Obtaining the powder-like raw materials with the further research into properties of eggplant powders

Abstract

Results of the research into development of the advanced technological and technical solutions for the processing of eggplants are reported. The proposed technology resolves the task on the rational use of eggplants. Owing to the infrared drying, a qualitatively new product is obtained, which makes it possible to maximally retain nutrients. During thermal treatment, the following physical-chemical characteristics of the dried material change: density, heat capacity, elasticity, porosity, chemical composition, and others. Therefore, we studied and report here the results of studying the properties of eggplant powders. The organoleptic, physical-chemical, and structural-mechanical indicators were determined, which makes it possible to calculate the required amount of powder, which could be introduced as an additive, without affecting the structural-mechanical properties of the finished product. The rational conditions for restoring the rehydration of eggplant powders were established: temperature in the range from 45 °С to 60 °С; duration of swelling 10‒15 minutes, ratio of powder to liquid 1:3 and 1:4. The content of toxic elements (lead, cadmium, arsenic, copper, zinc) and the microbiological indices (mesophilic aerobic, extra-anaerobic, Escherichia sticks, Salmonella bacteria) were investigated. Compliance with the requirements for this type of raw material is established and the safety of the developed eggplant powders is confirmed. It has been established that the developed food powder has a number of positive qualities, namely: a long shelf life, it does not require additional storage space, it is easily restored. Owing to the technology of infrared drying, which is one of the methods for eggplant canning, the productivity of the technological process of making powders improves. This is explained by that over the same time interval we obtain twice as much of the dried product compared with convective methods. Taking into consideration the nutritional value of eggplants, powders can be used in various combinations to ensure the predefined properties in the resulting product. That will reduce the time for cooking, and expand the range of functional products.