extraction, subcritical water, biologically active substances, extract, soybean meal


The work is devoted to the study of the process of subcritical water extraction of soybean meal and the influence of extraction parameters on the properties of liquid and dry extracts. The aim of the study is to establish the influence of the parameters of the process of subcritical water extraction (temperature: 120–160 °С, duration of extraction: 5…15 min, hydromodulus: 1 : 15…25) on the properties of liquid and dry extracts of soybean meal and their optimal values. An empirical method was used to establish the nature of the dependence of the indicators of extracts on the parameters of the extraction process. It is assumed that in the studied ranges of extraction parameters, the dependence of the extract indicators corresponds to a quadratic model. To determine the coefficients of the interpolation model, it was planned to conduct a fractional-factorial experiment 33–1 on an orthogonal compositional plan of the 2nd order. Liquid extracts were obtained in a laboratory facility based on a high pressure reactor. Dry extracts were obtained by evaporation. For liquid extracts, the pH and solids content were determined. For dry extracts, the content of minerals, residual water, protein, and isoflavones was determined. Extracts were analyzed by instrumental methods in accordance with the requirements of the State Pharmacopoeia of Ukraine using modern equipment. On the basis of the results obtained, the coefficients of quadratic interpolation models were established, the analysis of which made it possible to establish the optimal extraction parameters that ensure the maximum values of the extracts. It was found that in the studied ranges of duration and temperature of extraction, the content of solids in liquid extracts and protein in dry extracts have maxima, however, their value increased monotonously with an increase in the proportion of water in the extraction mixture. The content of mineral substances had a maximum only in temperature, and isoflavones in the duration of extraction. The results obtained can be used to improve the technology for obtaining protein soy concentrates and isolates using the method of subcritical water extraction. Due to the environmental friendliness of this extraction technology, the obtained extracts can be directly used to increase the nutritional value of various food products.


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