Feed Extrusion Research Articles

Insight into the relationship between the starch crystalline structure and textural quality and physicochemical properties of reconstituted rice: Influence of feed moisture content

Reconstituted rice was prepared by extrusion with different feed moistures (30 %, 33 %, 36 %, 39 % and 42 %), and the relationship between the crystalline structure, physicochemical properties, and textual quality of reconstituted rice was studied. The results revealed that, with the feed moisture increased (33 %–36 %), the gelatinization degree reached 97.28 % and the bound water content increased by 23.58 %. The water absorption index and swelling power index reached 8.35 g/g and 9.46 g/g, respectively, and the texture properties were close to those of native rice. Higher extrusion feed moisture (39 %–42 %) increased the setback value (206.00 cP) and breakdown value (721.33 cP) of starch, and the hardness and gumminess of reconstituted rice were also increased (p < 0.05). The starch crystalline structure was disrupted by extrusion and changed to a surface fractal structure, the relative crystallinity decreased from 26.87 % to 6.68 %, and the degree of order decreased from 1.680 to 1.006. Correlation analysis revealed that the crystalline structure of starch and water distribution would affect the textural and hydration properties of reconstituted rice. The results provide theoretical references and data support for improving the edibility and quality of reconstituted rice and enhancing the utilization rate of broken rice.

Incorporation of brewer's spent grain into plant‐based meat analogues: benefits to physical and nutritional quality

SummaryBrewer's spent grain (BSG) is the major by‐product of brewery industry. Due to being rich in dietary fibres and proteins, it has great potential to be upcycled in plant‐based foods and contribute to the sustainability of our food system. This study investigated the incorporation of BSG at different concentrations to soy protein‐based high‐moisture meat analogues (HMMAs). Colour, textural properties, and macrostructure of the resulting HMMAs were examined. In vitro protein digestibility of selected HMMAs was also measured. At 15% BSG incorporation level, the presence of BSG favoured texturisation and lowered the hardness of HMMAs. However, higher BSG incorporation levels impaired the formation of a fibrous structure in the HMMAs that mimics the mouthfeel of animal‐based products. When extrusion feed moisture increased from 60% to 70%, the hardness and chewiness of the HMMAs decreased from 223.18 and 188.94 N to 127.80 and 103.16 N, respectively, while the cohesiveness and springiness were not significantly affected. In general, the higher the BSG incorporation level, the darker and browner were the HMMAs. IVPD of HMMAs varied from 74.58% to 76.15% and was higher in the HMMAs containing BSG, indicating that BSG complements soy protein digestibility. BSG incorporation may improve the texture of HMMAs and contribute to the intake of dietary fibre.

Prediction of extruded aquafeed physical quality parameters through a dough viscosity model

AbstractA widely used dough viscosity model in food extrusion was adopted and employed for the analysis and prediction of extruded aquafeed physical quality parameters. The data for the analysis were collected from previously published articles. The analysis was based on the assumption that pellet physical quality parameters, such as bulk density, oil adsorption, hardness, and durability, are correlated to the dough viscosity property changes in the extrusion process. The physical qualities of feed were modeled using the modified viscosity model. The model was evaluated using the data collected from experiments conducted in three different pilot extrusion systems. The results showed that the new model has the capability to predict the physical quality parameters of extruded aquafeed pellets in the three studied scenarios. The absolute average deviations of the model regression for the pellet qualities were 8.5% for hardness, 4.8% for bulk density, 6.5% for oil adsorption, 15.7% for Holmen durability, and 0.7% for pellet diameter. The new model can correlate the physical qualities of aquafeed pellets across different recipes, extruder configurations, and systems.Practical ApplicationsFood or aquatic feed extrusion process operation heavily depends on the operator's experiences and is still a black‐box process. In this study, a dough viscosity model was applied to explain the relationship between extrusion variables and extruded pellet physical qualities. The new model can be used for a quantitative description of a feed formulation extrusion process and feed pellet quality optimization.

Contributing towards meeting Africa Agenda 2063: progress made by Nigerian Agricultural Engineers in the development of small-scale agricultural machinery

One of the major aspirations of the African Union's Africa Agenda 2063 is to eradicate poverty and achieve a high standard of living, quality of life and wellbeing for all. It is key to develop relevant machinery to meet this target. Hence in this study, the importance of agricultural machinery and its development as a way to achieve the Agenda 2023 vision is highlighted. The research efforts of Agricultural Engineers towards helping to feed the populace effectively by way of developing small-scale machines and systems have been reviewed. The machines and systems include those for planting and weeding, bird scarring on rice fields, fruit harvesting, food and feed extrusion, wet sieving, drying and food cutting. The challenges faced during these activities are also highlighted. Finally, the recommendations towards improving the development of agricultural machinery in Nigeria were elucidated. It is hoped that this study goes a long way to encourage researchers who are in this discipline to do more while also ensuring wider patronage so we can realise the 'The Africa We Want'.

Modeling of a screw extruder 3D printer using pellets or crushed polymer waste as the raw material

In this article, the process of moving polymer material in the screw extruder of a 3D printer, which uses granules or crushed polymer waste as raw materials, is chosen as the object of mathematical modeling. It is noted that the modeling of screw extruders is a highly relevant task, as it is an essential tool for optimizing production processes in the polymer industry and other industries where they are used. It allows you to study and optimize the material cylinder's processes thoroughly. It is noted that the modeling of screw extruders for 3D printers, which use granules or shredded plastic waste, is a critical factor in supporting innovation, increasing production efficiency, improving product quality, and developing new technological solutions in various industries. It was noted that during the movement of the material along the channel of the extruder screw, several of its states continuously changed from a solid at the entrance of the channel to a viscous liquid at the exit. In the feed zone, the polymer is solid and moves along the material cylinder due to friction. A physical model was used in the simulation, in which compacted polymer particles do not move relative to each other during movement through the channel. This is because the internal friction forces in the polymer greatly outweigh the friction of the polymer on the steel, and the particles move as a single elastic compressible medium due to the balance of dry friction between the cylinder wall and the screw. The geometrical parameters of the extruder in the feed zone are shown. A diagram of the expanded extruder channel for calculating productivity is given. A diagram of the movement of material in it was drawn up to determine the productivity of the extruder feed zone. A mathematical model of productivity was obtained depending on the diameter of the screw, the frequency of rotation, the depth of the screw channel, and the angle of elevation of the screw line of the screw cutting. The pressure in the extruder channel was calculated. A scheme for calculating the forces acting on the material in the feeding zone is given. A formula was obtained for determining the pressure in the material loading zone from the hopper, which connects the characteristics of the polymer material and the geometric parameters of the loading hopper. Keywords: 3D printer, screw extruder, modeling; polymer material; loading area; bunker; productivity; pressure.

Multi-Source-CT for inline inspection of extruded profiles

The market for extruded profiles for different applications (automotive, construction sector) is a big part of the plastics processing industry. Currently, the whole production process runs almost without quality checks. Only random tests are done to check the profile for its geometry, dimensions and defects. For extruded pipes and other rotation-symmetric products, there are special inline-inspection systems. However, none of these systems is capable of checking the whole inner and outer geometry of an arbitrarily formed profile. Due to this, we evaluate a concept for a multi-source-CT system, which is able to inspect the whole geometry of extruded profiles during the production process. In this work, we evaluate a concept and build a prototype system to validate the functional capability. Considerable attention is paid to the use of commercially available components because of the cost-effectiveness of the whole system. On the whole, the system comprises 16 x-ray-sources and two polygon-shaped detectors. The components are separated into two rings, each with eight x-ray sources and one detector. The rings are arranged around the extrusion line so that extruded profile traverses through the rings during the extrusion. The whole system is semi-static, which means the components are rigid relative to each other, but the system makes an eccentric movement perpendicular to the direction of extrusion. Due to this, the number of projection angles increases from 16 to about 420 projection angles, which is sufficient for reconstruction. To further increase the sampling rate, three x-ray-sources are pulsed simultaneously. Therefore, we are able to do a full 3D scan of extruded profiles with an extrusion feed of up 100 mm/sec.

Extrusion parameters and physical transformations of an extrudate for fish: Effect of the addition of hydrolyzed protein flour from by-products of Oncorhynchus mykiss

IntroductionThe food industries play a fundamental role in feeding for the functions of animal metabolism. Fish feed extrusion cooking includes process-independent factors such as temperature (°C), screw speed (RPM), throughput, feed, and moisture content that influence the final product's nutritional value and physical properties. The evidence suggests that the application of hydrolyzed protein flour (HPH) is a crucial step for the techno-functional properties of the product. Therefore, this work aimed to study the effect of hydrolyzed protein meal from silage of trout (Oncorhynchus mykiss) on the parameters of the extrusion system and their physical transformations.MethodsIn this study, the influence of hydrolyzed protein meals ranges between 10 and 30% as a substitute for fish meals. The physical properties of the extrudate were monitored, evaluating the hardness, durability, buoyancy, expansion index, and apparent density.ResultsConsistent with this, parameters such as feed composition, screw speed, moisture content, and extrusion process affected the composition and properties of the final product.DiscussionThe physical properties indicated that the hydrolyzed protein flour presented cohesiveness and decreased the mean retention time in the extruder barrel and the specific mechanical energy (SME). Hydrolyzed protein flour during the extrusion process produces pellets with high durability and low hardness due to the high porosity presented, which allows for obtaining nutritional characteristics in the extruded product.

Strength and its variability in 3D printing of polymer composites with continuous fibers

Additive manufacturing (AM) of polymer composites with continuous fibers could play a major role in the future of aerospace and beyond but will require printed materials to achieve new levels of reliability. This study characterized the strength distribution of selected thermoplastic matrix composites as a function of printing via fused filament fabrication (FFF). Experimental and commercial composite filaments of continuous carbon or Kevlar fibers were printed with volume fraction (Vf) ranging from approximately 28 to 56 %. The strength was evaluated under uniaxial tension after specific stages of printing and Weibull statistics were applied to characterize the strength distribution. There was a significant reduction in strength of the printed material with respect to the unprinted condition, regardless of reinforcement type, fiber volume fraction or printer used. Damage introduced by feed extrusion of the filament, and fiber failures induced at material deposition were most detrimental. For carbon fiber filaments, the reduction ranged from approximately 10 % for an experimental material to over 60 % for a commercial filament. There was no correlation in the strength degradation or variability with Vf. The prevention of process-related fiber damage is key to advancing AM for continuous fiber composite and application to designs intended for stress-critical applications.

Identifying changes in soybean protein properties during high-moisture extrusion processing using dead-stop operation

To provide additional evidence and better understand the high-moisture texturing extrusion process of soybean protein isolate (SPI), the physico-chemical changes of SPI during extrusion were investigated. SPI in the extruder feeding zone, barrel zones 1 (80 °C) to 4 (135 °C), and the cooling die (80 °C) were obtained from a dead-stop operation. The lowest values associated with the denaturation enthalpy and the extractable protein occurred in zone 3 (150 °C). The minimum level of the protein subunit content was identified in zone 4. The highest value of the average protein molar mass occurred in zone 3. The β-sheet ratio in the protein increased, and the unordered ratio decreased after extrusion. The surface hydrophobicity of the protein decreased with water injection in zone 1; however, it increased in zone 2 (110 °C). Overall, SPI undergoes swelling, denaturation, aggregation, and depolymerization due to water injection, heating, and shearing during high-moisture extrusion.

Organic-Inorganic Hybrid Material Synthesis by on Line Coupling Twin Screw Extruder with a Microwave Oven

Abstract A new process for elaborating continuously organic-inorganic hybrid materials by reactive extrusion is presented. This synthesis consists in formulating a copolymer of ethylene and vinyl acetate (EVA)/tetrapropoxysilane (TPOS or Si(OC3H7)4)/catalyst blend by a corotating twin screw extruder followed by two successive reaction steps: on line microwave crosslinking reaction and hydrolysis-condensation reactions leading to a silica network cografted onto the organic matrix. Extrusion feed rate (Q), temperature, microwave oven power (P), and microwave curing time (tmw) were studied. Crosslinking density was evaluated before and after hydrolysis-condensation reactions and compared with the previous results obtained in static conditions. These materials tailored by an on line process present a permanent elasticity at high temperature (up to 200 °C) and a certain optical transparency. This new approach offers the possibility to synthesize massive samples based on organic-inorganic hybrid material.

The Adjustable Grooved Feed Extruder

Abstract Grooved feed extruders have been around since about the 1960s. These extruders offer considerable advantages over conventional extruders, such as higher throughput, better stability, and the ability to process very high molecular weight polymers. There are some important disadvantages as well, for instance, higher motor load, wear is more likely, high pressures in the grooved region, and the screw design has to be adapted. The disadvantages of the grooved feed extruder disappear when the grooved feed extruder is made with a mechanism that allows adjustment of the groove depth. This paper will report on the development of grooved feed extruders that incorporate an adjustment mechanism that allows the depth of the grooves to be changed, during actual operation, from zero to full depth. Operational data from actual extrusion experiments are presented.

A case study on elimination of premature failure source from manufacture of fluoroelastomer inflatable seals for Sodium-cooled Fast Reactor towards sustainability

An innovative model of engineering failure analysis leading to a prospective model of sustainability and decarbonisation, supported by design-material-failure threads, emerge from two defective test inflatable seals (Seals; ∼2 m dia) subjected to laboratory investigations i.e. visual, dimensional, physico-mechanical, material fingerprinting and analysis of variation. The Seals of 500 MW(e) Prototype Fast Breeder Reactor (PFBR) design were industrially manufactured (year: 2007) by cold feed extrusion and continuous cure (CFECC) of a peroxide cured, Viton GBL 200S:600S blend compound, APA-1, 2007. Primary aim was to implement life maximization (global design thread) potential (≥30 y) of advanced polymer architecture (APA) fluoroelastomer (FKM) in reactor inflatable seals (∼6.3 m/∼4.2 m dia) with repeatability and reproducibility by eliminating premature failure source from improper manufacture.Unfeasibility of or unlikely value addition from validation-modelling-simulation-microstructure study necessitated innovative treatment i.e. extracting maximum from the minimalist investigation by maximizing interpretation-data mining-cross verification and utilizing past (validated) FEA results of standard FKM PFBR inflatable-backup seals (life: 10 y) through design-material threads. The treatment was reinforced by reorientation of perspective. Distribution of laboratory data along Seal circumference was interpreted as phenomenological manifestation of thermomechanical-electrochemical interactions in the APA-1, 2007 macromolecular realm, brought about by thermomechanical loads from the progressing CFECC with time. The data was thus utilised to reconstruct the CFECC (2007) in terms of processing parameter variance with respect to a benchmark CFECC study on identical seal design. Incorrect cure index (of APA-1, 2007; global failure thread) was ascertained as the source of premature failure by tracing the origin of departures e.g. tracking the straying of APA-1, 2007 tensile stress-strain behaviour (structure property correlation) and cracking failure limits (global material thread) from the desired (i.e. ≥30 y) along the abstracted echelons (i.e. reconstructing manufacture, molecular-phenomenological interplay) of the CFECC in terms of unacceptable macromolecular transitions. The novel approach and methodology predict new-seal-failure-situation in reactor (by residual stress) and/or continuing operation-safety uncertainty of inflatable seal and reactor (by undercure) from the incorrect cure index. The identified source and template for permanent rectification are crucial for FBR-Gen IV cover gas elastomeric sealing. The applicability extends to other nuclear and inaccessible-hazardous, critical/very critical elastomeric usage (marine, air, space, oilfield, gas etc.) as well.The research findings provide complete description of (APA-FKM) residual stress and tensile stress-strain behaviour by the first principles and an analogy of mechanical-entropy spring, accompanied by a new commentary on structure-property-performance correlation of APA-FKM. The findings are expected to enrich understanding of rubber failure. The failure analysis of a very critical nuclear component grows vastly in connotation using global threads to suggest a prospective conceptual benchmark template for sustainability-decarbonisation-augmentaion i.e. better realization of life maximization potentials in applications by synthesizing improved specifying-manufacturing-quality monitoring with the global threads.This study could provide basis for new research on defect modeling-simulation-validation and encourage formulation-modeling-validation of new constitutive relations, considering incorrect cure index and its effects. The concepts and routes of maximum from minimum, working by first principal, reconstruction, threads and molecular-phenomenological interplay are expected to find wider scope beyond this research.

THE IMPACT OF PRODUCTION TREATMENTS OF FEED CONCENTRATE PRODUCED FROM WASTE OF CEREAL PRODUCTION ON ITS BIOLOGICAL VALUE AND EFFICIENCY IN THE COMPOSITION OF COMPOUND FEED FOR CARP

The following article presents a new raw component in compound feed for carp – feed concentrate produced from cereal production waste. The feed concentrate is based on several types of cereal fodder meal - wheat, pea, barley, as well as wheat bran and unshelled oat grain. The feed concentrate is balanced according to the needs of carp and can be used as feed for carp instead of wheat grain or as a part of compound feed for carp. Heat-moisture processing of compound feed before extrusion is one of the main stages that further ensure the stability of technological processes and the final quality of the feed concentrate. The amino acid composition was determined at various temperatures of the feed concentrate after heat-moisture treatment of + 40, 60, 70 and 80º С at a constant moisture content of the concentrate of +282° С. Amino acid score has been calculated for feed concentrates that have been exposed to various heat treatments. The amino score was calculated in relation to the carp's need for essential amino acids. It was found that an increase in the temperature of the concentrate during heat-moisture treatment leads to a decrease in the content of essential amino acids. For example, the total content of methionine and cysteine in the composition of the feed concentrate at a temperature of +75° C was 0.46%, with the minimum allowable total content of these amino acids in the composition of feed 0,5%. Heat-moisture treatment at a product temperature above +75° C leads to a decrease in the content of essential amino acids and the biological value of the feed concentrate.The process of extrusion of feed concentrate from waste of cereal production has been studied. The glucose content in the feed concentrate was studied at various extrusion modes. The glucose content indicates the degree of modification of the starch during the extrusion process, and the more glucose the product contains, the better it is absorbed by the carp. When extruded with an increase in temperature, the starch passes into a viscous-flowing (gelatinized) state, forming a so-called melt, the cooling of which also leads to the formation of a three-dimensional gel network. The feed concentrate granule becomes monolithic in structure; it becomes quite hard and can harm the intestines of carp. Therefore, it contains wheat bran in an amount of 1%, as a component that is able to weaken the feed concentrate granule. The degree of starch destruction in the composition of the extruded feed concentrate with the addition of wheat bran reached its maximum and the granule became porous, its hardness decreased. It was detected that when the temperature of the feed concentrate after extrusion rises above +100°C, the biological value of the feed concentrate decreases, and it becomes unbalanced in the content of such essential amino acids as lysine, threonine, methionine and cysteine. Therefore, the optimum product temperature after extrusion is +90-100˚C.The effectiveness of extruded feed concentrate was determined in the composition of granulated feed for two- and threeyear-old carp. The feed ratio of the compound feed containing the feed concentrate was 0.9 units, which is 64% lower than of the control compound feed, which includes a non-extruded grain group that is not balanced in terms of carp needs.

Effect of synchronization of fermentation processes in body of young cattle

Indicators of rumen digestion of young cattle has been studied when fed with concentrates with high level of degradable protein and non-structural carbohydrates subjected to barothermal treatment. Extrusion of concentrated feed decreases degradability of concentrates protein by 26-28%. Correlation of indicators of rumen digestion in steers with the method of preparation for feeding with concentrates with high level of degradable protein and non-structural carbohydrates has been determined. So, in animals receiving feed subjected to barothermal treatment, the number of ciliates in rumen fluid increases by 5.4%, total nitrogen – by 2.9%, and concentration of ammonia and volatile fatty acids decreases by 8.1 and 3.4% Thus, processing of concentrates stimulates development of microflora of proventriculus and reduces the rumen protein loss. Barothermal treatment of concentrates with a high protein degradability and high level of non-structural carbohydrates increases productivity of animals and efficiency of feed. The average daily weight gain in animals of experimental group increases by 4.8-6.0%. As a result, the feed cost is reduced by 2.7-6.9%, and protein – by 2.6-5.7%.

Environmental adaptive features of local dogs and Kalmyk’s shepherd dog “Barg”

The article presents the results on the study of the biological characteristics of the Kalmyk’s shepherd dog "Barg" and local dogs, as well as indicators of the physiological state of animals (pulse frequency, breathing and body temperature). The indicators of natural immunity in the studied dog breeds and morphological, biochemical blood composition of animals were investigated. Analyzing the above mentioned data, it is possible to conclude that the extrusion of feed for experimental dogs contributes to a more intense metabolic process in the body, which is confirmed by the best biochemical blood indicators.

Effects of particle size distribution and processing conditions on the techno-functional properties of extruded soybean meal

Soybean meal (SBM) is a protein-rich, soybean oil industry by-product which can be extruded for improved techno-functionality and potential utilization as a food ingredient. The effects of SBM particle size distribution [PSD] (small, medium and large), extrusion feed moisture content (15, 21 and 27 g water/100 g dry SBM) and barrel temperature (110, 130 and 150 °C at the die) on techno-functional properties of SBM extrudates were investigated. A decrease in barrel temperature from 150 to 110 °C generally improved nitrogen solubility index, gel forming capacity, oil holding capacity and emulsion capacity of extrudates. In addition, increasing feed moisture content from 15 to 27 g water/100 g dry SBM generally enhanced oil and water holding capacities. Nitrogen solubility index of extrudates made from large PSD feed was generally higher than that of medium PSD extrudates. PSD of SBM also affected the torque and specific mechanical energy requirements during extrusion cooking, SBM with large PSD requiring a higher level of mechanical energy input to be processed when compared to that with medium PSD. This work provided a comprehensive understanding of how feed particle size, extrusion moisture and barrel temperature can be manipulated to provide new opportunities in producing novel food ingredients from SBM.

Development of pelleted feed containing probiotic Lactobacillus rhamnosus GG and Jerusalem artichoke for Nile Tilapia and its biocompatibility studies.

Growth performance and immune systems of tilapias could be improved by Lactobacillus rhamnosus GG (LGG) and Jerusalem artichoke. This research aimed to determine the effects of Jerusalem artichoke on LGG viability after drying and pelleting and their subsequent exposure to simulated gastrointestinal conditions. Fresh LGG cells were added into wall material solutions, including alginate (AL), alginate + milk powder (AM), and alginate + milk powder + Jerusalem artichoke at different concentrations (AMJ). The solutions were then spray dried to obtain LGG powders. The powder with the highest cell number was then selected to mix with tilapia feed mash and pelleted using a nonthermal feed extruder to obtain pelleted feed containing LGG and Jerusalem artichoke. The LGG viability spray dried powders and pelleted feed were analyzed for their cell counts after drying and after exposure to simulated gastrointestinal conditions. The result showed that the number of viable cells in AMJ was significantly higher than AM and AL after drying. The number of viable cells under both simulated gastric and bile salt fluids was improved with the increasing of Jerusalem artichoke concentrations. The number of viable cells after pelleting process could be maintained. LGG in the pelleted feed could also survive under the simulated gastric and bile salt conditions. The study indicates that JA enhanced LGG viability after drying and exposure to simulated gastrointestinal conditions. The pelleted feed containing LGG and Jerusalem artichoke could be applied in tilapia farming, providing convenience to the farmers, and valuable effects to the fish.

Impact of Die Surface Holes Distribution Patterns of Fish Feed Extruder on Performance Indicators and Pellets Quality

Die holes distribution is the most important factor of any feed pelleting system, as far as machine efficiency is concerned. This study was carried out with fish diet, where had been processed without steam addition (cold pelleting). The aim of the study was to explore the impact of fish feed extruder die surface holes distribution patterns on extruder productivity, total consumed power, specific energy requirements, pelleting efficiency, pellets bulk density and durability and economical evaluation. The optimum results were recorded with die that had holes distributed in the surface of die in star pattern, observed improvement in extruder productivity, pellets durability and pelleting efficiency by up to 10.75 and 15.64 %, 0.51 and 4.74 % , 0.53 and 1.63 %, respectively at constant moisture content of 36 % and screw speed of 96 rpm(12.7 m. min-1), comparing to triangular pattern and scattering pattern respectively, and decreased, bulk density, total consumed power, specific energy requirements and pelleting cost by up to 1.86 and 6.27 %, 14.98 and 47.34%, 12.2 and 6.2 % , 28.8 and 35.6%, respectively at constant moisture content of 36 % and screw speed of 96 rpm (12.7 m. min-1), compared to triangular pattern and scattering pattern respectively.

THEORETICAL STUDIES OF A DEVICE FOR THE EXTRUSION OF WHEAT GRAIN

The extrusion of the raw material mass makes it possible to obtain full-fledged feed mixtures balanced in nutrients and useful substances, having a long shelf life (more than six months) without reducing the basic qualities. For the most efficient production of animal products, rational use of feed is necessary, which includes methods to increase their biological and nutritional value. The balance of the extruded feed and its high nutritional value provide a significant increase in the productivity of farm animals and poultry. The desire to increase the productivity of a single-screw extruder, the efficiency of preparing a feed mixture, and reducing the cost of producing a feed mixture is an urgent task that depends on the design parameters of the extruder, in particular on the design of the working body - the auger. (Research purpose) To reduce the leakage of material between the inner surface of the extruder housing and the edge of the screw screw of the extruder during the extrusion of feed. The estimated indicator "specific productivity" is proposed, its application makes it possible to objectively determine the efficiency of the extruder and establish a relationship between productivity and power costs for the extrusion process. (Conclusions) A screw design has been developed where the edge of the extruder screw adjacent to the housing is made grooved, which will reduce the energy intensity of the process and increase the extrusion productivity.

Экструдирование кормов для аквакультуры (обзор)

Extrusion is one of the most important technological operations in aquafeed production. Indeed, the digestibility of feed nutrients considerably increases as a result of extrusion. The review deals with the issues of vegetable and animal raw materials processing for aquafeed production through extrusion. The analysis of scientific publications discussing the monitoring subject showed that extrusion of multicomponent mixtures (compound feed) had been studied insufficiently. Research objectives were to generalize and analyze English-language scientific publications containing information on the technologies of compound fish feed extrusion, to clarify the information on the rational parameters of their implementation and the effects on the properties of finished extruded feed. Search, selection, as well as systematic review of highly cited English-language scientific articles on the research subject for the period 2000–2020, were carried out. In the course of the analysis of literary sources, it was detected that the properties of the finished extruded feed were mostly affected by the extrusion temperature, raw material moisture and screw speed. The regularities of changes in the properties of ready-extruded feed granules, as a result of changes in extrusion parameters, have been determined. The results of the analyzed scientific articles made it possible to establish the peculiarities of the extrusion of compound feed for aquaculture based on plant raw materials, in particular starch. We defined the regularities of compound fish feed extrusion containing raw materials with a considerable amount of protein of animal origin, in particular its new type: insects’ biomass. This new type of protein-containing raw materials of animal origin can successfully replace expensive fish meal in the fish feed composition. The essential factor, limiting the application of animal raw materials in fish feed, in particular insects, is its moisture, which should not exceed 30% so that the extrusion process was fully effective. Reducing the feed mixture moisture is possible when combining various types of animal and plant raw materials with high and low moisture. This will ensure the acceptable moisture of the mixture and get the high-quality extruded feed. Aquafeed extrusion is a promising trend. However, it requires additional research to determine the parameters of the extrusion process common to all types of both plant and animal raw materials and their mixtures.