Production Of Extrudates Research Articles

DESIGN A SINGLE SCREW EXTRUDER FOR POLYMER-BASED TISSUE ENGINEERING

In the area of tissue engineering, single screw extrusion (SSE) has gained attention due to its versatility and efficiency in fabricating polymer-based scaffolds. Furthermore, advancements such as the implementation of extrusion techniques and the integration of bioactive agents have significantly expanded the capabilities of SSE. This study aims to investigate the configuration of a custom-designed plastic extrusion for tissue engineering, highlighting its potential in fabricating suture technology for various regenerative biomedical applications. Furthermore, the challenges and future perspectives in SSE technology are discussed, with a focus on the need for additional research to optimize processing parameters, enhance structure bioactivity, and facilitate clinical usage. SSE provides precise regulation of structure morphology, mechanical properties, and porosity, which are critical factors that influence cell behavior and tissue regeneration. Overall, SSE holds great promise as a scalable and cost-effective manufacturing technique for producing polymer-based structures with tailored properties, advancing the field of tissue engineering towards effective clinical solutions. The paper provides a comprehensive overview of a filament extruder production machine that is capable of manufacturing high-quality filament sutures (FS) using thermoplastic materials, specifically bio-protein derived from human serum albumin. The main focus of the paper is to explain the design and operation principles of the filament extruder. The extruder is equipped with a die that can measure a range starting from 2.5 mm and going down to smaller scales. This allows for the extrusion of filaments with a diameter as small as 1.75 mm. Although the design of the extrusion apparatus closely resembles that of commercially available machines, the focus here is on its adaptability and cost-effectiveness for laboratory-scale production. Overall, the research contributes to advancing the understanding of extrusion processing technologies in the context of biomedical applications, with a specific focus on utilizing human serum albumin-derived thermoplastics for manufacturing FS.

Optimization of the extrusion parameters for the production of lentil-quinoa extrudates enriched with pumpkin.

This study aimed to develop a protein-fiber-rich extruded product based on yellow lentil, quinoa, and pumpkin flours. The final product quality is affected by formulation and extrusion parameters. Therefore, the effect of the pumpkin-flour ratio (A: 25-75%) and feed moisture content (C: 14-22%) besides barrel screw speed (B: 120-180 rpm) on the physical attributes of extrudates was investigated. Box-Behnken experimental design and stepwise-response surface method were used to analyze the effects of various process variables and ingredients on extrudates. The pumpkin-flour ratio had a significant positive correlation with bulk density (BD), water solubility index (WSI), and oil absorption index. Whereas the correlation between pumpkin-flour ratio with hardness, porosity, expansion ratio (ER), and water absorption index (WAI) was negative (P < 0.05). The feed moisture content positively affected the water activity (aw) and WAI and negatively affected the harness of samples (P < 0.05). The screw speed had a positive effect on ER, porosity, and WSI, whereas it negatively influenced the hardness, BD, and aw. By increasing the pumpkin-flour ratio, air cell size and wall thickness of samples had been decreased. The results showed that 44.2% pumpkin flour, 22% feed moisture, and 172.1 rpm screw speed gave an optimized product. There was no significant difference between predicted and experimental values (except for ER). The optimized snack was a good source of fiber (around 15%), protein (17.3%), and antioxidants (TPC = 15.28 mg GAE.g-1 and antiradical scavenging activity (DPPH) = 33.66%). The caloric value of the optimized snack was 362.6 cal.100g-1. The current formulation can be considered as the base of snack food or plant-based meat alternatives.

JUSTIFICATION OF THE DESIGN OF A 3D PRINTER EXTRUDER NOZZLE USING GRANULES AND CUT POLYMER PARTICLES AS INPUTS

The article defines extrusion as a continuous process of converting a solid bulk polymer into a viscous state followed by pushing it through a molding tool. It is emphasized that extruders are one of the most promising types of equipment for processing polymer materials and are used in various industries, including 3D printing. Attention is focused on the fact that one of the important parts of each extrusion unit is the extrusion head. It is the main tool that determines the final shape of extruded products. It is emphasized that the extruder nozzle has a significant impact on the quality of 3D printing. Four parameters characterizing the nozzle are highlighted: its external size, internal structure, diameter of the hole for extruding the polymer, and the material from which it is made, and each is considered in detail. The main physical and mechanical properties of nozzles made of different materials are presented. A classification of nozzles was developed on the basis of the conducted review. The formula for determining the volumetric productivity of a 3D printer extruder is given, depending on the design of its dosing zone and nozzle resistance. An expression for determining the total resistance coefficient of the nozzle is given, which is defined as the sum of the resistance coefficients of individual geometrically simple sections of its internal structure. It is proposed to use in the extruder of a 3D printer that uses granules or crushed polymer particles as raw materials for the construction of nozzles for 3D printers that print with filament. With their use, a new nozzle design for screw extruders was developed and presented. Based on the analysis of the internal structure of nozzles for 3D printers that print with filament and forming devices of plastic processing equipment, the design of the extruder nozzle using a mandrel was developed and presented.

Highly protein-loaded melt extrudates produced by small-scale ram and twin-screw extrusion - evaluation of extrusion process design on protein stability by experimental and numerical approaches

Understanding of generation, extent and location of thermomechanical stress in small-scale (< 3 g) ram and twin-screw melt-extrusion is crucial for mechanistic correlations to the stability of protein particles (lysozyme and BSA) in PEG-matrices. The aim of the study was to apply and correlate experimental and numerical approaches (1D and 3D) for the evaluation of extrusion process design on protein stability. The simulation of thermomechanical stress during extrusion raised the expectation of protein degradation and protein particle grinding during extrusion, especially when TSE was used. This was confirmed by experimental data on protein stability. Ram extrusion had the lowest impact on protein unfolding temperatures, whereas TSE showed significantly reduced unfolding temperatures, especially in combination with kneading elements containing screws. In TSE, the mechanical stress in the screws always exceeded the shear stress in the die, while mechanical stress within ram extrusion was generated in the die, only. As both extruder designs revealed homogeneously distributed protein particles over the cross section of the extrudates for all protein-loads (20–60%), the dispersive power of TSE revealed not to be decisive. Consequently, the ram extruder would be favored for the production of stable protein-loaded extrudates in small scale.

Corn Extrudates Enriched with Health-Promoting Ingredients: Physicochemical, Nutritional, and Functional Characteristics

The objective of this study was to evaluate the effects of different types of powder additions on the properties of corn extrudates. The following ingredients, which are good sources of bioactive compounds, were used to substitute corn flour: legume protein sources (2% pea, 5% broccoli, and 5% lucerne), plants (15% beetroot and 15% rosehip), and condiments (2% chili, 2% turmeric, 2% paprika, and 2% basil). The total polyphenolic content (TPC) and antioxidant activity (AA) increased when the corn flour was replaced with the different types of ingredients. The highest TPC was found for rosehip followed by the beet, basil, and broccoli additions. Compared to the raw formulations, all the extrudates, except the rosehip extrudate, showed a decrease in the TPC ranging from 11 to 41%, with the smallest loss (11%) occurring for basil and the highest loss (41%) occurring for the control extrudate, respectively. The same observation was recorded for the AA. For the extrudate enriched with rosehip, the TPC and AA increased by 20% and 16%, respectively. The highest level of protein digestibility was in the corn extrudate with the pea addition followed by broccoli and lucerne. The extruded corn samples with condiment additions had a lower glycemic index than the control extrudate. This study demonstrated the potential for the production of gluten-free corn extrudates enriched with ingredients from different sources with improved nutritional properties, conferring also a natural color in the final extrudates.

Chemical, functional, rheological and structural properties of broken rice–barnyard millet–green gram grits blend for the production of extrudates

AbstractBroken rice is an underutilized by‐product of the rice milling industry. It was added with green gram and barnyard millet to investigate as a source of nutrition‐based value‐added food product. The study was carried out to examine the influence of formulated composite flour obtained from broken rice (Oryza sativa) (50%–80%), barnyard millet (Echinochloa esculenta) (10%–30%), and green gram (Vigna radiata) (10%–30%) on the chemical properties, functional properties, pasting properties, oscillatory test, flour behavior, and microstructure of extrudate. The ash, crude fiber, crude protein, fat, and carbohydrate of the extrudate ranged from 1.62%–1.78%, 1.88%–2.43%, 13.47%–14.57%, 4.9%–7.48%, and 66.86%–70.8%, respectively. The water absorption index (WAI) and water solubility index (WSI) for the flour ranged from 5.06%–6.18 g/g and 2.34%–3.99%. The formulated composite flours having a higher percentage of broken rice showed significant differences (p &lt; 0.05) in their pasting properties, pasting temperature, peak viscosity, breakdown viscosity, and setback and final viscosity. The pasting properties gave better results using a twin‐screw extruder with operating conditions of barrel temperature of 110°C, screw speed of 290 rpm, and 14% moisture content (w.b.). The microstructure of the extrudate obtained from 80% broken rice, 10% barnyard millet, and 10% green gram grits flour possessed a more integrated, well‐defined porosity, indicating a completely gelatinized structure.Practical applicationDetermination of biochemical, structural, and rheological properties of ingredients are essential for the production desirable ready‐to‐eat snacks. In this context, the present study evaluated the functional and rheological properties of broken rice–barnyard millet–green gram blend for the production of nutritious snacks with desirable physical and textural properties. The findings of the study would be useful for food products industries using millets and broken rice as a major raw material.

Physical and Functional Characteristics of Extrudates Prepared from Quinoa Enriched with Goji Berry

In this research, the possibilities of applying the extrusion process to produce functional food from quinoa enriched with goji berries were studied. The physical (expansion ratio, bulk density, hardness, and specific mechanical energy) and functional (water solubility index, water absorption index) characteristics were determined and optimized by the response surface methodology. Extrudates were produced using a laboratory single-screw extruder. The full factorial experimental design was used (N = 22) with three complementary center points to show the interactions of the amount of goji berry (1, 3, and 5%) and the feed moisture content (13, 16, and 19%) of the mixture on the physical and functional characteristics. Increasing moisture content from 13 to 19% resulted in extrudates with a lower expansion ratio, water absorption index, water solubility index, specific mechanical energy, and higher density and hardness. Increasing the amount of goji berries from 1 to 5% led to a decrease in expansion ratio, water absorption index, and hardness, and an increase in density, water solubility index, and specific mechanical energy. Optimal extrusion conditions for production of extrudates from quinoa enriched with goji berry were 16.3% feed moisture content and 1.32% goji berry’s amount.

Physical, Chemical and Functional Attributes of Neera Honey Infused Extrudates.

Owing to the demand for the consumption of healthy extrudates, this study explored the infusion of neera (coconut inflorescence sap) honey in rice flour, corn flour and coconut milk residue blend-based extrudates. Neera honey, the concentrated coconut inflorescence sap, has numerous nutrients and a natural source of essential vitamins. Hence, the potential of neera honey as a biofortifying compound for the production of healthy extrudates was investigated. The rice and corn based extrudates supplemented with different concentration of neera honey have been prepared until the mix reaches 16 and 20% (w.b.) of feed moisture. Effect of addition of neera honey on the physical properties (expansion ratio, bulk density, specific length), functional properties (water absorption, water solubility, oil absorption), biochemical properties (total carbohydrates, total sugar, reducing sugar, phenolics, flavonoids, antioxidants), color parameters(L*, a*, b*), proximate compositions (moisture content, ash, protein, fat) and mineral profile of extrudates were recorded. Results suggest that addition of neera honey had a significant (p ˂ 0.05) impact on all the physico-chemical parameters evaluated. Incorporation of neera honey (feed moisture -20%) resulted in extrudates with less expansion, high bulk density and specific length, having high sugar, protein, phenolics, vitamin C and antioxidant activity. The combination of 60% rice flour + 25% corn flour +15% coconut milk residue samples infused with neera honey upto 16% feed moisture was found suitable for the preparation of nutritious extrudates based on functional characterization and minerals evaluation.

Value-Added Application of Bourbon Spent Grain and Proso Millet for High-Fiber Extruded Product

Highlights Distillers spent grain (DSG) constitutes a major disposal problem for the bourbon industry. The impact of DSG particle size and addition level on the quality attributes of extruded products was evaluated. Particle size and addition level modulated the extrusion of DSG-proso millet-based extrudate. Some quality of extrudates with up to 10% DSG addition level and 300 µm particle size compared favorably with the control. Abstract. Bourbon is an important export for the US, especially in the state of Kentucky, which accounts for 95% of global production. The disposal of the main byproduct of bourbon distilling is a major problem for the industry. Distiller’s spent grain (DSG) produced contains insoluble and soluble fibers and protein, making it an attractive option as a health-promoting functional ingredient in food production. The objective of this research was to determine the DSG properties needed for the development of high-fiber extruded products with millet as the base-starch ingredient. Samples were produced using a co-rotating twin-screw extruder. A two-way factorial design was used to test the effect of DSG particle size (180, 300, and 500 µm) and addition levels (5%, 10%, and 15%) on some physico-functional properties of the extrudates, such as specific mechanical energy, water solubility index, water absorption index, radial expansion ratio, fracturability, hardness, porosity, degree of gelatinization, and pasting properties. In general, higher DSG addition levels resulted in decreased radial expansion and porosity, and created harder, bulkier, and darker color products. However, samples produced with medium particle size DSG (300 µm) at 5% addition level saw no significant decrease in expansion or hardness compared to the control (0% DSG). Similarly, at 10% DSG addition level and coarse (500 µm) particle size, there was no significant difference in porosity compared to the control group. This study shows that optimized particle size and DSG addition level allow the incorporation of bourbon spent grain into an extruded-expanded product without significant loss of attributes but with higher dietary fiber content. Keywords: Bourbon, Distillers Spent Grain, Extrusion, High-fiber, Proso Millet.

Hot-Melt Extrusion of the Thermo-Sensitive Peptidomimetic Drug Enalapril Maleate.

The aim of this research was the production of extrudates for the treatment of hypertension and heart failure and the investigation of the degradation of the peptidomimetic drug enalapril maleate (EM) during hot-melt extrusion (HME). A fast HPLC method was developed to quantify enalapril maleate and possible degradation products. Screening experiments revealed that the diketopiperazine derivative (Impurity D) was the main degradation product. Hot-melt extrusion of enalapril maleate with the polymer Soluplus® enabled extrusion at 100 °C, whereas a formulation with the polymer Eudragit® E PO could be extruded at only 70 °C. Extrusion at 70 °C prevented thermal degradation. A stabilizing molecular interaction between enalapril maleate and Eudragit® E PO was identified via FT-IR spectroscopy. Dissolution studies were carried out to study the influence of the formulation on the dissolution behavior of enalapril maleate. These promising results can be transferred to other thermo-sensitive and peptidomimetic drugs to produce extrudates which can be used, for instance, as feedstock material for the production of patient-specific dosage forms via Fused Deposition Modeling (FDM) 3D printing.

Effects of thermal energy on extrusion characteristics, digestibility and palatability of a dry pet food for cats.

The influence of specific thermal energy (STE) applications on extruder preconditioner was evaluated in a dry food for cats. In the first study, six STE applications were tested with mass temperatures of 45°C, 55°C, 65°C, 75°C, 85°C and 95°C. The extrusion parameters, starch gelatinization and kibble formation were evaluated. Diets were given to cats to evaluate digestibility, faecal characteristics and palatability. In the second experiment, three treatments were compared: low STE-a preconditioner temperature of 45°C (L STE); high STE-a preconditioner temperature of 95°C (H STE); high STE (preconditioner temperature of 95°C) combined with an increase in the mass flow rate to obtain a motor amperage similar to that of the L STE (H STEflow ). Data were analysed by polynomial contrasts (Experiment 1) or Tukey's test (Experiment 2; p<0.05). An increase in STE reduced motor amperage, mass pressure and specific mechanical energy (SME) implementation (p<0.001) and increased total specific energy (TSE) and mass temperature (p<0.01). The increase in STE induced greater kibble expansion and starch gelatinization (p<0.001). No changes in apparent nutrient digestibility or faeces characteristics were observed (p>0.05). Lower STE and starch gelatinization induced higher butyrate and total volatile fatty acid (VFA) contents in faeces (p<0.01). Cats showed greatest preference for the formulation with the highest STE (p<0.01). In the second experiment, when the motor amperage was increased in the H STEflow treatment to a value similar to that of the L STE, the mass flow rate increased 40%, and the electric energy consumption remained unchanged (p<0.001), with gains observed for efficiency and cost. In conclusion, STE application is important for sufficient TSE implementation, enhancing kibble expansion, starch gelatinization, cat preferences for food, extruder productivity and reducing SME application. Foods with lower starch gelatinization lead to increased VFA in faeces, with possible implications for gut health.

Extrusion of wheat gluten-peanut oil complexes and their rheological characteristics

In order to clarify the effects of extrusion treatment on the processing properties of extrudates, providing a theoretical basis for the production of gluten-based extrudates with favorable sensory quality. This study examined the effects of various extrusion temperatures on the rheological properties of wheat gluten-peanut oil complexes (WPE) and wheat gluten (WG). At the extrusion temperature conditions of this study, the dynamic moduli of gluten in WG and WPE reached the maximum, and the creep strain reached a minimum at 160 °C. Extrusion treatment resulted in the decrease in β-sheet and α-helix content and an increase in the amount of β-turns and random coils. The secondary structural changes and increase in the number of disulfide bonds led to gluten aggregation, thus affecting their rheological properties. These results enhance our understanding of the variations in the rheological properties of extrudates and promote the potential application of gluten-based complexes in extrusion.

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.

Impact of thermal processing on levels of acrylamide in a wheat‐lentil flour matrix

AbstractA growing demand for plant‐based protein has seen a resurgence in the utilisation of pulses such as lentil and chickpea as a protein‐rich substrate to produce food products traditionally based on animal or cereal protein. Additionally, pulses offer metabolic benefits due to the bioactivity of compounds including phenolic acids, simple and complex carbohydrates and a more complete amino‐acid profile which is not found in cereal grains. However, there is an increasing concern in the formation of acrylamide in food which occurs when asparagine, an abundant amino acid found in pulses, forms a complex with the reducing sugars; glucose, fructose, and maltose. Recent studies in animal models have shown that acrylamide is carcinogenic and therefore is a concern for humans. High levels of acrylamide have been reported particularly in fried products, primarily due to the Maillard reaction which amplifies the formation of acrylamide. This study investigated the levels of acrylamide in bread, cookies, and extruded products prepared with wheat‐lentil composite flour. Our research found that extrusion resulted in a significantly lower concentration of acrylamide compared to traditional baking. Additionally, increasing the amount of lentil within the composite significantly increased the net concentration of acrylamide for all bread, cookies and extrudate products.

Реакционная экструзия нанокомпозитов на основе этиленовых сополимеров и минеральных наполнителей

The paper presents the results of a study of the influence of the temperature regime of reaction extrusion on the main physicomechanical characteristics of nanocomposites based on copolymers of ethylene with butylene and ethylene with hexene and natural minerals - clinoptilolite and vesuvian. The optimal temperature regime of extrusion of nanocomposites based on copolymers of ethylene and natural minerals was established. At a maximum extrusion temperature of 230 °C in the dosing zone, counterflow increases, which contributes to an increase in the residence time of the nanocomposite melt and, accordingly, to a decrease in extruder productivity. The possibility of mechanochemical synthesis of nanocomposites vulcanized with dicumyl peroxide on an extruder using monotreme technology has been proved. It was found that as a result of vulcanization of nanocomposites based on ethylene copolymers, a significant increase in the ultimate tensile stress and a decrease in the elongation at break are observed. With an increase in the maximum extrusion temperature in the extruder head to 230 °C, it does not lead to the appearance of a counterflow. At the same time, it was shown that with an increase in the temperature regime of extrusion of vulcanized nanocomposites over 200 °C, the time spent by the melt in the material cylinder practically does not undergo changes. A fundamental feature of the effect of chemical crosslinking with dicumyl peroxide on the processing process and the regularity of changes in the properties of nanocomposites are established. The probable mechanism of the vulcanization process in the melt of the polymer matrix and its selective effect on the reaction extrusion process, structural features and properties of nanocomposites are presented.

Modeling and Numerical Study of Ceramic Paste Extrusion

The extrusion processes of ceramic pastes, including 3D printing, are used for the production of high-value products. Ceramic paste extrusion is a complex process which depends on the paste rheological properties, die and extruder geometries, and operational parameters. Modeling and quantitative analysis of paste molding are important to design proper extrusion process for the production of high-value extrudates of desired strength, shape, and morphology. In this paper, the mathematical model of ram extrusion of ceramic materials is established, and the paste continuity and momentum equations for non-Newtonian fluid based on the modified Herschel-Bulkley viscous model were solved numerically. The effects of die geometry and paste feed rate on the distributions of paste velocity and pressure in the extruder and die were investigated numerically. As a result, the steeper radial profile of longitudinal velocity and higher value of longitudinal velocity were obtained in the narrow die. The pressure significantly increases in the die at a high feed rate, and the pressure profile is almost flat in the barrel. The rate of increase of the maximum pressure decreases with an increase of paste feed rate. The pressure steeply increases in the die of small diameter. The maximum pressure linearly increases with the ratio of die length to diameter.

Encapsulating probiotics in novel resistant starch wall material for production of rice flour extrudates

Rice flour was substituted with RS4 microcapsules at 0%, 5%, 10%, 15% and 20% substitution levels to prepare functional extrudates. Pasting properties of rice flour -RS4 blends displayed significant (p ≤ 0.05) decreases in pasting properties with increasing RS4 content. The increase of RS4 content in flour resulted in the fall of both storage modulus (G′) and loss modulus (G″). The amylose content, RS content and water intake capacity of extrudates increased significantly with increasing RS4 content. Addition of RS4 microcapsules up to 20% did not affect the textural parameters of extrudates. Thermal transition temperatures of rice extrudates also increased with the percentage of increased RS4. SEM images of RS4-rice flour extrudate samples showed a more discontinuous structure with cracks and void spaces compared to control. FT-IR spectra revealed a new peak between 1244 and 1266 cm−1 in RS4 enriched extrudates which is attributed PO stretching in RS4. The survival of probiotics after extrusion demonstrated that RS4 microcapsules can be incorporated into the extrudates for preparation of functional foods. Addition of RS4 to rice extrudates up to 20% did not affect the overall acceptability of these products by consumers.

Simulation of the Extruder Screw Parameters

Extrusion of feed ensures a high quality of the fi nished product.(Research purpose) To increase structural elements durability of the press extruder by optimizing their strength characteristics.(Materials and methods) The authors studied the technological principle of extrusion. The experiment planning method was applied. They examined the process of press extruder operation with a variable pitch screw during the lentils processing. The strength characteristics of the press-extruder elements were checked during design or strength calculations.(Results and discussion) The authors showed the role of the main geometrical parameters of the extruder screw – the slope of the turn and the cutting step – in the preparation of high-quality grain feed. It was found that the turn pitch should be calculated depending on the friction coeffi cient of the starting material against the press-extruder body, the type and properties of the supplied material. The auger fatigue stresses were determined as a result of constant sign shear load and temperature eff ects. The drive power, the extruder productivity were calculated to clarify the screw characteristics, as well as the hydraulic resistance of the matrix output head, the distance of the technological zones. It was confi rmed that the prefabricated screw structure, consisting of sections with diff erent pitch, gave the press extruder versatility.(Conclusions) The authors found that the key was one of the most loaded structural elements of the press-extruder screw. The maximum calculated voltage from a constant load was calculated – 26.98 megapascals. It was determined that the stress in the cross-section of the key under temperature action was 591 megapascals, which exceeded the yield stress for the selected material, equal to 360 megapascals for steel 45. In the course of experimental studies, a value of impact strength was obtained that corresponded to the standard value of the initially selected steel grade (38 kilojoules per cubic meter), but didn’t meet the requirements for this structural element (at least 50 kilojoules per cubic meter).

Response Surface Method in Evaluating the Extrusion Effects on Molecular Degradation and Physical Properties of Sago Starch

This study was aimed to measure the effect of extrusion on the molecular degradation and physical characteristics of the sago starch by employing response surface method. The starch was extruded in a twin screw extruder with moisture contents of 25, 32.5, and 40%; melt temperature of 86, 95 and 104oC; and screw speed of 100, 150, and 200 rpm. The extruded products were then analyzed for degree of molecular degradation, reducing sugars of the water soluble materials, water solubility index (WSI), water absorption index (WAI), enzyme susceptibility, gelatinization endothermic energy (∆H), and specific mechanical energy (SME). Increased mechanical and thermal energy input received by the products in the extruder gave rise to a significant degradation of the molecular weight of the macromolecules. It was believed that granule structures of the extruded starch have been reshaped. The extrusion process conditions did not significantly affect the WSI, WAI, reducing sugar content, and ∆H. All extruded samples had a much lower gelatinization endothermic energy than native starch.

Effect of sprouting conditions on the properties of direct expanded extruded wheat

AbstractThe present study investigates the use of flour from sprouted wheat for the production of extruded, directly expanded products. Until now, studies on the use of sprouted material in extrusion have not been concerned with differences in the sprouted material. This contribution documents the first attempt to study the effect of the variation of the sprouting process on extrudate properties. Extrudates were produced at standard conditions using material produced by the variation of sprouting times (steeped, 1, 3, 5, 7, and 9 days sprouted). It was found that an increasing duration of the sprouting process also increases the starch degradation and hence sugar generation. During this process, vitamin C levels showed an increase of up to 10‐fold. The accompanying changes in viscosity propagate systematically into different observations. With increased starch degradation back pressures in the extrusion die were reduced, extrudates show less sectional expansion, but densities were decreased because longitudinal expansion was increased significantly. The extrudates made with sprouted material were preferred during sensory assessment. The degree of sprouting, which was defined earlier proved to be a useful property to characterize the progress of the sprouting process and correlated well with changes observed for the sprouted flour and extrudate properties.Practical applicationThe use of sprouted wheat in the production of direct expanded extrudates is a promising opportunity to change and improve extrudate properties. On the one hand, the nutritional value of the extrudates is improved due to the use of sprouted wheat flour which contains newly synthesized vitamins, more essential amino acids, and a decreased phytic acid content. On the other hand, the texture of the extrudates is improved and less additives are needed in the production. Due to the starch degradation in the sprouting process short‐chain sugars were formed, which naturally increase the sweetness of the extrudates.