Histological, Histochemical and Chemical Study on Katsuwonus pelamis Fish Skins

In this study, possibility of using Skipjack Tuna (Katsuwonus pelamis) fish skins as a new and alternative raw material source for leather industry was investigated. The structural and chemical properties of fish skins have a high impact on the preparation of special production recipes and the manufacturing of high performance valuable fish leathers. For this purpose, characteristic properties of Skipjack Tuna fish skins were evaluated by histological, histochemical and chemical methods. The chemical characteristics of fish skins were determined by analyzing fat content (%), total Kjeldahl nitrogen (%), hide substance (%), volatile matter (%), total ash (%) and fatty acid methyl esters and total amino acid content through instrumental analysis. Histological and histochemical analyses were carried out by Hematoxylin-Eosin and Van Gieson staining techniques. As a result of histological and histochemical investigations, fish skins were found thin and tough due to their surface characteristics, had less collagen content compared to other raw materials commonly used in leather industry and the fibers were orientated in parallel but opposite to striated muscles differently from the other skins. Besides, the fat content, Kjeldahl nitrogen, hide substance, volatile matter and total ash of Katsuwonus pelamis fish skins were found 24.47±1.76%, 10.20±0.28%, 57.32±1.55%, 37.33±4.01% and 1.23±0.0002% respectively. The results of the study revealed that Katsuwonus pelamis fish skins could be an alternative raw material to be used in the production of high value added luxury leathers.