Extruder Barrel Research Articles

Intelligent MIMO ORFBLS-Based Setpoint Tracking Control with Its Application to Temperature Control of an Industrial Extrusion Barrel

Intelligent MIMO ORFBLS-Based Setpoint Tracking Control with Its Application to Temperature Control of an Industrial Extrusion Barrel

Exploring textural, solubility and rheological characteristics of high‐moisture extruded meat analogues: effects of wheat gluten and rice protein incorporation in pea protein isolate and feed moisture levels

SummaryThis research explores the development of high‐moisture meat analogues (HMMA) by blending wheat gluten (WG) and rice protein (RP) with pea protein isolate (PPI) in a twin‐screw extruder under high‐moisture extrusion conditions. The study investigates the effects of incorporating RP and WG with PPI on textural, rheological and colour properties, as well as the underlying protein–protein interactions through protein solubility. From the compositional analysis of these secondary ingredients, there was no significant difference between them. However, results from the extrusion indicated that WG‐PPI showed good fibration and higher instrumental anisotropy than RP‐PPI blend extrudates. RP‐PPI blends exhibit inferior textural and rheological properties, attributed to RP's limited crosslinking ability within the protein matrix. This has resulted in a poor structure and lower textural values at higher incorporation of RP (50%) in the pea protein matrix. This was due to the insoluble protein fraction of the RP resulting in a non‐melting in the extrusion barrel. These findings underscore the importance of understanding protein interactions in developing optimised HMMA formulations, paving the way for further exploration into developing modified RP with improved physiochemical properties which can be integrated into meat analogues.

Impact of extrusion temperature and moisture incorporation on nutrient digestibility in barramundi (Lates calcarifer) diet

This study aimed to evaluate the influence of extrusion temperature and moisture incorporation procedure on nutrient digestibility of diets fed to barramundi (Lates calcarifer). A single premix was processed under six contrasted extrusion processing conditions, with extruder barrel temperatures set at 100 °C and 110 °C, and liquid water either incorporated in the preconditioner, in the barrel, or in both. In a subsequent 33-day feeding trial, grow-out fish (758.3 ± 24.5 g) were fed the 6 diets and apparent digestibility coefficients (ADC) were assessed for 42 fatty acids, 17 amino acids, protein, lipids and energy. Digestibility of protein (92.3–93.7%), lipid (84.1–89.4%), and energy (69.4–75.2%) also remained unaffected by extrusion settings (P > 0.05). However, lower extrusion temperature and moisture incorporation in both preconditioner and barrel resulted in higher digestibility of poly-unsaturated fatty acids (PUFA), long-chain poly-unsaturated fatty acids (LC-PUFA), omega-3, omega-6 and 22:6 docosahexaenoic n-3 (DHA). Moreover, lower extrusion temperature significantly improved ADCs of essential amino acids, except lysine, histidine, and threonine (P < 0.05). The results showed no significant impact (P > 0.05) of the tested extrusion parameters on fish growth (TGC: 2.11 ± 0.17), feed intake, or feed conversion performance (FCR: 1.67 ± 0.13). The study unveils diverse responses to extrusion temperature and moisture levels regarding amino acid and fatty acid digestibility. These findings highlight the advantages of preconditioning during the extrusion process to enhance fatty acid digestibility.

Mechanism of l-cysteine-induced fibrous structural changes of soybean protein at different high-moisture extrusion zones

In this study, the fibrous structure formation mechanism of soybean protein during high moisture extrusion processing was investigated using a dead-stop operation, and based on the interaction between soybean protein concentrate (SPC) and L-cysteine (CYS). The thermal properties, SDS-PAGE and particle size distribution of the samples from different extrusion zones were investigated. It was revealed that the addition of a moderate amount of CYS (0.1 %) promoted the fibrous structure formation in the SPC extrudates and optimised the textural properties of the SPC extrudates. In the extruder barrel, addition of CYS (0.1 %) promoted protein depolymerisation and unfolding in the mixing and cooking zones, and facilitated protein aggregation in the die and cooling zones. Protein solubility and raman spectroscopy revealed that disulfide bonds were principally responsible for fibrous structure formation; favoured when the intermolecular disulfide bonds (t-g-t mode) was increased. Finally, the transformation of protein conformation was revealed by secondary structure and surface hydrophobicity, which confirmed that the effect of CYS on protein conformation mainly occurred in the cooling zone. This study provides a theoretical basis for the application of CYS to regulate the fibrous structure of meat analogues.

To Standardise Parameters for Preparation of Extruded Feed Using Various Conventional and Non-Conventional Ingredients

The purpose of this research was to optimise extruder parameters for the preparation of floating fish diets with appropriate physicochemical qualities. The impact of temperature (90-120oC), moisture content (15%-30%), die diameter (2.0-4.0 mm) and pre-conditioning duration (15-30 m) on physical properties of the pellets such as bulk density, floatability, expansion ratio and water stability, were examined. Accordingly, four iso-nitrogenous (crude protein 35%) experimental diets were formulated for GIFT tilapia advance fry by replacing 50% of GNOC protein of the control diet (T0) by sunflower oilcake (SFOC) (T1), by linseed oilcake (LSOC) (T2) and by fish based silage (T3) protein. The pellets extruded using a combination of 120 oC extruder barrel temperature, 25% moisture content of feed mix, 2.0 mm die diameter and 30 minute of pre-conditioning duration gave most required pellet floatability (90-100%), expansion ratio (1.43-1.61), water stability (95-99%) and bulk density (0.8 - 0.9 g/cm3) for T1 and T2. However, fish silage when incorporated in the feed mix, it affected negatively in all the physical characteristics of a floating feed and resulted in higher bulk density and lower floatability, expansion ratio and also water stability.

Mung bean flour‐added extruded snack production: Evaluation of the pasting properties of flour blends and the physicochemical, morphological, and functional properties of the product

AbstractThis study investigated the effect of partially substituting corn semolina (CS) with mung bean flour (MBF) (20%–60%) as well as feed moisture (FM) (16%–20%) and extruder barrel temperature (BT) (140°C–170°C) on the physicochemical, functional, sensorial, and morphological properties of extruded snacks. Additionally, the pasting properties of MBF, CS, and the blends employed in the formulations were studied. The addition of 40% MBF to the formulations resulted in a decrease in the peak viscosity, while the addition of 60% MBF increased it. The final viscosity and setback viscosity exhibited a decrease, while the breakdown viscosity showed an increase with the addition of MBF. The degree of crystallinity, expansion ratio, apparent density, hardness, crispiness, water solubility index, and morphology of the extrudates were strongly dependent on the MBF content, FM, and BT. The expansion ratio and crispiness of the extruded products decreased with increasing MBF content, BT, and FM. The increase in BT and decrease in FM reduced the degree of crystallinity of the extrudates. Analysis of the microstructure revealed that the addition of MBF increased the thickness of the extrudate cell walls and reduced the size of air cells. The size and expansion of the air cells also decreased with increasing FM. Based on our study, the optimal conditions for the MBF‐containing snacks were determined as 143°C BT, 16% FM, and 40% MBF. Notably, the MBF‐containing snacks exhibit lower starch digestibility compared to the MBF‐free sample; the latter exhibited a higher degree of anisotropy, indicating a higher‐organized structure.Practical applicationThe use of mung bean flour (MBF) as a substitution for corn semolina and the effects of feed moisture (FM) and barrel temperature (BT) in extruded snack production were studied. The results showed that MBF is a promising ingredient for enhancing the functionality and nutritional value of extruded snacks. The expansion ratio, apparent density, hardness, crispiness, water solubility index, crystallinity, and morphology of the extrudates were significantly dependent on MBF amount, FM, and BT. The expansion ratio and crispness of the snacks decreased with the increase in the MBF amount, BT, and FM. The addition of MBF to the formulation was appreciated by the panelists. The MBF enhances the quality characteristics of the snacks and decreases starch digestibility. The findings of this study provide a reference for the impacts of extrusion parameters on the production of high‐protein content snacks.

Continuous Direct Mechanocatalytic Suzuki-Miyaura Coupling via Twin-Screw Extrusion.

This work establishes the first direct mechanocatalytic reaction protocol within an extruder, focusing on the Suzuki-Miyaura reaction. Through the coating of either the extruder screws or barrel with Pd, we executed the cross-coupling reaction without the reliance on molecular catalyst compounds or powders, and solvents continuously. We identified the influence and interplay of crucial reaction parameters such as temperature, mechanical energy input, residence time, rheology, and catalyst contact time and finally obtained 36 % and 75 % of the reaction product after one and four reactor passes respectively.

Reduction of Alternaria Toxins via the Extrusion Processing of Whole-Grain Red Sorghum Flour.

This study delved into the impact of two extrusion processing parameters-screw speed (SS at 400, 600, 800 RPM) and material moisture content in the extruder barrel (M at 12, 15, 18%) at constant feed rate (50 kg/h)-on reducing the content of alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and tentoxin (TEN) in whole-grain red sorghum flour. Ultra-performance liquid chromatography combined with a triple-quadrupole mass spectrometer (UPLC-MS/MS) was employed for the determination of Alternaria toxin levels. The extruder die temperature fluctuated between 136 and 177 °C, with die pressures ranging from 0.16 to 6.23 MPa. The specific mechanical energy spanned from 83.5 to 152.3 kWh/t, the torque varied between 88 and 162.8 Nm, and the average material retention time in the barrel ranged from 5.6 to 13 s. The optimal parameters for reducing the concentration of all Alternaria toxins with a satisfactory quality of the sorghum snacks were: SS = 400 RPM, M = 12%, with a reduction of 61.4, 76.4, 12.1, and 50.8% for AOH, AME, TeA, and TEN, respectively.

Physical characteristics of extrudate from mixed corn grit – red bean flour with treatment of moisture content and extruder barrel temperature

Extruded snacks, typically derived from low-protein corn, can significantly benefit from the incorporation of red beans to boost their protein content and enhance overall nutritional value. In this study, the influence of feed moisture content and extruder barrel temperature on various physical attributes of the extruded products, including moisture content, particle density, bulk density, expansion ratio, and hardness, were examined. The snacks were produced using a SYSLG-IV twin-screw extruder with a throughput capacity of 10-15 kg/h. The ingredient composition remained consistent, consisting of a 20% red bean flour and 80% corn grit blend. Three moisture content levels (14%-18%) and three different extruder barrel temperature settings (120°C-140°C) were used as variables. The results demonstrated that both variables significantly impacted the physical properties of the extruded snacks. Specifically, an increase in feed moisture content or a decrease in barrel temperature led to higher moisture content (1.01%-1.82%), greater particle density (0.17 g/cm3-0.39 g/cm3), increased bulk density (0.12 g/cm3-0.32 g/cm3), greater hardness (8.34 N-32.18 N), and reduced expansion ratio (2.17-3.0).

Physical characteristics of extrudate with treatment composition ratio of mixed corn grit-soybean flour and extruder barrel temperature

Yellow corn is one of the key component in the production of popular RTE snacks. However, corn’s nutritional quality is relatively low, necessitating the incorporation of additional ingredients such as soybean to enrich the protein content. This study primarily aims to explore the influence of soybean flour composition and temperature of barrel on the physical characteristics of extrudates to produce nutrition-rich snacks. The materials utilized in the experiment consisted of corn grit (mesh 24) and soybean flour (mesh 80). Extrudates were produced using SYSLG twin-screw extruder machine with a 10-15 kg/h production capacity. The study’s experimental design employed two factors: the composition factor of soybean flour (at 10%, 20%, and 30%) and the final temperature of the barrel (at 120°C, 130°C, and 140°C). The physical attributes of the extrudates were assessed based on the parameters such as expansion ratio, extrudate texture (hardness), moisture content, WAI, and WSI. The study findings revealed that increased soybean flour composition reduced the expansion properties and a more rigid material texture. On top of that, all extrudates exhibited moisture content of less than 4% (wb). The water absorption index decreased with higher soybean flour composition and barrel temperature, whereas the water solubility index showed an increasing trend. Among the tested conditions, the treatment with temperature of the barrel of 140°C and a soybean ratio of 20% demonstrated the best quality results.

High-moisture extrusion of curdlan: Texture and structure

High-moisture extrusion is a promising thermomechanical technology extensively employed in manufacturing fibrous meat analogues from plant-based proteins, garnering considerable research attention. However, polysaccharide-based extrusion has been rarely explored. The present study investigates the effects of varying extruder barrel temperatures (130 °C–200 °C) on the texture and structure of curdlan extrudates, and highlights the formation mechanism. Results showed that the single chain of curdlan aggregates to form triple-helix chains upon extrusion, consequently enhancing the crystallinity, particularly at 170 °C. The hardness, chewiness, and mechanical properties improved with increasing barrel temperature. Moreover, barrel temperatures affected the macrostructure, the extrudates maintained intact morphologies except at 160 °C due to the melting of curdlan gel as confirmed by the differential scanning calorimetry thermogram. Microstructural analysis revealed that curdlan extrudates transited through three phases: original gel (130 °C, 140 °C, and 150 °C), transition state (160 °C), and regenerated gel (170 °C, 180 °C, 190 °C, and 200 °C). The steady state of regenerated gel (170 °C) exhibited higher crystallinity and smaller fractal dimension, resulting in a more compact and crosslinked gel network. This study elucidates the structure transition of curdlan gel at extremely high temperatures, offering valuable technical insights for developing theories and methods with respect to polysaccharide-based extrusion that may find applications in food-related fields.

Influence of Extruder Setup and Process Parameters on the Product Quality of Solid Polymer Electrolytes Using Melt Extrusion

All solid-state batteries (ASSBs) are the next generation battery technology, in which the classical liquid electrolyte is replaced by an ion-conducting solid electrolyte. Materials that are used as solid-state electrolytes are generally divided into three material classes: polymers, oxides and sulphides. Electrolyte materials for ASSBs have been extensively studied regarding their electrochemical performance and their stability towards the electrode materials. Nevertheless, the commercialization of ASSBs is still hindered by the material availability in case of oxide and sulphides and the knowledge of scaled production routes for all kinds of separators. Polymers are readily available on the global market. It is thus possible to focus more on the processing routes of polymer based solid electrolytes. The use of thermoplastics as matrix for solid electrolytes (SE) offers the prospect of facile upscaling of the process from lab-scale to industrial series production by the implementation of a solvent-free thermal extrusion process. A twin-screw extruder offers the possibility of continuously mixing the SE components to produce homogeneous polymer based SEs. With two feeding units, the addition of the components takes place separately. This eliminates the time-consuming premixing step to obtain a homogeneous mixture.Thermoplastic poly(ethylene oxide) (PEO) is one of the most investigated materials for polymer based SEs due to its capability to dissolve alkali salts like Lithium(bistrifluoromethanesulfonyl)imide (LiTFSI). The thermal process route of PEO and its effect on the polymeric properties are currently under investigation. Previous works from our research group show that the processability of PEO not only depends on the conductive salt (LiTFSI), but also on its molecular weight and applied process parameters. [1] With increasing molecular weight, PEO becomes more sensitive towards thermal and mechanical load that leads to chain scissoring and degradation even at small load. Hence, the use of low molecular weight PEO (Mw= 100.000 g mol-1) is preferable for the dry production of PEO based SEs.The aim of this work is to optimize the extrusion process using a co-rotating twin-screw extruder for the solvent free production of solid PEO/LiTFSI-electrolytes in a molar ratio of 20:1 (EO:Li). Here, we investigate the effects of several extruder set-ups on the mixing behaviour of PEO and LiTFSI. Therefore, type of dosing and screw design are varied. The screw can be designed with conveying, kneading and mixing elements. We compare the dry extrusion of a premixed PEO/LiTFSI (20:1) batch with dry extrusion of PEO/LiTFSI (20:1) using two feeding units, one for each component. Process parameters, such as pressure at the extruder die, actual screw speed, torque and barrel temperature are continuously measured during the production. Process temperature and screw speed are optimized to avoid degradation of PEO. PEO/LiTFSI-electrolytes are produced with a process temperature of 90 °C across the whole extruder barrel and with screw speeds of 5 – 15 rpm. The products are evaluated by their homogeneity and quality of the extruded electrolytes. Optical microscopy is used for macroscopic evaluation and the Li-salt distribution is checked with SEM/EDX. Conductivity and rheology measurements are performed to determine the lithium concentration within the electrolyte and loss of molecular weight, respectively. For the determination of the ionic conductivity, we examine electrochemical impedance spectroscopy (EIS). The characterization of the extruded electrolytes helps to find optimal process parameters for the production of polymer based SEs.

Study on the Residence Time and Texture Prediction of Pea Protein Extrusion Based on Image Analysis.

This paper initially involves three main processing parameters: screw speed, feeding speed, and initial material moisture content, exploring the RTD of materials inside the extruder barrel under varying parameters and clarifying the impact of parameter variations on RTD. Finally, machine vision technology was utilized to link extruded product images to texture features, and a texture prediction model based on image features was established using a Back Propagation (BP) neural network. Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) were applied to optimize the BP neural network. The results indicate that the feeding speed has a stronger impact than the screw speed on the extrusion process, and an increase in the initial material moisture content tends to shorten the RTD. Specifically, an increase in screw speed results in a denser product structure, while higher feeding speeds lead to reduced pore size in the microstructure. As the initial material moisture content increased from 55% to 70%, the average residence time MRT decreased from 265.21 s to 166.62 s. Additionally, elevated moisture content causes a more porous microstructure. After optimizing the texture prediction model of extruded products through the application of Particle Swarm Optimization and Genetic Algorithm models, it was discovered that the Genetic Algorithm was more effective in reducing errors (p < 0.05) than the Particle Swarm Optimization algorithm. It was found that the Particle Swarm Optimization model exhibited better prediction performance. The results of the prediction indicated a significant association between the image features of the product and hardness, resilience, and chewiness, as corroborated by correlation coefficients of 0.93913, 0.94040, and 0.94724, respectively.

Additive Manufacturing of Poly(phenylene Sulfide) Aerogels via Simultaneous Material Extrusion and Thermally Induced Phase Separation.

Additive manufacturing (AM) of aerogels increases the achievable geometric complexity, and affords fabrication of hierarchically porous structures. In this work, a custom heated material extrusion (MEX) device prints aerogels of poly(phenylene sulfide) (PPS), an engineering thermoplastic, via in situ thermally induced phase separation (TIPS). First, pre-prepared solid gel inks are dissolved at high temperatures in the heated extruder barrel to form a homogeneous polymer solution. Solutions are then extruded onto a room-temperature substrate, where printed roads maintain their bead shape and rapidly solidify via TIPS, thus enabling layer-wise MEX AM. Printed gels are converted to aerogels via postprocessing solvent exchange and freeze-drying. This work explores the effect of ink composition on printed aerogel morphology and thermomechanical properties. Scanning electron microscopy micrographs reveal complex hierarchical microstructures that are compositionally dependent. Printed aerogels demonstrate tailorable porosities (50.0-74.8%) and densities (0.345-0.684g cm-3), which align well with cast aerogel analogs. Differential scanning calorimetry thermograms indicate printed aerogels are highly crystalline (≈43%), suggesting that printing does not inhibit the solidification process occurring during TIPS (polymer crystallization). Uniaxial compression testing reveals that compositionally dependent microstructure governs aerogel mechanical behavior, with compressive moduli ranging from 33.0 to 106.5MPa.

Investigation of boiling heat transfer process in the barrel of a gravity heat pipe type extruder

Gravity heat pipe barrels produce gas films during the processing of thermoplastic materials, which affect the heat transfer, so there is an urgent need to study the nucleate boiling process and mechanism at different locations in the barrel. The results showed that the local heat flux at the vapor-liquid-solid three-phase contact was the largest, and different process conditions had different effects on the departure diameter and departure time of boiling bubbles. The tail vortex disturbance generated by bubble departure drives the merging and growth of bubbles to departure, which in turn improves the heat transfer. The rounded bottom of the barrel reduced the air film and increased the heat transfer efficiency compared to the horizontal bottom of the barrel. This study can deepen the understanding of the mechanism of bubble boiling heat exchange in gravity heat pipe-type barrels and provide theoretical support for more relevant application scenarios.

Changes in physicochemical and structural properties of pea protein during the high moisture extrusion process: Effects of carboxymethylcellulose sodium and different extrusion zones

This study investigated effects of carboxymethylcellulose sodium (CMC) on the conformational evolution of pea protein during the high moisture extrusion process. The morphological observation showed that the addition of CMC facilitated the formation of fibrous structure of pea protein. In comparison with the pea protein in the melting zone and extrudate, the combination of CMC increased the denaturation enthalpy of pea protein by 2.09 % and 2.34 %. Compared with the material in the mixing zone, the degree of grafting between CMC and pea protein in the die was enhanced by 98.95 %. In general, the supplementation of CMC depressed the exposure of hydrophobic groups in the pea protein. In the extrusion barrel, the CMC increased the unfolding of protein molecular chains while it promoted the refolding of protein chains in the die. For the extrudate, the addition of CMC decreased the contents of α-helix and β-sheet of pea protein by 9.67 % and 6.93 % while the contents of β-turn and random coil were increased, leading to changes in the molecular weight distribution of protein molecules. In conclusion, these results provided new strategies toward producing the high-quality pea protein-based meat analogues by adding CMC.

Recycling of plastic wastage by die shredder machine

Recycling plastic is one of the best ways to cut down on the amount of trash that needs to be taken care of, so we put it at the top of the list of priorities for this project. A “shredder” is a machine that can cut plastic into pieces of different sizes. The shredder machine has a crusher assembly with a single axle shaft. Its main job is to cut things, and how well it does that depends on how strong it is at shear and impact. Because recycling equipment is so expensive and hard to set up, our company was the first to think of making machines that shred plastic. The motor, frame, blades, and spacers are all attached to the rotor's central hexagonal shaft. A V-belt drive system sends power from the motor shaft to the hexagonal shaft. This depends on the material being cut. This is done before cutting the material. Now, the hexagonal shaft will turn in the same direction as the blades in the mechanism box.Everyone looks at the frame, shredding blade, shredding shaft, extrusion barrel, and extrusion screw. Because of the changes made to the control system, the temperature control on the extrusion machine and the direction control on the AC motor now work.

Extrusion of process flavorings from methionine and dextrose using modified starch as a carrier.

This study aimed to produce process flavorings from methionine and glucose via Maillard reaction by extrusion method. Modified starch was used as a carrier to reduce the torque and facilitate the production process. Five formulations of process flavorings with different ratios of methionine: dextrose: modified starch: water as MS5 (72:18:5:5), MS15 (64:16:15:5), MS25 (56:14:25:5), MS35 (42:12:35:5), and MS45 (40:10:45:5) were prepared and feded into the extruder. The temperatures of the extruder barrel in zones 1 and 2 were controlled at 100, and 120°C, with a screw speed of 30 rpm. The appearance of the obtained products, torque, pH before and after extrusion, color, volatile compounds, and sensory evaluation were determined. The extrudate from the formulation containing the highest amount of modified starch (MS45) gave the highest L* (lightness) of 88.00, which increased to 93.00 (very light) after grinding into a powder. The process flavorings from all formulations exhibited similar sensory scores in terms of aroma, taste, and water solubility, with a very slight difference in color. However, MS25, MS35 and MS45 indicated the torque at 10 Nm/cm3, while MS5 and MS 15 exhibited higher torque at 18, and 25 Nm/cm3, respectively. Extruded process flavorings from MS25 were analyzed for their flavor profiles by gas chromatography-mass spectrometry. Twelve volatile compounds including the key volatile compounds for sulfurous and vegetable odor type, dimethyl disulfide, methional, and methanethiol, were found. Four pyrazine compounds presented nutty, musty and caramelly odor; and 3-hydroxybutan-2-one and heptane-2,3-dione, which gave buttery odor type, were also detected. The results demonstrated a successful production of process flavorings using modified starch as carrier to facilitate and reduce the torque during the extrusion process.

Management of ground tire rubber waste by incorporation into polyurethane-based composite foams

Rapid economic growth implicated the developing multiple industry sectors, including the automotive branch, increasing waste generation since recycling and utilization methods have not been established simultaneously. A very severe threat is the generation of enormous amounts of post-consumer tires considered burdensome waste, e.g., due to the substantial emissions of volatile organic compounds (VOCs). Therefore, it is essential to develop novel, environmentally friendly methods for their utilization, which would hinder their environmental impacts. One of the most promising approaches is shredding, resulting in the generation of ground tire rubber (GTR), which can be introduced into polymeric materials as filler. The presented work is related to the thermomechanical treatment of GTR in a twin-screw extruder with zinc borate, whose incorporation is aimed to enhance shear forces within the extruder barrel. Modified GTR was introduced into flexible polyurethane (PU) foams, and the impact of modification parameters on the cellular structure, static and dynamic mechanical performance, thermal stability, as well as thermal insulation, and acoustic properties was investigated. Emissions of VOCs from applied fillers and prepared composites were monitored and evaluated. Depending on the treatment parameters, beneficial changes in foams’ cellular structure were noted, which enhanced their thermal insulation performance, mechanical strength, and thermal stability. It was proven that the proposed method of GTR thermomechanical treatment assisted by zinc borate particles might benefit the performance of flexible PU foamed composites and hinder VOC emissions, which could broaden the application range of GTR and provide novel ways for its efficient utilization.

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.