Use of dill extracts as a natural preservative on shelf-life extension of rainbow trout croquettes during refrigerator storage.

In this study, changes in quality parameters of rainbow trout croquettes treated with dill extracts obtained by brewing (BDA) and distillation (DDA) methods were investigated during 61 days of refrigerated storage (+2 ± 1°C). Physicochemical, microbial, and sensory parameters of the rainbow trout croquettes were analyzed once every 4 days. It was observed that the precooking process and additives influenced the nutrient composition and color change of the croquettes. Total volatile base nitrogen and thiobarbituric acid values did not exceed the limit values in any group during refrigerated storage and these values were found as 23.10 ± 0.89 mg/100 g and 3.13 ± 0.08 mg MDA/kg in the control group (C), 21.00 ± 0.92 mg/100 g and 2.77 ± 0.14 mg MDA/kg in BDA group, and 21.70 ± 0.92 mg/100 g and 2.85 ± 0.07 mg MDA/kg in DDA group, respectively. Extract treatments, especially DDA, resulted in a significant reduction in the counts of total aerobic mesophilic and psychotropic bacteria in trout croquettes compared to the control group. It was determined that the sensory scores of all croquette groups decreased during storage and the acceptability scores of the C, BDA, and DDA groups reached on the 33rd, 57th, and 61st days of storage, respectively. According to the results, this work demonstrated that the dill extracts both distilled and brewed can be used as a natural additive to improve the quality and extend the shelf life of rainbow trout croquettes.

Facile Synthesis of Hybrid Nanoflowers Using Glycine and Phenylalanine and Investigation of Their Catalytic Activity.

In the context of the proposed work, two different amino acids (Glycine, Phenylalanine) have interacted with copper ions in a phosphate buffer (PBS) in place of enzymes. This interaction resulted in the nucleation of copper phosphate crystals and the formation of flower-shaped amino acid-copper hybrid nanostructures (AA-hNFs), which grew through self-assembly. While Cu (II) ions in the structure of AA-hNFs were used as Fenton's agent for the catalytic activity. SEM, energy dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy measurements were used to define the AA-hNFs' characterisation. The peroxidase-like activities of AA-hNFs were investigated by UV/VIS spectrophotometer. Metal nanoparticles have peroxidase-like activity. A class of enzymes known as peroxidases is able to catalyze the conversion of hydrogen peroxide into hydroxyl radicals. These radicals also take part in electron transfers with substrates, which results in color during oxidation. When cupric oxide nanoparticles are added to the peroxidase substrate while H2 O2 is present, a blue color product with a maximum absorbance at=652 nm can result, demonstrating the catalytic activity of a peroxidase. The morphology and composition of AA-hNFs were carefully characterized and the synthesized parameters were optimized systematically. Results showed that the nanoparticles were dispersed with an average diameter of 7-9 µm and indicated a uniform flower shape. The results of the investigation are anticipated to significantly advance a number of technical and scientific sectors.

Parazoanthus axinellae Extract Incorporated Hybrid Nanostructure and Its Potential Antimicrobial Activity.

This study, it was aimed to examine the change in the antimicrobial effect of sea anemone Parazoanthus axinellae extract by forming its nanoflowers. A scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were expended to observe the morphologies of the Cu NFs that had been produced. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were expended to analyze the managing assemblies in P. axinellae extract, which perform an effective part in the synthesis routine, as well as the crystal assembly of NFs. P. axinellae extract mediated the HNFs (Hybrid nanoflowers) are at high, pure crystalline nature, flower shape with a crystallographic system at the nanoscale with mean crystallite size 21.9 nm using XRD, and average particle size ~10 nm by SEM. The broad absorption band at 2981-2915 cm-1 in the FT-IR spectra of anemone extract and Cu-anemone NFs represents the unique peak of hydroxy groups. In addition, Cu NFs were tested for their antibacterial properties. Cu NFs have been discovered to exhibit antibacterial properties. It is suggested that P. axinellae extract and various inorganic components be used to synthesize a variety of NFs and assess their suitability for usage in biomedical fields.

Formation of Umbilicaria decussata (Antarctic and Turkey) Extracts Based Nanoflowers with Their Peroxidase Mimic, Dye Degradation and Antimicrobial Properties.

This work describes a unique and environmentally friendly approach for creating three-dimensional (3D) organic-inorganic flower shaped hybrid nanostructures called "nanoflower (NF)" by using Umbilicaria decussate (U. decussate) extract and copper ions (Cu2+ ). U. decussate species were collected from certain place in Antarctic and Turkey and extraction of each species were completed in methanol and water. The U. decussate extracts were used as organic components and Cu2+ acted as inorganic components for formation of U. decussate extracts based hybrid NFs. We rationally used these NFs as novel nanobiocatalyst and antimicrobial agents. These NFs exhibited peroxidase mimic, dye degradation and antimicrobial properties. The NFs were characterized with various techniques. For instance, the morphologies of the NFs were monitored by scanning electron microscope (SEM), presence of elements in the NFs were presented using Energy Dispersive X-Ray Analysis (EDX). Fourier-transform infrared spectroscopy (FT-IR) was used to elucidate corresponding bending and stretching of bonds in the NFs. The NFs acted as effective Fenton agents in the presence of hydrogen peroxide, and we demonstrated their peroxidase-like activity against guaiacol, dye degradation property towards malachite green and antimicrobial activity for Aeromonas hydrophila, Aeromonas sobria, Escherichia coli, Salmonella enterica and Staphylococcus aureus.

Seasonal monitoring of microplastic pollution in the Southeast Black Sea: An example of red mullet (Mullus barbatus) gastrointestinal tracts.

This study investigated seasonal presence of microplastic (MP) in gastrointestinal tracts of red mullet (Mullus barbatus) sampled from the Southeast Black Sea Region. A total of 335 MPs were detected in 120 individuals. While the most MP was observed in the winter and autumn seasons, quite few MPs were found in the summer and spring seasons. MP size did not show significant difference among seasons. While all of the MPs in the autumn and spring and most of the MPs in the winter were fiber-shaped, most of the MPs in the summer were fragments. The most observed MP color for all seasons was white. While polymer structures did not show much variation in spring and summer, six different polymers were determined for both autumn and winter. In general, less MPs were detected during fishing ban period (summer) and the characteristic properties of the detected MPs suggest a MP pollution in the region due to intense fishing activities.

Decade of microplastic alteration in the southeastern black sea: An example of seahorse gastrointestinal tracts.

Unconscious and excessive use of plastic supports the diversity and abundance of microplastics (MPs) in marine environments. As a result of MP exposure, organisms in the marine environment are faced with adverse scenarios up to death. In this study, ten-year MP composition was investigated in gastrointestinal tracts (GITs) of low-mobility seahorses (90 individuals per period) from the Southeastern Black Sea. Seahorse GITs sampled during both 2012 and 2022 contain 102 and 135 MP items, respectively. The number of MPs per unit individual seahorse and unit seahorse weight was higher in the 2022 period. On the other hands, no significant differences were observed between the MP lengths of both periods. The majority of MPs in both sample periods were materials shorter than 1000 µm. Of the eight found synthetic polymers, five belonged to the 2012 period, while seven were observed during the 2022 period. Additionally, the most abundant synthetic polymer for both periods is polyvinyl stearate (PVS). As a result, 43% of the total plastic material belonged to the 2012 period, while 57% was observed in the 2022 period. Considering both the diversity of polymers and the abundance of plastics, the region was adversely affected by plastic materials in the 2022 period.

Synthesis of Axinyssa digitata Extract Directed Hybrid Nanoflower and Investigation of Its Antimicrobial Activity.

First time in this study, the antibacterial effects of Axinyssa digitata sponge extracts and Axinyssa digitata-based cupper hybrid nanoflowers (Cu hNFs) were evaluated. Herein, hybrid nanoflowers (Cu hNFs) were produced by combining Axinyssa digitata sponge extract with Cu2+ ions in Phosphate-buffered saline (PBS) (at pH 7.4) at room temperature for three days using green synthesis method. The shape and size of hNFs were evaluated using scanning electron microscope (SEM) images. Energy dispersive X-ray spectroscopy (EDX) mapping was used to determine the presence of Cu metals and other components. X-ray diffraction (XRD) is a non-destructive analysis method that was used to determine of the crystallographic properties of materials and the phases they contain. Fourier-transform infrared spectroscopy (FT-IR) peaks were used to discuss the presence of functional groups that played a key role in the synthesis. The Cu-hNFs had antimicrobial activity against selected microorganisms. This research is expected to provide knowledge on hNFs synthesis and antimicrobial activity application investigations using Axinyssa digitata rather than biomolecules obtained through costly and time-consuming methods.

Effects of high-molecular-weight chitosan coating prepared in different solvents on quality of catfish fillets during 6-month frozen storage.

Effects of high-molecular-weight (800 kDa) chitosan coating on quality of catfish fillets were examined during 6-month frozen (-20 °C) storage. Coating solutions, included distilled water (Control), 800AC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and 800AS3% (3% w/v chitosan in 3% w/v aspartic acid). Changes in physicochemical, microbial, and consumer perception of chitosan-coated catfish fillets during frozen storage were examined. The 800AS3% coating was found to be effective in inhibiting microbial growth, controlling lipid oxidation, reducing drip loss and cooking loss, and retaining color and texture of catfish fillet during frozen storage. After 6-month frozen storage, the aroma of thawed fillets coated with 800AS3% was accepted by 77.92% of consumers with 66% positive purchase intent. This study demonstrated that a nonpungent aspartic acid, instead of commonly used pungent acetic acid, can be used in preparation of preservative high-molecular-weight chitosan coating. PRACTICAL APPLICATION: The findings of this study indicated that high-molecular-weight chitosan coating showed preservative effects on quality of frozen raw catfish fillets. In our previous study, chitosan (800 kDa) at 1% and 3% concentrations showed antibacterial activity in vitro. The nonpungent aspartic acid can be used as a solvent to dissolve high-molecular-weight chitosan instead of the commonly used pungent acetic acid. The most effective coating treatment was 3% w/v chitosan in 3% w/v aspartic acid. This finding would be applicable to other seafood and fish products.

Determination of metal content in anchovy (Engraulis encrasicolus) from Turkey, Georgia and Abkhazia coasts of the Black Sea: Evaluation of potential risks associated with human consumption.

In this study, metal compositions in anchovy (Engraulis encrasicolus) sampled from 11 different sites representing Turkey, Georgia, and Abkhazia coasts of the Black Sea were investigated. For this purpose, micro (Al, Zn, Mn, Co, Cr, Cu, Fe, Ni, Cd, Pb, Se, As, and Hg) and macro (K, Ca, Na, Mg, P) element content in edible muscle tissue of anchovy were determined. In addition, the potential risks associated with human consumption of the samples were evaluated using quality indices such as estimated weekly intake (EWI), target hazard quotient (THQ), and total exposure hazard index (HI). The results showed that the potassium (K) concentration was the highest in edible tissue of the anchovies from all stations. Anchovies were also found to be rich in phosphorus and calcium. When the metal content of anchovies was compared, there were statistically variations among metal concentrations (except for Co, Ni, Cu, Cr, Cd, Pb, and Hg) in the muscle tissue of anchovies according to the stations (P<0.05). The concentrations of Pb, Cd, Zn, Cu, Ni, and Cr in anchovy were found below the maximum permissible values determined by various national and international organizations for seafood. Besides, when the samples were examined in terms of EWI, THQ, and HI quality indices, it was determined that anchovy consumption did not pose a potential hazard to human health for the consumption of the anchovy. The present study conclusively indicated that no health problem can be raised from human consumption of the examined commercial anchovy along the Turkey, Georgia, and Abkhazia coasts of the Black Sea.