L.S. Solomina
All-Russian Research Institute of Starch Products, branch of the Gorbatov Federal Science Center of Food Systems, Russian Academy of Sciences, ul. Nekrasova, 11, pos. Kraskovo, Moskovskaya obl., 140051, Russian Federation
Abstract. The purpose of the studies was to determine the optimal technological parameters (extrusion temperature, reagent concentration, and rotational speed of the extruder screws) for the production of citrate starch ester with increased dynamic viscosity. As a raw material we used wheat starch; as a reagent, we used food citric acid. The concentration of its solution was changed in the range 0–0.50% to the weight of starch dry matter (DM). The moisture content of the mixture (starch and reagent) in all experiments was 25%. The temperature was changed in the range of 140–190 C with an interval of 10 C; the rotational speed of the screws was 125– 145 rpm in increments of 5 rpm. The influence of the duration of mixing the paste and its stability during storage was determined using the example of samples obtained at a citric acid concentration of 0.40% of the mass of starch DM; the processing temperature in the first case was 170 C; in the second case, it was 160 C and 170 C. The rotational speed of the laboratory stirrer was 300 rpm; the stirring time varied from 10 minutes to 60 minutes with an interval of 10 minutes. The storage time of the 10% paste at room temperature was eight days. With an increase in the extrusion temperature from 140 C to 190 C, the dynamic viscosity of the wheat citrate starch samples decreased 1.5 times. The highest dynamic viscosity of the samples in the studied range of reagent concentrations was observed at 0.40% of the weight of starch DM. This indicator allows obtaining a citrated starch ester of white colour with a maximum dynamic viscosity of 925 mPa s at a temperature of 160 C. With an increase in the extrusion temperature from 140 C to 170 C, we observed an increase in the content of reducing substances in the finished product, while at temperatures of 180 C and 190 C it decreased. The dynamic viscosity of the paste with a mixing time of 60 minutes and storage time of a week remained practically at the same level.
Keywords: wheat starch; citric acid; technological parameters; extrusion method; dynamic viscosity; citrate starch ester.
Author Details: L. S. Solomina, Cand. Sc. (Tech.), leading research fellow (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.).
For citation: Solomina LS [Formation of rheological properties of citrate starch ether]. Dostizheniya nauki i tekhniki APK. 2021; 35(6):68-72. Russian. doi: 10.24411/0235-2451-2021-10612.