Study of ultrasonic influence on the degree of pectin extraction from fermented beet pulp with citric acid solution

The aim of the study is to identify the effect of ultrasound exposure on the degree of pectin extraction from fermented beet pulp with a citric acid solution. The task is to determine the modes of ultrasound exposure in the process of pectin extraction from fermented beet pulp, providing the maximum degree of pectin extraction. The object of the study is fermented beet pulp, as well as pectin extract obtained from fermented beet pulp. An aqueous solution of citric acid with a concentration of 0.33 % was chosen as an extractant for pectin extraction, which, according to preliminary studies, performs only the function of an extractant, without leading to hydrolysis of the components of the fermented beet pulp. The study of the biochemical composition of fermented beet pulp was carried out according to the methods given in GOST 28561-90, 25555.4-91, 26889-86, 29059-91 and the work of Ermakov A.I., Arasimovich V.V., Yarosh N.P. “Methods of biochemical study of plants” (Moscow, 1987). The mass fraction of pectin in the pectin extract was determined using the calcium-pectate method. To study the effect of ultrasound exposure on the degree of pectin extraction from fermented beet pulp, pectin was extracted under different conditions. During the extraction process, the following constant factors were adopted: extraction temperature - 55 °C, concentration of aqueous citric acid solution - 0.33 %, ratio "fermented beet pulp: aqueous citric acid solution" - 1 : 10; discreteness of ultrasound exposure - 10 min; extraction time - 60 min. The variable factors were the specific power of ultrasound exposure, W/cm3, and the time of ultrasound exposure, s. As a result of the conducted studies, the optimal modes of ultrasound exposure were established, namely: specific power of 0.24 W/cm3 for 15 s with a processing resolution of 10 min, providing the maximum degree of pectin extraction - 53.05 %, while the purity of the obtained pectin extract was 70.8 %.