Evaluation the effect of mycotoxins on shrimp ( Litopenaeus vannamei ) muscle and their limited exposure dose for preserving the shrimp quality

Evaluation of the combined impact of aflatoxin B1 and deoxynivalenol fed to Penaeus vannamei and mitigation properties provided by a yeast cell wall extract

The purpose of this study was to examine how white shrimp (Penaeus vannamei) responded to varying concentrations of combined mycotoxins (aflatoxin B1 (AFB1) and deoxynivalenol (DON)) as well as the mitigating effects of an adsorbent (yeast cell wall extract, YCWE). The experiment comprised of five groups receiving isonitrogenous and isolipidic diets: CON (control group), LDA (CON with 20 μg/kg AFB1 and 1500 μg/kg DON), HDA (CON with 100 μg/kg AFB1 and 3000 μg/kg DON), LDAM (LDA with 0.2 % YCWE), and HDAM (HDA with 0.2 % YCWE). Results showed that the contents of total protein, total cholesterol, hemocyanin, and enzyme activities (e.g., catalase, phenoloxidase) in plasma were lower in HDA group, while the alanine aminotransferase activity and malondialdehyde content were higher. The HDA group showed up-regulated expression of apoptotic genes in the hepatopancreas but down-regulated expression of immune-related and antioxidant genes. In the LDA and HDA groups, the higher expression of inflammatory genes in hepatopancreas, the lowest chewiness of muscle and the higher abundance of potential pathogens (e.g., Escherichia-Shigella) in the intestine were observed. However, LDAM and HDAM diets were able to enhance the immune response, antioxidant capacity, and hepatopancreatic and intestinal health of shrimp, especially increased the abundance of intestinal bacteria for detoxification (e.g., Pseudomonas). Moreover, dietary YCWE also led to significantly greater mycotoxin content in the feces. In conclusion, the combined mycotoxins AFB1 and DON can negatively affect the health of shrimp, even at lower doses. But adding YCWE to the diets can effectively mitigate these negative effects.

Immunotoxicity and the mechanisms of aflatoxin B1-induced growth retardation in shrimp and alleviating effects of bile acids

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins prevalent in the environment and food chain, posing severe health risks to humans and animals. Bile acids are natural detergents synthesized from cholesterol and play a key role in the excretion of toxins in vertebrates. Here, pacific white shrimp (Litopenaeus vannamei) served as an animal model to examine the toxicity mechanisms of AFB1 and assess the potential alleviating effects of bile acids against AFB1. Our results revealed that AFB1 exposure significantly inhibited the growth performance and immune response of shrimp, accompanied by AFB1 accumulation and histological damage. Mechanistically, AFB1-induced DNA damage activated DNA repair mechanisms and induced the arrest of cell cycle via the ATR-cyclin B/cdc2 pathway. Additionally, AFB1 directly suppressed the immune response and growth performance of shrimp by inhibiting Toll and IMD pathways and the secretion of digestive enzymes. Notably, dietary bile acids significantly reduced AFB1 accumulation and alleviated AFB1-induced growth retardation and immunotoxicity in shrimp, and CCKAR, ATR, and Relish may be key mediators of the alleviating effects of bile acids. Our study provided new insights into the toxicity mechanisms of AFB1 in invertebrates and highlighted the potential of bile acids to alleviate AFB1 toxicity.

Effects of Lipopolysaccharide and Deoxynivalenol on the Survival, Antioxidant and Immune Response, and Histopathology of Crayfish (Procambarus clarkii)

Bacterial lipopolysaccharide (LPS) in the aquatic environment has been reported to cause diseases in red swamp crayfish (Procambarus clarkii). In addition, deoxynivalenol (DON) is one of the primary mycotoxins found in aquaculture. However, the potential synergistic toxic effects of LPS and DON on crayfish are yet to be fully elucidated. In this study, crayfish were exposed to LPS (1 mg kg-1), DON (3 mg kg-1), and their combination (1 mg kg-1 LPS + 3 mg kg-1 DON, L+D) for a duration of six days. Co-exposure to LPS and DON exhibited the lowest survival rate compared to the control or individual treatments with LPS or DON alone. In the initial stage of the experiment, the combined treatment of LPS and DON showed a more pronounced up-regulation of antioxidant and immune-related enzymes in the sera compared to the other treatment groups, with a fold change ranging from 1.3 to 15. In addition, the (L+D) treatment group showed a down-regulation of immune-related genes, as well as Toll pathway-related genes in the hepatopancreas compared to LPS or DON. Moreover, the (L+D) treatment group demonstrated a 100% incidence of histopathological changes in the hepatopancreas, which were significantly more severe compared to the other three groups. In conclusion, our study provides physiological and histopathological evidence that the co-exposure to LPS and DON exerted synergistic toxic effects on crayfish. The observed effects could potentially hinder the development of the crayfish aquaculture industry in China.

Mycotoxins in Seafood: Occurrence, Recent Development of Analytical Techniques and Future Challenges

The co-occurrence of mycotoxigenic fungi and mycotoxins in aquatic food commodities has recently become a source of severe worldwide food insecurity since these toxicants may damage human health. The consumption of aquatic food itself represents a relatively novel and non-negligible source of mycotoxins. Mycotoxins in seafood lead to important human genotoxins, carcinogens, and immunosuppressors. Consequently, it is crucial to quantify and characterize these contaminants in aquatic food products subject to extensive consumption and develop new regulations. The present paper provides an overview of recent advancements in liquid chromatography and mass spectrometry and the coupling of these techniques for identifying and characterizing mycotoxins in various fresh, comestible, and treated marine products. The disposable data display that a multiplicity of fungal species and further mycotoxins have been detected in seafood, comprising aflatoxins, ochratoxins, fumonisins, deoxynivalenol, zearalenone, and trichothecenes. In addition, a wider and up-to-date overview of global occurrence surveys of mycotoxin occurrence in seafood in 2017–2022 is explored. In this regard, the predominant occurrence of enniatins has been documented in seafood products. Likewise, special attention has been given to current EU seafood legal and existing national regulations of mycotoxins in seafood. In this way, rigorous national and international guidelines are needed for palpable and effective measures in the future. Nevertheless, controlling mycotoxins in aquatic foods is an ambitious aim for scientists and industry stakeholders to ensure sustainable global food safety.

A TMT-based proteomic approach for investigating the effect of electron beam irradiation on the textural profiles of Litopenaeus vannamei during chilled storage

To elucidate the effect of electron beam irradiation (EBI) on the textural quality of Litopenaeus vannamei, the tandem-mass-tag labeled proteomic method was conducted to illustrate the protein changes in shrimp muscle. The results suggested that shrimp irradiated with 5 kGy exhibited optimum textural traits of hardness, springiness, and chewiness. In total, 486 proteins were identified as differentially abundance proteins (DAPs) in multiple comparison groups. Bioinformatics analysis revealed that most of DAPs participated in cellular process, binding, and catalytic. etc. Various signaling pathways, such as RNA transport and oxidative phosphorylation, were notably enriched by DAPs. The correlation analysis indicated that some DAPs such as Myosin-XVIIIa, projectin, and beta-thymosin 3 were remarkably correlated with the textural properties, which could be proposed as potential biomarkers to assess the irradiation-induced textural variation in shrimp. This study provided an insightful understanding at the protein level to improve the application of EBI to shrimp preservation.

Protective mechanisms of three antioxidants against T-2 toxin-induced muscle protein deterioration in shrimp

BACKGROUND

Quercetin (Q), tea polyphenols (TP), and rutin (R) are widely used plant-derived active ingredients. They possess antioxidant, anti-inflammatory, and anti-tumor properties, and can reduce the muscle damage caused by mycotoxins. However, few studies have examined the protective mechanisms of quercetin, tea polyphenols, and rutin on muscle quality. To elucidate their protective mechanisms, shrimp were exposed to both T-2 toxin and these three antioxidants for 20 days in a dose-escalating trial. The changes in the protein composition of shrimp muscle were measured. The target proteins associated with T-2 and antioxidants were screened and identified by non-labeled quantitative proteomics.

RESULTS

The T-2 toxin induced abnormal expression of 21 target proteins, leading to the deterioration of muscle proteins in shrimp. The three antioxidants ameliorated the T-2 toxin-induced damage to muscle proteins by increasing the sarcoplasmic and myofibrillar protein content and decreasing the alkali-soluble protein content. Quercetin had the strongest protective effect. The protective processes of these antioxidants involved the upregulation of target proteins involved in carbohydrate metabolism (enolase, malate dehydrogenase), protein translation (elongation factor 1-alpha and eukaryotic translation initiation factor 2 subunit alpha), and cytoskeleton component (actin 2, fast-type skeletal muscle actin 1). Quercetin regulated the largest number of target proteins, making it the best protective agent against T-2 toxin.

CONCLUSION

The T-2 toxin (4.80-24.30 mg/kg feed) induced changes in target proteins and muscle composition of shrimp, leading to a deterioration in muscle proteins. Quercetin (2.00-32.00 g/kg feed) had significant protective effects against this deterioration in muscle protein in shrimp. © 2022 Society of Chemical Industry.

NIR Hyperspectral Imaging Technology Combined with Multivariate Methods to Identify Shrimp Freshness

In this study, a hyperspectral imaging system of 866.4–1701.0 nm, combined with a variety of spectral processing methods were adopted to identify shrimp freshness. To gain the optimal model combination, three preprocessing methods (Savitzky-Golay first derivative (SG1), multivariate scatter correction (MSC), and standard normal variate (SNV)), three characteristic wavelength extraction algorithms (random frog algorithm (RFA), uninformative variables elimination (UVE), and competitive adaptive reweighted sampling (CARS)), and four discriminant models (partial least squares discrimination analysis (PLS-DA), least squares support vector machine (LSSVM), random forest (RF), and extreme learning machine (ELM)) were employed for experimental study. First of all, due to the full wavelength modeling analysis, three preprocessing methods were utilized to preprocess the original spectral data. The analysis showed that the spectral data processed by the SNV method had the best performance among the four discriminant models. Secondly, due to the characteristic wavelength modeling analysis, three characteristic wavelength extraction algorithms were utilized to extract the characteristic wavelength of the SNV-processed spectral data. It was found that the CARS algorithm achieved the best performance among the three characteristic wavelength extraction algorithms, and the combining adoption of the ELM model and different characteristic wavelength extraction algorithms obtained the best results. Therefore, the model based on SNV-CARS-ELM obtained the best performance and was elected as the optimal model. Lastly, for accurately and explicitly displaying the refrigeration days of shrimps, the original hyperspectral images of shrimps were substituted into the SNV-CARS-ELM model, thus obtaining the general classification accuracy of 97.92%, and the object-wise method was used to visualize the classification results. As a result, the method proposed in this study can effectively detect the freshness of shrimps.

Effects of lysozyme combined with cinnamaldehyde on storage quality of olive flounder (Paralichthys olivaceus) fillets

Effects of lysozyme (LYS) combined with cinnamaldehyde (CA) on quality enhancement of olive flounder (Paralichthys olivaceus) fillets during refrigerated storage at 4 °C for 20 days were assessed. Changes of total viable count (TVC), K-value, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), texture profile analysis (TPA), and trichloroacetic acid-soluble peptide (TCA-soluble peptide) in samples were determined periodically. Results demonstrated that the combination of LYS and CA treatment enhanced the antibacterial activity against S. putrefaciens and P. fluorescens, and lowered TVC values. Meanwhile, LYS combined with CA significantly retarded the increases of TBA value, TVB-N, K-value, and TCA-soluble peptide content compared to the control. Furthermore, the combined treatment also effectively maintained the texture properties of flounder fillets during the storage period. The efficiency was better than that of LYS or CA treatment alone. Thus, LYS combined with CA is promising in olive flounder shelf life extension.

Application of Gelatin Incorporated with Red Pitaya Peel Methanol Extract as Edible Coating for Quality Enhancement of Crayfish (Procambarus clarkii) during Refrigerated Storage

China is one of the largest producers of red pitaya in the world and responsible for disposal of the huge amount of peel generated as a waste. The objective of this research was to evaluate the effect of the addition of red pitaya peel extract (RPPE, 1.0%, 2.0%, or 3.0% (w/v)) and 0.1% ε-polylysine (ε-PL) to a fish gelatin edible coating on the preservation of deshelled crayfish (Procambarus clarkii) during refrigerated storage. The physicochemical and water migration of the samples were determined during 8-day storage. Deshelled crayfish packaged in edible coatings exhibited significantly (p<0.05) lower values for total volatile basic nitrogen (TVB-N), K value maintenance, and free amino acids (FAAs). This study shows that application of an edible coating incorporated with RPPE and ε-PL is an effective strategy in retarding the quality deterioration in deshelled crayfish during storage.