Influence of the in vivo addition of alpha-tocopheryl acetate with three lipid sources on the lipid oxidation and fatty acid composition of Beluga sturgeon, Huso huso, during frozen storage

Exploring the Internal Environmental Changes of Muscle Cells and Apoptotic Phase of Mitochondria in Dry-Cured Loin Using Electrical Stimulation: Promoting the Precise Regulation of Loin Ham Quality

Traditional dry-curing methods have a long cycle time and low efficiency, resulting in the inconsistent quality of dry-cured ham. By applying electrical stimulation (ES) technology in the dry-curing process, it was found that ES affected mitochondrial apoptosis by modulating the intracellular environment of muscle cells, which, in turn, enhanced the quality of dry-cured pork loin. Specifically, ES accelerated glycogen and ATP depletion, which led to a rapid decline in pH. Meanwhile, compared to the control group (CK), the activities of Na+-K+-ATPase and Ca2+-ATPase in the ES group (ES) increased by 160% and 124%, respectively, leading to the generation of H+ gradient and Ca2+ overload in mitochondria, which in turn triggered mitochondrial apoptosis and increased the apoptosis rate by 259%. In addition, Western blot analysis showed that ES promoted the Desmin and Troponin-T degradation levels. This study highlights the advantages of ES in dry-cured ham processing, which is expected to be a precise regulation technology.

Essential Oils Against Spoilage in Fish and Seafood: Impact on Product Quality and Future Challenges

The preservation of fish and seafood represents a significant challenge for the food industry due to these products' high susceptibility to microbial spoilage. Essential oils (EOs), classified as Generally Recognized as Safe (GRAS), have become a natural alternative to synthetic preservatives due to their antimicrobial and antioxidant properties. This review aims to analyze the specific potential of EOs in extending the shelf life of fish and seafood products, offering a natural and effective preservation solution. It provides a detailed overview of EOs applications and mechanisms, highlighting their role in controlling spoilage microorganisms while maintaining product quality. The main methods of EOs application include immersion, spraying, and pipetting, with antimicrobial effectiveness influenced by factors such as concentration, exposure time, and food characteristics like chemical composition and biofilms. Direct EOs application shows challenges that can be countered by exploring nanoemulsion technology as an effective strategy to enhance EOs stability and controlled release, maximizing their preservation impact. Additionally, coatings made from chitosan, gelatin, Farsi gum, and carrageenan, combined with EOs such as oregano, clove, and thyme have shown efficacy in preserving species like rainbow trout, mackerel, and shrimp. However, the commercial feasibility of using EOs in fish preservation depends on consumer acceptance and regulatory compliance. This review offers valuable insights for the industry and researchers by highlighting the practical applications and commercial challenges of EOs in seafood products, underscoring the importance of consumer acceptance and regulatory adherence for market viability.

Implications of vitamin D for flesh quality of grass carp (Ctenopharyngodon idella): antioxidant ability, nutritional value, sensory quality, and myofiber characteristics

BACKGROUND

Muscle represents a unique and complex system with many components and comprises the major edible part of animals. Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and immune response. In recent years, dietary vitamin D supplementation in livestock has received increased attention due to biological responses including improving shear force in mammalian meat. However, the vitamin D acquisition and myofiber development processes in fish differ from those in mammals, and the effect of vitamin D on fish flesh quality is poorly understood. Here, the influence of dietary vitamin D on fillet quality, antioxidant ability, and myofiber development was examined in grass carp (Ctenopharyngodon idella).

METHODS

A total of 540 healthy grass carp, with an initial average body weight of 257.24 ± 0.63 g, were allotted in 6 experimental groups with 3 replicates each, and respectively fed corresponding diets with 15.2, 364.3, 782.5, 1,167.9, 1,573.8, and 1,980.1 IU/kg vitamin D for 70 d.

RESULTS

Supplementation with 1,167.9 IU/kg vitamin D significantly improved nutritional value and sensory quality of fillets, enhancing crude protein, free amino acid, lipid, and collagen contents; maintaining an ideal pH; and reducing lactate content, shear force, and cooking loss relative to respective values in the control (15.2 IU/kg) group. Average myofiber diameter and the frequency of myofibers > 50 μm in diameter increased under supplementation with 782.5-1,167.9 IU/kg vitamin D. Levels of oxidative damage biomarkers decreased, and the expression of antioxidant enzymes and nuclear factor erythroid 2-related factor 2 signaling molecules was upregulated in the 1,167.9 IU/kg vitamin D treatment compared to respective values in the control group. Furthermore, vitamin D supplementation activated cell differentiation by enhancing the expression of myogenic regulatory factors and myocyte enhancer factors compared to that in the control group. In addition, supplementation with 1,167.9 IU/kg vitamin D improved protein deposition associated with protein synthesis molecule (target of rapamycin) signaling and vitamin D receptor paralogs, along with inhibition of protein degradation (forkhead box protein 1) signaling.

CONCLUSIONS

Overall, the results demonstrated that vitamin D strengthened antioxidant ability and myofiber development, thereby enhancing nutritional value and sensory quality of fish flesh. These findings suggest that dietary vitamin D supplementation is conducive to the production of nutrient-rich, high quality aquaculture products.

Assessment of Safety, Effects, and Muscle-Specific Accumulation of Dietary Butylated Hydroxytoluene (BHT) in Paralichthys olivaceus

Butylated hydroxytoluene (BHT) is a commonly used antioxidant added to animal/fish feed to limit lipid autoxidation and peroxidation. Although there have been reviews and reports of BHT toxicity in animals, limited information is available with respect to the toxic effects and accumulation of BHT due to oral exposure in aquaculture species. Therefore, 120 days of feeding trial was conducted to evaluate the effects of dietary BHT on the marine fish olive flounder Paralichthys olivaceus. Graded levels of BHT were added to the basal diet in increments of 0, 10, 20, 40, 80, and 160 mg BHT/kg, corresponding to 0 (BHT₀), 11 (BHT₁₁), 19 (BHT₁₉), 35 (BHT₃₅), 85 (BHT₈₅), and 121 (BHT₁₂₁) mg BHT/kg diets, respectively. Fish with an average weight of 77.5 ± 0.3 g (mean ± SD) were fed one of the six experimental diets in triplicate groups. Growth performance, feed utilization, and survival rate were not significantly affected by the dietary BHT levels among all experimental groups, whereas BHT concentration in the muscle tissue was found to increase in a dose-dependent manner up to 60 days of the experimental period. Thereafter, BHT accumulation in muscle tissue showed a declining trend among all treatment groups. Furthermore, the whole-body proximate composition, nonspecific immune responses, and hematological parameters (except triglycerides) were not significantly influenced by the dietary levels of BHT. Blood triglyceride content was significantly higher in fish fed the BHT-free diet compared to all other treatment groups. Thus, this study demonstrates that dietary BHT (up to 121 mg/kg) is a safe and effective antioxidant without exhibiting any adverse effects on the growth performance, body composition, and immune responses in the marine fish olive flounder, P. olivaceus.

The apoptosis of grass carp (Ctenopharyngodon idella) muscle during postmortem condition regulated by the cytokines via TOR and NF-κB signaling pathways

Postmortem alteration by apoptosis has significant effects on flesh quality. Currently, the information necessary to understand the apoptotic behavior and the molecular mechanisms during postmortem alteration in fish muscle is still lacking. Activation of apoptosis and the cytokines involved in regulating apoptosis in fish muscle were evaluated during postmortem condition at 4 °C for 5 days in terms of apoptotic morphology changes, nucleus DNA fragmentation, caspases activation and related gene expressions. The triggering apoptotic mechanisms associated with multiple cytokines transcriptional levels showed that the up-regulated pro-apoptotic mediators [IFN-γ2, TNF-α, IL-6, IL-1β, IL-17D, IL-12p35 and IL-10 (except IL-15)] and the down-regulated anti-apoptotic mediators of [IL-8 and IL-11 (except TGF-β and IL-4)] both regulated apoptosis at early stage, which were regulated by NF-κB and TOR, respectively. Results suggested that transcriptional regulation of multiple cytokines produce a positive outcome on triggering apoptosis.

The individual and combined effects of hypoxia and high-fat diet feeding on nutrient composition and flesh quality in Nile tilapia (Oreochromis niloticus)

Hypoxia and high-fat diet (HFD) feeding are two factors commonly existing in aquaculture. However, their individual and combined effects on nutrient composition and flesh quality in fish have not been investigated. The present study evaluated the alterations of growth, nutrient composition and flesh quality in Nile tilapia (initially 7.0 ± 0.1 g and 5.6 ± 0.2 cm) fed with normal fat diet (5.95% fat) or HFD (11.8% fat) at two dissolved oxygen levels (1.1 ± 0.1 and 7.2 ± 0.1 mg/L) for 8 weeks. The results showed that hypoxia and HFD had similar effects in inducing lipid deposition, reducing flesh protein and amino acids content, pH values and water holding ability. Hypoxia had additional adverse effects in decreasing meat yield, flesh contents of n-3 PUFA and glycogen, increasing flesh fragmentation and causing liver damages. The combination of hypoxia and HFD significantly decreased feed intake, survival rate and muscle protein content, but didn't affect flesh quality-related parameters.

Quality enhancement of frozen Nile tilapia fillets using rosemary and thyme oil

ABSTRACT The food industry and the frozen fish sector in particular have benefitted greatly from advancements in food processing technologies. This study investigated the effect of adding natural antioxidants such as rosemary and thyme oil to frozen fillets of Nile tilapia (Oreochromis niloticus) in order to preserve their quality for consumers. Fillets were treated with rosemary and thyme at two concentrations (1% and 1.5%) and then were stored at 4°C. Samples were analyzed over 4 days for bacteriological (aerobic plate count, psychotropic count, and coliform count), chemical (determination of pH, thiobarbituric acid reactive substances-TBARS, and total volatile base nitrogen-TVB-N), and sensory quality examination (color, texture, and odor). Significant differences (P<0.05) were observed among different groups in terms of aerobic plate count, psychotropic count, and coliform count during the storage. Moreover, pH, TVB-N, and TBARS mean values in the treated groups were lower than those in the untreated group. The best sensory quality was obtained at the highest concentrations (1.5%) of thyme and rosemary oil.

Influence of chitosan nanoparticles and fennel essential oils (Foeniculum vulgare) on the shelf life of Huso huso fish fillets during the storage

Fish and fishery products are important parts of the human diet, but the microbial, chemical, and physical deteriorations limit their shelf life. Using the modified atmospheric packaging system and edible coatings is one of the main procedures to improve the shelf life of fish. In this research, the effect of chitosan nanoparticles (CNPs) loaded with fennel essential oils along with modified atmosphere packaging (MAP) system on chemical, microbial, and sensorial properties of Huso huso fish fillets during storage at fridge were evaluated. The results showed that coating fish fillets with CNPs and fennel EO significantly reduced the peroxide value, total volatile nitrogen, and thiobarbituric acid value compared with the control samples. Microbial analyses showed a lower number of mesophilic, psychotropic, pseudomonas, and lactic acid bacteria in coated fillets compared with control and MAP packaging. Fish fillets coated with CNPs and EO showed high acceptability in all sensorial attribute through the storage. It can be concluded that using CNPs and fennel EO along with MAP packaging can enhance the shelf life for H. huso fillets up to 18 days in the fridge.

Preservation of fatty acid signatures in three vertebrate species after six months of storage at various temperatures

Fatty acid (FA) signatures (FAS) are important tools to assess the foraging ecology of wild animals. The present study was conducted to assess how well the general FAS and the proportions of individual FA are preserved in fat samples stored at different temperatures (–196, –80, –20, +4 and +20°C). Using three species (laboratory rat, American mink and rainbow trout), FAS were determined immediately upon sampling. Thereafter, eight subsamples per storage temperature from the inner part of the sample unaffected by oxygen and light were re-analyzed after 1, 2, 3, 7, 28, 84 and 168 days. Each time the remaining sample was sealed in its vial after replacing air with nitrogen gas. The results were tested with the mixed model and discriminant analyses. Generally, the FAS were well preserved regardless of storage temperature, and only a few major FA showed significant changes even after the 6-month period at room temperature. After an initial first-day change in proportions, presumably due to post-mortem enzymatic activities, the remaining minor changes could not be clearly attributed to either further autolysis, decomposition or autoxidation. In the discriminant analysis, the species-specific differences dominated and remained distinct even after 6 months. Furthermore, the analysis mostly classified the samples preserved at sub- and above-freezing temperatures separate from each other, and the general deviation from the initial analysis results was present as early as after 1 day. If FAS are to be analyzed in a very precise manner, the analysis should be performed immediately upon sampling. However, FAS remain adequately reliable for long periods of time even without preservation in deep freeze, widening the availability of potential samples for studies on foraging ecology and related disciplines.

Nutritive values, flavor amino acids, healthcare fatty acids and flesh quality improved by manganese referring to up-regulating the antioxidant capacity and signaling molecules TOR and Nrf2 in the muscle of fish

Flesh quality, amino acid and fatty acid composition, antioxidant status and related molecule expression in fish muscle were estimated by feeding grass carp with diets containing 3.65-27.86mg/kg diet of manganese (Mn) for 8weeks. Results demonstrated that optimal Mn increased toughness, collagen content, and pH, and decreased the cooking loss, and cathepsin B and L activities to enhance the flesh quality of fish. Meanwhile, optimal Mn increased the protein, lipid, the total essential amino acid (AA) (especially umami AA), and healthcare fatty acids, C18: 1c+t, C20: 3n-3, C20: 4 and DHA contents. These might be partially related to the decreased lipid peroxidation and protein oxidation, and the enhanced activities of Mn superoxide dismutase (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) modulated by their gene expression, Nrf2 and TOR signaling. We firstly demonstrated that Mn improved flesh quality, flavor and healthcare function in fish muscle.

Flesh quality loss in response to dietary isoleucine deficiency and excess in fish: a link to impaired Nrf2-dependent antioxidant defense in muscle

The present study explored the impact of dietary isoleucine (Ile) on fish growth and flesh quality and revealed a possible role of muscle antioxidant defense in flesh quality in relation to dietary Ile. Grass carp (weighing 256.8±3.5 g) were fed diets containing six graded levels of Ile (3.8, 6.6, 9.3, 12.5, 15.2 and 18.5 g/kg) for eight weeks. The results indicated that compared with Ile deficiency (3.8 g/kg diets) and excess (18.5 g/kg diets) groups, 9.3–15.2 g Ile/kg diet supplementations promoted fish growth and muscle fat deposition, whereas 6.6–15.2 g Ile/kg diets supplementation enhanced muscle nutrients (protein and total EAAs) deposition. Furthermore, muscle shear force, pH value, and hydroxyproline concentration were improved by 9.3–12.5, 9.3 and 9.3 g Ile/kg diet supplementations, respectively. However, muscle cooking loss, lactate content, and activities of cathepsin B and L were decreased by 6.6–15.2, 9.3–12.5, 9.3–12.5 and 9.3–15.2 g Ile/kg diet supplementations, respectively. Additionally, 6.6–15.2 and 6.6–12.5 g Ile/kg diet supplementations attenuated malondialdehyde and protein carbonyl contents, respectively. The activities of copper/zinc superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GPx), and glutathione content were enhanced by 6.6–9.3, 6.6–12.5 and 6.6–15.2 g Ile/kg diet supplementations, respectively. Moreover, the relative mRNA expressions of antioxidant enzymes, including Cu/Zn-SOD (6.6–12.5 g/kg diets) and GPx (12.5 g/kg diets), as well as antioxidant-related signaling molecules, including NF-E2-related factor 2 (Nrf2) (6.6–12.5 g/kg diets), target of rapamycin (6.6–12.5 g/kg diets), ribosomal S6 protein kinase 1 (9.3–12.5 g/kg diets) and casein kinase 2 (6.6–12.5 g/kg diets), were up-regulated when Ile diet supplementations were administered at these levels, respectively, whereas the relative mRNA expression of Kelch-like ECH-associated protein 1 was down-regulated with 9.3 g Ile/kg diet supplementations. Collectively, the present study indicated that optimum isoleucine improved flesh quality, partly due to the activation of antioxidant defense through the Nrf2 signaling pathway.

Proximate composition and lipid stability of dourado (Salminus brasilensis, Cuvier, 1817) fillets exposed to different levels of ammonia and oxygen in vivo

BACKGROUND

The ammonia and oxygen levels of water are physicochemical parameters that affect fish physiology. Thus, we hypothesized that in vivo exposure to stressful ammonia and oxygen levels will affect the post-mortem quality of the fish. Therefore, in this study, the effects of in vivo exposure to stressful ammonia and oxygen levels on the composition and content of thiobarbituric acid reactive substances in fillets from dourado (Salminus brasiliensis) and on the lipid oxidation of these fillets during frozen storage were evaluated.

RESULTS

Short-term exposure (12 h) to stressful environmental conditions (low oxygen and high ammonia levels) did not change the composition of the flesh. However, longer exposure (15 days) to these stressful conditions caused significant changes in the composition of the flesh. Exposure to a stressful ammonia level before slaughtering increased the susceptibility of the fish fillets to lipid oxidation during frozen storage. In contrast, exposure to low oxygen levels did not increase the lipid oxidation rate of the fillets.

CONCLUSION

These results indicate that the in vivo exposure to high ammonia levels may reduce the quality and stability of dourado fillets.

Lipid stability during the frozen storage of fillets from silver catfish exposed in vivo to the essential oil of Lippia alba (Mill.) NE Brown

BACKGROUND

Lippia alba is effective in sedating and reducing stress to fish during transportation. Because some in vitro studies have demonstrated the antioxidant activity of L. alba, we hypothesized that its use in vivo could result in antioxidant effects post mortem. Therefore, in this study we evaluated whether the essential oil of L. alba (EO) used as sedative for fish transport would increase the lipid stability of fillets from silver catfish during frozen storage.

RESULTS

The exposure to the EO in vivo did not affect conjugated diene values. However, EO (30 and 40 µL L(-1)) delayed the peak formation of peroxides (from the third to the sixth month of storage) and thiobarbituric reactive substances (from the ninth to the twelfth month of storage) when compared to control fillets. After exposure to 40 µL L(-1) EO the free fatty acid content was higher than for control at the start of fillet storage, with no differences among groups thereafter.

CONCLUSION

The essential oil of L. alba used as sedative in the water to transport silver catfish can delay lipid oxidation of fillets during frozen storage. Thus L. alba may be a promising source of natural active compounds for use in aquaculture and the food industry.

Effect of dietary vitamin E on growth, muscle composition, hematological and immunological parameters of sub-yearling beluga Huso huso L

This study was designed to determine the effect of dietary vitamin E on growth, some hematological and immunological parameters and muscle proximate analysis of beluga Huso huso. Experimental fish were fed practical diets supplemented with 0, 25, 50, 100, 200 and 400 mg Dl-all-rac-α-tocopherol acetate kg diet(-1) for 8 weeks. 360 fish (mean initial weight 49.7 ± 0.1 g) were distributed into eighteen 785 L circular concrete tanks and each diet was fed to triplicate groups of fish. At the end of experiment (8 weeks), growth parameters such as final weight (FW), weight gain (WG), total length (TL), feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), condition factor (CF), hepatosomatic index (HSI), muscle composition, and some physiological indicators, including hematological and immunological parameters, such as hematocrit (Hct), total leukocyte count (WBC), lymphocyte, neutrophil, eosinophil and monocyte, cortisol, glucose, erythrocyte fragility, lysozyme and complement activity were determined. FW, WG, SGR, PER and CF in fish fed unsupplemented vitamin E were significantly lower than those fish fed the other five diets. However FW and PER in fish fed control diet had not significant differences with fish fed at 400 mg kg(-1). FCR were significantly higher in fish fed control diet than other groups. TL and survival rate had no significant differences among fish groups. HSI in fish fed 0 and 25 mg vitamin E kg diet(-1) were significantly lower than the other treatments. Muscle composition analysis showed no significant differences among the treatments. Erythrocyte fragility, Hct, WBC, lymphocyte, neutrophil, eosinophil and monocyte, lysozyme and complement activities were not significant. Also cortisol and glucose concentrations had not significant differences between treatments. Results indicated that vitamin E had no significantly effect on muscle proximate analysis, hematological and immunological parameters of sub-yearling beluga but has a direct effect on growth performance of beluga sturgeon and this vitamin is an essential nutrient required for normal growth in this species.