Determination of the histological structure of sea cucumbers (Holothuria tubulosa) and (Holothuria polii) by some chemical components after freezing and drying

The aim of this study was to determine the effects of processing methods such as freezing and drying on the nutrient content of Holothuria polii and Holothuria tubulosa from sea cucumber. Holothuria polii and Holothuria tubulosa samples from Aegean Sea were purchased as alive from the commercial firm in İzmir (Turkey). Approximately100 samples each species were used for experiments. These species were transported to laboratory in seawater with air. The body of each specimen was cut from the anus nearly to the oral organ, and then their viscera were removed and washed with cold water, weighed and measured. Both species samples were put into boiling water and boiled for 30 min. Then they were allowed to drip dry at environment temperature (+27 °C for 72 h) and placed on grill for sun drying in Antalya (at Faculty of Fisheries Campus). Fresh sea cucumbers (HP and HT) in rapidly frozen to minus 35 degrees, the main purpose is to make the sea cucumber body water freezing. Frozen samples were stored minus 18 degrees until analysed (Approx. 72 hours). Physical and chemical analyses of frozen and dried products obtained from sea cucumbers and histological evaluations were performed. After the biometric measurements of the species, the chemical structure was examined; Water, crude protein, oil, ash (inorganic matter) analysis were performed. Histological analysis of HP and HT; According to the histochemical techniques, by passing through the routine histological process steps. stained with specific staining methods (such as Masson trickom) and examined under microscope. All samples were analysed in three independent replications (n = 3). The obtained results showed that the values of protein, fat and ash of the freeze and dry samples of HP and HT significantly (P<0.05). Also the values of moisture, fat and ash of the HP and HT wet samples varied significantly (P<0.05). The highest values of protein (19.17%) HT frozen samples, (66.32%) HT dried samples and fat (6.31%) HT dried samples and ash (7.78%) HP frozen samples, (22.57%) HP dried samples were investigated. According to the histological evaluation; especially, HT frozen samples are consisted better results than HP frozen samples. HP frozen samples; the cell size was smaller than the fresh sample, larger than the dried sample, the connective tissue was irregular and the intercellular space was more found. For our country, firstly, the species and natural resources that we have should be determined in detail and sustainable catching should be provided. In addition to this, by giving importance to the investment studies related to marine breeding, the dependence on natural resources should be reduced and scientific researches should be accelerated on the processing of sea cucumber industrially.