Extrusion Treatment Research Articles

Effects of Extrusion Treatment on the Physicochemical and Baking Quality of Japonica Rice Batters and Rice Breads

Gluten-free rice bread made from japonica rice finds challenge in achieving a good shape and structure, presenting a significant obstacle in the baking industry. This study aims to improve the quality of rice bread with japonica rice flour by hot extrusion treatment (without additives). The effects of extrusion on the amylose content, gelatinization degree, hydration capacity, short-range molecular ordering, and microstructure of japonica rice flour were investigated. The results show that the amylose content of the extruded flour increased by 12.43% and the gelatinization degree of it increased by 13.23 times, showing disrupted starch granules, numerous pores, and a better hydration capacity. The addition of extruded flour improved the overall viscoelasticity of the batter. Compared to the control group, the specific volume and porosity of the optimized rice bread were increased by 19.46% and 61.92%, respectively. The gas cell density was increased by 4.63 times, and the average gas cell area of rice bread was reduced by 47.14%. The correlations among the raw material properties of rice flour, the batter properties, and the quality of rice bread products were revealed by principal component analysis. This study demonstrates that the addition of moderate amounts of extruded japonica rice flour could improve the quality of rice bread products.

Effects of grape seed proanthocyanidin on emulsifying capacity of soy protein isolate in extrusion field and its underlying mechanism.

Soy protein isolate (SPI) has poor emulsifying ability because of its low molecular flexibility and compact structure, limiting its application in extruded protein-based foods. Extrusion technology has emerged as a promising way to alter the structural properties of proteins. Therefore, the impacts of grape seed proanthocyanidin (GSP) on structural and emulsifying characteristics of SPI in extrusion field were explored in this study. After extrusion treatment, the molecular chains of SPI were unfolded. In comparison with extruded SPI, the interaction with GSP led to a rightward shift in particle size distribution and an enhancement in zeta potential values of the protein. As GSP concentration increased from 20 to 80 g kg-1, the free sulfhydryl content of SPI was reduced by 4.17%, 25%, 29.24% and 35.85% compared with that of extruded SPI. The addition of GSP altered the secondary structure of SPI and enhanced the microenvironment polarity. Meanwhile, SDS-PAGE results indicated that the protein presented lower molecular weight with the introduction of GSP. Compared with extruded SPI, the supplementation with GSP increased the molecular flexibility while it decreased the surface hydrophobicity of SPI. Correlation analyses demonstrated that these structural changes induced an improvement in emulsifying activity and emulsion stability of SPI. GSP mainly binds to SPI through hydrogen bonds and hydrophobic interactions under the extrusion environment. This study demonstrated that GSP is a potential modifier, which can be applied to improve the emulsifying capacity of extruded SPI-based foods. © 2025 Society of Chemical Industry.

Effects of soy protein isolate hydrolysate on the structural and functional properties of yam starch during extrusion.

This study investigated the interaction between yam starch (YS) and soy protein isolate hydrolysate (SPH), and their effects on in vitro digestibility of starch through extrusion treatment. Results indicated that SPH with 6% hydrolysis degree had the lowest relative molecular mass. X-ray diffraction and Raman spectroscopy revealed an increase in the relative crystallinity of extruded yam starch (EYS) from 17.45% to 22.45% and a decrease in the half-peak width at 480cm-1. Its short-range ordering improved with increased SPH addition. Differential scanning calorimetry results demonstrated that SPH enhanced the thermal properties of EYS. Additionally, the solubility, peak viscosity, and setback viscosity of EYS decreased with an increase in the SPH content. Particle size analysis revealed that SPH addition decreased the particle size of EYS. Scanning electron microscopy and confocal laser scanning microscopy showed that the surface of EYS roughened and SPH molecules attached to the surface. In vitro digestion results indicated that SPH hindered the contact between EYS molecules and digestive enzymes and increased the resistant starch content of EYS from 8.31% to 23.39%. This study presents a new method for modification of starch using protein hydrolysates during extrusion.

Effects of extrusion temperature on structure and physicochemical properties of proso millet starch.

Due to its thermal stability, and high viscosity, proso millet starch has limited practical applications. Extrusion can alter the functional properties of starch by pre-gelatinization, but the specific effects of extrusion temperature on starch behavior are not clear. In this study, proso millet starch was modified using extrusion at varying temperatures (70°C, 90°C, 110°C), and its structure as well as physicochemical properties were evaluated. As the extrusion temperature increased, the starch granules were gelatinized, and the particle size increased significantly. The relative crystallinity of extruded starch decreased and the short-range order was enhanced notably, but the starch still exhibited an A-type structure. Starch chains degraded, migrated, and aggregated, showing an increase in the double helix content, but there was no difference in the single helix structure with temperature. With the increase of extrusion temperature, the amorphous layer of extruded starch thickened. Moreover, the peak viscosity, breakdown viscosity and setback viscosity initially increased and then decreased, the peak temperature and enthalpy change increased. The water absorption index, water solubility and swelling power significantly decreased with increasing temperatures. The freeze-thaw stability and transparency of extruded starch decreased, and showed a downward trend with prolonged time. The above results indicate that extrusion treatment effectively modifies the thermal stability and viscosity of proso millet starch, laying a foundation for applying it different industrial applications.

Effect of Yam Flour Modified with Plasma-Activated Water Combined with Extrusion Treatment on the Quality of Chinese Noodles.

Yam noodles were produced by replacing high-gluten wheat flour with yam flour modified with plasma-activated water and twin-screw extrusion (PAW-TSE). The effects of varying amounts of modified yam flour on the color, cooking characteristics, texture, and in vitro digestibility of the noodles were investigated. As the amount of modified yam flour increased, the noodles became darker in color, while the bound water content increased, and the free water content decreased. The modified yam flour also affected the cooking properties, reducing the optimal cooking time, decreasing the water absorption, and increasing the cooking loss. Textural analysis revealed that the addition of modified yam flour improved the texture of raw noodles, enhancing their elasticity and chewiness after cooking, thus providing a better eating experience. Furthermore, the modified yam flour increased the resistant starch content, thereby enhancing the nutritional value of the noodles. These findings provide valuable insights for food manufacturers seeking to develop healthier and more appealing noodle products, potentially leading to greater consumer acceptance and market success.

Synergism of cold extrusion and ball milling for improving rheological properties of whey protein isolate

Impact of cold extrusion combined with ball milling on the rheological properties and gel water distribution of whey protein isolate (WPI) was investigated. The viscosity and shear stress of WPI after cold extrusion and ball milling (MEWPI) were increased compared to WPI, and the effect of the combined treatment was superior to cold extrusion WPI (EWPI) or ball milling WPI (MWPI). The Péclet number of MEWPI was greater than 1, proving that increase in viscosity was caused by the enhancement of hydrophobic interactions between protein molecules. Meanwhile, MEWPI also showed the most obvious offset in the fitting of Cox-merz rule, which implied the formation of massive intermolecular aggregates. Besides WPI, a solid flow behavior with fractal structure was exhibited by EWPI, MWPI and MEWPI with G′> G″ at all frequencies and MEWPI had the lowest fractal dimension. The T22 of MEWPI, EWPI, and MWPI were advanced by 113.63, 108.06, and 73.57 ms compared to WPI, respectively, meaning that cold extrusion combined with ball milling most significantly reduced the mobility of immobile water in the gels, and the water retention effect was preferable to that of the individual treatments. Overall, synergism of ball milling and cold extrusion treatment significantly improved the rheological properties and gel water distribution of WPI, promoting the use of WPI as a natural thickener in the food industry.

Effects of Extrusion on the Available Energy and Nutrient Digestibility of Soybean Meal and Its Application in Weaned Piglets.

Experiments were conducted to investigate the effects of extrusion devices on the available energy and nutrient digestibility of soybean meal (SBM), and further to investigate the impact of different levels of extruded SBM on the growth performance and nutrient digestibility of weaned piglets. In Exp. 1, eighteen crossbreed growing pigs with an initial body weight (BW) of 32.6 ± 2.7 kg were randomly assigned to three treatments, including a corn basal diet, SBM, and extruded SBM diets. In addition, six cannulated pigs (initial BW, 22.3 ± 1.8 kg) were allocated across an 6 × 3 Youden square design. The experimental treatments included a N-free diet and three diets containing 40% of different SBM sources. The results indicated that extrusion reduced the anti-nutritional factors in soybean meal without affecting the digestibility of available energy and nutrients. In Exp. 2, 192 pigs (initial BW, 6.60 ± 0.54 kg) were allocated across four diets supplemented with 0%, 3%, 6%, and 9% extruded SBM. The four treatments were randomized and each comprised six replicate pens containing four boars and four gilts. The results showed that average daily feed intake (ADFI) decreased linearly with the increase in extruded SBM levels from d 0-14 (p < 0.05), and average daily gain (ADG) increased; ATTD was higher in the GE, DM, OM, and CP of piglets in the 9% extruded SBM group (p < 0.05). In conclusion, the extrusion treatment reduced ANFs in SBM, and adding 9% extruded SBM to the diet improved the growth performance of weaned piglets by increasing the digestibility of nutrients.

Understanding the Impact of Extrusion Treatment on Cereals: Insights from Alterations in Starch Physicochemical Properties and In Vitro Digestion Kinetics.

In this study, three samples were randomly selected from corn, wheat, and broken rice before and after extrusion for electron microscope scanning, Fourier transform infrared spectral analysis, and in vitro digestion to investigate the impact of extrusion on physicochemical characteristics and starch digestion kinetics of cereals. The cereals used for extrusion were sourced identically before and after the process, with each analysis conducted in triplicate. The results showed that the extrusion compromised the physical structure of cereal, resulting in loose structure arrangement, and the ratio of Fourier transform infrared spectral absorbance at wavelength 1047 cm-1 and 1022 cm-1, which characterized the short-range order of starch, was significantly reduced (p < 0.05). In addition, the proportion of rapidly digestible starch (RDS), the velocity parameter k of digestive kinetics and the predicted glycemic index of cereals were significantly increased by extrusion (p < 0.05). Digestibility kinetics showed a total increase of 10.7%, 7.3%, and 5.4% for cereals, along with a sharp rise in digestion rate within the first 15 minutes. The findings revealed that the compromising of starch's structural integrity and the increase in proportion of RDS not only enhanced overall starch digestibility, but also significantly accelerated its digestion, particularly during the initial 15 min of intestinal digestion.

Effect of Hot Extrusion on Microstructure, Texture, and Mechanical Properties of Mg-Zn-Mn-0.5Ca Alloy

This paper investigates the microstructure, texture, and mechanical properties of the Mg-4Zn-1Mn-0.5Ca alloy subjected to hot extrusion under varying conditions of temperature (260 °C, 300 °C, 340 °C) and extrusion speed (0.01 mm/s, 0.1 mm/s, 1 mm/s). The primary objective is to determine the optimal extrusion parameters within the selected experimental range for achieving superior mechanical properties. The results indicate that, when extruded at a constant speed of 0.1 mm/s, the alloy exhibits optimal performance at 340 °C, with a yield strength of 202 MPa, ultimate tensile strength (UTS) of 306 MPa, and elongation at fracture of 18.9%. A decrease in extrusion temperature leads to an increase in yield strength but a reduction in ductility. Specifically, the UTS reaches its peak at 342 MPa at 300 °C, while it drops slightly to 329 MPa at 260 °C. The final results show that the comprehensive mechanical properties of the Mg-4Zn-1Mn-0.5Ca alloy obtained by hot extrusion treatment with an extrusion temperature of 300 °C and extrusion speed of 0.1 mm/s are the best and can effectively improve the mechanical properties of the alloy and provide a good choice for the preparation of other biodegradable magnesium alloy products.

Orthodontic extrusion with fixed appliances for treatment of intrusive luxation injuries: A prospective study of 28 permanent maxillary incisors.

Limited evidence exists on the treatment options of tooth repositioning after intrusive luxation. The study aimed to investigate the outcomes and complications of orthodontic extrusion in treating intruded maxillary permanent incisors. A prospective study was conducted involving 28 intruded maxillary permanent incisors treated with orthodontic extrusion, compared with a retrospective control group of 29 teeth that underwent spontaneous re-eruption. The success rate of tooth repositioning, as well as pulp condition, periodontal healing, and root development were assessed and compared. The success rate of orthodontic extrusion was 96.4%, excluding one tooth that was ankylosed before treatment. There were no significant differences in pulp condition between the orthodontic extrusion and control groups for teeth with immature root development. Teeth with mature root development in the orthodontic group, however, showed a significantly higher rate of pulp necrosis (100%, p < .05). Periodontal healing outcomes were similar across both groups, regardless of the maturity of root development. The root length continued increasing during orthodontic extrusion treatment. Orthodontic extrusion treatment could effectively reposition moderately to severely intrusive permanent incisors, without increasing the risk of complications compared with spontaneous re-eruption.

Impact of hydroxypropylation coupled with extrusion treatment on the morphological, structural, and rheological properties of sorghum and corn starch

The purpose of the present study to prepare hydroxypropyl derivatives (HP) instant (partially cold-water swell-able) starches via extrusion technique (Ex) from sorghum and corn. The native and hydroxypropylated (at propylene level 5 % and 12 %) starch extrudates were evaluated for functional, structural, thermal and rheological properties. The development of extrudates provides ease to industries as they are easily soluble in aqueous mediums and does not require any prior heating. The degree of substitution (DS) for all extrudates varied between 0.0083 and 0.1530 which is under limit and save to consume. The X-ray diffraction (XRD) analysis revealed that all extrudates exhibited V-type pattern while the intensity of peaks increased due to hydroxypropylation. The starch extrudates showed gel-like behavior since storage modulus (G′) was greater than loss modulus (G″). Non-Newtonian shear thinning behavior was observed for all extrudates. At lower temperature, HP-Ex at higher substitution level (12 %) demonstrated higher complex viscosity than native and low-substituted extrudates. Creep recovery of HP-Ex dispersion was more pronounced than native extrudates suggesting elastic nature of sorghum and corn starch extrudates. The differential scanning calorimetry (DSC) results revealed that HP-Ex were observed to gelatinize at lower temperatures and needed lower enthalpy of gelatinization (ΔHgel) because of their weakened structure after modification.

Research on the deformation behavior of pure zinc fabricated by forward extrusion and composite extrusion

Zinc and its alloys are biomedical biodegradable materials with broad application prospects. In this paper, commercially pure zinc bars were subjected to two different types of extrusion treatments, forward extrusion (FE) and composite extrusion (CE), at 120°C to study the changes in microstructure and mechanical properties. Compared to the virgin annealed state of pure zinc, the yield strength of CE decreased significantly from 73.67 MPa to 40.87 MPa, while the elongation of FE increased markedly from 9.23 % to 59 %. The anomalous phenomenon of decreasing strength and increasing ductility of extruded pure zinc is significantly different from that of extruded zinc and magnesium alloys. To investigate the reason for this anomaly, a detailed study of the microstructure evolution of pure zinc under three processing states was carried out using EBSD. Grain growth and texture weakening lead to a loss of strength, whereas the increase in ductility after extrusion is attributed to the activation of more slip systems.

Effect of guar gum on the physicochemical properties and in vitro digestive characteristics of extruded starches

The present study assessed the impact of guar gum (GG) on the physical and chemical attributes and the in vitro digestibility of maize starch (MS), pea starch (PS), and sweet potato starch (SPS) subjected to extrusion treatment. Starch with 25 % moisture content and combined with GG in a 9:1 ratio was selected for extrusion. Scanning electron microscopy and differential scanning calorimetry reveal that extrusion disrupts the ordered structure of starch and induces aggregation of starch granules, resulting in a more cohesive structure, and GG addition led to the further evolution of this structure into a more intricate and irregular form. Rheological assessments demonstrated a remarkable enhancement in the gelatinization characteristics of starch with GG addition, which led to elevated flow resistance and increased viscosity. On evaluating the in vitro digestive characteristics, we noted that adding GG to starch augmented the levels of slow-digestible starch and resistant starch. Consequently, this resulted in diminished digestibility and a lowered glycemic index. In summary, GG synergistically interacts with starch, forming intricately assimilable components. Moreover, the effects of extrusion vary across different starches, which proves advantageous for SPS and GG amalgamation, thereby enhancing their resistant components. Conversely, extrusion manifests contrasting outcomes for MS and PS.

Digestion behavior of plant-based meat analogs with anisotropic fibrous structure in a semi-dynamic gastric digestion system

Plant-based meat analogs have increasingly attracted the attention of the food industry in recent years. However, the digestion behavior of this innovative solid food in human stomach is poorly understood. In this study, plant-based meat analogs with different internal structures were prepared with/without high-moisture extrusion technology and at different temperatures. A semi-dynamic gastric digestion system which involves the mimic processes of the secretion of gastric juice and the gastric emptying was applied. After extrusion treatment at high temperature (150 ℃), the EHT had the highest anisotropic index (H⊥/H∥=1.90) and an ideal meat-like structure. It was found that particle disintegration and swelling simultaneously occurred in the bolus of the EHT but not in the sample without extrusion treatment (the HLT) in the early stage of gastric digestion. This difference might be attributed to the compact and well-arranged anisotropic structure of the EHT resulting from the extrusion, and leads to difficult enzymatic hydrolyzation unless the particles swell and unfold the polymer chains. The difficulty in particle disintegration in the EHT during gastric digestion is the consequence of the relatively slow gastric emptying rate and the decrease of protein degradation. As a result, the EHT which underwent extrusion treatment at high temperature and possessed the best anisotropic fibrous structure exhibited the slowest gastric digestion. This novel solid food shows good potential as a desired nutritional food for people on diet.

An integrated pretreatment strategy for enhancing enzymatic hydrolysis efficiency of poplar: Hydrothermal treatment followed by a twin-screw extrusion

To reduce the dependence on chemical inputs during biomass pretreatment, an integrated process on the basis of hydrothermal pretreatment followed by twin-screw extrusion for poplar was proposed. A comparative study was conducted on the pore structure, crystallinity, relative surface lignin concentration, cellulose accessibility, and enzymatic hydrolysis efficiency of the pretreated materials. Results suggested that the relative surface lignin concentration of fibers pretreated by hydrothermal treatment (conducted at 170 ℃ for 90 min) coupled with extrusion (HE) treatment was decreased compared to the sole hydrothermal (H) process, which had a positive impact on the subsequent enzymatic hydrolysis. Additionally, the HE process resulted in an increase in pore size by 34.4%, pore volume by 447.5%, and specific surface area by 93.5%, which enhanced the penetration and interaction of water into the fibers and thus increased cellulose accessibility by 143.2%. SEM and TEM observations revealed that fibers were separated and finely fibrillated, large amounts of fragmentary structure and cracks appeared on the fiber. In addition, the cell wall structure was deformed and damaged, when pretreated by HE process. Overall, this work showed that hydrothermal treatment followed by twin-screw extrusion was an achievable strategy for high fermentable sugar production of hardwood.

Optimisation and study of a welding process for aluminium and galvanised steel based on resistance welding

In this study, taking six-series aluminium alloy and DC06 galvanised steel resistance spot welding as the object of study, the impacts of the electrode cap shape and process parameters on the joint welding performance were analysed, and the electrode cap was optimised. The optimised process parameters involved the use of spherical asymmetric electrodes and a pre-welding preheating step for zinc extrusion treatment, followed by a double pulse for welding. The optimal parameters resulted in an aluminium/steel spot welding head average pull shear failure load of 2858.7 N and aluminium/aluminium spot welding head failure force of 2436 N, reaching 117.3% of its original value. The minimum force value (2253.4 N) was greater than 92.5%, and the failure section was all from the aluminium side in parent material button failure, achieving good final results.

Variations in the effects of extrusion treatments and ferulic acid addition on starch digestibility with different botanical backgrounds

In the current study, the effects of extrusion using a haake rheometer with a twin-roll mixer, with and without FA addition, on the structures and in vitro digestibility of starches from different sources were investigated. After extruding for 15 min at 90 °C with a moisture content of 40 %, no matter FA was added or not, lager Ap molecules were preferentially debranched, while Am with longer CL were depolymerized simultaneously, resulting to reduced averaged molecular size of Ap and shortened Am chains. Of all starches, regardless of their botanical backgrounds, although synergic effects were found between extrusion and FA addition on reducing their relative crystallinity and the ordered structures, distinctly different effects on the in vitro digestibility of these starches have also been observed especially regarding the digestion of starch branches with DP > 10 Particularly, the Am chains with DP 10–1000 was remaining undigested when FA was added. This study provides important information concerning how to adjust starch digestibility into a healthy range through altering the starch structures using extrusion technique with the addition of phytochemicals or not.

Effects of the extrusion and enzymatic extrusion treatment on the apparent viscosity of degerminated maize grits

Effects of the extrusion and enzymatic extrusion treatment on the apparent viscosity of degerminated maize grits

Understanding the degradation mechanisms of cyanide and starch in cassava flour during extrusion processing

In the realm of food applications, cassava faces limitations due to the presence of cyanide compounds. This study investigated the effect of extrusion process on starch degradation, cyanide removal, and the intricate relationship between starch and cyanide in cassava flour. The extrusion treatment led to a significant enhancement in the degree of gelatinization and amylose content, reduced starch content, as well as diminished parameters, such as ratios of 1047 /1022 cm−1 and 995/1022 cm−1, degree of branching, and molecular weight. Meanwhile, the total cyanide was reduced by 5.06 mg/kg (dry basis) with a removal rate of 78.82%. Correlation analysis revealed that the hydrogen bonds linking cyanide and starch molecules were predominantly disrupted within the extruder. This disruption facilitated the degradation of cyanide and the volatilization of hydrogen cyanide (HCN). Consequently, extrusion has emerged as an effective method to reduce HCN content in cassava, thereby enhancing its suitability for a wider range of culinary applications.

Preparation of Mg-6Zn-1Y-0.5Zr alloy sheet with excellent mechanical properties and electromagnetic interference shielding effectiveness by extrusion plus rolling

Magnesium (Mg) alloy sheets with excellent mechanical properties and electromagnetic interference shielding effectiveness (EMI SE) have great application prospects. This study investigates the microstructure, mechanical properties, and EMI SE of extruded and rolled Mg-6Zn-1Y-0.5Zr sheets. In the Mg-6Zn-1Y-0.5Zr alloy subjected to extrusion and rolling, the predominant internal second phases are Mg-Zn-Y and MgZn, with the volume fraction of the second phase increasing with cumulative strain. After the extrusion treatment, the average grain size of the Mg-6Zn-1Y-0.5Zr alloy was 2.7 μm. Increasing the rolling reduction to 37% resulted in an average grain size of 5.27 μm, while a rolling reduction to 75% decreased the grain size to 4.06 μm. The Mg-6Zn-1Y-0.5Zr alloys exhibited consistent trends in ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) under extrusion and various rolling strain treatments. These properties showed a relationship with cumulative strain, initially increasing and then decreasing. However, the EMI SE of the Mg-6Zn-1Y-0.5Zr alloy exhibited a positive correlation with cumulative strain. The sheets obtained through a combination of extrusion plus 37% rolling treatment exhibited excellent mechanical properties and EMI SE. The Mg-6Zn-1Y-0.5Zr alloy demonstrated UTS, YS, and EL values of 331.4 MPa, 251.3 MPa, and 18.7%, respectively. The EMI SE in the frequency range of 30–1500 MHz ranged from 79 dB to 113 dB, satisfying the requirements of the electronic information field regarding the mechanical properties and EMI SE of Mg alloy sheets.