This study examined effects of rigor status (pre- vs post-rigor) and storage temperature (-10 vs -20 degrees C) on quality of snakehead fish meat. Pre-rigor frozen meat had lower thaw loss and centrifugation loss compared to post-rigor, likely due to a higher pH. Storage temperature did not affect the content of glycogen, lactic acid, and adenosine triphosphate (ATP), but the subsequent degradation of ATP-related compounds was altered in pre-rigor meat. In addition, protein denaturation and proteolysis was generally greater in post-rigor frozen meat. This study demonstrated that the timing of freezing is critical for the quality of frozen fish.
The pink perch (Nemipterus japonicus) is reported to harbor bacterial pathogens, and there is a lack of documented safe sanitization methods. This study aimed to isolate bacterial strains associated with pink perch fish, assess phytochemicals for their antibacterial activity, and evaluate the antibacterial mechanism of selected phytochemical compounds. Cinnamaldehyde showed potent activity against Psychrobacter sanguinis and Kurthia gibsonii (ZOI: 19.30-20.30 mm; MIC: 1.562-3.125 mg/mL), suppressing growth across all phases. Fish treated with cinnamaldehyde exhibited reduced MDA and carbonyl levels during 12-day refrigerated storage, with bacterial counts within safe limits and sensory qualities rated 'good' for 6 days.
This study evaluated the effects of seaweed type, soaking conditions, and drying methods on physicochemical and organoleptic properties of nori coatings, representing the first systematic evaluation using five Indonesian seaweed species. The optimal pretreatment was soaking in rice washing water for 24 h, followed by clean water for 48 h. Oven drying at 70 degrees C for 180 min produced the best nori coatings. Among the tested species, Euchema spinosum showed the most favorable characteristics, including a thickness of 0.103 +/- 0.01 mm and tensile strength of 539.80 +/- 66.54 gf, indicating its potential as a raw material for nori coatings.
Postmenopausal osteoporosis is characterized by progressive bone loss and an increased risk of fractures, while current pharmacological approaches mainly suppress bone resorption and present long-term limitations. This study aimed to evaluate the anti-osteoporotic potential of enzymatic hydrolysates derived from salmon (Oncorhynchus keta) head by-products (SBPE) as asustainable nutraceutical candidate for bone health. The hydrolysates from salmon (Oncorhynchus keta) head by-products were generated via peptic digestion, and chondroitin sulfate content was quantified using LC- MS/MS and revealing an average level of 124.33 +/- 10.07 mu g/mg. Osteogenic activity was evaluated in osteoblast cultures, zebrafish, and ovariectomized (OVX) rats. In MC3T3-E1 osteoblasts, SBPE increased alkaline phosphatase (ALP) activity by 16 +/- 2.18%, elevated osteoprotegerin (OPG) expression by 8.76 +/- 1.24%, and reduced receptor activator of nuclear factor-kappa B ligand (RANKL) levels by 11.71 +/- 1.77%, indicating enhanced osteogenic differentiation. SBPE also significantly increased skeletal mineralization in zebrafish in adose-dependent manner (25-100 mu g/mL) and preserved bone mass and trabecular architecture in OVX rats. X-ray micro-computed tomography (Micro-CT) analysis confirmed structural improvement, while serum osteocalcin and alkaline phosphatase levels increased without adverse effects. These findings demonstrate that chondroitin sulfate-enriched salmon by-product hydrolysates exert bone-protective effects across multiple models, highlighting their potential as asustainable nutraceutical resource for preventing postmenopausal osteoporosis and promoting bone health.
This study involved fermentation of an underutilized fish species with low commercial value. The ferment used is one of the most important food-grade molds employed in industrial production. Fish fermentation in West Africa is most often of the lactic type, which differs from our study using Aspergillus oryzae. This type of fermentation is interesting because it could enhance the product nutritionally, thanks to the fungus's strong enzymatic capacity. This manuscript describes a technology for the production of fermented fish and an assessment of product quality. These results are important for the formulation of natural broths.
Compared effect of 4-hexylresorcinol (4 HR) and beetroot powder (BT) to sodium metabisulfite (SMS) in Fennereopenaeus indicus (Indian prawn) to prevent melanosis in telson region of frozen thawed pre-cooked peeled undeveined (PUD) tail-on shrimp during refrigeration. Total volatile base nitrogen (TVBN) of 4 HR and BT reached 35 mg N/100 g on 18th day of storage, while SMS reached 30.8 mg N/100 g. Aerobic plate count and psychrotrophic count of SMS exceeded 5 and 7 log CFU/g, respectively, on 14th day, while in 4 HR and BT on 18th day. Moderate melanosis was observed in SMS from the 4th day until the end, while in BT and 4 HR slight melanosis was observed throughout storage.
To investigate the role of the structural characteristics of different fat types in the construction of fish paste gel networks, this study used soy protein isolate to construct high internal phase emulsions (HIPEs) with lard, olive oil, and sunflower oil. Fat type significantly affected droplet size, interface structure, and rheology. Sunflower oil HIPE (rich in unsaturated fatty acids) formed a flexible interfacial film with high stability. Compared to direct oil addition, HIPEs reduced spatial interference with protein crosslinking, constructing a denser gel network. This provides a theoretical basis for lipid design in aquatic products.
This study investigated arginine-modified surfactin (Arg-Surfactin) as a preservative for large yellow croaker. Arg-Surfactin exhibited enhanced antibacterial efficacy against Pseudomonas fluorescens (MIC: 1.0 mg/mL, MBC: 4.0 mg/mL) and Shewanella putrefaciens (MIC: 0.125 mg/mL, MBC: 0.5 mg/mL), surpassing the performance of surfactin with improved thermal stability. It induced membrane damage by increasing permeability, nucleic acid leakage, and cellular deformation, and can effectively extend the shelf life of large yellow croaker. Microbiome analysis revealed a significant reduction in Pseudomonas spp. abundance. These findings highlight Arg-Surfactin potential as a novel bio-preservative for aquatic products by targeting spoilage bacteria through membrane disruption mechanisms.
Low trophic marine species are rich in nutrients, making them valuable for food and feed applications. However, these species contain endogenous enzymes that quickly lead to the rapid deterioration of the raw material after harvest. This study investigates how temperature and pH influence proteolytic enzymes in Calanus, krill, Benthosema glaciale, Maurolicus muelleri, and an unsorted biomass sample. Protease activity peak occurred at 50 degrees C for all species, and temperatures above 60 degrees C reduced activity. Across species, Calanus showed the highest proteolytic activity. Future research should focus on enzyme characterization and technological processes to control enzymatic activity while preserving nutrient quality.
This study investigated the effects of carrageenan, konjac flour, and nettle extract (NE) on reduced-salt restructured trout steaks. Eight formulations (2% or 1% salt, with/without hydrocolloids and/or 200 ppm GAE NE) were evaluated. Hydrocolloids altered composition and significantly improved water holding capacity and cooking yield. Carrageenan increased hardness, gumminess, and chewiness, whereas konjac produced softer textures. Konjac limited lipid oxidation, while NE showed limited antioxidant efficiency. Both konjac and NE reduced trimethylamine levels. Salt reduction did not affect sensory acceptability, although NE slightly decreased texture scores. Hydrocolloid selection may enhance quality and delay deterioration in low-salt fish products.
The aim of this study was to evaluate the quality of mechanically separated tilapia meat (MSM) obtained from fish below commercial size at different rigor mortis stages. One hundred five tilapia specimens donated by a producer in Paraiba, Brazil were classified into two weight classes (<150 g and >150 g) and evaluated at three rigor mortis stages: pre-rigor, rigor mortis, and full rigor. Regarding the proximate composition, MSM from tilapia weighing < 150 g exhibited higher moisture (79.95 +/- 1.06%) and ash (1.42 +/- 0.09%) contents and a lower lipid content (2.88 +/- 0.25%), compared to the >150 g class. The rigor stages only influenced the calcium content, with MSM in the pre-rigor stage showing the highest value (1.48 +/- 0.05 mg/100 g) (p < 0.05). In terms of thiobarbituric acid reactive substances (TBARS) values, the smaller tilapia MSM (<150 g) exhibited the lowest value (2.15 +/- 0.25 mg MDA/kg of sample) at the end of frozen storage. Among the rigor mortis stages, MSM obtained during the rigor mortis phase showed the lowest value (2.07 +/- 0.24 mg MDA/kg of sample) at the end of frozen storage. Specifically, smaller tilapia exhibited better oxidative stability and a more favorable composition, while rigor mortis affected parameters such as calcium and TBARS. These findings highlight the potential for sub-commercial size fish for value-added products.
This study investigated ice cream enriched with fish roe oil, substituting cream at 0, 5, 10, and 20%. The extracted oil, rich in unsaturated fatty acids, was encapsulated using enzymatically hydrolyzed defatted fish roe. Microcapsules showed high encapsulation efficiency (87.63 +/- 1.74%) and spherical morphology. Ice cream with 5% enrichment maintained desirable texture and microstructure. Higher enrichment reduced oxidative stability, with 20% showing increased lipid oxidation and presence of volatile compounds, especially hexanal. Sensory quality degraded at 20% fortification. Overall, incorporating up to 5% encapsulated fish roe oil and protein hydrolysate is promising for functional ice cream without quality compromise.
Glycation via the Maillard reaction (MR) is a safe and economical alternative for the technological and bioactive utilization of some animal by-product proteins. The study focused on the controlled glycation of these proteins using glucose and dextran at 50 degrees C for 6 hours. The resulting glycoconjugates demonstrated significant antioxidant activity (TEAC), inhibition of oxidative hemolysis, chelation of metals (Fe+2 and Cu+2), and the ability to inhibit angiotensin-converting enzyme (ACE). Although they exhibited weak antimutagenic activity, the findings suggest that the glycation of giant squid by-products could lead to their potential use as functional food or nutraceutical ingredients due to their bioactive properties.
To optimize the prawn peeling machine, the PSO-BP-NSGA-II algorithm was proposed to refine parameters, including the speeds, inclination angle, and reciprocating angle of the rollers, and rubbing frequency. A multi-objective optimization model was developed targeting peeling success rate and meat yield. Experimental validation under optimal parameters of large roller at 59 r/min, small roller at 41 r/min, 18 degrees inclination, 188.5 degrees reciprocating angle, and 89 rubs/min, achieved 92.95% peeling success rate and 78.51% meat yield. Compared to RSM, the proposed method increased peeling success by 5.47% and meat yield by 1.27%. The results support research on the automated shrimp-processing products.
This study examined the effects of different impregnation methods and solutions on texture of soft-pack (retort) canned abalone. Results showed that room temperature and pressure immersion, with either pure water or sodium alginate, did not significantly affect abalone meat hardness. Ultrasonic immersion caused myofibril rupture, leading to a looser structure. Combining sodium alginate with ultrasonic immersion decreased hardness. Vacuum immersion utilized negative pressure to create larger voids, accelerating sodium alginate absorption and enhancing water retention, achieving tenderization without lipid oxidation. Overall, sodium alginate and vacuum impregnation proved most effective for improving abalone texture.
In this study, we evaluated the effects of pomegranate juice as a natural additive in marinated pike-perch (Sander lucioperca) stored at 4 degrees C for 120 days. Quality was assessed through physico-chemical, microbiological, and sensory analyses. Pomegranate juice decreased solids content and salt, reduced L* values and increased a* values, and significantly limited rises in TVB-N and TBA compared to the control. Total mesophilic and psychrotrophic bacteria, as well as yeasts and molds declined during storage, whereas lactic acid bacteria levels increased. Sensory scores decreased over time, and samples became unacceptable by day 90. Overall, pomegranate juice showed potential as a functional ingredient.
