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BACKGROUND: Temperature, which affects numerous physiological processes, has been described as the 'main ecological factor' for fish. The aim of this modeling study is to explore the impact of climate‐induced temperature changes on fish fillet quality and shelf life. RESULTS: Temperature stress in rainbow trout affected ash and moisture, and inhibited myofibril fragmentation in the fillets. However, with the increase in temperature, there was a decrease in the total amount of saturated fatty acids (∑SFA) and there were significant increases in the total amount of omega 3 (∑n3) and 22:6n‐3 (DHA). It was determined that temperature increase had a negative effect on color, texture, water‐holding capacity, water activity, pH, lactic acid, and glycogen levels in fillets, and it had a positive effect by delaying microbial spoilage, especially in cold storage. CONCLUSION: This study suggest that the effects of climate change on product quality and shelf life in fish requires further research. It highlights knowledge gaps to guide future research in this emerging field. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: In this study, the effects of biofilm coatings obtained by immobilization of different borates – namely borax (BX), colemanite (COL), and ulexite (UX) – with chitosan (Ch) on the shelf life of rainbow trout fillets were investigated. The immobilization and characterization of borates in Ch were confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and zeta potential analysis. In determining the shelf life of fillets that were covered by immersion and stored for 15 days, microbiological (total aerobic mesophilic, psychrotrophic, lactic acid, Pseudomonas, and Enterobacteriaceae bacteria counts) and chemical analyses (total volatile basic nitrogen, thiobarbituric acid reactive substance, and pH levels) were performed at 3 day periodic intervals. In addition, the biodegradation of borates was determined using inductively coupled plasma mass spectrometry in biofilm‐coated fillets on the 1st, 8th, and 15th storage days. RESULTS: The microbial results of the coatings enriched with borates (BX, COL, and UX) at different levels (0, 0.03, and 0.06 mg L−1) (due to the immobilization with Ch) show the shelf life was extended by 3–6 days in all of the treatment groups compared with the control. CONCLUSION: It was concluded that BX, COL, and UX coatings enriched by immobilization with Ch increase shelf life and improve fillet quality. In addition, the enrichment of BX, COL, and UX with Ch showed explicit natural protective effects. This study demonstrates that Ch‐enriched coatings of BX, COL, and UX can be used as natural bioactive nanocarriers to provide bioactive food ingredients in the seafood processing industry. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The mechanisms of various metal nanoparticles (NPs) are still a matter of debate in aquatic toxicology. In order to close this gap, the number of studies on this subject is increasing. The aims of this study are to explore the interactions of PdCu@f‐MWCNT NPs with zebrafish and get to know if it has an ecotoxicological risk. In this study, we synthesized, characterized PdCu@f‐MWCNT NPs, and investigated its ecotoxicological effects. The chemical and morphological structures of PdCu@f‐MWCNT nanomaterials were elucidated with advanced analysis techniques such as scanning electron microscope (SEM), X‐ray spectrophotometer (EDX), transmission electron microscope (TEM), and X‐ray diffraction (XRD) analyses. The ecotoxicological risks were investigated by conducting biochemical analyses and malformation defects in zebrafish. The results were obtained using multiple marker applications including oxidative stress parameters, proinflammatory cytokine expressions, DNA damage, and apoptosis markers. The obtained findings showed embryonic development, survival rate, and incidence of malformation increasing in parallel with the dose increase in zebrafish exposed to PdCu@f‐MWCNT NPs at 10–1000 μg/L levels. Despite the observed decreases in antioxidant enzyme activities, GSH level, AChE activity, and NRF‐2 level, inductions in malondialdehyde (MDA) level, IL‐6, TNF‐α, NF‐kB, DNA damage, and apoptosis levels were observed with increasing dose. Considering these findings, it has been determined that there are toxic effects in zebrafish at all levels above the concentration that we examine as a safe dose (10 μg/L). The effects of all studied concentrations of this NP above the safe dosage, especially on oxidative stress, malformation, and immune system, were found to be quite significant. The more widespread use of nanotechnology in the future will mean more contact of aquatic organisms with NPs. As a result, it is clearly seen that these organisms, which form the important link of the food chain, and the aquatic environment are living at risk conditions. [ABSTRACT FROM AUTHOR]

In this study, the neuroprotective action potential by ulexite (UX) (18.75 mg/L) against acetylferrocene (AFC) (3.82 mg/L) induced neurotoxicity was aimed to investigate in brain tissues of Oncorhynchus mykiss. For this purpose, the effects on neurotoxicity markers, proinflammatory cytokines, antioxidant immune system, DNA, and apoptosis mechanisms were assessed on brain tissues in the 48–96 h of the 96‐ trial period. In this research, it was determined that brain‐derived nerve cell growth factor (BDNF) level and acetylcholinesterase (AChE) activity were inhibited in the brain tissue compared to the control group by AFC. In addition, inhibition in glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) values (which are antioxidant system biomarkers), and inductions in malondialdehyde (MDA) and myeloperoxidase (MPO) amounts (which are indicators of lipid peroxidation) were determined (p < 0.05) after exposure to AFC. And, while tumor necrosis factor‐α (TNF‐α) and IL‐6 levels were increased in the AFC‐exposed group, Nrf‐2 levels were found to be remarkably decreased. Upregulation was also detected in 8‐hydroxydeoxyguanosine (8‐OHdG) and caspase‐3 levels, which are related to DNA damage and apoptosis mechanism. On the contrary, UX (single/with AFC) suppressed the AChE and BDNF inhibition by AFC. Moreover, UX mitigated AFC‐induced oxidative, inflammatory, and DNA damage and attenuated AFC‐mediated neurotoxicity via activating Nrf2 signaling in fish. Collectively, our findings revealed that UX supplementation might exert beneficial effects and may be considered as a natural and promising neuroprotective agent against AFC‐induced toxicity. [ABSTRACT FROM AUTHOR]

Cysteine is important for protein synthesis, detoxification, and diverse metabolic functions. However, cysteine metabolism has been poorly described in fish, and the role of the therapeutic effect in pesticide toxicology on aquatic organisms is unknown. The aim of this study was to determine the effects of regular cysteine treatment on the hematology, biochemistry, apoptosis, oxidative DNA damage, and antioxidant parameters in fish blood after chemical application. Therefore, fish were exposed to cypermethrin for 2 weeks. Then two different concentrations of N-acetylcysteine (NAC) were applied for a 4-day treatment period and compared with the group of the self-healing process. At the end of the treatment, the hematological index, blood biochemical parameters, paraoxonase (PON), arylesterase (ARE), and myeloperoxidase (MPO) activities in the fish blood samples were investigated. With regard to the hematological parameters, statistical differences were obtained except for mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) (P < 0.05). Enzyme activities (ARE, PON, and MPO), as well as some biochemical parameters (creatinin [Cre], alanine amino transferase, total glyceride, alkaline phosphatase, iron, calcium, low density lipoprotein-cholesterol [LDL-C], sodium, and potassium), were found to be importantly different among all groups at the P<0.05 level, while 8-hydroxydeoxyguanosine and caspase-3 levels were determined to be high in the pesticide group but decreased significantly in NAC-treated groups (P < 0.05). According to the results of the study, acute cysteine treatment showed an ameliorative effect on the hematological index, biochemical parameters, PON, MPO, and ARE in the blood in the all the treatment group fish. The positive effect of NAC on protein synthesis, detoxification, and diverse metabolic functions against cypermethrin toxicity was more effective in 1.0mM NAC. NAC has an important therapeutic effect on pesticide-induced hematoxicity for fish in terms of all the data. [ABSTRACT FROM AUTHOR]

In this study, the relationship between stunning techniques and protein oxidation which are accepted as the main cause of food spoilage was investigated. For this purpose, the antioxidant status, in vivo myofibrillary protein (MP) oxidation and sensitivity, and postmortem oxidation (inducted with hydroxyl radical system) of rainbow trout (Oncorhynchus mykiss) fillets killed by hitting to head (T1), neck crushing (T2), and convulsion (T3) methods, were investigated. Statistically significant differences (p <.05) were found among all parameters examined and it was observed that the most stressing technique was the convulsion method. It was determined that in protein profiles myosin were influenced too much from stunning technique and in actin observed oxidation‐induced reductions. Reductions in S‐S and S‐H were also found to be increased in carbonyl concentrations, but the most effective values in both processes were determined by the convulsive technique. Our results show that short‐term stunning techniques (hitting to head, neck crushing) give better meat quality results in terms of O. mykiss welfare and low MP oxidation rates. In general, we can say that T3 group fillets are more sensitive to oxidative damage, while T1 and T2 groups give better results in maintaining meat quality with low MP oxidation rates. [ABSTRACT FROM AUTHOR]