COMPARISON OF FUNCTIONAL AND TECHNOLOGICAL PROPERTIES AND AMINO ACID COMPOSITION OF PROTEIN ISOLATES OF PLANT ORIGIN

The aim of the study is to compare the functional and technological properties and amino acid composition of chickpea and rapeseed protein isolates obtained by defatting, pretreatment with cellulolytic enzyme preparations, alkaline extraction and acid precipitation at the isoelectric point. The paper presents the results of the study of the amino acid profile and functional and technological properties of rapeseed and chickpea protein isolates. The protein solubility, water-binding and fat-binding capacities, fat emulsifying properties, emulsion stability, foaming capacity and foam stability were determined. Commercial soybean and pea protein preparations were used for comparison. Chickpea proteins had a higher biological value compared to soybean isolate, which was 75.84 %. In terms of amino acid composition, the isolates obtained are comparable to soybean and pea isolates. Chickpea isolate is rich in Asp, Glu, Arg, Leu and Lys, while rapeseed protein isolate contains large amounts of Asp, Glu, Tre, Arg and Ala. Chickpea and rapeseed proteins have a solubility of 21–26 %, which is significantly lower than pea and soybean isolates. Rapeseed protein isolate has relatively high water-binding ((310 ± 15) %) and weak fat-binding capacity ((155 ± 8) %), while high fat-emulsifying properties ((64 ± 3) %) and emulsion stability ((89 ± 4) %) are noted. Chickpea protein isolate has similar functional and technological properties, while the values of water-binding ((388 ± 19) %) and fat-binding capacity are higher ((195 ± 10) %) than for rapeseed isolate. Chickpea proteins have better foaming capacity and foam stability, the values of which are (70 ± 3) and 47 %, respectively. One of the ways to improve the functional and technological properties of the obtained protein isolates is targeted proteolysis, in connection with which further research should be focused on determining the conditions for their modification.