Consumer properties of a spiny dogfish (Squalus acanthias)

Abstract

Background. The consumption level of fish and fish products in 2017 in Ukraine was 9.6 kg on a per capita basis, in particular not more than 2 kg of domestically produced ones. Today the portion of imported raw materials for fish product manufacturing is more than 90 %.
Spain, Portugal, Australia and New Zealand are the main importers of spiny dogfishes to Ukraine and the biggest imports were recorded in 2016.
A spiny dogfish has been identified as the one of the prospective types of raw materials in Ukraine; its stock is not used to the full extent and is sufficient for the fish-processing industry. That’s why a spiny dogfish is a reserve to develop Ukrainian fishery and food technologies.
The aim of this paper is to assess parameters characterizing consumer attributes of a spiny dogfish in an integrated fashion in order to use it in food technologies.
Material and methods. The object of this research is mature specimen of the Black Sea spiny dogfish (between 15 and 17 years, 8.6–10.4 kg weighing) caught in the Black Sea near the Zmiinyi Island in the autumn – winter period (November – February 2016) [6].
The morphotype and main identification attributes of the Black Sea spiny dogfish have been assessed visually.
Microbiological studies have been undertaken by classical approaches [7; 8].
The content of heavy metals has been specified by the atomic emission spectroscopy with the inductively coupled plasma using Optima 2100 DV of Perkin Elmer (USA) [9].
The qualitative and quantitative amino acid composition has been specified by the ion exchange liquid column chromatography on the automatic analyzer Т 339 (Czech Republic) [10].
Absolute fatty acid methyl esters have been obtained by the gas chromatography and identified with the chromatograph HRGC 5300. The content of methyl ethers has been calculated according to the inner normalization [11].
The connection between structural characteristics of the Black Sea spiny dogfish and elastic properties depending on storage conditions (cooling, freezing) has been made with the multifunctional MIG-1.3 measurement complex using the information study module by the axial tension method [12].
Results. The biggest problem on the fish and fish product market is that countries underreport the catching and realization of fishes, in particular spiny dogfishes. The key aspect of research is to specify identification attributes of the spiny dogfish.
It has been established that the maximum body depth of the spiny dogfish reaches 23.2 % of the body length and the minimum – 3.8 % of the body length. The weight composition of the spiny dogfish depends on its age, sex, size and catching period. It has been also established that the muscular tissue is 40.1 % of the total spiny dogfish mass, head – 17.3, internal organs – 16.4, liver – 16.0, fins 5.0 and cartilages 4.0 % [6]. A number of mesophilic aerobic and facultative aerobic microorganisms in the muscular tissue of the Black Sea spiny dogfish did not exceed permissible limits [3].
As a result of toxicological safety assessment of the spiny dogfish it has been established that the quantitative content of heavy metals (Lead, Cadmium, Copper, Zinc) in the muscular tissue of the spiny dogfish is within the limits not exceeding the maximum permissible concentration for sea fish in accordance with the legislation of Ukraine.
The biological value of spiny dogfish protein has been assessed according to the content of amino acids of which the amount of nonessential amino acids was 5.781±0.257 and that of essential amino acids was 8.901±0.361 mg per 100 g of the product.
Monounsaturated fatty acids predominate in the fat separated from the spiny dogfish liver. Among them the oleic acid is a dominant fraction. Among saturated fatty acids the palmitic acid that increases the lipoprotein synthesis is dominant.
The density parameter in samples from different parts of the spiny dogfish carcass at different storage conditions has been determined in order to establish the dependence of the elasticity coefficient on the structure of the researchable object.
Conclusion. The Ukrainian food product market is saturated with imported fish raw materials which makes impossible to develop the domestic aqua- and mariculture as well as to use the available hydrobiont stock effectively.
The conducted research of consumer properties of the Black Sea spiny dogfish allows giving scientific credence of long-term benefit and expediency of its use in the fish-processing industry and food technologies.