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The aim of this study was to investigate the preservative properties of alga Gelidium sp. flour when included in the glazing medium employed for the frozen storage (−18 °C) of horse mackerel (Trachurus trachurus). Different concentrations (low, medium, and high) of an aqueous extract were tested and compared to a control water-glazing condition. Quality changes (lipid oxidation and hydrolysis, fatty acid (FA) profile, and trimethylamine (TMA) formation) were determined after 3- and 6-month storage periods. A general quality loss (lipid oxidation with hydrolysis development and TMA formation) with the frozen storage period was detected in all samples. The presence of an alga flour (AF) extract in the glazing medium led to a lower (p < 0.05) TBARS and fluorescent compound formation and to higher (p < 0.05) polyene values in frozen fish. Furthermore, a preserving effect on free fatty acids was detected in AF-treated fish. On the contrary, the AF-glazing treatment did not affect (p > 0.05) the TMA formation and the total n3/total n6 FA ratio. In general, preservative effects were found to be higher in frozen fish corresponding to the medium concentration tested. Current results show the potential of Gelidium sp. flour as a natural source of preservative hydrophilic compounds for the quality enhancement of frozen horse mackerel. [ABSTRACT FROM AUTHOR]

Kudoa thyrsites infection of marine fish typically results in myoliquefaction, which is only apparent 24 to 56 h post‐mortem. The traditional methods for the detection of K. thyrsites infected fish are time‐consuming and destructive, reducing its marketability. This poses a challenge for the fish industry to remove infected fish before it reaches the market or further processing activities. This study investigated the use of near‐infrared (NIR) spectroscopy, in combination with soft independent modelling of class analogy (SIMCA) and partial least square discriminant analysis (PLS‐DA), for discriminating K. thyrsites infected fish from uninfected fish. Performance of the classification models was evaluated by calculating the sensitivity, specificity and precision. A total of 334 fish samples (200 sardine, 64 hake and 70 kingklip) were used for this study. Infection of K. thyrsites was determined with the use of qPCR assays. Ninety per cent (90%) of the sardine samples, 78% of the hake samples and 37% of the kingklip samples were infected. Class groups of infected and uninfected fish samples were created for the purpose of generating SIMCA and PLS‐DA classification models for each species of fish, as well as for a species independent data set. Principal component analysis (PCA) of NIR spectra did not show any clustering for infected and uninfected samples. Calibration and test sample sets were generated for the purpose of building and testing the SIMCA and PLD‐DA classification models. SIMCA and PLS‐DA were unable to classify test samples correctly into the two classes. The number of misclassifications (NMC) was higher for the SIMCA models than for the PLS‐DA models, with more than 60% incorrectly classified. SIMCA classified most of the test samples into both classes. The precision for PLS‐DA were 89% for sardine, 81% for hake, 0% for kingklip and 87% for species independent models, however, most samples were classified at infected. The use of NIR spectroscopy and classification models such as SIMCA and PLS‐DA showed limited use as a method to distinguish between K. thyrsites infected and uninfected fish samples. Textural and chemical changes during extended frozen storage of the fish samples may have masked the effects associated with K. thyrsites infection. Further studies are suggested where NIR spectroscopy is used in combination with texture analysis and image spectroscopy. [ABSTRACT FROM AUTHOR]

Marine sponges have recently emerged as efficient natural environmental DNA (eDNA) samplers. The ability of sponges to accumulate eDNA provides an exciting opportunity to reconstruct contemporary communities and ecosystems with high temporal and spatial precision. However, the use of historical eDNA, trapped within the vast number of specimens stored in scientific collections, opens up the opportunity to begin to reconstruct the communities and ecosystems of the past. Here, we define the term 'heDNA' to denote the historical environmental DNA that can be obtained from the recent past with high spatial and temporal accuracy. Using a variety of Antarctic sponge specimens stored in an extensive marine invertebrate collection, we were able to recover information on Antarctic fish biodiversity from specimens up to 20 years old. We successfully recovered 64 fish heDNA signals from 27 sponge specimens. Alpha diversity measures did not differ among preservation methods, but sponges stored frozen had a significantly different fish community composition compared to those stored dry or in ethanol. Our results show that we were consistently and reliably able to extract the heDNA trapped within marine sponge specimens, thereby enabling the reconstruction and investigation of communities and ecosystems of the recent past with a spatial and temporal resolution previously unattainable. Future research into heDNA extraction from other preservation methods, as well as the impact of specimen age and collection method, will strengthen and expand the opportunities for this novel resource to access new knowledge on ecological change during the last century. [ABSTRACT FROM AUTHOR]

Enterococci, common hospital-acquired infections in immunocompromised patients, have garnered attention in clinical microbiology. To determine the clinical relevance of enterococci as food-borne pathogens, 116 fish, 90 vegetables, and 120 human diarrheal samples were tested for E. faecalis and E. faecium pathogenicity. Conventionally, 69 of 326 (21.17%) samples were positive for Enterococcus species, 52 (15.95%) of which were molecularly classified as E. faecalis and 13 (3.99%) as E. faecium. The E. faecalis contamination percentage of fresh fish (19.70%) was higher than frozen fish (4%). Cauliflower had the highest E. faecalis percentage (16.67%) when fish and vegetable samples didn't harbor the E. faecium atpA gene. 23.33% and 10.83% of participants' samples were molecularly confirmed as E. faecalis and E. faecium positive, respectively. E. faecalis isolates had all virulence genes, with gels being the most common (65.38%), while cylA and asa1 genes couldn't be detected in E. faecium isolates. E. faecalis showed the highest resistance against vancomycin and tetracycline (69.23%), whereas E. faecium extremely resisted tetracycline (76.92%) and erythromycin (69.23%) with the recognition of MDR among 44.2% of E. faecalis and 38.5% of E. faecium isolates. The great similarity of our isolates showed the clinical importance of food-borne antibiotic-resistant enterococci. [ABSTRACT FROM AUTHOR]

Tuna is delicious and nutritious, and it needs to be thawed before consumption as sashimi. The quality of tuna is closely related to the thawing method. This paper studied natural air thawing, water soaking thawing, flowing water thawing, and microwave thawing. The best thawing method was obtained by analyzing the water holding capacity, texture, chromatic aberration and other indicators of tuna. The results showed that the pH of tuna was positively correlated with its water holding capacity while a negative correlation was observed between metmyoglobin (Met Mb) and redness value. Compared with other three thawing methods, water soaking had the lowest thawing loss rate, and water holding capacity and redness value of the tuna were the highest. Besides, it did not denature proteins obviously, and it arranged muscle bundles closely and the hardness and adhesiveness of the tuna were the best. In conclusion, water soaking thawing can better maintain the quality of tuna, and further research can be conducted to optimize the water soaking thawing process. the LV group can better maintain the color, texture, freshness ［ (8. 367±0. 404) mg/ 100 g], and water-holding capacity (77. 827%±0. 215%) of the tuna meat, and it can effectively inhibit the oxidation of lipids and proteins during the thawing process of tuna. At the same time, the LV group showed the smallest damage to the microstructure. In conclusion, low-voltage electrostatic field thawing can maintain tuna meat quality better. This paper provides the theoretical basis and practical exploration for improving the thawing quality of frozen fish products. [ABSTRACT FROM AUTHOR]

Summary: The quality of fish is easily damaged during the frozen process, and the ice glazing technology can better maintain the quality of frozen fish. However, the traditional ice glazing technology is not yet stable and some of the properties need to be improved. This research optimised ice glazing technology by adding different antioxidants to the traditional ice glazing, which improved the stability of the ice glazing and lessened the dry consumption of mackerel during frozen storage. The lipid oxidation and protein denaturation of mackerel were inhibited with the addition of antioxidants to the ice glazing, the freshness of mackerel was maintained better, and the production of histamine was also decreased during frozen storage. It was found that the ice glazing with the addition of antioxidant bamboo leaves (AOB) had better water retention, lower TVB‐N value, and histamine content compared to the addition of theaflavins (TF) and sodium isovitamin (VC). Moreover, the sample treated by the ice glazing with AOB showed less lipid oxidation and protein denaturation. Therefore, ice glazing with the addition of AOB could be an optional method for relieving the quality deterioration of mackerel during frozen storage. This research also provides insights into the coupling of antioxidants and ice‐coating techniques. [ABSTRACT FROM AUTHOR]

We hypothesized that removing water from fish muscle homogenate by freeze‐drying might be a cost‐effective way to stabilize nutrients and allow higher temperatures for long‐term frozen storage prior to analytical measurements. To test our hypothesis, fish muscle fillets from lipid‐rich farmed Atlantic salmon (n = 5) and lean wild‐caught European plaice (n = 5) were homogenized and fresh‐frozen at −20 and −80°C. A subset of these samples was freeze‐dried prior to further frozen storage at the respective temperatures. Using validated methods, vitamins, amino acids, and fatty acids were measured after a short time of storage (starting point) and up to 1 year (endpoint), with intermediate analytical checkpoints of 1, 3, and 6 months. Trends in the degradation of certain nutrients during the different frozen storage conditions are discussed. In general, by freeze‐drying fish homogenate samples prior to frozen storage at −20°C for up to 1 year, amino acids, vitamins, and fatty acids were stabilized in both salmon and plaice when compared to wet‐frozen storage of the same samples, and storage at −80°C did not improve preservation of the freeze‐dried samples. For wet‐frozen samples, −80°C would be recommended for 1‐year storage of fillet homogenate samples, even though several nutrients preserved well at −20°C. Practical Application: We present individual nutrient stability profiles in muscle homogenates from fatty fish (salmon) and lean fish (plaice) during different frozen storage conditions over time. Based on these data, freeze‐drying followed by frozen storage at −20°C for at least 1 year could be applied prior to analyses of amino acids, fat‐soluble vitamins, water‐soluble vitamins, and fatty acids. Of note is that freeze‐drying followed by frozen storage before analysis led to slightly increased measurements of several fatty acids in plaice samples, possibly attributable to an increase in dry weight or an enhancement in extraction efficiency through freeze‐drying. [ABSTRACT FROM AUTHOR]

Fish make up an essential component of daily diets due to their nutritional composition. In this study, formalin concentration in imported fish products in Bayelsa State, Nigeria, was undertaken. The effect of household heat processing treatments on the formalin concentrations, and the potential risk associated with consumption of these fish products, were evaluated. Fish products of different species were obtained from wholesale and retail outlets, and were prepared as raw, cooked, fried and smoked samples. Formalin was extracted from the prepared fish samples using a mixture of acetone and dichloromethane, and quantified using GC-MS. The average daily intake (ADI) of formalin was used to estimate potential health risk. Results showed low concentration of formalin in the raw fish samples, while heat processing treatments (frying and boiling) significantly elevated formalin concentrations. The formalin concentrations of heat processed fish samples with respect to the raw samples followed the order: smoked < raw < boiled < fried; and raw < smoked < boiled < fried for wholesale and retail products respectively. However, all formalin concentrations were below guideline values. The ADI of formalin were below established guideline values, suggesting that the intake of formalin in fish before and after household heat processing treatments may not pose significant risk to consumers of the imported frozen fish products. [ABSTRACT FROM AUTHOR]

Morganella morganii is a psychrotolerant organism recognized as a histamine-producing bacteria by decarboxylation of histidine amino acid, it has been involved in cases of histamine fish poisoning reported in different seafood products. In this study, we collected a total of 125 random samples of frozen Mackerel fish stored at -18°C from different fish markets in New Valley Governorate, Egypt. Through isolation from the tissue of fish samples on Chromogenic agar plates, bacteria forming light brown colonies were identified. Confirmatory identification of bacteria was conducted using 16S rRNA as a species-specific gene, revealing the presence of 14 M. morganii strains from samples, representing an incidence of 11.2% of all samples. Morganella morganii is a prominent adaptive nosocomial bacterium that can cause urinary tract infections and bacteremia. [ABSTRACT FROM AUTHOR]

Monopterus albus is one of China's renowned and superior aquaculture species, with its seedlings mainly sourced from wild capture. One of the bottlenecks in M. albus aquaculture is the high mortality rate and low feeding initiation rate from stocking wild fry to the initiation of feeding. In production, trash fish is commonly used to wean M. albus juveniles onto feeding. In this study, we introduced three other natural feeds, earthworms (EW), yellow mealworms (YMW), and fly maggots (FM), with frozen trash fish (TF) serving as the control group, to evaluate the effects of these four natural feeds on the survival rate, feeding initiation, antioxidant enzymes activity, and body composition of M. albus juveniles under recirculating water aquaculture conditions. The experiment comprised four treatments, each with three replicates. Each replicate consisted of stocking 150 M. albus juveniles weighing 10.02 ± 0.89 g in size, raised for 5 weeks. The survival rate of the YMW group was 73.33%-85.33%, which was significantly higher than that of the other three bait groups (p < 0.05). The four bait groups showed no significant differences in final body weight and specific growth rate (SGR) (p > 0.05). The EW group showed the highest final body weight, with an average SGR of 2.73, whereas the YMW group had an average SGR of 1.87. The average daily feeding amount was significantly higher in EW and YMW groups than in the other two groups (p < 0.05). The percentage of feeding amount to fish weight in the EW group reached 7.3% in the fifth week. After 5 weeks of cultivation, NO2--N content was significantly higher in the waters of the TF and EW groups than in the waters of the FM and YMW groups (p < 0.05), there was no significant difference in TAN content among the treatment groups (p > 0.05). Liver malondialdehyde content was significantly higher in the TF group than in the other bait groups (p < 0.05). GSH-Px activity was significantly higher in the EW group than in the FM group and YMW group. No significant differences in SOD and CAT activity and T-AOC were observed among the bait groups (p > 0.05). The increase in crude protein content was significantly higher in the TF group than in the FM group, but the increase in crude ash content was significantly lower in the TFgroup. In conclusion, Tenebrio molitor could potentially serve as one of the alternative feeds during the initial stages of M. albus juveniles stocking. [ABSTRACT FROM AUTHOR]

Introduction: Trace metals in fish play different important roles, both for the fish itself and humans who consume them. However, some of these metals are toxic at low concentrations, and are considered as health hazards. In this study, the concentration of six trace metals (Pb, Cd, Ni, Cu, Mn and Zn) were determined in imported frozen fish species available in Bayelsa State, Nigeria. The effect of domestic heat processing techniques (cooking, frying and smoking) on the trace metals concentration, and the potential risk due to consumption of these metals in fish were also evaluated. Methods: Six different species of imported frozen fish species were purchased from wholesale and retail outlets, and were prepared as raw, cooked, fried and smoked samples. A mixture of acids was used for digestion of fish samples, while Flame atomic absorption spectrometer was used for quantification of metals. The hazard index was employed for evaluating the non-carcinogenic risk of metals in fish. Results: The average trace metals concentration in the raw fish samples followed the order: Zn > Cu > Cd > Ni > Mn. Pb was undetected in all fish samples. The concentration of the detected trace metals ranged as follows - Cd: 3.45–9.40 mg/kg, Ni: 1 for both child and adult exposure scenarios. Conclusion: The results suggest trace metal contamination of fish samples by Cd, with significant potential non-carcinogenic risk. Since Cd is toxic, continuous screening of imported fish products is necessary, in order to safeguard public health.

Objective/Background: Oncorhynchus mykiss is the most popular type of freshwater fish consumed by Iranians. It has delicious taste and high nutritional value. The purpose of processing and preserving fish is to get it to the end consumer in a good, usable condition. Methods: This study is a descriptive study that compares and determines the analysis results of proximate, protein, and fat between fresh and processed fish using the standard method of AOAC and compares the analysis of this study with that of other studies. The effect of the processing methods' nutritional composition is determined. In addition to fresh fish, 5 treatments are used for the 5 different methods of fish processing. Results: The fresh fish and the different processed samples were analyzed by standard AOAC methods, and their pH was measured. After analyzing the macronutrient compounds of different samples, the energy values were then calculated in kcal. The moisture content ranged from 72.50% for fresh fish to 19.50% for frozen fish, while the fat content ranged from 8.09% for fresh fish to 64.47% for frozen fish. The ash contents were found to range from 4.82% to 5.82%, while the protein contents were found to range from 10.47% to 13.59%. The results showed that quick freezing of fish preserved nutrients with a high percentage of energy. This sample was recommended for consumption, followed by samples thawed in oven and in hot water. The fried and boiled samples were in the next stages of quality and energy values. Conclusions: Because the fat content of this type of fresh fish is high, and if fish feed and its nutrition are protein materials with high biological value, it will be useful to increase the percentage of meat protein for it to grow. [ABSTRACT FROM AUTHOR]

The giant grouper fish (Epinephelus lanceolatus), one of the largest and rarest groupers, is a fast-growing economic fish. Grouper sperm is often used for cross-breeding with other fish and therefore sperm cryopreservation is important. However, freezing damage cannot be avoided. Herein, we performed a transcriptome analysis to compare fresh and frozen sperm of the giant grouper with frozen storage times of 0, 23, 49, and 61 months. In total, 1911 differentially expressed genes (DEGs), including 91 in El-0-vs-El-23 (40 upregulated and 51 downregulated), 251 in El-0-vs-El-49 (152 upregulated and 69 downregulated), and 1569 in El-0-vs-El-61 (984 upregulated and 585 downregulated), were obtained in the giant grouper sperm. DEGs were significantly increased at 61 months of cryopreservation (p < 0.05). GO and KEGG enrichment analyses of the DEGs revealed significant enrichment in the pilus assembly, metabolic process, MAPK signaling pathway, apoptosis, and P53 signaling pathway. Time-series expression profiling of the DEGs showed that consistently upregulated modules were also significantly enriched in signaling pathways associated with apoptosis. Four genes, scarb1, odf3, exoc8, and atp5f1d, were associated with mitochondria and flagella in a weighted correlation network analysis. These genes may play an important role in the response to sperm freezing. The experimental results show that long-term cryopreservation results in freezing damage to the giant grouper sperm. This study provides rich data for studies of the mechanism underlying frozen fish sperm damage as well as a technical reference and evaluation index for the long-term cryopreservation of fish sperm. [ABSTRACT FROM AUTHOR]

Marine foods are highly perishable products due to their high content of polyunsaturated fatty acids, which can be readily oxidized to form peroxides and secondary oxidation products, thus conferring such foods undesirable organoleptic characteristics and generating harmful compounds that are detrimental to the health of consumers. The use of preservation methods that minimize lipid oxidation is required in the fishing and aquaculture industries. Low temperature storage (chilling or freezing) is one of the most commonly used preservation methods for fish and seafood, although it has been shown that the oxidation of the lipid fraction of such products is partially but not completely inhibited at low temperatures. The extent of lipid oxidation depends on the species and the storage temperature and time, among other factors. This paper reviews the effect of low temperature storage on the lipid quality of fish, either alone or in combination with other preservation techniques. The use of antioxidant additives, high hydrostatic pressure, irradiation, ozonation, ultrasounds, pulsed electric fields, and the design of novel packaging can help preserve chilled or frozen fish products, although further research is needed to develop more efficient fish preservation processes from an economic, nutritional, sensory, and sustainable standpoint. [ABSTRACT FROM AUTHOR]

Summary: Thawing is necessary to restore the freshness of fish before cooking because fish is often frozen to retain its freshness. Frequently, fish is partially thawed (or 'tempered') as it is easier to handle in this form than fully thawed fish. However, the conventional tempering techniques – immersion in water and still air tempering – take a long time and alter the fish's characteristics. Hence, the aim of this study was to use the heat generated inside the frozen fish, or ohmic heating, to alter the tempering process. Compared with conventional tempering operations, in this study, three voltage levels (20, 30 and 40 V/cm) were used for ohmic tempering. The fish quality and yield findings revealed that 30‐V/cm ohmic heating was more appropriate, even though ohmic heating at 40 V/cm provided the shortest tempering time. The main operating expense for ohmic tempering was the power cost of USD 58.5/100 kg, whereas the major operating expense for water immersion was the cost of water supply and wastewater treatment, which was around USD 108/100 kg. By using ohmic heating instead of still air and water immersion to temper the frozen fish, not only was less time required while retaining the freshness of the fish but the cost of tempering was also reduced. [ABSTRACT FROM AUTHOR]

The current study was conducted to determine the impact of immersion using garlic, sumac, and citric acid on certain qualitative characteristics of Japanese threadfin bream (Nemipterus japonicus) during frozen storage. Fish were immersed with 1% addition of each natural substance and stored at -18 C for 150 days. The results revealed that immersion with garlic, sumac, and citric acid prevented lipid oxidation and reduced the production of free fatty acids (FFA), volatile nitrogen bases (TVN), and thiobarbituric acid (TBA) in the groups treated with natural substances compared to untreated and water-immersed groups. The lowest pH value was 6.11 at day zero for the frozen fish, which increased to 6.98 at the end of storage for the same treatment. The lowest TVN, FFA, and TBA values were observed in the garlic-treated fish at day zero: 4.2mg nitrogen/100g fish, 0.12%, and 0.27mg malondialdehyde/100g fish, respectively. These values increased significantly during the final storage period to 29.4mg nitrogen/100g fish, 0.88%, and 5.41mg malondialdehyde/100g fish for the frozen fish only at 150 days of storage, with significant differences among treatments and storage periods (P<0.05). The lowest percentage of lost fluids was 2.33% for the garlic immersion treatment at day zero, while the highest value was 5.49% for the frozen fish only at 150 days. In conclusion, the study demonstrated the potential use of these substances in immersion as natural antioxidants and inhibitors of enzymatic, microbial, and quality loss. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the preservative properties of alga Gelidium sp. flour when included in the glazing medium employed for the frozen storage (−18 °C) of horse mackerel (Trachurus trachurus). Different concentrations (low, medium, and high) of an aqueous extract were tested and compared to a control water-glazing condition. Quality changes (lipid oxidation and hydrolysis, fatty acid (FA) profile, and trimethylamine (TMA) formation) were determined after 3- and 6-month storage periods. A general quality loss (lipid oxidation with hydrolysis development and TMA formation) with the frozen storage period was detected in all samples. The presence of an alga flour (AF) extract in the glazing medium led to a lower (p < 0.05) TBARS and fluorescent compound formation and to higher (p < 0.05) polyene values in frozen fish. Furthermore, a preserving effect on free fatty acids was detected in AF-treated fish. On the contrary, the AF-glazing treatment did not affect (p > 0.05) the TMA formation and the total n3/total n6 FA ratio. In general, preservative effects were found to be higher in frozen fish corresponding to the medium concentration tested. Current results show the potential of Gelidium sp. flour as a natural source of preservative hydrophilic compounds for the quality enhancement of frozen horse mackerel.

Salting pretreatment is an effective method to improve the quality of frozen fish. This study investigated the quality changes and proteomic profile differences of frozen yellowfin tuna fillets pretreated with ultrasound-assisted salting (UAS) and static salting (SS). This study was centered on three aspects: physicochemical indicators' determination, histological observation, and proteomic analysis. The results showed that UAS significantly increased yield, salt content, and water-holding capacity (WHC), decreased total volatile base nitrogen (TVBN) compared to SS (p < 0.05), and significantly increased water in the protein matrix within myofibrils. Histological observations showed that the tissue cells in the UAS group were less affected by frozen damage, with a more swollen structure and rougher surface of myofibrils observed. Furthermore, 4D label-free proteomics revealed 56 differentially abundant proteins (DAPs) in UAS vs. NT comparison, mainly structural proteins, metabolic enzymes, proteasomes, and their subunits, which are associated with metabolic pathways such as calcium signaling pathway, gap junction, actin cytoskeletal regulation, and necroptosis, which are intimately associated with quality changes in freeze-stored tuna fillets. In brief, UAS enhances the potential for the application of salting pretreatment to improve frozen meat quality, and 4D label-free proteomics provides knowledge to reveal the potential links between quality and molecular changes in processed frozen meat to optimize future UAS meat processing. [ABSTRACT FROM AUTHOR]

Validation of sensory evaluation employs a process similar to any other method validation procedure in analytical chemistry. However, the parameters often measured in sensory testing are different, because the human sensory apparatus and brain are the instruments being calibrated. A total of 10 fish samples were examined by an expert 5-member evaluation panel for the visual presence of parasites in frozen fish. From each frozen hake sample, a group of six slices of fish muscle was formed by longitudinal sectioning. The total of 60 sliced samples were divided into 10 plates with six samples each. The first plate contained six slices, each of which contained parasites. The attribute agreement analysis showed strong agreement in the overall ratings. It was found that at least 75% of all tests achieved the highest level of agreement. The results of the tests were presented in the form of tables and graphs summarizing the subjective test results using Fleiss' Kappa and Cohen's Kappa statistics. [ABSTRACT FROM AUTHOR]

In the history of industrial freezing in France, World War One is often seen as a watershed. Lacking adequate channels of its own to import frozen meat for soldiers, France became dependent on British supply networks, which later served as a basis for the interwar expansion of French cold chains. However, focusing on the wartime connection to Britain obscures prewar French initiatives to freeze meat and fish notably in the empire. Examining such initiatives, as well as contemporary debates about how to make more animal protein available and whence to draw it, this article emphasizes how imperial freezing initiatives inspired expanded use of freezing in interwar France. Prewar experiments gained little immediate traction and war hindered them in the short term, but in the longer term, they were at least as important as war experiences in shaping the interwar development of frozen food in France. [ABSTRACT FROM AUTHOR]

The differentiation of fresh and frozen-thawed fish is a relevant authenticity aspect as in the European Union fish holds a high statistical risk of being adulterated. Here, nuclear magnetic resonance spectroscopy (NMR) in combination with principal components analysis followed by linear discriminant analysis (PCA-LDA) was used for a non-targeted based differentiation of fresh from frozen-thawed fish. To identify the most promising NMR approach(es), six different approaches were applied to 96 fish samples (mackerel, trout, cod). These approaches included different sample preparation procedures and different NMR methods to investigate both the lipid fraction and the polar fraction of the fish samples. After cross-validation embedded in a Monte Carlo resampling design, six independent classification models were obtained. Evaluation of the multivariate data analysis revealed that the most promising approaches were the 1H NMR analysis of the lipid fraction (correct prediction of about 90.0%) and the 1H NMR based screening of minor components of the lipid fraction with a correct prediction of about 91.9%. 1H NMR analysis of the water extract of the fish samples showed a correct prediction of about 82.6%. Hence, a general differentiation of fresh from frozen-thawed fish via non-targeted NMR is feasible, even though the underlying sample batch contained different fish species. Additional fish samples need to be analyzed with the three most promising NMR approaches to further improve the developed classification models. [ABSTRACT FROM AUTHOR]

In Taiwan, the number of applications for inspecting imported food has grown annually and noncompliant products must be accurately detected in these border sampling inspections. Previously, border management has used an automated border inspection system (import food inspection (IFI) system) to select batches via a random sampling method to manage the risk levels of various food products complying with regulatory inspection procedures. Several countries have implemented artificial intelligence (AI) technology to improve domestic governmental processes, social service, and public feedback. AI technologies are applied in border inspection by the Taiwan Food and Drug Administration (TFDA). Risk management of border inspections is conducted using the Border Prediction Intelligent (BPI) system. The risk levels are analyzed on based on the noncompliance records of imported food, the country of origin, and international food safety alerts. The subjects of this study were frozen fish products, which have been under surveillance by the BPI system. The purpose of this study was to investigate the relevance between the noncompliant trend of frozen fish products using the adoption of the BPI system and the results of postmarket sampling inspections. The border inspection and postmarket sampling data were divided into two groups: IFI and BPI groups (corresponding to before and after the adoption of the BPI system, respectively). The Chi-square test was employed to analyze the noncompliant differences in products between before and after the BPI system adoption. Despite the number of noncompliance batches being statistically insignificant after the adoption of the BPI system, the noncompliance rate of frozen fish products at the border increased from 3.0% to 4.7%. Meanwhile, the noncompliance rate in the postmarket decreased from 2.1% to 1.9%. The results indicate that the BPI system improves the effectiveness of interception of noncompliant products at the border, thereby preventing the entrance of noncompliant products to the postmarket. The variables were further classified and organized according to the scope of this study and product characteristics. Furthermore, ordinal logistic regression (OLR) was employed to determine the correlations among border, postmarket, and major influencing factors. Based on the analysis of major influencing factors, small fish and fish internal organ products exhibited significantly high risk for fish body type and product type, respectively. The BPI system effectively utilizes the large amount of data accumulated from border inspections over the years. Additionally, real-time information on bilateral data obtained from the border and postmarket should be bidirectionally shared for effectively intercepting noncompliance products and used for improving the border management efficiency. [ABSTRACT FROM AUTHOR]

As dark meat has a faster deterioration rate and its unintentional mixing occurs during processing, it is crucial to know the status and freshness indicators of dark meat to ensure fishery product quality. In this method, fluorescence fingerprints (FFs) was applied as a rapid and noninvasive quality authentication method to determine differences between white and dark meat in the evaluation of freshness indicators at frozen state. Spotted mackerel (Scomber australasicus) fish chunks with different postmortem conditions (0–40 h ice stored) were obtained and frozen. A new generation of fluorescence spectrophotometer (F‐7100) was used to acquire FFs of the frozen fish chunks (containing white and dark meat). Adenosine triphosphate metabolites and pH were determined in both white and dark meat using their relevant biochemical methods. Higher K‐values in dark meat might be attributed to a higher accumulation rate of inosine (HxR) in dark meat than in white meat. The pH decrease rate in white meat was higher than that in dark meat during postmortem ice storage periods of fish. Principal component analysis of FFs spectra demonstrated clear discrimination (PC1 + PC2 = 91.7%) between white and dark meat of frozen fish due to the influence of freshness parameters based on the fluorescence features of fish meat. Furthermore, partial least squares regression validation models revealed that freshness indicators of white meat could be predicted more accurately at the frozen state than those of dark meat. This method could be applied during the processing of fishery products, thereby facilitating quality control activities and making it a promising authentication tool for the fisheries industries. [ABSTRACT FROM AUTHOR]

Objective: This research aims to investigate the microbial diversity of Budu prepared from fresh and frozen fish from the Pariaman and Pasaman districts in West Sumatra Province, Indonesia, as well as provide basic information about Budu quality. Materials and Methods: To obtain the bacterial microbial composition, deoxyribonucleic acid extraction was carried out using amplicon-sequencing of the 16S-rRNA gene in the V3-V4 region from two types of Budu and carried out in duplicate. Results: Budu prepared with fresh (Pariaman) or frozen (Pasaman) fish was dominated by Firmicutes (78.455%-92.37%) and Proteobacteria (6.477%-7.23%) phyla. The total microbial species in Budu from Pariaman were higher (227 species) than in Pasaman (153 species). The bacterial species found are Lentibacillus kimchi (1.878%-2.21%), Staphylococcus cohnii (0.597%-0.70%), Peptostreptococcus russeli (0.00%-0.002%), Clostridium disporicum (0.073%-0.09%), Clostridium novyi (0.00%-0.01%), Nioella sediminis (0.00%-0.001%), and Shewanella baltica (0.00%-0.003%). Lentibacillus kimchi, S. cohnii, and C. disporicum are found in both Budu. Nioella sediminis and S. baltica are found in Budu Pariaman. Peptostreptococcus russeli and C. novyi were found in Budu Pasaman. Conclusion: Metagenomic analysis of Budu from different fish, Pariaman (fresh fish) and Pasaman (frozen fish) showed that the biodiversity of bacteria was barely different. Both Budu found lactic acid bacteria from the Enterococcaceae family, genus Vagococcus, and pathogenic bacteria, such as S. cohnii, P. russeli, C. disporicum, and S. baltica. The discovery of various species of pathogenic bacteria indicates that development is still needed in the Budu production process to improve Budu quality. [ABSTRACT FROM AUTHOR]

To provide consumers with high-quality and safe products, to prevent the entry of low-quality and dangerous food products into the consumer market, monitoring programs are provided. The results of monitoring samples of frozen fish of various families and species for the period 2020–2022 have been given. Labeling, organoleptic indicators of fish samples have been analyzed for compliance with the requirements of regulatory documents. The mass fraction of glaze, the mass fraction of phosphates in terms of P2O5, the content of histamine, toxic elements: lead, cadmium, mercury, arsenic have been determined. Labeling deficiencies are revealed in 1.3 % of the samples. A small, inaccessible font (less than 9 points) makes it difficult for the consumer to obtain complete information about the product. An excess of the mass fraction of glaze on average 0.7–0.8 % in pike perch samples has been revealed. The actual values of the mass fraction of phosphates have not exceeded the maximum allowable limits. The lowest content of phosphates has been noted in samples of pike perch (from 2.3 to 2.0 g/kg), the highest in pink salmon (from 5.0 to 4.1 g/kg) and salmon (5.2–4.7 g/kg). The content of histamine in all samples has been within the normal range. The smallest amount of histamine has been found in samples of mackerel (from 18.0 to 11.0 mg/kg) and pollock (17.0–11.0 mg/kg), the largest in pink salmon (25.0–16.0 mg/kg) and herring (22.0–19.0 mg/kg). The concentration of heavy metals has not exceeded the maximum allowable values. The results obtained are of practical importance for manufacturers in the development of labeling that satisfies consumer demand for information about the product and for consumers in the formation of the diet.

Commercial cryoprotectants can delay quality loss in frozen fish mince, but they are associated with a sweet taste and high calorie content. Young apple polyphenols (YAP), extracted from unripe apples, show potential as an alternative cryoprotectant. This study evaluated the cryoprotective effect of YAP at varying levels (0.3%, 0.7%, and 1%) in unwashed bighead carp mince. The changes in sulfhydryl content, carbonyl content, thiobarbituric acid reactive substances, intrinsic fluorescence intensity, and Fourier transform infrared spectrum indicated that YAP retarded oxidation and structural changes in myofibrillar proteins during the first 8 weeks of frozen storage, as well as lipid oxidation, which protected the structure of myofibrillar protein. At higher concentrations (0.7% and 1%), YAP maintained gel properties, gel springiness, and water‐holding capacity of the gel prepared from frozen fish mince, potentially through the promotion of cross‐linking of myofibrillar proteins. Overall, YAP can be used as a cryoprotectant and antioxidant in fish mince. Practical Application: Our research found that young apple polyphenols have the potential to be an alternative to commercial cryoprotectants. Young apple polyphenols may be used as a sugar‐free and healthy cryoprotectant for frozen fish mince production in the future. [ABSTRACT FROM AUTHOR]

Excessive exposure to trace elements is associated with occurrence of a wide range of undesirable health effects. This study aimed at monitoring the concentrations of some trace elements in imported frozen fish fillet samples obtained from food retail stores in Jordan. In this study, 30 frozen fish fillet samples(Pangasiushypophthalmus)were collected and analysed for aluminium (Al), arsenic (As), copper (Cu), mercury (Hg), tin (Sn), and zinc (Zn) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The measured concentrations of these elements were used to calculate the possible health risk in Jordanian people. The concentrations of elements were such that Sn > Al > Zn > Cu > As > Hg, with Al was higher than those reported in the literature and As was higher than the maximum permissible levels. The THQ for Alwas 83.6, a value ≫1, making non-carcinogenic effects significant to the adult population. Cancer risk factor for As was 3.84 × 10−4, a value of 38.4 fold above the acceptable lifetime carcinogenic risk (10−5). The results of the current study suggest that consumption of imported frozen fish fillets were potentially dangerous for Jordanian consumers. [ABSTRACT FROM AUTHOR]

Feed is the main source of material and energy for farmed fish, and its nutritional value and balance are important factors affecting fish's growth rate and physical health. In order to explore the effects of two different feed sources on the growth, serum biochemical indexes, liver antioxidant capacity, and lipid metabolism of young cobia fish, 300 young cobia fish with an initial body weight of 43.14 ± 1.25 g were selected for the experiment and randomly divided into two treatments. Each treatment had five replicates, and each replicate had 30 fish. They were fed with formulated feed and frozen fresh fish, respectively, for 12 weeks. The results showed that the weight gain rate, specific growth rate, and feed conversion rate of juvenile cobia fish fed with formulated diet were extremely significantly lower than those of the frozen fresh fish group (P < 0.01), and condition factor was significantly lower than that of the frozen fresh fish group (P < 0.05). However, protein efficiency rate, hepatosomatic index, and viscerosomatic index were significantly higher than those of frozen fresh fish group (P < 0.05). The content of water, crude protein, and crude ash in the whole fish had no significant difference (P > 0.05), while the content of crude lipid decreased significantly (P < 0.05). The serum aspartate aminotransferase activity and sugar content of cobia in the formulated diet group were significantly higher than those in the frozen fresh fish group (P < 0.05). In contrast, the total cholesterol, triglyceride content, alkaline phosphatase activity, and phosphorus content were significantly lower than those in the frozen fresh fish group (P < 0.05). Compared with the frozen fresh fish group, the antioxidant enzyme activities in the liver of the formulated diet group were significantly decreased (P < 0.05) except malondialdehyde (MDA) and the activity of fatty acid synthase, while there was no significant difference in the malate dehydrogenase. The study showed that under the experimental conditions, frozen fresh fish was more suitable for feeding juvenile cobia, and the formulated diet had adverse effects on the liver of juvenile cobia. Therefore, the nutritional composition of frozen fresh fish and the metabolic characteristics of cobia were used for reference to optimize and adjust the nutritional formula of juvenile cobia. [ABSTRACT FROM AUTHOR]

Freezing is the most commonly used technology to preserve the quality of fish and extend its shelf-life. The fish subjected to freezing and thawing processes could be sold as unfrozen ones. In this study, the ability of mid-infrared spectroscopy (MIR) to differentiate between fresh Sevruga (Acipenser stellatus) samples (F) kept up to 13 days at 4 °C from: (i) frozen–thawed (2 weeks at − 20 °C), then refrigerated up to 10 days at 4 °C (F-T R), and (ii) refrigerated up to 13 days at 4 °C, then frozen–thawed (2 weeks at − 20 °C) (R F-T) Sevruga samples was investigated. The application of factorial discriminant analysis (FDA) to the concatenated three spectral regions in the MIR (3000–2800 cm−1, 1700–1500 cm−1 and 1500–900 cm−1) allowed to distinguish clearly between samples according to their storage time, regardless of the quality of raw Sevruga samples since correct classification rate amounting to 92.16% was obtained. The electrophoresis analysis indicated that proteins undergo oxidation and degradation during storage impacting their secondary structure. For example, the level of the α-helix for Sevruga samples aged 1 day was 11.93%, 12.13%, and 11.83% for respectively F, F-T R, and R F-T groups that decreased throughout storage attaining on days 10 amounts of 11.90%, 11.70%, and 11.76%, respectively. It could be concluded that MIR spectroscopy could be used as a rapid screening tool to discriminate rapidly between fresh and frozen–thawed Sevruga fish, since 92.16% of correct classification was obtained. [ABSTRACT FROM AUTHOR]

The bacterial community of the intestinal microbiota influences many host functions, and similar effects have been recently reported for the fungal community (mycobiota). Cobia is a tropical fish that has been studied for its potential in marine aquaculture. However, the study of its bacterial community has been underreported and the mycobiota has not been investigated. We analyzed the gut bacterial and fungal profile present in the intestinal mucosa of reared adult cobias fed two diets (frozen fish pieces (FFPs) and formulated feed (FF)) for 4 months by sequencing the 16S rRNA (V3-V4) and internal transcribed spacer-2 (ITS2) regions using Illumina NovaSeq 6000. No significant differences in the alpha diversity of the bacterial community were observed, which was dominated by the phyla Proteobacteria (~96%) and Firmicutes (~1%). Cobia fed FF showed higher abundance of 10 genera, mainly UCG-002 (Family Oscillospiraceae) and Faecalibacterium, compared to cobia fed FFPs, which showed higher abundance of 7 genera, mainly Methylobacterium-Methylorubrum and Cutibacterium. The inferred bacterial functions were related to metabolism, environmental information processing and cellular processes; and no differences were found between diets. In mycobiota, no differences were observed in the diversity and composition of cobia fed the two diets. The mycobiota was dominated by the phyla Ascomycota (~88%) and Basidiomycota (~11%). This is the first study to describe the gut bacterial and fungal communities in cobia reared under captive conditions and fed on different diets and to identify the genus Ascobulus as a new member of the core fish mycobiota. [ABSTRACT FROM AUTHOR]

With the total world production of 13.7 MMT (2018-19), India is the second-largest fish producer in the world, contributing 1.07 per cent of the global GDP and providing 14 million people with significant employment opportunities throughout the value chain in harvesting, processing, packaging and distribution. The statistics for the last 10 years regarding the trade in fisheries and related products, namely the trading of seven products with HS codes, were gathered from the ITC and OECD as the secondary source of information. With 1.37 MT in volume and a value of Rs.45,106.89 crore, or roughly 10 per cent of all exports and 5.23 per cent of the country's agricultural GVA, fish and fish products have recently emerged as the largest group of agricultural exports from India. China has a higher CAGR of 28.87 per cent in the top exporting nations and India is the top exporting nation with UAS (36.15%), China (17.37%) and Japan (7.38%) in terms of percentage of total exports. As the top three exporters to India, Bangladesh (25.01%), Uzbekistan (23.27%) and Myanmar (13.14%), respectively. Oman and China, with CAGR shares of 69.76 and 60.15 per cent, respectively, have the highest percentages with India. Between these nations that are close to India, Bangladesh and Myanmar have a higher import percentage share destination. The nation has more than unit is relatively more advantageous in products of mollusks, crustaceans and frozen fish with 9.15, 2.92 and 1.14, respectively. Live fish has 7.7 USD million with less than IUV 9.18 USD million. Compared to importing, exporting of live fish will rise, followed by that of crustaceans, fish fit for human consumption, dried, salted or brine, etc. Products with lower EUV than IUV of fish, crustaceans, molluscs and other aquatic invertebrates can be reduced here. These products have HS Codes of '0303, '0304', '0307' and '0308', respectively. [ABSTRACT FROM AUTHOR]

Impurities found in fish have been a major cause of disease and illness to consumers. This study's objective was to evaluate the total aflatoxin, heavy metal and microbial load in two frozen fish: Scomber scombrus and Clupea harengus from two (2) cold room facilities in Omu-Aran and Ilorin. Heavy metals, aflatoxin and microbial load were investigated using standard methods. Health risk was also determined using health risk index (HRI), daily intake of metals (DIM), and health quotient (HQ), and total toxicity of metals (TTM). Cd, Cu, Ni, Pb, Mn and Cr did not differ significantly (p>0.05) in both species from both locations. Nickel was lower than the recommended limit by World Health Organization (WHO). Level of Mn and Cr were higher in both species. Mn load was higher in the muscles of the sampled fish than in the gills from September through to November with highest value of 1.26±0.08 and 1.30±0.12 obtained for S. scombrus and C. harengus. Highest concentrations of all metals was observed in the gills except manganese and copper [Cd = 0.03 (S. scombrus), Cr = 1.22±0.13 (S. scombrus), Ni = 0.025±0.04 (S. scombrus), Pb = 0.06±0.02 (S. scombrus)]. HRI was > 1 in the different age groups for the different metals. TTM was > 1 in both species. Total aflatoxin level was higher in the gills (4.25 – 5) ppb than in the muscle (1.5 - 3) ppb for both locations respectively. Vibrio spp. and non-coliform bacteria were high in both species from both locations. The study concludes that heavy metal loads (Mn, Cd, Cu, Cr, and Ni) were more than the permitted limitations imposed by FAO, WHO and EU legislation for fish and fish products placing consumers at health risk. [ABSTRACT FROM AUTHOR]

The antioxidant properties of the liquor resulting from commercial octopus cooking were analysed for this study. Two different concentrations of octopus-cooking liquor (OCL) were tested as glazing systems during the frozen storage period (−18 °C for up to 6 months) of whole Atlantic horse mackerel (Trachurus trachurus). Compared to water-control glazing samples, an inhibitory effect (p < 0.05) on lipid oxidation development (the formation of thiobarbituric acid reactive substances and fluorescent compounds) was detected in frozen fish treated with the most concentrated OCL-glazing system. Additionally, a preservative effect (p < 0.05) on polyunsaturated fatty acids (measurement of polyene index) was also proved. However, no effect (p > 0.05) on the free fatty acid content and on the ω3/ω6 ratio was detected with the presence of the OCL in the glazing system. An increased lipid quality in frozen horse mackerel was established by including the OCL solution in the glazing system. According to previous research, the observed preserving properties were explained on the basis of the presence of antioxidant compounds in the cooking liquor. A novel and valuable combination of glazing processing and the employment of a marine waste substrate is proposed to enhance the lipid stability of frozen fish. [ABSTRACT FROM AUTHOR]

The effect of previous frozen storage (−18 °C for 6 months) and different coating media (aqueous: water and brine; oily: sunflower, refined olive, and extra-virgin olive oils) on the essential macroelement and trace element content of canned Atlantic mackerel (Scomber scombrus) was studied. Previous frozen storage led to an increased (p < 0.05) content of canned samples of K (oil-coated samples) and Ca (all coating conditions) and to a decreased (p < 0.05) content of P (aqueous-coating samples) and S (water- and oil-coated samples). For trace elements, a content increase (p < 0.05) in Cu and Se (brine-canned samples) and Mn (water- and refined-olive-oil-coated samples) was detected in canned fish muscle with frozen storage. Concerning the coating effect, aqueous-coating samples showed lower (p < 0.05) Mg, P, S, K, and Ca contents than their corresponding oil-coated samples. For trace elements, lower average contents were found for Co, Cu, Mn, Se, and Fe in aqueous-coating fish muscle when compared to their counterparts coated in oily media. Content changes in the different elements in canned fish muscle are discussed based on interactions with other tissue constituents and modifications that such constituents undergo during processing (i.e., protein denaturation, liquor losses from the muscle, lipid changes). [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of the study was to verify the existence and pathogenicity of Aeromonas hydrophila (A. hydrophila) in fish by validating the bactericidal effects of microwave and Gamma radiation on infected fish fillets. A total of 100 frozen Basa fish fillet samples were collected randomly from different markets in Zagazig, Sharkia Governorate, Egypt, and subjected to microbiological examination. The results revealed a 14% prevalence rate of A. hydrophila in fish fillets, which were tested for the presence of seven virulence genes: aerA, act, ast, alt, hyl, ahhR, and ahh1. All isolates exhibited traits related to virulence. The most predominated gene was ast (64.2%), followed by aerA, act, hyl, and ahhR (57.14% for each). Then, an experimental protocol for several treatments showed that Gamma radiation at a dose of 1 kGy decreased the count of A. hydrophila in fish fillets by 4.4 log10 CFU/g whereas doses of 2 and 3 kGy eradicated the pathogen. The same positive effect was recorded towards the microwave after cooking for 1, 2, and 3 minutes. Therefore, using microwave cooking and Gamma-irradiation alone and in combination with other decontamination methods may be more efficient in lowering the pathogen counts in fish meat. [ABSTRACT FROM AUTHOR]

Copyright of Marsh Bulletin is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Marsh Bulletin is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we develop a dynamic Inverse Almost Ideal Demand System model to derive own- and cross-price flexibilities for wild-caught fish, Australian farmed salmon and imports of fresh and frozen fish. We find that the growth of fresh fish imports and Australian farmed salmon production have both individually had a significant negative impact on the prices received for Australian wild-caught species, particularly the lower valued species. Continued growth in imports and the farmed salmon sector may negatively impact prices and hence profitability in wild-caught fisheries in Australia in the future. [ABSTRACT FROM AUTHOR]

To further clarify the effect of lethal conditions on the quality of grouper(Epinephelus lanceolatus) and to improve the quality of grouper during refrigeration, five different lethal methods were used to treat grouper, with the following groups: Ⅰ: lethal by ice burial; Ⅱ: lethal by knocking on the head; Ⅲ: lethal by subjecting live grouper to temperature gradients of 18, 14, 10 and 6 ℃ (each temperature treatment for 20 min); Ⅳ: lethal by subjecting live grouper to temperature gradients of 18, 12 and 6 ℃ (20 min at each temperature); Ⅴ: lethal by subjecting live grouper to temperature gradients of 18, 6 ℃ (20 min at each temperature). The grouper was then rapidly reduced to 0 ℃ in the centre of the fish body by micro-freezing machine and refrigerated at 0-4 ℃. The effects of changes in the sensory evaluation, textural characteristics, pH, lactic acid content, sulfhydryl content, volatile salt nitrogen (TVB-N), total bacterial colony count and other quality evaluation indicators of the fish during the freezing period were subsequently measured and analyzed. The results showed that the five groups of lethal treatments had significant effects on the quality of fish meat during refrigeration, in descending order: sensory evaluation and TVB-N: group Ⅴ> group Ⅰ> group Ⅱ> group Ⅳ> group Ⅲ, texture: group Ⅳ> group Ⅴ> group Ⅱ> group Ⅰ> group Ⅲ, lactic acid content and pH: group Ⅴ> group Ⅰ> group Ⅱ> group Ⅳ> group Ⅲ, sulfhydryl content and total bacterial colony: group Ⅰ> group Ⅱ> group Ⅴ> group Ⅳ> group Ⅲ. > group Ⅳ > group Ⅲ. This indicated that the lethal treatment by gradient cooling was significantly better than the lethal treatment by head knocking and ice burying, and the temperature difference interval in gradient cooling should not be too wide. The results of the quality evaluation of all the indicators showed that group Ⅲ had the best lethal treatment, as the narrower temperature range made the process of grouper death less stressful, and the lactic acid content, pH and total sulfhydryl group were relatively stable, which was more effective than the other four groups in delaying the reduction of textural characteristics and sulfhydryl group content and inhibiting microbial activity, thus prolonging the shelf life of the fish samples. [ABSTRACT FROM AUTHOR]

The Gulf of Trieste (Northern Adriatic Sea, Italy) is the coastal area of the Mediterranean Sea most highly contaminated by mercury (Hg) due to fluvial inputs from the Isonzo/Soča River system, draining over 500 years' worth of cinnabar extraction activity from the Idrija mining district (Western Slovenia). The aim of this research is to investigate the concentration of Hg in hair samples taken from the general population of the Friuli Venezia Giulia (FVG) Region coastal area, as a marker of chronic exposure to Hg. Three hundred and one individuals — 119 males and 182 females — were recruited by convenience sampling in Trieste in September 2021. An amount of approximately 100 mg of hair was collected from the occipital scalp of each participant to measure the respective Hg concentrations (expressed as mg/kg). Moreover, participants completed a self-report questionnaire collecting extensive socio-demographic and life-style information. A multiple linear regression analysis was employed to investigate factors associated with increased levels of Hg concentration in hair. A mean Hg concentration in hair of 1.63 mg/kg was found, slightly above the 1.0 mg/kg threshold recommended by the WHO for pregnant women and children, although still well below the no observed adverse effects level (NOAEL) of 10 mg/kg. Among respondents, 55.6% showed a Hg concentration in hair > 1 mg/kg, 22.9% > 2 mg/kg, and 2 participants exhibited Hg levels > 10 mg/kg. The adjusted mean hair Hg level increased in those subjects who reported a preference for shellfish/crayfish/mollusks (RC = 0.35; 95%CI: 0.16; 0.55), whereas it decreased in those who reported a preference for frozen fish (RC = -0.23; 95%CI: − 0.39; − 0.06). Though a risk alert for Hg exposure for coastal residents from FVG is deemed unnecessary at this time, it is recommended that pregnant women limit their ingestion of locally caught fish to < 4 servings/month. [ABSTRACT FROM AUTHOR]

Histamine is the biogenic amine responsible for scombroid poisoning in various types of fish and fish products. The study evaluated histamine content and bacteriological quality of salted and freeze sardine samples. All fish samples were cultured on Reinforced Closterdial medium; mannitol salt (MS) agar and violet red bile glucose (VRBG) agar, the positive colonies were sub-cultured on histamine-forming bacterium agar, followed by biochemical and PCR identification. Production of histamine in the fish muscles was measured by high performance liquid chromatography. The mean histamine values were about; 8.25 mg/100g. The mean of total aerobic counts was; 4×104 ± 2.1×104 while, the total anaerobic count; 5×104 ±1.2×10³ Log CFU/g. Enterobacteriacea spp. about; 5×104 ±2.5×104 Log CFU/g while, the mean value of Staphylococcus spp. about; 3×104 ±3.7×104 Log CFU/g. The mean value of histamine-forming bacterial were; 3.3×106 Log CFU/g. Molecular Identification For Enterobacteriaceae were Klebsiella pneumonia, Staphylococcus xylosus, Escherichia coli and Enterobacter cloacae. We concluded that during storage, there was a positive relationship between the histamine levels and the histamine-forming bacteria (HFB) numbers, while, histamine and the bacteria forming histamine were recorded in all examined sardine samples. [ABSTRACT FROM AUTHOR]