Kinetics of the process of drying fish concentrate from Atherina mochon pontica

Abstract

Background. A perspective reserve species of fishes of the Azov Black Sea basin is the aterina Black Sea (Atherina mochon pontica) which has no wide industrial use [1].
Considering the high biological potential of an aterina Black Sea the technology of processing it into a fish concentrate by drying has been offered. Process of drying is one of the main stages of technology of receiving a concentrate from an aterina Black Sea. We have chosen a method of drying of an aterina Black Sea in a drying installation of the convective SSh-1 type.
Dried minced fish from an aterina Black Sea is a concentrate of nutrients, in particular biologically active, and its use in technology of culinary products allows to increase the biological value of food products, first of all due to increase in content of proteins and mineral substances.
The aim of study is establishment of the optimum modes of drying of chopped fish mass from aterina Black Sea in a drying cabinet in order to receive a fish concentrate and a research of its functional and technological properties.
Material and methods. A research object is chopped mass from aterina Black Sea of spring catch from the basin of the Black Sea (Odessa).
Sampling is made in accordance with GOST 31339: 2006 [11], a mass fraction of moisture and solids was established by drying at a temperature of 100–105 °C, of protein by Kyeldal’s method, ashes by a weight method after a product was mineralized in the muffle furnace at a temperature of 600 °C in accordance with GOST 7636: 85 [12].
Drying of chopped fish from aterina Black Seat was carried out in the drying device SSh-1 at a temperature of 50, 70 and 100 °C. Reduction of weight when drying was controlled every 30 min. On the basis of the obtained data curves of drying of a concentrate from aterina Black Sea are constructed.
Coefficient of water absorption of a dried fish concentrate from aterina Black Sea was determined by ability to swell in water at the temperatures of 20, 35 and 55 °C.
Results. The technological scheme (fig. 1) of obtaining a concentrate from aterina Black Sea which consists of the following stages was developed: preparation of raw materials for production – I subsystem; drying in the drying device – ІI subsystem; commodity registration of a concentrate – III subsystem.
The modes of drying were picked up according to the main criteria – temperature and time of drying. Kinetics of process of drying is presented in fig. 2.
The curves of drying show that at the air temperature of 100 °C drying to necessary moisture content lasted 180 min., аt 70 °C – after 270 min. and at 50 °C – after 5.5 h.
To justify the optimum mode of drying of fish concentrate from aterina Black Sea change of its organoleptic and physical and chemical indicators (tab. 1) were investigated.
Taking into account that it is planned to use the fish concentrate from aterina Black Sea ready to prepare dishes and culinary products, its rehydration properties were defined. Coefficient of water absorption increases with temperature increase of water.
At a temperature of drying of 50 and 70 °C coefficient of water absorption is higher than at 100 °C that can be explained by the ability of a fish concentrate to hold moisture better at low temperatures of drying. At a temperature of drying of 100 °C proteins of fish concentrate lose property to be dissolved and hold water, thus a coefficient of water absorption is lower.
Conclusion. The rational mode of drying was established based on the studied kinetics of drying of minced fish from aterina Black Sea and quality of a ready concentrate: temperature is 70 °C, duration – 180–220 min.