İbrahim Erkoyuncu's research while affiliated with Ondokuz Mayıs Üniversitesi and other places

Seafoods are consumed as raw, semi-cooked or cooked in different societies and they are valuable animal protein sources. They are suitable foods for growing of microorganisms because of their high water and protein contents, near neutral pH value. Pathogen microorganisms cause adverse effect (causing disease) on human body. Some pathogens are only effective in human, some species are only in animal while some of harmful to both animal and human. Pathogen microorganisms and their toxins are dangerous for people consuming these foods especially as raw or semi-cooked. Pathogen microorganisms could be observed in seafoods caught newly fresh and also could be transmitted by cross contamination from human or substances added during marketing, transporting, heading, eviscerating or processing. The type and natural habitats of seafoods pathogens are so variable. Staphlococcus aureus, Salmonella spp., Clostridium perfringens, Clostridium botulinum, Vibrio parahaemolyticus, Vibrio cholerae, Vibrio vulnificus, Listeria monocytogenes are among the some seafood pathogen microorganism. Seafood toxins formed by algae and bacteria, cause huge economic losses. This study provide information concerning with seafood pathogens and their toxins and food poisoning caused by them.

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Omega-6 and omega-3 fatty acids, polyunsaturated fatty acids, are essential fatty acids. Minor differences in their molecular structure of omega-3 and omega-6 fatty acids act very different role in the body. These important fatty acids may cause some discomfort in humans if not taken recommended proportions. It is advised to get more omega-3 fatty acids, or at least equal amounts of these fatty acids. However due to changes in consumption habits in recent years, an increase in ratio of omega-6 to omega-3 ratio has been observed. One of the omega-3 fatty acids, eicosapentaenoic acid, C20: 5n-3 (EPA) play a role in the prevention of cardiovascular problems, while another one docosahexaenoic acid, C22: 6n-3 (DHA) is more effective for the visual function, growth and brain development. Fish, especially oily fish are excellent sources of long chain omega-3 fatty acids.In this review, using the results of studies in recent years, omega-6 and omega-3 fatty acids and impact on health and the importance of fish flesh contained wellbalanced amounts of these fatty acids has also been mentioned.

Salting is a fish-preservation method and it is used in many countries of the world. It is also used in the preprocessing of fish before processing technologies such as smoking, drying, and canning are employed. The main function of salting is the removal of some of the water from fish flesh and its partial replacement by salt. Salting reduces the water activity of fish; hence, microbial and enzymatic activities are also reduced. The ripening of salted fish is the biochemical process that causes the change in chemical and physicochemical characteristics of the fish tissues. The end of the salting process is the moment when all the fish has reached the required salinity, and acquired the appropriate taste, consistency, and odor.

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The aim of this research was to determine the fatty acid composition and lipid and protein levels of anchovy meal produced during the commercial fishing period. The protein content was 74.69%, 76.17% and 74.40% in November, December and January, respectively. The lipid content ranged from 8.57% to 9.14% for anchovy meal produced during the fishing season. The total saturated fatty acid content was 33.25%, 33.46%, and 33.61% in November, December and January, respectively. Within the saturated fraction, the major fatty acid was palmitic acid (C 16:0), the content of which was 20.30%, 19.96% and 20.66%, respectively. The monounsaturated fatty acid contents ranged from 20.23% to 21.62%. Concerning the monounsaturated fatty acids, oleic acid (C 18:1n-9) was present in larger percentages (12.29% to 13.44%) than the others. Among polyunsaturated fatty acids the largest concentration was for docosahexaenoic acid (DHA, C 22:6n-3), varying from 17.44% to 19.16%. The eicosapentaenoic acid (EPA, C 20:5n-3) content, which is another important fatty acid, was between 7.52% and 8.36%. The concentrations of n-3 PUFA (27.04%-27.95%) of anchovy meal were higher than those of n-6 PUFA (4.14%-4.95%). The ratio of n-3 to n-6 fatty acids of anchovy meal was 5.47 in November, 6.17 in December, and 6.75 in January.

In this study, changes in the chemical and microbiological properties of bonito (Sarda sarda, Bloch 1793) salted by dry salting (lakerda) and stored for 6 months at 4 ± 1C were investigated. The fresh gutted and sliced bonitos were used as raw material for salting by using the ratio of fish to salt as 5:1 by weight. Salted fish remained in the liquid pickle formed by salt and the liquid extracted from the fish. This solution was not drained during the storage period. The product is described as “lakerda” in Turkey. In the fresh fish, total volatile basic nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) values were 11.21 mg/100 g and 1.19 mg/100 g, respectively. During the storage period, TVB-N and TMA values increased slowly to 27.67 mg/100 g and 4.99 mg/100 g, respectively, at the end of the storage period. In the first month after salt processing, the total mesophilic bacteria count was 4.6 × 102 cfu/g. In the later months, mesophilic, psychotropic, coliform bacteria and yeast-mold did not reproduce. According to the results, bonito salted by dry salting and stored at 4 ± 1C was in good quality in terms of chemical and microbiological properties during the storage period of 6 months.