This study investigates the effect of taxifolin and arabinogalactan premixed with dihydroquercetin (Lavitol V) at different concentrations on the quality changes of trout soup at 4 +/- 1 degrees C for 31 days. Shelf life studies included physiochemical, sensory, and microbiological quality measures. The shelf lives of the fish soups were extended for 2-4 and 7-10 days with taxifolin and Lavitol V, respectively, with significant variations (p < 0.05), the longest shelf life corresponding to Lavitol V for 31 days. The highest TBA and TVB-N were obtained for the control as 3.72 mg MA/kg and 11.21 mg/100 g, respectively. Therefore, Lavitol V has a good potential for future applications in seafood preservation.

The marine environment is teeming with a diverse array of algae, dinoflagellates and phytoplankton. These organisms possess the remarkable capacity to produce toxic compounds that can be passed to humans through the ingestion of seafood, resulting in potential health risks. Similarly, seafood can be susceptible to contamination from various microorganisms, viruses and parasites, thereby, potentially compromising food safety. Consuming seafood that contains toxins or pathogenic microorganisms may have serious health consequences, including the potential for severe illness or even fatality. This chapter delves into the various hazards that arise from biochemical and microbiological factors, with particular emphasis on the Mediterranean region. In addition, it provides a succinct analysis regarding the effect of COVID-19 pandemic on the safety of seafood.

The activities of silver (Ag) complexes of graphitic carbon nitride with different metal ratios in the catalytic reduction reaction of 4-nitrophenol to 4-nitroamine were investigated in this study. For this purpose, the compounds of urea: dicyanodiamine in a ratio of 3:7 and the Ag(NH2COCN2)6NO3 complex were reacted together in order to prepare Ag@g-C3N4 by thermal decomposition in a single step. The resulting products were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Field Emission Scanning Electron Microscope- Energy Dispersive X-ray spectroscopy (SEM-EDS), and High-Resolution Transmission Electron Microscope (HRTEM) and the binding properties of Ag in the structure were determined. AAS analysis was also used to determine the amount of silver. The catalytic activities of Ag@g-C3N4 were evaluated for the reduction of p-nitrophenol (PNP) to p-aminophenol (PAP) in the presence of excessive sodium borohydride (NaBH4) as a reducing agent by monitoring conversion at lambda 400 nm. The prepared Ag@ g-C3N4 nanocatalysts were observed to have very good catalytic activity in the range of 95.1-99.6 % in the catalytic reduction reaction in which PNP was used as a model and the catalyst: substrate ratio was studied at 1:5, 1:50 and 1:100. Especially with the leaching problem and the high activity of silver atoms directly added to the g-C3N4 structure with the new synthesis technique, a new material has been added to the literature.

This study demonstrates the effects of the freezing and frozen storage of anchovies prior to brining and dry-salting on quality changes and food safety during refrigerated storage (4 ± 1 °C). Fresh anchovies were divided into two groups, one of which was used as a control representing fresh raw material; the other was the experimental group and consisted of frozen and thawed anchovies stored at −18 °C for a year. Five different salt concentrations were used for brining (10, 15, 20, 25 and 30%) in addition to the dry-salting method. Microbiological, chemical, physical and sensory analyses were carried out during storage. Salt concentration and salting method had significant effects on the shelf-life of salted anchovy products, with the highest shelf-life corresponding to dry-salted anchovies (p < 0.05). The effect of using frozen and thawed raw materials for salting on the shelf-life depended on the processing method since the experimental dry-salted group had a shelf-life one month longer than that of the control group, while the opposite situation occurred for the brined samples, with one exception. Strong correlations were usually found between sensory values and chemical quality parameters (R2: 0.83–0.99 for the control group and 0.63–0.99 for the experimental group). The results demonstrated that the experimental group, with some exceptions, had better values for most quality and food safety parameters in comparison to the control group, indicating the advantage of using frozen and thawed raw materials before salting to prevent spoilage and enhance food safety. Considering that the experimental group was produced from one-year-stored raw material compared to the control group, the advantage of the freezing and frozen storage of anchovies can be accepted as much higher versus when freezing is not implemented. The positive effect is due to the fact that frozen anchovies absorb salt faster after thawing, especially in groups with high salt concentrations. Therefore, it can be concluded that frozen salted anchovies can be utilized for longer as they have a longer shelf-life, particularly when using either the 30% brining or dry-salting method.

This study represents new information on the nutritional value of soup prepared from cultured Rainbow trout (Oncorhyncus mykiss). The proximate contents of soup were represented by 87.56% moisture, 7.22% protein, 1.59% crude fat, 0.07% carbohydrate, 1.17% dietary fibre and 2.44% ash. The energy value was calculated as 48.0 kcal/100g. Amino acid values were in the range of 183.5-1128.5mg/100g while mineral contents were varied as 0.6µg/g-19.5mg/g. The value of polyunsaturated fatty acids (PUFA) was higher than saturated fatty acids (SFA). Total PUFA and eicosapentaenoic acid + docosahexaenoic acid (EPA+DHA) were observed as 37.2 and 7.2%, respectively. These values corresponded to the values of 673.3 and 123.2 mg/100g of the edible portion of the soup within the same respect. The results of this study demonstrated that a portion of trout soup would almost cover daily recommended n-3 PUFA intake, however, higher amounts are required for the necessary levels of EPA+DHA. The vitamin B12 content was well above the recommended levels. The values of α and β tocopherols were observed as 272.0 and 1131.0 µg/100g (wwb), respectively. This study indicates that trout soup has a good nutritional value for human consumption for a healthy diet.

This study represents new information on the nutritional value of soup prepared from cultured Rainbow trout (Oncorhyncus mykiss). The proximate contents of soup were represented by 87.56% moisture, 7.22% protein, 1.59% crude fat, 0.07% carbohydrate, 1.17% dietary fibre and 2.44% ash. The energy value was calculated as 48.0 kcal/100g. Amino acid values were in the range of 183.5-1128.5mg/100g while mineral contents were varied as 0.6µg/g-19.5mg/g. The value of polyunsaturated fatty acids (PUFA) was higher than saturated fatty acids (SFA). Total PUFA and eicosapentaenoic acid + docosahexaenoic acid (EPA+DHA) were observed as 37.2 and 7.2%, respectively. These values corresponded to the values of 673.3 and 123.2 mg/100g of the edible portion of the soup within the same respect. The results of this study demonstrated that a portion of trout soup would almost cover daily recommended n-3 PUFA intake, however, higher amounts are required for the necessary levels of EPA+DHA. The vitamin B12 content was well above the recommended levels. The values of α and β tocopherols were observed as 272.0 and 1131.0 µg/100g (wwb), respectively. This study indicates that trout soup has a good nutritional value for human consumption for a healthy diet.

In this study, comparative analyses were carried out with ion chromatography mass-spectrometry (IC-MS/MS) which has no derivatization step, high-performance liquid chromatography (HPLC) technique, as well as two quantitative and two semi-quantitative immunoassays. The results demonstrated that HPLC and quantitative immunoassay methods were well-correlated with IC-MS/MS in determining histamine in various types of fish products. The best correlation was observed with the HistaSure ELISA Fast Track kit (R2 = 0.9903). More than half of the values (68%) obtained by two methods were also statistically similar. The results of semi-quantitative test kits also supported histamine values estimated by quantitative methods, with some exceptions. The best results were found for HistaSure Lateral Flow in supporting the quantitative techniques. Therefore, these methods are found suitable for monitoring histamine in fish products in terms of food safety. Good correlations were also observed HPLC and IC-MS/MS in determining cadaverine, putrescine, and tyramine with the highest value observed for tyramine as R2 = 0.9785. However, no correlation was observed for other biogenic amines, and the majority of the results were significantly different from each other for these amines (p < 0.05). The differences may be caused by the drawbacks reported previously for HPLC. However, further studies are required to confirm the possible effects. This study provides a comparative evaluation of several methods in terms of their suitability in determining biogenic amines in fish products for both monitoring and regulatory purposes.

A new method was proposed for the determination of underivatized biogenic amines based on ion-exchange chromatography coupled with mass spectrometry detection. The method was applied to the analysis of 10 biogenic amines in fresh and processed fish products. The amines were extracted from muscle tissue with water without any additional derivative step or sample clean-up. Separation of biogenic amines was done by the IonPac (4 × 50 mm) column, applying a gradient eluent by mixing formic acid (2 mol L−1) and Milli-Q water (formic acid concentration from 400 mM to 2 M). The results demonstrated a linear response in the range of 0.01 to 10 mg L−1. The detection limits for the fish products ranged from 20 ng/g up to around 400 ng/g for histamine and putrescine, respectively. Spermidine and spermine showed significantly higher detection limits. This current method can be used for the determination of biogenic amines in both fresh and processed fish products for regulatory purposes and monitoring food-safety issues relating to these amines, particularly histamine. It is also a useful method for evaluation of other commercial analytical test kits and commonly used methods that are possibly affected by the food matrix due to processing or other drawbacks arising from the derivatization process.

This study provides utilization of salmon fillet by-products as canned soup at plant scale conditions and evaluation of nutritional value and consumer acceptance. The final product tested proved to be microbiologically sterile and had high consumer acceptance. The canned salmon soup contained 87.11% moisture, 7.32% protein, 2.89% fat, and 0.08% ash. Fatty acids results demonstrated that a portion of the soup would well cover daily recommended n-3 poly-unsaturated fatty acid intake. The values for vitamins, minerals, and amino acids indicate a good contribution to its nutritional value. Therefore, it was concluded that salmon fillet waste has a high potential to become raw material for health-preserving soup.

Introduction. The aim of this study is to estimate the nutritional value of fish soup from cultured brook trout in terms of a healthy diet for human consumption. Materials and methods. Fish soup was prepared from 23.65% previously cooked trout mince and 18.76% vegetables, and cooked for 35 mins. The final product was analyzed for the proximate composition, fatty acids and, mineral contents as well as carotenoids and vitamins B1, B2 and B6. Inductively coupled plasma Mass Spectrometer (ICPMS) was used for mineral content after decomposition of lyophilized samples. Fatty acids methyl esters were separated by gas chromatography by flame ionization detector (FID). High performance liquid chromatography (HPLC) was used for the estimation the contents of vitamins and carotenoids. Results and discussion. The proximate contents of soup were represented by 87.79% moisture, 8.18% protein, 2.89% crude fat, 1.17% dietary fibre, 0.62% ash and 0.03% carbohydrate. The energy value was calculated as 58.82 kcal/100g. The value of total polyunsaturated fatty acids (Sigma PUFA) was higher than the values of total monounsaturated (Sigma MUFA) and saturated fatty acids (Sigma SFA) and accounted as 43.89, 34.93 and 19.83%, respectively. The main PUFA corresponded to linoleic acid as 27.14% followed by docosahexaenoic acid (DHA) as 7.92%. Total eicosapentaenoic acid+docosahexaenoic acid (Sigma EPA+DHA) was observed as 9.21% which was accounted as 239.04 mg/100g soup. The results of this study demonstrated that a portion of trout soup (about 200g) would well cover daily recommended n-3 PUFA intake while slightly higher amount is required for daily EPA+DHA intake. Mineral contents were varied in the range of 1.77-31.52 mg/g (dwb), while the results obtained for vitamin B1, B2 and B6 and for carotenoids were comparable with the data given for different types of soups in literature. Conclusion. This study indicates that a nutritious fish soup can be produced from brook trout for human consumption suitable for a healthy diet.

This study identifies the effect of freezing raw material on the storage quality of salted Atlantic bonito ( Lakerda ) at refrigerated (4 ±1 ° C) and ambient (17 ±3 ° C) conditions. It also shows the effect of different salt:fish ratios on the shelf-life and biogenic amine development during storage. The products with the lowest salt content corresponded to the lowest sensory acceptance. Previously frozen raw material (FRM) had higher salt uptake compared to freshly salted fish (FSF). Water phase salt (WPS %) level usually reached to suggested seafood safety levels (20%) within the 1 st week. There were significant differences (p<0.05) amongst the samples treated with different salt ratios and stored at different temperatures. Higher salt content caused higher thiobarbituric acid value indicating acceleration of lipid oxidation.  Lower biogenic amine values were observed with products produced from FRM. Overall results demonstrated the advantage of using FRM for dry salting of Atlantic bonito in terms of food quality.

The biochemical composition of fish differs according to seasons and habitat. This study aims to compare seasonal variations in the fatty acid composition of garfish (Belone euxini), Mediterranean horse mackerel (Trachurus mediterraneus) and red mullet (Mullus barbatus), commercially caught from different zones of Eastern Black Sea of Turkey. The results demonstrated significant seasonal variations in the levels of total saturated fatty acids (Sigma SFA), monounsaturated fatty acids (Sigma MUFA) and polyunsaturated fatty acids (SPUFA) in the fish (p<0.05). The highest percentage of omega-3 and Sigma PUFA fatty acids were observed in autumn for red mullet and Mediterranean horse mackerel, while the highest values of these fatty acids were found in spring for garfish. The highest eicosapentaenoic acid + docosahexaenoic acid (EPA+DHA) levels were obtained for garfish and the lowest for red mullet. Significant seasonal variations were also observed among the three-fish species in values of fatty acids expressed as mg/100g in the edible portion (p<0.05). Considering, the highest levels of EPA+DHA, only 145 g of garfish is found enough to meet the weekly requirement of EPA+DHA for winter; although, consumption of approximately 431 g of edible muscle is required for red mullet to meet the same requirement. About 295 g edible muscle of Mediterranean horse mackerel was needed to meet the requisite amount of nutrients in summer. Therefore, this study implies that garfish has a better nutritional value for human consumption due to higher contents of EPA+DHA compared to other two species.

A new method for determination of underivatized biogenic amines in cheese based on ion exchange chromatography coupled with tandem mass spectrometric detection was proposed. The method was applied to the analysis of 10 biogenic amines (trimethylamine, putrescine, cadaverine, histamine, 2-phenylethylamine, spermine, spermidine, tryptamine, agmatine, and tyramine) in different types of cheese. The amines were extracted only with water without any additional derivatization step or sample cleanup. This is a great advantage in terms of simplicity of sample pretreatment procedure compared with other currently existing methods in the literature. Biogenic amines were separated using cation exchange column, under gradient elution conditions by mixing formic acid (1.00 M) and deionized water. Detection was achieved using tandem MS/MS, with the instrument set into multiple reaction monitoring mode to ensure high specificity. The detection and quantification limits were in the ranges of 12-46 μg/L and 40-153 μg/L, respectively. The exceptions were spermidine and spermine, with detection limits of 0.8 and 5.4 mg/L, respectively. The linearity for most of the biogenic amines was from 10 μg/L up to 10 mg/L. The best recoveries were observed for trimethylamine, tyramine, and cadaverine, and were 89, 94, and 102%, respectively. The results showed that this method can be used for routine determination of biogenic amines in different types of cheeses as well other food matrices. It must be stressed that the proposed method is capable of determining 10 biogenic amines, including tyramine, which is reported to cause food intoxication commonly associated with cheeses.

Mariculturing of horse mackerel is not known in the world. Additionally, limited studies exist on quality changes of smoked horse mackerel at refrigerated temperatures. Therefore, in this study, between 1+ and 2-year-old wild and cultured horse mackerels were hot smoked and stored at refrigerated conditions. Chemical, microbiological, and sensory analyses were performed weekly to investigate quality changes and to determine the shelf stability of the products. The results of thiobarbituric acid, trimethylamine, and total bacteria counts were obtained within the acceptable levels. Although the counts of histamine-forming bacteria increased significantly (p < 0.05) during storage, histamine values were well below the permitted limits set by Food and Drug Administration and European Union (EU). Sensory results showed that both storage groups had 3 weeks of shelf life. Total volatile basic nitrogen values supported sensory results. Therefore, the results indicate that culturing of horse mackerel did not alter the quality during storage at 4 +/- 1 degrees C.

Monthly variations of lipid and fatty acid contents in muscle, liver, and roes of Alosa immaculata from the Black Sea were investigated. Lipid contents of muscle were higher than the levels obtained for liver and roes at 15.8-21.2%. Significant variations occurred in fatty acid levels (p < 0.05). Edible muscle and roe samples contained higher total polyunsaturated fatty acids (Sigma PUFA) in comparison with total saturated (Sigma SFA) and monounsaturated fatty acids (Sigma MUFA), while the majority of fatty acids were represented by Sigma MUFA for liver samples. The highest Sigma PUFA for edible muscles and roes were both obtained in March as 38.3 and 39.5%, respectively, while the highest Sigma MUFA level was found for liver in February as 42.3%. The study showed that about 43-106 g of edible shad muscle will be enough to cover the weekly requirement of EPA + DHA, while less than 12 g of shad muscle should satisfy the daily n-3 PUFA intake. The results indicate that A. immaculata caught from the Turkish Black Sea is a good source of omega-3. This information can be used for commercialization of shad and also may aid further studies on physiology of shad species. Moreover, these results are useful to evaluate the utilization of by-products of this species for sustainable fisheries.

On-growing of horse mackerel is not known in the world. Recently, we have initiated on-growing of the Mediterranean horse mackerel in the Black Sea. Therefore, we aim to compare proximate composition and fatty acid profile of on-growing and wild horse mackerels to evaluate the effect on their nutritional value. Captured horse mackerels less than 13 cm were kept on-growing in sea cages and fed sea bass feed for a year in the southern Turkish Black Sea. Results showed seasonal variations in the proximate contents and fatty acid profile of both on-growing and wild fish groups (p < 0.05). Protein contents of the wild horse mackerel group were significantly higher than the on-growing mackerel group, while the opposite situation was observed for lipid contents (p < 0.05). Despite higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels (as fatty acid methyl esters %) of wild horse mackerel in comparison with on-growing group, much higher EPA + DHA contents were accounted for in on-growing fish in the edible portion resulting from higher lipid contents of these samples. The results suggest that lower amounts of fish meat, 50-90 g, from on-growing mackerel would cover the daily suggested value of EPA + DHA; this level is calculated as 51-150 g for wild fish meat.

Smoking is a traditional preserving method used for both fish and meat products around the world. Smoked fish products have wide acceptance today due to their accustomed taste and aroma as well as their extended shelf-life. In this study, we aimed to determine quality changes and shelf-life of wild hot-smoked Mediterranean horse mackerel (Trachurus mediterraneus, Steindachner, 1868) during frozen storage (-20 +/- 2 degrees C) in comparison with its cultured counterparts. After gutting, cleaning and draining the samples, they were salted in 10% brine solution for 1 h and hot smoked within the same day. The samples were placed in styrofoam plates covered with a stretched film and frozen at -40 degrees C for 24 h. Then, all samples were stored at -20 +/- 2 degrees C until spoilage. Chemical, microbiological and sensory analyses were performed monthly to investigate their quality changes and the shelf stability of the products. The results of total volatile basic-nitrogen, thiobarbituric acid and trimethylamine were obtained within the acceptable levels. Histamine values were found well below the permitted limits set by Food and Drug Administration and European Union. Sensory results showed that both storage groups (wild and cultured) had 7 months of shelf-life. This study showed that hot-smoked wild and cultured horse mackerel can be stored at -20 +/- 2 degrees C for 7 months. Culturing did not make any significant differences (P<0.05) in sensory quality despite of differences in chemical and microbiological changes between wild and cultured groups during storage. On the other hand, better consumer acceptance was observed for cultured samples indicating the advantage of culturing this species for a better market value. We also observed that frozen storage can retard the formation of biogenic amine contents and therefore, it is suggested to apply for such products to avoid histamine health risk.

Summary This study represents significant monthly variations of total lipid and fatty acid composition of muscle and liver tissue of B lack S ea bonito ( P < 0.05). Average total lipids of bonito muscle and liver were 8.4% and 25.1%, respectively, and the highest polyunsaturated fatty acid ( PUFA ) was observed in September and March as 52.9% and 46.6%, respectively. Bonito muscle was found to contain good amounts of eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) in a range of 252.0–1169.1 mg/100 g and 712.1–3324.1 g/100 g, respectively. Higher levels were found in liver at 3323.3 mg/100 g for EPA and 6996.5 mg/100 g for DHA . Although 25–100 g edible muscle is necessary to reach 1 g per day of EPA + DHA requirement for a healthy diet, only 9.8–87.9 g of bonito liver is enough to cover the recommended daily amount for these fatty acids. The results indicate that bonito livers constitute a rich and underexploited source of PUFA s.