Studying the temperature variation during ultrasonic irradiation of fruit and vegetable raw materials

The research objective was studying the evolution of the temperature field at ultrasonic impact on eggplant peel particles, being the waste by production of vegetable caviar, for the observance of the temperature restrictions when carrying out technological operations on the extraction from them water-soluble substances among which anthocyanins were present. At industrial processing of the eggplant there was waste, and their considerable share was made by the blanket, generally the peel which was initial raw materials for the production of natural food dye, and also after the extraction of it water-soluble substances and the subsequent drying - demanded product for pharmacotherapy. At ultrasonic radiation of the substance there was the growth of the temperature which values could go beyond technological restrictions. For the reason that experimental definition of the temperature variation in the volume of the part weighed in the water suspension was almost impossible, it was reasonable to use model approach to the solution of the given task by the adaptation of mathematical model of the transfer of thermal energy and the substance to the object of studying and its decision under certain regional conditions. For the purpose of the assessment of the adequacy of the solution of this model which was constructed for the average part of eggplant peel, a series of the experiments for finding of the variation of the temperature at the influence of ultrasonic radiation on suspension was carried out. Empirical researches were carried out at the original laboratory stand connected with the computer supplied with the Thermo Chart software product. The equation of thermal energy transfer was solved by means of numerical technique of final differences. The found distribution of the temperature on the volume of the particle shows that carrying out the operation on ultrasonic impact on it should not exceed 10 minutes; differently it was not possible to guarantee the safety of the quality of anthocyanins at their extraction from the particles of the peel of eggplants. It was possible to recognize the model of transfer of thermal energy constructed and adapted for the object of the research adequate and suitable for operational use in engineering practice.