Aquatic Products Research Articles

Effect of atmospheric cold plasma treatment on the flavor of high-fat aquatic products: A case study of golden pomfret (Trachinotus ovatus, family Bramidae) oil using GC-MS, GC-IMS, and an E-nose

This study examines the effects of atmospheric cold plasma (AP) treatment on golden pomfret oil, particularly its physicochemical properties and flavor compounds. Volatile flavor compounds in the golden pomfret fish oil were investigated following AP treatment and cold storage for 30 d using gas chromatography-mass spectrometry, gas chromatography-ion mobility mass spectrometry, and an electronic nose. The relative odor activity values revealed that certain molecules, including pentane, tridecane, styrene, methyl palmitate, benzyl benzoate, 1-methyl-2-pyrrolidinone, and oleic acid, were potential markers for distinguishing between the aromas at fresh group, 30 d of storage, and 30 d of AP storage. The content of volatile compounds changed during low-temperature refrigeration. AP treatment was a protective measure against flavor changes during storage. This information can aid in exploring the formation mechanism of the characteristic odor of AP-treated golden pomfret oil and its related metabolic pathways.

A lanthanide luminescent sensor doped polymer dots for ratiometric fluorescence detection of hydrogen sulfide

As one of the indexes of food freshness, hydrogen sulfide content is closely related to food spoilage. A dual-emission sensor for H2S detection was reported in this paper. Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] Polymer dots (MEH-PPV-Pdots) were prepared by copolymer of poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and styrene-maleic anhydride. The sensor was obtained by embedding purple MEH-PPV-Pdots in a green MOF. The accommodated MEH-PPV-Pdots were considered as the reference signal, while copper ions on the host skeleton served as accessible reaction sites, allowing MEH-PPV-Pdots/Tb0.99Cu0.01-MOF to selectively sense H2S. The sensor exhibited reduced green fluorescence and proportional response to H2S. Because H2S can transfer charge on copper ions and thus affect the green light emitted by rare earth ions. The results showed that the sensor had good stability to H2S in HEPES buffer, fast response, obvious color change, high selectivity and sensitivity. The sensor has been applied to the detection of aquatic products, showing good visualization effect.

Occurrence of organophosphate flame retardants in agricultural products from Korean markets

Organophosphate flame retardants (OPFRs) are widely used in various products encountered in daily life including home appliances, furniture, and plastics. This study developed a method to determine the presence of 11 OPFRs in agricultural products to monitor OPFR contamination in Korean local markets. The method was based on QuEChERS extraction with liquid chromatography-tandem mass spectrometry using gradient elution with a run time of 13 min. The selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery, and precision of developed method were validated based on the CODEX guidelines. The LOD values for 11 OPFRs ranged from 0.05 to 0.66 ng/g, which were comparable to the values obtained in previous studies. The established method was successfully applied to agricultural products collected in a Korean market. A 32 product types with seven replicates (total 224 samples) were monitored for OPFR contamination. These products included popular fruits and vegetables in Korea such as apples, cucumber, corn, etc. The agricultural products with the highest average of total OPFR concentration was eggplants (12.50 ng/g ww), and the OPFR types with the highest average concentration across all tested agricultural products was tris (1-chloropropan-2-yl) phosphate (TCIPP), with an average value of 1.48 ng/g. The estimated daily intake values were much lower than the reference dose values of OPFRs, which showed that exposure to OPFRs through agricultural products is generally safe. The results of this study could be used as the basis for expanding monitoring of OPFRs to aquatic and meat products, and will also be helpful in informing industries about the current risk of OPFR contamination.

Assessment of fish health status for waterless transportation based on image features and deep learning models

In the current aquaculture industry, the detection of physiological stress indicators in fish during waterless transportation is considered to be an effective method to monitor their health status. However, commonly used detection methods are invasive and interfere with the accuracy of detection results. In order to solve this problem, this study takes grouper as an example, combines multi-sensor physiological stress indicators monitoring, and designs a health status assessment and classification model based on image features and deep learning models, which inputs real-time fish image feature information data acquired during low-temperature waterless transportation into the optimised CNN-BiGRU classification model based on whale optimisation algorithm (WOA) proposed in this study, so as to achieve an accurate assessment of the health status of the fish. By inputting the image feature datasets based on time series and classified into the WOA-CNN-BiGRU, BiGRU, and GRU classification models for training, validation, and testing, respectively, the effectiveness of the classification performance of the models was verified by using accuracy, precision, recall and F1-value composite scores as the metrics. It was found that the WOA-CNN-BiGRU model had excellent classification performance, followed by the BiGRU and GRU models, especially in classifying the health status assessment of small size grouper. This study proposes an efficient and inexpensive method for real-time monitoring and accurate assessment of the health status of fish during waterless transportation, and also provides a reference for vigour monitoring and health assessment of other similar aquatic products.

Comparative profiling of volatile compounds in white and brown Hypsizygus marmoreus during fruiting body development and postharvest storage

Hypsizygus marmoreus (HM) is a nutritious edible mushroom with high industrial yield and rapid market development. HM has become increasingly popular among customers due to its abundant bioactive compounds, chewy texture and unique aroma. The volatile organic compound (VOC) fingerprints of white and brown HM varieties during fruiting body growth and postharvest storage were established by HS-SPME-GC-MS and HS-GC-IMS. A total of 46 aroma VOC were identified from fresh mature HM. Based on odor activity, 12 VOC have been defined as the characteristic VOC, of which five are prevalent in aquatic products and are the main contributors to HM's unique seafood flavor. The brown variety exhibited higher diversity and abundance of VOC. C8 compounds in brown HM was 5.722 mg/kg, which was 1.99 times higher than that in white HM (2.872 mg/kg). Aromatic compounds such as aldehydes, alcohols, ketones, and terpenes are also more abundant in brown varieties (6.35 mg/kg), which was 1.864 times that of white varieties (3.406 mg/kg). C8 compounds increasingly accumulated in white HM during development, especially intensifying before maturing. After stored at 4 ℃ up to 45 d, the VOC profiles of HM remained less changed despite slight decrease, which helps explain their long shelf-life. The findings of this study shed light on elucidating the VOC that contribute to the unique aroma of HM, as well as tracking the odor changes during industrial production and shelf-life.

Aeromonas veronii-associated bacteremia in the course of treatment of acute myeloid leukemia: a case report and review of the literature

PurposeThis study aimed to report a case of acute myeloid leukemia (AML) complicated by Aeromonas veronii infection-induced bacteremia and to review relevant literature on the etiology, prevention, treatment, and prognosis of bacteremia in immunocompromised populations, aiming to reduce mortality in individuals with hematologic and other end-stage diseases and improve patient outcomes.Methods and resultsWe reported the case of a 23-year-old male patient with relapsed AML characterized by AML1:ETO and ASXL positivity, classified as a high-risk group. The patient presented with fever, abdominal pain, diarrhea, nausea, and vomiting after consuming partially cooked fish. The patient was admitted with high leucocytes, C-reactive protein, procalcitonin, and interleukin-6 levels. Peripheral blood high-throughput sequencing (Next-Generation Sequencing NGS) confirmed infection with Aeromonas veronii, while an abdominal CT scan indicated a liver abscess with gas formation. Culture of the drainage fluid from the ultrasound-guided liver abscess puncture demonstrated growth of Aeromonas veronii. Based on the sensitivity results, the patient was treated with intravenous ciprofloxacin and cefoperazone-sulbactam. After treatment with antibiotics, blood transfusion, liver protection, and azacitidine 100 mg ih, combined with dry white sand(interferon alpha-1B, interleukin-2, and thalidomide), the critical condition of the patient improved, and he was discharged. This study was approved by the Ethics Committee of Medical Research in the Second Affiliated Hospital of Henan University of Science and Technology. Informed consent was obtained from this patient and we have obscured the patient's identifying information. All methods were carried out in accordance with relevant guidelines and regulations.ConclusionWhen patients with a recurrence of AML have a history of consuming or contacting aquatic products, clinicians should be vigilant about Aeromonas veronii infection. The presence of Aeromonas veronii in peripheral blood must alert clinicians to the possibility of severe sepsis and septic shock. Early diagnosis and prompt treatment are crucial to reducing patient mortality.

Mitigating inland waters’ greenhouse gas emissions: current insights and prospects

ABSTRACT Natural and constructed inland waters emit globally significant amounts of greenhouse gasses (GHGs) into the atmosphere. As a result of human-induced alterations in the landscape, these emissions tend to increase. While proper management of waterbodies is fundamental to reaching the global sustainable development goals as well as the Paris Agreement, insights on climate-smart inland water management are still underexplored. Here we review and discuss physical, chemical, and biological management measures applied in a wide range of inland waters to (1) reduce external loads of compounds fueling aquatic GHG emissions, (2) reduce the aquatic production of GHG-fueling compounds, and (3) minimize GHG production and stimulate GHG consumption. Some measures are well studied and others are in the exploration phase, resulting in a varying degree of confidence with respect to their effectiveness. Climate-smart water management (e.g., through the reduction of organic matter and nutrient loading) generally not only reduces GHG production and emission but also improves the ecological state of aquatic environments. Reductions in GHG emissions from 5% (fish effect) to ∼90% (salinization effect) were observed among the climate-smart measures discussed here. Certainly, the global effect of the different measures also depends on the application scale. Depending on the local context, the implementation of one or more of these measures can be considered in a GHG mitigation program.

Do pyrethroid pesticide residues in Chinese mitten crab aquaculture areas have an impact on the ecological environment? ——A case study of Yangcheng Lake

Pyrethroid pesticides are widely used in agriculture, aquaculture, and daily life in China, leading to concerns about their environmental residues. However, there is limited information available regarding the compositional distribution, bioaccumulation, and associated health and environmental risks of pyrethroids in the aquaculture areas of Eastern China. This study investigated the residues, distribution, and risk assessment of pyrethroids including deltamethrin, permethrin, fenvalerate, cypermethrin and bifenthrin in Yangcheng Lake using solid-phase extraction and gas chromatography-tandem mass spectrometry. The risk assessment of water, sediment, and aquatic products of Yangcheng Lake was conducted using various evaluation methods. The results revealed that pyrethroids were found at higher levels in both water and sediment in Yangcheng Lake with some seasonal variations observed in their distribution patterns. Compared with other watersheds in China, typical aquaculture areas of the Yangtze River Delta showed higher detection rates and quantities of pyrethroid pesticides. Ecological risk assessments indicated high risks to the environment from all five tested pyrethroids at Yangcheng Lake; deltamethrin posed the highest risk among them. Dietary assessment results showed no risks associated with aquatic products from Yangcheng Lake but drinking water at certain sites presented unacceptable health risks.

The interaction of Lactiplantibacillus plantarum and Latilatilactobacillus sakei regulated the formation of characteristic quality attributes of low-salt fermented tilapia

The regulation of quality characteristics of fermented aquatic food based on microbial metabolic interaction is a hot spot in the innovative processing of aquatic products around the world. In this study, electronic sensory system, gas phase method and liquid phase method based on mass spectrometry were used to study the effects of the interaction between Lactiplantibacillus plantarum and Latilactobacillus sakei on the quality and flavor of dry-cured tilapia. The targeted supplementation of Latilactobacillus sakei S199 can improve the texture and flavor characteristics of tilapia meat fermented by Lactiplantibacillus plantarum 550. Latilactobacillus sakei S199 can cross metabolize with Lactiplantibacillus plantarum 550 to produce more 1-Octen-3-ol, 3-methyl-1-Butanol, 1-Hexanol, 2-ethyl-1-Hexanol, (E)-2-Octen-1-ol, 2-Heptanone, 3-Octanone, 2-Pentyl-Furan, and 2,5-diethyltetrahydro-Furan, and reduce the content of Heptanal, Nonanal, and Benzaldehyde to enhance the aroma of fermented tilapia fish. The aroma intensity increased by three times, from 129.46 μg/kg to 373.02 μg/kg, white the bitterness of tilapia meat fermented by the two bacteria was reduced by half, from 231.26 μg/g to 153.65 μg/g. The interaction of Lactiplantibacillus plantarum 550 and Latilactobacillus sakei S199 promoted proteolysis and utilized the FAAs and other small molecular compounds to generate other flavor compounds. The results were helpful to understand the effect of the interaction between Lactiplantibacillus plantarum 550 and Latilactobacillus sakei S199 on the flavor formation of dry cured tilapia.

Effects of live transport methods on the survivability, physiological responses, and flesh quality of turbot (Scophthalmus maximus)

AbstractWaterless transport is an alternative method for live aquatic products. However, the changes that occur in the fish body after transportation are not known. Herein, the effects of different transport methods on quality of turbot (Scophthalmus maximus) were investigated. Fish were divided into four groups: Group A (water, 17°C), Group B (waterless, 3°C), Group C (water, 3°C), and Group D (control, 17°C). In the case of 100% survival, the maximum transport time was 40 h for Group A, 55 h for Group B, and 90 h for Group C. Both crude protein and crude fat decreased significantly (p < 0.05) in the treatment groups compared with the control group. Compared with control group, lactic dehydrogenase (LDH), lactic acid (LA), and serum cortisol (COR) increased significantly (p < 0.05) in all treatment groups. After fish recovered, LDH, LA, and COR values were all significantly (p < 0.05) lower than their corresponding non‐recovered group. Compared with the control group, the expression of proteins related to muscle motility and stress capacity both decreased in the low‐temperature, waterless group. Together, obvious damage may occur to flesh quality, liver, and heart of turbot when the transport time is >40 h, regardless of the transport method.

The flavor enhancement mechanism of ultrasound-assisted curing and UV-assisted drying in semi-dried tilapia fillets based on flavoromics, lipidomics, and metabolomics

This study aimed to investigate the effects of ultrasound-assisted curing and UV-assisted drying on the quality of semi-dried tilapia fillets through flavoromics, lipidomics, and metabolomics. Both treatments enhanced myofibril pore space and reduced moisture content (−14.84 %, P < 0.05), with ultrasound demonstrating greater effectiveness. Additionally, they also facilitated lipid oxidation (P < 0.05), which altered the flavor profile. UV treatment enhancing key aroma compounds (ROAV >1), especially octanal, 1-octen-3-one, ethyl-isovalerate, and 2-pentyl-furan, more effectively than ultrasound (P < 0.05). 420 lipid molecules and 213 metabolites were identified, including 162 differential lipids and 69 differential metabolites (VIP > 1). Correlation analysis indicated that triglycerides, fatty acids, organic acids, and nucleosides were key precursors of flavor. The sensory evaluation demonstrated that ultrasound and UV treatments synergistically enhanced fillet quality. This study introduces an innovative processing method aimed at the industrialized and efficient production of high-quality air-dried aquatic products.

Molecular Cloning, Prokaryotic Expression, and Immunological Characterization of β-Enolase from Grass Carp (Ctenopharyngodon idella).

β-Enolase is a cross-allergen commonly found in fungi, plants, and aquatic products. Although studies on the allergenicity of fish enolase have been reported in recent years, they are still limited to a few species of marine fish. Therefore, the detection of freshwater fish in the food industry requires more studies of the molecular characterization as well as the allergenicity of enolase. In this study, the nucleotide sequence of β-enolase from grass carp was obtained by molecular cloning technology. Structural domain analysis showed that it contained the characteristic structural domains of the enolase superfamily, and homology analysis indicated that enolases are highly conserved evolutionarily. Recombinant β-enolase was obtained by prokaryotic expression, and its allergenicity was assessed by β-enolase-sensitized mice, which confirmed the ability of β-enolase to trigger an allergic response and cause a rise in Th1 and Th2 immune responses in mice. These results suggest that β-enolase could be used as a characterizing substance for the detection of fish allergens in the food industry as well as the preparation of drugs for allergy-related studies.

Multi-tracer evidence of hydrology and primary production controls on dissolved organic matter composition and stability in the semi-arid aquatic continuum

Autochthonous dissolved organic matter (Auto-DOM) produced by a biological carbon pump using dissolved inorganic carbon (DIC) from carbonate weathering plays an important role in carbon cycling within inland waters. However, little is known regarding how environmental conditions impact the composition and fate of organic matter, especially in surface waters of the semi-arid Loess Plateau, which is enriched in DIC by significant carbonate weathering. To obtain novel insight, we combined hydrochemistry, isotopic composition (δ2H, δ18O, and δ13CDIC), Rayleigh fractionation model, optical spectroscopy (absorbance and fluorescence), and Fourier transform ion cyclotron resonance mass spectrometry measurements to elucidate how primary production and hydrology impact the composition of DOM and the stability of the resulting Auto-DOM throughout the river–reservoir–wetland aquatic continuum of the Bahe River in the carbonate-mineral-rich semi-arid Loess Plateau where carbonate weathering is significant. The Rayleigh fractionation model results indicated that watershed DIC is primarily consumed through aquatic primary production rather than CO2 degassing. Further investigation revealed that primary production and evaporation co-occurred in this watershed. With the enrichment of the stable water isotope δ2H, the relative abundances of the allochthonous compounds decreased and the relative abundances of the autochthonous substances increased, suggesting that the terrestrial signal of riverine DOM decreased while autochthonous production increased along the flow pathway. In addition, associations between optical and molecular characteristics among DOM samples from different water bodies revealed that the stability ratio (Fmax(C2/(C2 + C4))) of Auto-DOM to the ratio of carboxylic-rich alicyclic molecules showed a consistent trend, suggesting that phytoplankton-derived and biomineralized C2 compounds are potentially recalcitrant DOM in inland waters. We conclude that hydrology and primary production affect the source, composition, and, potentially, the stability of DOM in DIC-enriched surface waters of the semi-arid Loess Plateau, which may lead to a more humic-like DOM composition in inland water and export this lower bioavailability DOC to the ocean in the long term.

The mechanism of improving the flavor quality of bighead carp (Aristichthys nobilis) by the short-term micro-flowing water treatment

The short-term micro-flowing water treatment (STMF) has been proven to improve the taste quality of bighead carp. However, few studies have focused on its impact on the aroma quality of bighead carp muscle and the underlying mechanism. This study investigated the effect of STMF on the aroma quality of bighead carp muscle using UPLC–MS/MS-based metabolomics and gas chromatography–mass spectrometry (SAFE–GC–MS) combined with semi-quantitative methods. A total of 56 volatile compounds were found in the bighead carp muscle by SAFE–GC–MS. During the STMF, the contents of hexanal and (E,E)-2,4-heptadienal decreased significantly, which decreased by 24.09 % and 20.80 % after 6 days of the STMF, respectively. However, the contents of (E)-2-octenal and (E)-2-nonenal showed a trend of rising first and then falling, with maximum values at the 6th day of the STMF. The Pearson’s correlation coefficient showed a good correlation between some sensory attributes and aroma compounds. The fatty acid, amino acid, and glutathione metabolism of bighead carp muscle were significantly changed after 2 days of the STMF, with the contents of carnitine and acylcarnitine increased and then the contents of glutamic acid and glutamine increased. The improvement of flavor quality could be related to metabolism of carnitine, glutamic acid, glutamine, and glutathione. This study may help to understand the mechanism of STMF in enhancing the aroma quality of aquatic products.

Evaluation of Proximate, Organoleptic and Vitamin C Changes of Seaweed Jelly Candy (Gracillaria Sp.) after the Addition of Honey Mango Juice

Aims: to determine the effect of the addition of honey mango juice on the characteristics of jelly candy Study Design: This research was designed using a completely randomized design (CRD) with four treatments namely A (addition of 0% mango juice), B (addition of 9.93%% mango juice), C (addition of 12.5% mango juice) and D (addition of 16.07% mango juice) with 2 replications. Proximate and sensory data of jelly candy were analyzed by analysis of variance (ANOVA) and followed by honest real difference test at α5% level Place and Duration of Study: This research was conducted at the Makassar Health Laboratory Center (Chemical Testing) and Departemen of Aquatic Product Processing and Storage Workshop (Organoleptic Test) of Pangkep State Polytechnic of Agriculture from April to July 2024. Methodology: The analysis conducted in this study included chemical and organoleptic analysis. Chemical analysis included: analysis of water content by distillation method, total sugar content. Vitamin C levels through iodometric titration. Organoleptic (sensory) analysis included Odor, taste, texture and color. Results: The results showed that the addition of mango juice to the characteristics of jelly candy was significantly different to water content, total sugar content and vitamin C. The best product based on chemical analysis is jelly candy in treatment D with the highest vitamin C content (5520.1 µg/g) and the highest total sugar content (38.92%) while the lowest water content (11.21%) was found in treatment A. Tests on organoleptic assessment of the highest panelists in treatment D, namely Odor 3.8 (like), taste 4.2 (like), texture 3.2 (normal), and color 3.7 (like).

Effects of phenolic acid grafted-chitosan hydrocolloids on the aldehyde contents from lipid oxidation in golden pompano (Trachinotus blochii) fillets during pan-frying

The effects of phenolic acid grafted-chitosan hydrocolloids (CS-g-GA/FA) on aldehyde contents from lipid oxidation in golden pompano fillets during pan-frying was investigated with an established high-performance liquid chromatography-mass spectrum method. Results indicated that pan-frying induced profound lipid oxidation and aldehydes generation with propanal, hexanal, nonanal, trans, trans-2,4-decadienal, and 4-hydroxy-2-nonenal as the abundant species. CS-g-FA and CS-g-GA effectively decreased their contents by 23.74–27.42 %, 61.69–67.42 %, 41.83–53.91 %, 29.91–48.79 %, and 61.57–65.39 % after 3 min. Most aldehyde contents decreased with the extension of pan-frying time due to the volatilization and reaction. In terms of substrate depletion, CS-g-phenolic acids effectively inhibited unsaturated fatty acids oxidation due to their decent antioxidant activity than CS. The significant lower retention rates of aldehydes in the CS-g-phenolic acids groups compared with control in chemical mode confirmed the carbonyl ammonia condensation. These results suggested that CS-g-phenolic acids serve as novel coating to reduce hazardous compounds during aquatic products thermal processing.

Revolutionizing Diabetes Care: The Role of Marine Bioactive Compounds and Microorganisms.

Diabetes is a metabolic condition characterized by high blood glucose levels. Aquatic products like microalgae, bacteria, seagrasses, macroalgae, corals, and sponges have been investigated for potential anti-diabetic properties. We looked at polyphenols, peptides, pigments, and sterols, as well as other bioactive substances found in marine resources, to see if they could help treat or manage diabetes, in addition to describing the several treatment strategies that alter diabetes and its implications, such as inhibition of protein tyrosine phosphatases 1B (PTP1B), α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV), aldose reductase, lipase, glycogen synthase kinase 3β (GSK-3β), and insulin resistance prevention, promotion of liver antioxidant capacity, natural killer cell stimulant, anti-inflammatory actions, increased AMP-activated protein kinase (AMPK) phosphorylation and sugar and metabolism of the lipid, reducing oxidative stress, and β-pancreatic cell prevention. This study highlights the revolutionary potential of marine bioactive compounds and microorganisms in transforming diabetes care. We believe in a future in which innovative, sustainable, and efficient therapeutic approaches will result in improved quality of life and better outcomes for people with diabetes mellitus by forging a new path for treatment, utilizing the power of the world's oceans, and capitalizing on the symbiotic relationship between humans and the marine ecosystem. This study area offers optimism and promising opportunities for transforming diabetes care.

Assessing the Role of Policy in the Evolution of Recreational Fisheries in Chinese Fishing Villages: An Analytical Hierarchy Process (AHP) and Delphi Method Analysis

Recreational fisheries in Chinese fishing villages have undergone significant transformation due to supportive government policies. This study develops a comprehensive indicator to objectively assess the development of recreational fisheries under rural revitalization policies. Six key dimensions were identified using the Analytical Hierarchy Process (AHP) and the Delphi method. The findings indicate that fishery resource conditions and environmental conditions are paramount, followed by service conditions, activities, policy conditions, and accommodation conditions. Key success indicators indicate the importance and priority of implementing policies, including “Tasting delicious aquatic products”, “Government support”, “Recreational fishing activities pricing”, and “Talent revitalization.” This study concludes by offering strategic recommendations to prioritize recreational fisheries within rural revitalization policies, utilizing identified indicators for policy implementation, and establishing a dedicated promotional group. These insights are essential for stakeholders and policymakers to promote sustainable and economically viable recreational fisheries in China.

Ecological responses to solar forcing during the Homerian Climate Anomaly recorded by varved sediments from Holzmaar, Germany

Features like solar cyclicities and trends as well as grand solar minima are used to attribute natural climate variability to solar forcing on decadal to millennial time scales. Here we focus on ecological responses of a Grand Solar Minimum on annually- laminated lake sediments from Holzmaar (Germany) covering the Homeric Climate Anomaly (HCA). Diatom assemblages and pigments of purple sulphur bacteria (Bphe a) analysed at decadal resolution document well-stratified conditions with relatively low lacustrine productivity prior to the HCA (2950–2750 cal. BP). Colder temperatures, a well-mixed water column and higher primary aquatic productivity established during the HCA (2750–2680 cal. BP) as indicated for Holzmaar by dominance of the planktonic diatom Stephanodiscus minutulus, decreasing Bphe a and peaking total chloropigment concentrations. The termination of the HCA after 2680 cal. BP is marked by additional anthropogenic signals related to deforestation that changed the catchment at the contemporaneous Bronze Age/Iron Age transition. Our high-resolution and well-dated multiproxy study based on varved sediments contributes to a better understanding of decadal-scale responses of aquatic ecosystems to solar forcing and compares well with hypotheses suggested by other investigations indicating colder and more windy climatic conditions as the consequences of a Grand Solar Minimum for mid-latitudes of the Northern Hemisphere.

Determination and safety evaluation of metal element contents of Oviductus Ranae produced from &lt;i&gt;Rana dybowskii&lt;/i&gt; by pond culture–forest grazing relay model in Heilongjiang Province, China

The aquatic products of grazing ecological culture exhibit a strong reliance on the production environment system, which may result in heavy metal contamination. In this study, 24 elements (Ag, Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, U, V, Zn) were determined for Oviductus Ranae (OR) from more than 1,000 individuals of Rana dybowskii produced by pond culture–forest grazing relay mode from six major production areas in Heilongjiang Province, China. Furthermore, we assessed the associated health risks. Our findings indicate that most of these 24 metal elements were detected in OR at a detection rate of 100%, with the exceptions being As (98.0%), Ga (98.0%), Co (98.0%), V (94.0%), Cd (89.0%), Pb (76.0%), Cs (74.0%), Tl (35.0%), and U (not detectable). Variations in element concentrations were significant across the six sampling sites, with characteristic elements identified to account for spatial differences. The total target hazard quotient was determined to be 0.152 in Heilongjiang Province, thereby suggesting a relatively low health risk associated with consuming OR from this region’s production systems according to existing standards and guidelines. Nevertheless, special attention is needed for monitoring the habitat environments of R. dybowskii from two sampling locations showing heightened pollution levels.