TECHNOLOGY AND EQUIPMENT FOR PROCESSING ACTIVATED AGRICULTURAL PLANT WASTE INTO BIOETHANOL

The article is devoted to the development of technology and equipment for the production of bioethanol from agricultural plant waste, activated by the steam explosion method. The value and novelty of research lies in obtaining new data on the effective acidic and enzymatic hydrolysis of activated raw materials, and developing a technology for the conversion of plant raw materials into bioethanol. The studies were carried out on the basis of the Department of Wood Materials Processing of Kazan National Research Technological University (Republic of Tatarstan, Kazan). A pilot plant for the production of bioethanol and the principle of its operation are presented. Pine wood waste and wheat straw (collected in Kukmor region of the Republic of Tatarstan in the period August-September 2021) were used as raw materials. Steam-explosive activation of raw materials was carried out at temperatures of 165 ⁰C and 210 ⁰C for 5 minutes. Acid hydrolysis parameters: H2SO4 concentration - 0.5% and 1.5%, hydromodule 1:15, hydrolysis temperature - 187⁰C, hydrolysis duration - 5 hours. Enzymatic hydrolysis parameters: preparation - Cellulox-A (OOO PO Sibbiopharm, Russia) - 6 and 12 g/kg of raw material, hydrolysis temperature - 45 ⁰C, substrate pH 4.7 (acetate buffer), raw material concentration in the substrate 33 g/l, the duration of hydrolysis is 72 h. Alcoholic fermentation of hydrolysates was carried out at 32-34⁰C using Saccharomyces cerevisiae yeast, fermentation duration 7 h, yeast concentration 25 g/l. The bioethanol yield in % of reducing substances was recalculated after determining the mass yield. It is concluded that the vapor-explosive activation of pine wood at a temperature of 210 ºC makes it possible to obtain by acid hydrolysis and anaerobic fermentation of reducing substances up to 0.26 kg (0.33 l) of ethanol from 1 kg of activated raw materials, and activation of wheat straw at the same temperature allows obtaining up to 0.172 kg (0.218 l) ethanol with 1 kg of activated straw

Use of pullulanase as a biocatalyst for starch hydrolysis: Part 1. Study of the effect of pullulanase on maize amylopectin starch

The use of debranching enzymes in starch hydrolysis is a topical direction for obtaining new types of starch products with controlled properties and a potential for the further use. The aim of the work was to study an effect of pullulanase (EC3.2.1.41) on maize amylopectin starch in the native and gelatinized state. The objects of the research were maize amylopectin starch and enzyme preparation Promozyme D6 (Novozymes, Denmark). High-performance liquid chromatography (HPLC) was used to determine the carbohydrate composition of hydrolysates. The mass fraction of reducing substances (RS) was determined by the Lane and Eynon method. A rotational viscometer was used to measure dynamic viscosity of the starch hydrolysis products. It was found that analyzed starch in the native state showed low enzymatic sensitivity to the action of pullulanase with insignificant changes in viscosity, solubility and iodine binding capacity of the samples. Pullulanase showed the highest effect on gelatinized starch during the first eight hours of incubation. After eight hours, the maximum degree of starch hydrolysis by pullulanase at a dose of 10 units/g dry matter (DM) was 4.7% on DM basis, iodine binding capacity of the hydrolysate was D600 = 0.343 (in the control experiment D600 = 0.154), and the viscosity of the hydrolysate decreased from 7887 mPa · s to 4.3 mPa · s. Hydrolysates cooled to 8 °C and held for 20 hours along with hydrolysates that were not cooled showed high susceptibility to attack by glucoamilase (97–98%) at 60 °C and 24 hours of saccharification, which suggested the absence of their resistance to the action of glucoamilase in the conditions of the experiment. The use of pullulanase in dextrinization of the analyzed starch, which was gelatinized and partly hydrolyzed by α-amylase (RS6.1%), enabled obtaining hydrolysates with the mass fraction of reducing substances in a range of 10–24% on DM basis with the process duration of 2 to 24 hours and the enzyme dose of 2–10 units, which contained mainly maltotriose, maltohexose and maltoheptose with their total amount of 45–60% on DM basis. The results indicate a need for further research of the biocatalytic action of pullulanase to develop new methods for enzymatic modification of starch.

Production and Properties of Microbial Polyhydroxyalkanoates Synthesized from Hydrolysates of Jerusalem Artichoke Tubers and Vegetative Biomass

One of the major challenges in PHA biotechnology is optimization of biotechnological processes of the entire synthesis, mainly by using new inexpensive carbon substrates. A promising substrate for PHA synthesis may be the sugars extracted from the Jerusalem artichoke. In the present study, hydrolysates of Jerusalem artichoke (JA) tubers and vegetative biomass were produced and used as carbon substrate for PHA synthesis. The hydrolysis procedure (the combination of aqueous extraction and acid hydrolysis, process temperature and duration) influenced the content of reducing substances (RS), monosaccharide contents, and the fructose/glucose ratio. All types of hydrolysates tested as substrates for cultivation of three strains—C. necator B-10646 and R. eutropha B 5786 and B 8562—were suitable for PHA synthesis, producing different biomass concentrations and polymer contents. The most productive process, conducted in 12-L fermenters, was achieved on hydrolysates of JA tubers (X = 66.9 g/L, 82% PHA) and vegetative biomass (55.1 g/L and 62% PHA) produced by aqueous extraction of sugars at 80 °C followed by acid hydrolysis at 60 °C, using the most productive strain, C. necator B-10646. The effects of JA hydrolysates on physicochemical properties of PHAs were studied for the first time. P(3HB) specimens synthesized from the JA hydrolysates, regardless of the source (tubers or vegetative biomass), hydrolysis conditions, and PHA producing strain employed, exhibited the 100–120 °C difference between the Tmelt and Tdegr, prevailing of the crystalline phase over the amorphous one (Cx between 69 and 75%), and variations in weight average molecular weight (409–480) kDa. Supplementation of the culture medium of C. necator B-10646 grown on JA hydrolysates with potassium valerate and ε-caprolactone resulted in the synthesis of P(3HB-co-3HV) and P(3HB-co-4HB) copolymers that had decreased degrees of crystallinity and molecular weights, which influenced the porosity and surface roughness of polymer films prepared from them. The study shows that JA hydrolysates used as carbon source enabled productive synthesis of PHAs, comparable to synthesis from pure sugars. The next step is to scale up PHA synthesis from JA hydrolysates and conduct the feasibility study. The present study contributes to the solution of the critical problem of PHA biotechnology—finding widely available and inexpensive substrates.

Determination of quality indicators of marmalade with addition of multi-component fruit and berry paste during storage

The object of research is the technology of jelly-fruit marmalade with the addition of multicomponent fruit and berry paste from apples, quince and black currant. Marmalade products are in demand due to their attractive appearance, excellent taste, aroma and good absorption by the body. This delicacy is characterized by the absence of fat, high sugar content and the presence of functionally physiological ingredients. Due to the growing interest of consumers in products of increased nutritional value, the technology of jelly-fruit marmalade with the addition of multicomponent fruit and berry paste from apples, quince and black currant has been improved. New confectionery products must first of all be safe for human health, therefore, organoleptic, physicochemical and microbiological indicators of the quality of marmalade were determined during storage. In terms of organoleptic quality indicators, both control and experimental marmalade samples have high quality indicators during the shelf life. The storage duration affects the consistency of the marmalade, which becomes protracted after 3 months of storage and contributes to a decrease in the color saturation of all samples. The loss of the mass fraction of moisture in the control sample of marmalade up to 6.1 % and the sample with fruit and berry paste – up to 5.0 %, an increase in acid accumulation by 4.0–20.6 % for the control and by 4.0–20 % for the sample marmalade with pasta. It is noted that the content of reducing substances increases in the control sample by 18.0–50.0 %, which is 11.8–15.0 %, and in the sample with the addition of paste – by 10.8–36.9 %, which is 12.3–15.2 %. The data obtained is admissible and meets the established quality requirements in accordance with the requirements of regulatory documents. Microbiological quality indicators have been determined and it has been established that new samples of marmalade with multicomponent paste, both freshly prepared and after a guaranteed shelf life, comply with the standards of all current requirements for the quality of food products. The safety of jellied fruit marmalade on agar with the addition of multicomponent fruit and berry paste from apples, quince and black currant has been proven during the guaranteed shelf life of 3 months.

Improving the marmalade technology by adding a multicomponent fruit-and-berry paste

The necessity to optimize the nutritional value of marmalade by using physiologically functional ingredients containing vitamins, dietary fiber, minerals, and other useful substances in its composition has been substantiated. Specifically, using the multicomponent fruit-and-berry paste from apples, quince, black currant has been proposed, which is obtained by an improved technique. The technique is characterized by the rapid dehydration (30...45 s, at 50 °C) of the blended paste in a rotor plant to 28...30 % of dry matter. When studying the dependences of the effective viscosity of paste compositions on the shear rate, it was found that the paste that demonstrated the best indicators contained apple in the amount of 40 %; quince ‒ 50 %; black currant ‒ 10 %. It has been experimentally proven that the rational amount of fruit-and-berry paste is 30 % with a decrease in agar by 30 %. This makes it possible to obtain the jelly-fruit marmalade on agar with a mass fraction of moisture of 18 %, a total acidity of 10 degrees, and a mass fraction of reducing substances not more than 28 %. The products have a sweet-sour taste, with a pleasant aftertaste and the smell of black currant, rich purple color, jelly-like form, and non-tight consistency. The strength of the new samples of marmalade with a decrease in the amount of agar is 18.9 kPa, similar to that of control. The improved technology makes it possible to expand the range of "healthy products", which is achieved by the partial replacement of raw materials with a fruit-and-berry paste, which contains a significant number of physiologically functional components. This allows for an increase in the nutritional value of marmalade, as well as a decrease in the formulation amount of agar, which is expensive, by 30 %. In addition, gentle concentration modes improve the process of paste making

Preparation of maltotetraose starch molasses using Maltotetraohydrolase Optimalt 4G

Одним из направлений решения актуальной задачи по расширению ассортимента сахаристых крахмалопродуктов является разработка способов получения мальтоолигосахаридов с различным углеводным составом, имеющих большой потенциал для использования в качестве пищевых добавок и ингредиентов продуктов здорового питания. Целью работы было изучение возможности получения нового вида крахмальной патоки с высоким содержанием мальтотетраозы с применением препарата мальтотетраогидролазы Optimalt 4G. Объектами являлись кукурузный крахмал, препараты альфа-амилазы Liquazyme Supra 2.8X и пуллуланазы Promozyme D6 (Novozymes), мальтотетраогидролазы Optimalt 4G (Du Pont), а также продукты гидролиза крахмала. Использованы методы определения массовой доли редуцирующих веществ (РВ), сухого вещества (СВ), углеводного состава, динамической вязкости гидролизатов и другие стандартные методы анализа. При осахаривании частично гидролизованной суспензии крахмала с концентрацией СВ 33 % и содержании РВ 7,9 % мальтотетраогидролаза наиболее активно действует в первые 3 ч осахаривания с резким снижением вязкости гидролизата с 197,6 до 20,0 мПа·с. При этом исчезали практически все олигосахариды с DР5-DР10, массовая доля ВМС снизилась на 60 %, увеличилось количество низкомолекулярных сахаров, а массовая доля мальтотетраозы составила 44,81 % против 2,38 % в исходном субстрате. Максимальное содержание мальтотетраозы 49,8 % в данных условиях наблюдалось в гидролизате после 8 ч инкубации, далее оно медленно снижалась. Установлена возможность получения крахмальной патоки с высоким содержанием мальтотетраозы до 45-48 % с использованием в качестве катализаторов гидролиза крахмала вышеуказанных ферментных препаратов. Использование композиции мальтотетраогидролазы с пуллуланазой увеличивает содержание мальтотетраозы на 1,5-2 %, снижает вязкость гидролизатов и позволяет сократить продолжительность гидролиза. Полученные данные являются актуальной основой для оптимизации технологических параметров процесса осахаривания с применением мальтотетраогидролазы с целью разработки технологии получения нового вида крахмальной патоки. One of the directions of solving the current problem of expanding the range of sugar starch products is the development of methods for producing maltooligosaccharides with a different carbohydrate composition, which have great potential for use as food additives and ingredients of healthy foods. The aim of the work was to study the possibility of obtaining a new type of starch syrup with a high content of maltotetraose using the preparation Maltotetraohydrolase Optimalt 4G. The objects were: corn starch, alpha-amylase preparations Liquazyme Supra 2.8X and pullulanase Promozyme D6 (Novozymes), maltotetraohydrolase Optimalt 4G (Du Pont), as well as starch hydrolysis products. Methods were used to determine the weight fraction of reducing substances (RS), dry solid (DS), carbohydrate composition, dynamic viscosity of hydrolysates and other standard methods of analysis. When a partially hydrolyzed suspension of starch with a concentration of DS 33 % and RS 7.9 % is saccharified, maltotetraohydrolase is most active in the first 3 hours of saccharification with a sharp decrease in the viscosity of the hydrolysate from 197.6 to 20.0 mPa·s. At the same time, almost all oligosaccharides with DP5-DP10 disappeared, the weight fraction of WMS decreased by 60 %, the number of low-molecular sugars of DP1-3 increased, and the weight fraction of maltotetraose was 44.81 % versus 2.38 % in the original substrate. The maximum maltotetraose content of 49.8 % under these conditions was observed in the hydrolysate after 8 hours of incubation, then it slowly decreased. It has been found that in order to obtain hydrolysates with a low DP1-3 content and increased (more than 45 %) maltotetraose, the degree of preliminary hydrolysis must be maintained within the range of RS 8-15 % by DS at an enzyme dosage of 0.06-0.08 units WMC/g DS starch and duration of saccharification up to 20 h. Use of maltotetraohydrolase composition with pullulanase during saccharification increases degree of hydrolysis and content of maltotetraose by 1.5-2 %, reduces viscosity of hydrolysates and reduces duration of hydrolysis. It is possible to produce starch syrup with high content of maltotetraose (up to 45-48 %) using the above enzyme preparations. The obtained data are the current basis for optimization of technological parameters of saccharification process with application of maltotetraohydrolase in order to develop technology of production of new kind of starch syrup.

Characteristics of water quality response to hypolimnetic anoxia in Daheiting Reservoir

Anoxia is a common phenomenon at the bottom of large reservoirs during thermal stratification. In an anoxic environment, an increasing amount of reducing substances and nutrients are released and settle at the hypolimnion of the reservoir, leading to water quality deterioration and eutrophication. This work presents a case study on Daheiting Reservoir, a part of the Water Diversion Project from the Luanhe River to Tianjin City. With the monitored data of the water temperature and dissolved oxygen content in the reservoir, and based on the mechanism of redox reactions, the water quality response to the hypolimnetic anoxia in Daheiting Reservoir was systematically analyzed. It was found that the release of total phosphorus from the sediments in Daheiting Reservoir was a joint effect of the biological and chemical processes, and the redox reaction in the anoxic zone boosted release of phosphorus. Anoxia in the reservoir caused the ammonia nitrogen released from sediments in the reservoir to accumulate at the hypolimnion, which increased the concentration of ammonia nitrogen in the water. Anoxia in the reservoir led to an increase in the concentration of iron and manganese, which accounts for the major driving factor of release of iron and manganese.

QUALITY ASSESSMENT OF MARMALADE JELLY WITH DIFFERENT COMPOSITION OF CARBOHYDRATES

Расширение ассортимента изделий пониженной сахароемкости, калорийности, себестоимости и повышенной пищевой ценности является приоритетным и актуальным направлением. Основным компонентом в традиционных рецептурах мармелада является сахар, употребление которого в значительных количествах ведет к развитию различных заболеваний. Патока крахмальная является универсальным сахаросодержащим продуктом, который по сравнению с сахаром имеет ряд конкурентных преимуществ, повышающих эффективность производственного процесса. Выбирая тот или иной вид патоки, можно заранее прогнозировать свойства и качество готового продукта. Высокоосахаренная патока обладает наибольшей сладостью и наименьшей энергетической ценностью, низкоосахаренная – содержит наибольшее количество декстринов и имеет повышенную калорийность. При получении мармеладных масс на патоке различных видов процесс уваривания необходимо проводить на 1–3 мин дольше. Конечное содержание редуцирующих веществ – глюкозы и мальтозы в уваренных мармеладных массах на патоке больше, чем в контрольном образце на сахаре, что обусловлено изначально большим их содержанием в рецептурной смеси до уваривания. Наибольшую вязкость имеет образец на низкоосахаренной патоке, что объясняется высоким содержанием в ней полисахаридов, которые придают массе высокие вязкостные свойства. Анализ цветности показал, что наибольшую насыщенность окраски имел образец мармелада на основе карамельной патоки. Опытные образцы полученных мармеладных масс имеют прочность больше допустимого значения и обладают удовлетворительной студнеобразующей способностью. Разработанные образцы мармелада из-за большего – в 1,5–3 раза содержания полисахаридов и меньшего легкоусвояемых углеводов можно отнести к продуктам пониженной сахароемкости и диетической направленности. Новая продукция конкурентоспособна по качественным и экономическим характеристикам. Expansion of the assortment of products of reduced sugar content, calorie content, cost price, increased nutritional value is a priority and an urgent trend. The main recipe ingredient in the traditional formulations of marmalade is sugar, the use of which in significant amounts leads to the development of various diseases. The starch kernel is a universal sugar-containing product, which, in comparison with sugar, has a number of competitive advantages that increase the efficiency of the production process. Choosing this or that kind of treacle, you can predict the properties and quality of the finished product in advance. The highest sweetness and the lowest energy value are highly sugared molasses, low-sugar content contains the greatest amount of dextrins and has an increased caloric content. When obtaining marmalade mass on molasses of various species, the process of boiling should be carried out longer for 1–3 min. The final content of reducing substances (glucose and maltose) in the fried marmalade masses on molasses is higher than in the control sample on sugar, which is due to the initially large content in the formula before boiling. The sample has the highest viscosity on low-saccharified molasses, which is explained by the high content of polysaccharides in it, which impart high viscous properties to the mass. Analysis of color samples showed that the highest intensity of color and saturation had a sample of marmalade based on caramel molasses. The experimental samples of the marmalade mass obtained have a strength greater than the allowable value and have a satisfactory gel-forming ability. The developed samples of marmalade because of the greater content of polysaccharides – 1,5–3 times and less easily digestible carbohydrates, can be attributed to products of reduced sugar content and dietary orientation. The new products are competitive both in terms of quality characteristics and economic efficiency.

Research of physical and mechanical properties, chemical composition and safety of melon variety «torpedo»

Представлены результаты исследований физико-механических свойств, химического состава и показателей безопасности составных частей (мякоть, кожура, семена) дыни сорта «Торпеда». В результате сопоставительного анализа химического состава мякоти, кожуры и семян дыни показано их существенное различие. Так, содержание жира в мякоти составляет 0,26±0,003 г, в кожуре - 1,24±0,01 г, в семенах - 26,21±0,31, содержание белка составляет 7,56±0,11; 9,92±0,14 и 21,52±0,32 г соответственно. Изучение содержания редуцирующих веществ и сырой клетчатки показало их высокое содержание в кожуре по сравнению с мякотью и семенами. Установлено, что высокое содержание калия (934,88±14,02 г) и натрия (270,54±3,78 г) сосредоточены в мякоти, высокое содержание железа (15,12±0,23) - в кожуре, а высокое содержание фосфора (854,72±0,82 г) - в семенах. По результатам исследований доказано, что показатели безопасности дыни сорта «Торпеда» полностью соответствуют требованиям ТР ТС 021/2011. The results of studies of the physical and mechanical properties, chemical composition and safety indicators of the constituent parts (pulp, peel, seeds) of «Torpedo» melon are presented. As a result of a comparative analysis of the chemical composition of the pulp, peel and seeds of the melon, their significant difference was shown. Thus, the fat content in the pulp is 0.26±0.003 g, in the peel - 1.24±0.01 g, in the seeds - 26.21±0.31, the protein content is, respectively, 7.56±0.11; 9.92±0.14 and 21.52±0.32 g. The study of the content of reducing substances and crude fiber showed their high content in the peel, in comparison with the pulp and seeds. It was found that a high content of potassium (934.88±14.02 g) and sodium (270.54±3.78 g) are concentrated in the pulp, a high content of iron (15.12±0.23) - in the peel, and a high phosphorus content (854.72±0.82 g) - in seeds. According to the research results, it has been proven that the safety indicators of the Torpedo melon fully comply with the requirements of TR CU 021/2011.

Effects of Straw Returning on Soil Physicochemical Properties and Microbial Diversity Under the Rice-crayfish Integrated System

This study represents the investigation of soil physicochemical properties and microbial diversity by the Biolog ECO analysis in a 7-year field experiment using winter flooded fallow + no straw returning (W), winter flooded fallow + straw returning (WS), and winter flooded fallow + straw returning + crayfish farming (WSC) at soil depths of 0-10 cm and 10-20 cm. Compared with the W treatment, the WS treatment has significantly more total reducing substances in the 0-10 cm layer and sucrase activity in the 0-20 cm layer. The WSC treatment has significantly more available N (AN), total N (TN) contents, acid phosphatase and sucrase activities in the 10-20 cm layer, while the pH value, total reducing substances, and Fe2+ content in the 0-20 cm layer was considerably lower compared with the WS treatment. Biolog ECO analysis reveals that microbial community composition in the WS and WSC treatments differs from that in the W treatment in the 0-20cm layer. The WS treatment increases significantly the diversity of bacterial community and the ability of utilizing carbon sources in the 0-10 cm layer, and the species abundance of bacterial community in the 0-20 cm layer. Meanwhile, in the 10-20 cm soil layer, the WSC treatment improves the species abundance of bacterial community and the ability of utilizing carbon sources compared with the WS treatment. These results indicate that straw returning under the rice-crayfish integrated system improves soil physicochemical properties, decreases reducing substances properties, and increases soil enzyme activity and functional diversity of microbial community, thereby contributing to soil condition.