The work is devoted to the study of pectin extracts ultrafiltration  using different types of membranes. Pectic extracts are the solutions of high molecular weight polysaccharides (MM from 15 to 50 kDa), which are destroyed in the process of heat treatment in the vacuum evaporating apparature, that leads to a significant deterioration in the quality of pectin. The impurity components in the pectin extract of a low molecular weight, which makes it possible to use ultrafiltration for both concentration and purification from ballast substances, that  is very important. The objects of research were pectin extracts obtained from citrus raw materials; the membranes of the type UAM-100 and 200A were used as filter membranes. The results of the study have been shown, that the use of UAM-100 membranes in a stationary cell allows to remove up to 20% of the solution within 20 minutes, and with - stirring up to 27%. The use of membranes with large openings (up to 200 A) makes it possible to activate the process of the separation and concentration of pectin extracts: the degree of concentration reaches up 45%, the content of solids in the concentrate increases up to 7.6%, and the content of pectin to up 6.4%, that is in 1,7 times. However, the loss of low molecular weight pectin in the filtrate is about 4%. A comparative analysis of the results of research has shown a high productivity with the use of the capron membrane 200A, as well as on the qualitative parameters of the pectins, released from the concentrates, the higher parameters for the uroconid component, molecular weight, pectin jelly strength and complexing ability were noted for pectins isolated using the UAM- 100 membrane.

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The article is devoted to the study of the chemical composition, physical and thermal-pfysical characteristics of damp apple pomaces and the identifying patterns of influence of drying temperature the functional composition and gel-forming ability of pectin. The research is aimed at obtaining initial data for the subsequent calculation of the main technological, hydro-mechanical, thermal, structural and economic characteristics of devices for drying the plant raw materials, ensuring the environmental safety and high quality of pectin-containing raw materials, the reducing heat and energy costs. As a result of the study of the thermal characteristics of apple pomaces, the critical points (temperature conductivity – 16.5 x 10-8 m2/s, thermal conductivity – 0.28 W/m K, heat capacity – 1627 j/(kg K)) at a humidity of 56 % are determined, which characterizing the transition from the extraction of weakly bound moisture to the extraction of moisture with strong bonds (colloidal, adsorption). It was found that the pomaces obtained from apples of late ripening have a higher content of solids (21-23 %), soluble pectin and protopectin (2.5-4.5 %). Dried pomaces obtained from apple varieties of late ripening contain up to 25 % pectin, which allow us to recommend them as a source of raw materials for the production of pectin. The optimum modes of preliminary washing of raw materials are offered, allowing to the remove the ballast substances as much as possible. It is established that when the drying temperature increases, the destructive processes are catalyzed: the strength of the pectin jelly and the uronide component and the degree of pectin esterification are reduced. The optimum drying temperature of damp apple pomaces is 80 0C, at which the quality of pectin extracted from the dried raw materials is maintained as much as possible. It is shown that the most effective for the pectin production is a fraction with a particle size of 3-5 mm, which allow us to extract up to 71 % of pectin from raw materials.

Для оценки эффективности применения мембранных технологий очистки и концентрирования пектиновых экстрактов исследован процесс микро-, ультра- и нанофильтрации пектиновых экстрактов различной природы. Исследования проводили на стендовой установке для одинарных фильтрующих элементов с использованием керамических мембранных элементов ПС-100М для микрофильтрации, полисульфонамидной мембраны УПМ-20 для ультрафильтрации и полиамидной мембраны ОПМН-П для нанофильтрации. Объектами исследований были пектиновые экстракты, полученные из яблочного и свекловичного сырья методом гидролиза-экстрагирования в кислой среде. Установлено, что одноэтапное концентрирование на керамических трубчатых или половолоконных мембранах не позволяет достичь желаемой степени концентрирования. Поскольку пектиновые вещества представляют собой высокомолекулярные кислые полисахариды с молекулярной массой более 20 кДа и при концентрировании кинематическая вязкость их растворов резко возрастает, экранируя поры мембран, исследована возможность двухэтапной очистки и концентрирования пектиновых экстрактов методом микро- и ультрафильтрации. Установлена высокая производительность процесса микрофильтрации для яблочного и свекловичного пектиновых экстрактов в первые 30 мин. Отмечено, что производительность керамических мембран при микрофильтрации яблочного экстракта в 2,5 раза выше, чем свекловичного, при ультрафильтрационном концентрировании с отсечкой по молекулярной массе 50 кДа – в 2,9 раз. Установлено, что для яблочных пектиновых экстрактов применение на стадии ультрафильтрации полисульфонамидной мембраны УПМ-20 неэффективно вследствие более высокой молекулярной массы яблочного пектина по сравнению со свекловичным. Требуется дополнительная третья стадия – нанофильтрация, обеспечивающая концентрирование пектинового экстракта из яблочных выжимок до содержания сухих веществ 4%. For evaluate the efficiency of membrane technologies for purification and concentration of pectin extracts, the process of micro-, ultra- and nanofiltration of pectin extracts of various nature has been studied. The research were carried out on a stand instrument for single filter elements with use of ceramic membrane elements PS-100M for microfiltration, polysulfonamide membrane UPM-20 for ultrafiltration and polyamide membrane OPMN-P for nanofiltration. The objects of research were pectin extracts obtained from apple and sugar beet raw materials by hydrolysis-extraction in an acid medium. It has been found that one-step concentration on ceramic tubular or hollow fiber membranes does not allow to achieve of the desired degree of concentration. Due to the fact that pectin substances are the high molecular acidic polysaccharides with a molecular mass of more than 20 kDa, and when concentrating, the kinematic viscosity of their solutions increases sharply, screening the membrane pores, the possibility of two-stage purification and concentration of pectin extracts by the micro and ultrafiltration method is studied. The high productivity of the microfiltration process for apple and sugar beet pectin extracts was established in the first 30 min. It was noted that the productivity of ceramic membranes in the process of microfiltration of apple extract is 2,5 times higher than that of sugar beet, and with ultrafiltration concentrating mass molecular weight cutoff of 50 kDa – by 2,9 times. It has been found that for apple pectin extracts the use of the UPM-20 polysulfonamide membrane in the ultrafiltration stage is not effective due to higher molecular mass of apple pectin compared to beet pectin. An additional third stage – nanofiltration is required, which provides the concentration of the pectin extract from the apple material to a solids content of 4%.