and are widely distributed in various foods. Dietary intake is considered to be the main route of human exposure to these chemicals. Aquatic products are an important component of residents' daily diets. However, there is still a lack of a complete research report on perchlorate and chlorate contamination in aquatic products. Thus, this study investigated the concentration of perchlorate and chlorate in shellfish, freshwater fish, freshwater shrimp, sea fish, and sea shrimp from Shenzhen and assessed human exposure risks. The detection frequency of chlorate was low, and the incidence of perchlorate was significantly lower than previous studies, demonstrating a substantial reduction in perchlorate contamination in Shenzhen waters. However, certain samples exhibited relatively elevated concentrations. The highest concentration of chlorate (43.1 µg kg−1) and perchlorate (14,865 µg kg−1) were both found in sea shrimp. Notably, the 95th percentile estimated daily intake (EDI) value of perchlorate derived from sea shrimp and shellfish surpassed the reference dose (RfD), while the EDI values of chlorate were all below the RfD. Therefore, Shenzhen residents are advised to consume sea shrimp and shellfish with caution to minimize the possible health risks linked to perchlorate and chlorate exposure.

Elevated CO2 exacerbates the risk of methylmercury exposure in consuming aquatic products: Evidence from a complex paddy wetland ecosystem

Elevated CO2 levels and methylmercury (MeHg) pollution are important environmental issues faced across the globe. However, the impact of elevated CO2 on MeHg production and its biological utilization remains to be fully understood, particularly in realistic complex systems with biotic interactions. Here, a complete paddy wetland microcosm, namely, the rice-fish-snail co-culture system, was constructed to investigate the impacts of elevated CO2 (600 ppm) on MeHg formation, bioaccumulation, and possible health risks, in multiple environmental and biological media. The results revealed that elevated CO2 significantly increased MeHg concentrations in the overlying water, periphyton, snails and fish, by 135.5%, 66.9%, 45.5%, and 52.1%, respectively. A high MeHg concentration in periphyton, the main diet of snails and fish, was the key factor influencing the enhanced MeHg in aquatic products. Furthermore, elevated CO2 alleviated the carbon limitation in the overlying water and proliferated green algae, with subsequent changes in physico-chemical properties and nutrient concentrations in the overlying water. More algal-derived organic matter promoted an enriched abundance of Archaea-hgcA and Deltaproteobacteria-hgcA genes. This consequently increased the MeHg in the overlying water and food chain. However, MeHg concentrations in rice and soil did not increase under elevated CO2, nor did hgcA gene abundance in soil. The results reveal that elevated CO2 exacerbated the risk of MeHg intake from aquatic products in paddy wetland, indicating an intensified MeHg threat under future elevated CO2 levels.

A novel enrichment and sensitive method for rapid determination of 4 sulfonamide antibiotics residues in fish

Sulfonamide antibiotics with superior performance are widely used in aquaculture. However, the residues of sulfonamide antibiotics in aquatic products may pose a threat to human health. In this work, a novel type of magnetic molecularly imprinted polymer (mMIP) was synthesized and coupled with ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) for the selective separation and determination of 4 sulfonamide antibiotics residues in tilapia. The structure and adsorption properties of the polymers were characterized and evaluated. The key mMIP variables were investigated to determine the optimal magnetic solid phase extraction conditions. Results showed that the mMIPs had saturated adsorption capacities of 137.4, 78.7, 65.2, and 58.4 mg/g for trimethoprim, sulfadiazine, sulfamethazine, and sulfamethoxazole, respectively. Under optimized conditions, the linear range of the method for the detection of the 4 sulfonamides was 0.1–100 ng mL−1 (R > 0.991), the detection limit was 0.015 μg kg−1 (S/N = 3), the recovery rate was 78.6–101%, and the relative standard deviation (RSD%) was 4.2–7.8%. This new rapid and ultra-sensitive pretreatment method was successfully applied to the monitoring of trace sulfonamide antibiotics residues in fish samples.

Improving the microbiological safety and quality of aquatic products using nonthermal processing.

Spoilage and deterioration of aquatic products during storage are inevitable, posing significant challenges to their suitability for consumption and the sustainability of the aquatic products supply chain. Research on the nonthermal processing of fruit juices, probiotics, dairy products, and meat has demonstrated positive outcomes in preserving quality. This review examines specific spoilage bacteria species and mechanisms for various aquatic products and discusses the principles, characteristics, and applications of six nonthermal processing methods for bacterial inhibition to maintain microbiological safety and physicochemical quality. The primary spoilage bacteria groups differ among fish, crustaceans, and shellfish based on storage conditions and durations. Four metabolic pathways utilized by spoilage microorganisms-peptides and amino acids, nitrogen compounds, nucleotides, and carbohydrates-are crucial in explaining spoilage. Nonthermal processing techniques, such as ultrahigh pressure, irradiation, magnetic/electric fields, plasma, and ultrasound, can inactivate microorganisms, thereby enhancing microbiological safety, physicochemical quality, and shelf life. Future research may integrate nonthermal processing with other technologies (e.g., modified atmosphere packaging and omics) to elucidate mechanisms of spoilage and improve the storage quality of aquatic products.

Composition of Stream Dissolved Organic Matter Across Canadian Forested Ecozones Varies in Three Dimensions Linked to Landscape and Climate

AbstractDissolved organic matter (DOM) is a key variable influencing aquatic ecosystem processes. The concentration and composition of DOM in streams depend on both the delivery of DOM from terrestrial sources and on aquatic DOM production and degradation. However, there is limited understanding of the variability of stream DOM composition at continental scales and the influence of landscape characteristics and disturbances on DOM across different regions. We assessed DOM composition in 52 streams at seven research sites across six forested ecozones in Canada in 2019–2022 using 26 indices derived from five analytical approaches: absorbance and fluorescence spectroscopy, liquid chromatography—organic carbon detection, Fourier‐transform ion cyclotron resonance mass spectrometry, and asymmetric flow field‐flow fractionation. Combined analyses showed clear clustering and redundancy across analytical techniques, and indicated that compositional variations were primarily related to three axes of DOM composition: (a) aromaticity, which was greater in low‐relief, wetland‐dominated catchments, (b) oxygenation, which was greater in colder and drier ecozones, and (c) biopolymer content, which was greater in lake‐influenced catchments. Variability in DOM composition among research sites was greater than variability of streams within a site and variability over time within a stream. Forest harvesting and wildfire disturbances had no common influence on DOM composition across research sites, emphasizing the need for regional studies. Our study provides a broad understanding of the variability of stream DOM composition and its associations with landscape and catchment characteristics at a subcontinental scale, and provides key insights for the choice and interpretation of DOM indices from various analytical approaches.

Microwave synthesized novel biomass carbon dots applied in the fluorescent detection of crystal violet.

To establish a new method for detecting crystal violet (CV), a harmful dye, herein, a genre of novel biomass carbon dots (CDs) was synthesized via a microwave method and employed as a fluorescent probe, in which water spinach and polyethylene glycol (PEG) performed as raw materials. Based on the inner filter effect (IFE) between the luminescent CDs and CV, the blue emission of this probe at 430 nm could be quenched by CV. Hence, a new strategy was proposed to selectively determine CV in aquaculture ambient. Moreover, under the optimal experiment conditions, this method showed a good linearity between the concentration of CV (c) and fluorescence quenching rate (ΔF/F0) in the concentration range of 4-200 μmol/L with the corresponding correlation coefficient (r) and the detection limit of 0.997 and 710 nmol/L, respectively. With advantages of environmental protectivity, sensitivity, affordability, and user-friendliness, the facilely fabricated CDs could be successfully applied in detecting CV in aquaculture samples, providing a technical foundation for monitoring the pollution of CV and ensuring the quality and safety of aquatic products.

Growth and Genome Features of Non-O1/O139 Vibrio cholerae Isolated from Three Species of Common Freshwater Fish

Vibrio cholerae is the etiological agent of cholera in humans. The bacterium is frequently detected in aquatic products worldwide. However, the current literature on the genome evolution of V. cholerae of aquatic animal origins is limited. Here, we firstly characterized the growth and genome features of V. cholerae isolates with different resistance phenotypes from three species of common freshwater fish. The results revealed that the non-O1/O139 V. cholerae isolates (n = 4) were halophilic and grew optimally at 2% NaCl and pH 8.0. Their draft genome sequences were 3.89 Mb–4.15 Mb with an average GC content of 47.35–47.63%. Approximately 3366–3561 genes were predicted to encode proteins, but 14.9–17.3% of them were of an unknown function. A number of strain-specific genes (n = 221–311) were found in the four V. cholerae isolates, 3 of which belonged to none of any of the known sequence types (STs). Several putative mobile genetic elements (MGEs) existed in the V. cholerae isolates, including genomic islands (n = 4–9), prophages (n = 0–3), integrons (n = 1–1), and insertion sequences (n = 0–3). Notably, CRISPR-Cas system arrays (n = 2–10) were found in the V. cholerae genomes, whereby the potential immunity defense system could be active. Comparative genomic analyses also revealed many putative virulence-associated genes (n = 106–122) and antibiotic resistance-related genes (n = 6–9). Overall, the results of this study demonstrate the bacterial broader-spectrum growth traits and fill prior gaps in the genomes of V. cholerae originating from freshwater fish.

The Impact of Caregiver Pressure to Eat on Food Neophobia in Children with Autism Spectrum Disorder: A Cross-Sectional Study.

(1) Background: With autistic children's high pervasiveness of eating problems and inappropriate feeding behaviors by their caregivers, this study wanted to inspect the connection between caregivers' pressure to eat and food neophobia in these children. (2) Methods: Cross-sectional overview of 160 guardians of kids aged 2 to 7 years. After one-on-one questioning by the researcher, the collected information on the socio-demographic characteristics of the children with autism, caregiver feeding behavior, and new food neophobia (FN) scores was entered into the Questionnaire Star system. (3) Results: The mean FN score was 25.56 ± 6.46. The caregiver's pressure to eat positively related to children's FN (β = 0.164 95% CI, 0.078, 2.163). In these children, we found a negative correlation between FN score and the frequency of vegetable intake (p ≤ 0.001), fruit intake (p ≤ 0.05), aquatic product intake (p ≤ 0.05), and dietary diversity score (p ≤ 0.01), and positively correlated with the frequency of snack intake (p ≤ 0.05). (4) Conclusions: Caregiver pressure to eat was positively associated with high levels of FN in Chinese kids with ASD, which in turn negatively impacted dietary quality. To improve eating habits, caregivers should reconsider their feeding strategies and avoid using forceful methods to ease food neophobia in these children.

The tracement of origins of aquatic products by characterization of their gut or gill microbiome via MALDI-TOF MS analysis

Tracement of the origin of seafoods and aquatic products is an important issue for avoiding the falsification of production regions of aquatic products. Herein, by analyzing black tiger shrimp (Penaeusmonodon) as a model of aquatic products, we demonstrated a method to trace the origin of aquatic products by analyzing the gut microbiome of black tiger shrimp (Penaeusmonodon) collected from three commercial farms in China, via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Multivariate analysis was executed on the obtained mass spectrometric datasets of bacteria extracted and collected from shrimp samples with different production regions. The gut microorganisms of black tiger shrimps can be identified by scoring the gut microbiota of black tiger shrimps collected from three producing areas. The black tiger shrimp from three production regions were found with distinguished characteristics of bacterial prevalence in their digestive gland microbiota. The dominant bacteria genus in digestive gland microbiota from black tiger shrimp samples from the three production regions are completely different. Single-blind shrimp samples with unknown production region was successfully screened by comparing the detected MS data in different ways. This strategy can trace the production region of the analyzed shrimp samples in a quick and efficient mode. The application of the present protocol was further demonstrated by analyzing the biometric species from gill tissue of Chinese mitten crab (Eriocheir sinensis) samples collected from crab-producing areas in Jiangsu Province (China), that is, Taihu Lake, Gaoyou Lake, and Hongze Lake for tracing their production area. It is expected to extend the presently developed method to provide clues for the origin traceability of other aquatic products.

β-Sitosterol Reduces the Content of Triglyceride and Cholesterol in a High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease Zebrafish (Danio rerio) Model.

Non-alcoholic fatty liver disease (NAFLD) is strongly associated with hyperlipidemia, which is closely related to high levels of sugar and fat. β-sitosterol is a natural product with significant hypolipidemic and cholesterol-lowering effects. However, the underlying mechanism of its action on aquatic products is not completely understood. A high-fat diet (HFD)-induced NAFLD zebrafish model was successfully established, and the anti-hyperlipidemic effect and potential mechanism of β-sitosterol were studied using oil red O staining, filipin staining, and lipid metabolomics. β-sitosterol significantly reduced the accumulation of triglyceride, glucose, and cholesterol in the zebrafish model. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that differential lipid molecules in β-sitosterol mainly regulated the lipid metabolism and signal transduction function of the zebrafish model. β-sitosterol mainly affected steroid biosynthesis and steroid hormone biosynthesis in the zebrafish model. Compared with the HFD group, the addition of 500 mg/100 g of β-sitosterol significantly inhibited the expression of Ppar-γ and Rxr-α in the zebrafish model by at least 50% and 25%, respectively. β-sitosterol can reduce lipid accumulation in the zebrafish model of NAFLD by regulating lipid metabolism and signal transduction and inhibiting adipogenesis and lipid storage.

Ecological response to global changes in Lake Genco, a remote alpine lake on the Southeast Tibetan Plateau, over the past two centuries

The ways in which natural ecosystems respond to global change have become an urgent concern to society. Lakes play a pivotal role in ecosystem changes because of their central position within watersheds and their involvement in various endogenous and cross-system ecological and biogeochemical processes, leaving natural archives accumulated in sediments over time. However, how lake ecosystems have responded to atmospheric changes during the past few centuries is still not fully understood. To analyse the process in more detail, we conducted a case study at Lake Genco, a remote alpine on the southeastern Qinghai-Tibetan Plateau (QTP) and recovered a 170-year history of lake's ecosystem from a 210Pb-dated sediment core. The air temperature increased between 1900 and 1950 CE and 1980 and 2020 CE. Geochemical and physical proxies (magnetic susceptibility, Sr/Ba, K/Al, Na/Al, Ti, Pb, P flux, TN and δ15Norg) indicated greater degrees of weathering and erosion, and higher nutrient loadings as terrestrial systems responded to atmospheric changes after 1900 CE. Higher primary aquatic productivity, richer biodiversity and weaker structural stability were found in Lake Genco between 1852 and 2017 CE, although the ecological response was quiet in terms of the compositional change in the diatom community, which was generally dominated by small planktonic Cyclotella ocellata. During warmer periods, diatom PC1 changed directionally due to the overall increase in the abundance of tychoplanktonic Fragilaria construens and periphytic Achnanthes minutissima and the decreasing abundance (∼10%) of C. ocellata. This study provides empirical evidence that ecological changes in remote lakes rely on interactions between the atmosphere and the landscape and helps us to understand the complexity of the various impacts of global climate change. More local and regional studies are needed to generalise the mechanism of biological responses to atmospheric changes in remote lakes, especially in the QTP.

Climate impacts and adaptation strategies for coastal erosion, aquaculture, and tourism along the Adriatic side of Apulia region

This study addresses the imperative need for adaptation strategies to climate impacts in coastal areas, particularly vulnerable to climate change effects. Under the Interreg project “AdriaClim,” our research aims to provide a comprehensive account of predicted climate impacts and corresponding adaptation measures for three key sectors for the coastal economy of the Puglia region (Southern Italy): coastal erosion, aquaculture, and tourism. Analyzing regional climate projections, predicted climatic anomalies for Apulia have been delineated. Together with a comprehensive description of the investigated sectors, the expected sectoral climate impacts have been identified. The respective adaptation measures for each sector have been evaluated in terms of coherence with the studied context and effectiveness, among those proposed in the literature. In aquaculture, climate change may influence ecosystem structure, functionality, production cycles, infrastructure, and organism physiology. Integrated multitrophic aquaculture (IMTA) emerges as a solution to enhance the resilience of Apulian aquatic production systems to climate change. For coastal tourism, the vulnerability to various climate impacts is emphasized. These impacts can directly influence tourist flows or indirectly alter the attractiveness of the Apulian Adriatic coast. Given the sector's strong ties to anthropic, natural, and cultural elements, a comprehensive adaptive approach proves most effective. Concerning coastal erosion, results underscore the prevalence of numerous stretches of eroding low coastline, with future projections indicating scenarios of widespread retreat along the southern Adriatic coast. Consequently, protective, and coastal management measures become imperative. The analyses and the obtained results serves as a valuable knowledge framework essential for formulating a climate change adaptation plan for the Apulian Adriatic coast, aligning with the regional authorities' orientations.

A smartphone-assisted sensing hydrogels based on UCNPs@SiO2-phenol red nanoprobes for detecting the pH of aquatic products

For some aquatic products, pH has been considered a useful index to reflect the changes in materials during the loss of freshness. Based on the inner filter effect (IFE) between deprotonated phenol red (PR) and upconversion nanoparticles (UCNPs), UCNPs coated with PR-doped SiO2 shell were embedded in agarose hydrogel to develop a smartphone-assisted method for pH sensing. With the enhancement of pH response using a phase transfer agent (i.e., tetra butyl ammonium hydroxide, TBAH), the proposed senor realized the colorimetric and fluorescence detection of pH in the range of pH 6.6–8 and pH 6–8, respectively. The sensor also showed satisfied reversibility when switched between pH 6 and 8 for at least 5 cycles. Moreover, this sensor displayed great sensitivity, stability, and portability in analyzing actual fish, shrimp, and shellfish samples, providing a new sight for evaluating the freshness of aquatic products.

A three-mode biosensor for hypoxanthine assay in aquatic products under various storage conditions

Establishing a rapid and accurate method for monitoring the freshness of aquatic products is of great importance. Hypoxanthine has been considered an essential indicator of aquatic products’ freshness. Here, a novel smartphone colorimetric / inductively coupled plasma mass spectrometry (ICP-MS) / photothermal three-mode sensing strategy was established for monitoring hypoxanthine. Hypoxanthine can be catalyzed by xanthine oxidase to H2O2 and uric acid, which can simultaneously degrade MnO2 nanosheets (NSs) to Mn2+. After filter-assisted separation, the smartphone and ICP-MS were performed by monitoring the color of the membrane and the Mn2+ in the filtrate. Additionally, MnO2 NSs can facilitate the oxidation of dopamine to form polydopamine nanoparticles, which exhibit strong photothermal efficiency. The approach successfully monitored the deterioration of aquatic products under various storage conditions through portable thermometers and smartphones with low limits of detection (LODs), providing a potential application for in-situ evaluation of the freshness of aquatic products.

Contamination of Food Products by Listeria monocytogenes in Iran during 2010-2023

Introduction: Mortality rate of Listeria infection is high and has been reported to be up to 30%. In this regard, the present study aimed to provide more information about food sources contaminated with the Listeria monocytogenes and offer suitable strategies to control this pathogen in supply centers, slaughterhouses, and processing centers. Method: Results of investigations on the prevalence of L. monocytogenes in food (seafood and aquatic products, red meat, poultry, and dairy products) during 2010-2023 were reviewed. In total, 61 acceptable studies were involved in the present research. After the selection of papers, their key results were extracted, including the prevalence of Listeria monocytogenes, cultivation method, sample type, and sampling location. Results: Listeria monocytogenes is prevalent in all types of seafood products, red meat, poultry, dairy products, and vegetables, as well as ready-to-eat and ready-to-cook foods. Consuming raw and undercooked foods contaminated with animal and human feces and direct contact with feces can cause Listeria infection in humans. L. monocytogenes is sensitive to amoxicillin, ampicillin, penicillin, and gentamicin antibiotics; therefore, these antibiotics can be used for listeriosis treatment. Conclusion: In previous studies, the importance of traditional meat and dairy supply centers in L. monocytogenes transmission has been addressed to a lesser extent. It can be concluded that appropriate standards should be developed and applied to control this food pathogen by regulatory systems. In addition, regular and periodic monitoring of food products and providing necessary training to people about how to prevent food poisoning can play an effective role in reducing listeriosis.

Correlations of dynamic changes in lipid and protein of salted large yellow croaker during storage

Protein and lipid are two major components that undergo significant changes during processing of aquatic products. This study focused on the protein oxidation, protein conformational states, lipid oxidation and lipid molecule profiling of salted large yellow croaker during storage, and their correlations were investigated. The degree of oxidation of protein and lipid was time-dependent, leading to an increase in carbonyl content and surface hydrophobicity, a decrease in sulfhydryl groups, and an increase in conjugated diene, peroxide value and thiobarbituric acid reactive substances value. Oxidation caused protein structure denaturation and aggregation during storage. Lipid composition and content changed dynamically, with polyunsaturated phosphatidylcholine (PC) was preferentially oxidized compared to polyunsaturated triacylglycerol. Correlation analysis showed that the degradation of polyunsaturated key differential lipids (PC 18:2_20:5, PC 16:0_22:6, PC 16:0_20:5, etc.) was closely related to the oxidation of protein and lipid. The changes in protein conformation and the peroxidation of polyunsaturated lipids mutually promote each other’s oxidation process.

Bimetallic Au and Pd Nanoparticles Modified WO3 Nanosheets for Enhancing the Sensitivity and Selectivity of Formaldehyde Assessment in Aquatic Products.

Formaldehyde, a common illegal additive in aquatic products, poses a threat to people's health and lives. In this study, a novel metal oxide semiconductor gas sensor based on AuPd-modified WO3 nanosheets (NSs) had been developed for the highly efficient detection of formaldehyde. WO3 NS modified with 2.0% AuPd nanoparticles showed a higher response (Ra/Rg = 94.2) to 50 ppm of formaldehyde at 210 °C, which was 36 times more than the pristine WO3 NS. In addition, the AuPd/WO3 gas sensor had a relatively short response/recovery time of 10 s/9 s for 50 ppm of formaldehyde at 210 °C, with good immunity to other interfering gases and good stability for formaldehyde. The excellent gas-sensitive performance was attributed to the chemical sensitization of Au, the electronic sensitization of Pd, and the synergistic effect of bimetallic AuPd, which facilitated the recognition and response of formaldehyde molecules. Additionally, the high sensitivity and broad application prospect of the 2.0% AuPd/WO3 NS composite-based sensor in real sample detection were also confirmed by using the above sensor for the detection of formaldehyde in aquatic products such as squid and shrimp.

Organophosphate esters and their metabolites in marine fish from Vietnam: Analytical method development and validation

Organophosphate esters (tri-OPEs), which are a significant group of emerging organic pollutants, have been widely found in aquatic products worldwide. While tri-OPEs have been extensively detected in aquatic products and are known to represent potential risks to human health, there is limited information available regarding their metabolites (di-OPEs). Currently, the techniques for analyzing the composition of tri- and di-OPEs have been distinguished and have certain drawbacks in terms of their expense, time requirements, and reliability. The objective of the study is to develop, validate, and utilize a modified QuEChERS technique for extracting tri- and di-OPEs in marine fish. As a result, EMR-Lipid and WAX were selected as adsorbents for the QuEChERS method to purify the samples and a combination of centrifugal vacuum and nitrogen at a temperature of 1 °C was selected as a technique to enhance the sensitivity of the developed method. The parameters of the method validation are in accordance with the criteria specified in SANTE/11312/2021 (a recovery ranging from 84.0% to 107.4% and RSD of precision below 20%). The aforementioned methodology was employed to assess the tri-OPEs and their metabolites in a total of 72 fish muscle samples obtained from the presence of OPEs in all recorded instances. The average concentration of ΣOPEs was determined to be 87.4±55.0 ng/g dw, with TBOEP and BEHP identified as the predominant compounds. Furthermore, no significant variation in the content of tri- and di-OPEs was observed in fish samples, regardless of species or geographical location.

Study on the applicability of novel molecular targets of Vibrio species by pan-genome mining in the field of nucleic acid detection

Vibrio spp. are ubiquitous in marine areas worldwide and can cause diseases in humans. Aqueous environments favor the transfer of genes between strains, resulting in the loss of strain-specific target genes. This study aimed to explore new molecular targets for the detection of Vibrio strains at the species level using pan-genome analysis for nucleic acid detection and differentiation of major pathogenic Vibrio in aquatic products. Pan-genome analysis and PCR validation revealed a total of 10 specific targets: three for Vibrio parahaemolyticus, one for Vibrio alginolyticus, three for Vibrio vulnificus, three for Vibrio fluvialis. We constructed primers for the selected genes, and we verified their specificity using various Vibrio species and non-Vibrio strains. After systematic optimization, a novel molecular target-based 4-multiplex PCR (4-mPCR) method was developed, exhibiting a detection limit of 103 CFU/mL for pure cultures and 104 CFU/g for fish samples. The initial inoculum was approximately 1 Log10 CFU/g, and all samples were positive after 4 h of enrichment. Not only that, the feasibility of the mined new targets in the field of nucleic acid detection was further validated by the 4-mqPCR and LAMP techniques. These results suggest that novel targets mined by pan-genomic have good generalizability for use in a variety of nucleic acid detection techniques and can help improve the accuracy of nucleic acid-based detection techniques in the detection of pathogenic Vibrio species in aquatic samples, with potential applications for food safety investigations and disease diagnosis.

The impact of pressure-shift freezing on the three-dimensional network structure and properties of myofibrillar proteins in surimi gel derived from freshwater fish

Freezing treatment can prolong the shelf life of surimi products, but it will lead to deterioration of surimi gel quality. This study compared the effects of three different processing methods — non-freezing processing (control), conventional air freezing (CAF), and pressure-shift freezing (PSF) — on the three-dimensional (3D) network structure of grass carp surimi gel. After PSF treatment, the pores in the 3D gel network structure were denser compared to the control group which facilitates interaction of water and network structure. Furthermore, the ultraviolet and fluorescence spectral analysis indicated that PSF treatment mitigates the decline in stability of the tertiary structure of myofibrillar protein (MP) during freezing. The microstructure of MP showed that PSF treatment promotes the cross-linking of MP to form protein aggregates and then promotes the gelation of MP. Industrial relevancePSF can increase the commodity value of low-value freshwater fish products and has potential in the development of new products of surimi gels. This study reported a novel idea and theoretical basis for the application of PSF technology in the frozen food and aquatic product processing industry.