In this study, proximate compositions, meat yields, mineral matter (Na, Mg, Ca, K), and heavy metal (As, Fe, Zn, Se, Mn, Co, Cu, Pb, Ni) contents of rainbow trout (Oncorhynchus mykiss) obtained from concrete pond systems and dam lake net cage were examined. Mineral and heavy metal contents were measured by ICP-OES instrumental analyser. According to the results of rainbow trout meat yield and nutritional composition analysis varied between; meat yield were 57.43-66.40%, crude protein were 16.99-19.93%, crude fat were 3.07-4.18%, crude ash were 0.98-1.58%, and moisture contents were 75.10-77.65%. Mineral contents of Ca 2.66-30.58 mg.kg-1, Na 19.53-36.04 mg.kg-1, K 252.79-310.05 mg.kg-1, and Mg 120.75-137.44 mg.kg-1 were detected in the presented ranges. Detected heavy metals were As 0.42-0.56 mg.kg-1, Fe 2.16-3.69 mg.kg-1, Zn 2.67-4.69 mg.kg-1, and Se 0.17-0.77 mg.kg-1. On the other hand, Mn, Co, Cu, Pb, and Ni were not detected. As a result of the study, it was found that the proximate composition, meat yield, mineral matter, and heavy metal contents of rainbow trout vary depending on the location and size of the fish (p<0.05). However, the heavy metal levels detected in muscle tissue did not exceed the consumption limits.

In this present study, various concentrations (0.5, 1, and 2%) of chitosan extracted through the chemical methods from the shells of crayfish (Astacus leptodactylus), pink shrimp (Parapenaeus longirostris), blue crab (Callinectes sapidus) shells, aqueous extracts of black cumin (Nigella sativa L), flaxseed (Linum usitatissimum), Chaste Tree (Vitex agnus-castus L.) and black cumin and flaxseed oil were tested in vitro for their antibacterial activities against tow pathogenic bacteria Escherichia coli and Staphylococcus aureus, using the disk diffusion method. On the other hand, were Eritromisin and florfenicol were used as a positive control. The negative control was Acetic Acid and cotton oil. Antimicrobial activity of chitosan is affected by different intrinsic and extrinsic factors. chitosan Source, molecular weight, deacetylation degree, viscosity, and solvent material, pH, ionic strength, metal ions, and bacteria cultures. In the present study, all four extracted chitosans were showed different antimicrobial effects on two different types of bacteria, while there are not any antibacterial effect of aqueous extracts and oils of the three plants seeds that used in this study.

Surimi, which is defined as the semi-processed minced meat of aquatic products that are discarded or have little fresh consumption, is usually offered for consumption by being made similar to valuable aquatic products such as shrimp, lobster tail, crab legs, and scallops. In this study, the chemical composition, myofibrillar proteins, and sensory properties of surimi manufactured from tilapia (Oreochromis niloticus) meat were investigated. Four study groups were created with different spice additives: red pepper, dill, thyme, and control (additive-free). Chemical composition analysis results of surimi were determined as total protein 12.85%, lipid 0.53%, ash 0.36%, moisture 86.59%, and myofibrillar protein 11.93%. Moreover, all groups were offered panelists to perform sensory analysis. At the end of the sensory evaluation, the groups received between 5.5 and 8.8 points on a 10-point scale from panelists regarding appearance, odor, chewiness, juiciness, taste and flavor, and overall acceptance. There were no differences between experimental groups in terms of appearance, odor, chewiness, and juiciness. However, statistical differences were observed between groups for taste and flavor as well as overall acceptance (p<0.05).