Determination of mechanical and thermophysical parameters of watermelon pulp for designing the process of its defrosting
On the Russian market, there is a need for biologically active vitamin and antioxidant complexes of natural origin, among which a universal bioactive composition can be distinguished, such as the carotenoid pigment complex lycopene (E-160d), with the help of which fruits and vegetables, for example, watermelons, have a rich red hue. It is known that, in addition to coloring ability, lycopene has biologically active properties, but its relatively high cost and low availability in the market are the limiting factors of its use in the daily food ration. From the technological scheme for the production of lycopene, two of the most energy-intensive and determining the quality of the finished product can be distinguished, such as defrosting watermelon pulp, as well as drying the recipe mixture. In this regard, it becomes obvious the need to search for new rational scientific and technical solutions to improve heat and mass transfer processes, the correct implementation of which is not possible without knowledge of the mechanical (density) and thermophysical characteristics of the feedstock in the region of negative and positive temperatures for the production of lycopene and the mechanism of their variation in within technological limitations for rational design of its defrosting. The aim of the study is to determine the mechanical and thermophysical characteristics of watermelon pulp and the mechanism of their variation within the framework of technological limitations during block defrosting of watermelon pulp, which is the object of research. To achieve this goal, the task of determining the technological temperature and humidity limits during defrosting, density, thermophysical parameters of the objects of research in the field of temperature variation below and above cryoscopic was solved. Certain data do not conflict with the known results, and their analysis shows that the process of defrosting watermelon pulp is carried out with a significant release of latent thermal energy of crystallization in certain temperature areas, which include the crystallization temperatures of solutions of their component components, as well as cryoscopic temperatures.