Search

BACKGROUND RESULTS CONCLUSION Texturized vegetable protein is currently a leading alternative to animal meat. This study examined the effects of soybean insoluble dietary fiber (SIDF) (0% to 20%) and CaCl2 (0% to 1%) on the structure and properties of extruded products made from a soybean protein isolate‐wheat gluten (SPI‐WG) composite.The study showed that SIDF (4% to 8%) increased the viscosity of extruded products, enhanced their specific mechanical energy, and improved their rehydration rate and tensile strength compared with a control group. The rehydration rate of the extruded products reached a maximum value of 331.67% in the 8% SIDF, 0.5% CaCl2 groups. The addition of excess SIDF prevented the cross‐linking of protein molecules to form a loose network structure. Analysis of the infrared spectrum and intermolecular forces showed that physical interactions between fibers and proteins were the dominant forces, with hydrophobic interactions and hydrogen bonds primarily maintaining the structure of the extruded products. The addition of CaCl2 (0.5%) led to protein aggregation and further improved the rehydration and tensile strength of extruded products.Soybean insoluble dietary fiber can improve the rehydration rate and quality of extruded products. The addition of CaCl2 mitigated the weakening of the protein structure caused by excess SIDF. These results provide a basis for the improvement of the quality of low‐moisture‐extruded texturized vegetable protein products with a high dietary fiber concentration and a high rehydration rate. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, textured vegetable protein (TVP) based on soy protein isolate, wheat gluten, and corn starch was prepared at a 5:3:2 (w/w) ratio using a low-moisture extrusion process. To evaluate the effects of extrusion parameters, die temperature and screw rotation speed, on the properties of TVP, these two parameters were manipulated at a constant barrel temperature and moisture content. The results indicated that increasing the die temperature increased the expansion ratio while decreasing the density of the extrudates. Simultaneously, increasing the screw rotation speed clearly increased the specific mechanical energy of the TVP. Furthermore, mathematical modelling suggested that the expansion ratio increases exponentially to the die temperature. However, extreme process conditions bring about a decrease in water absorption capacity and expansion ratio, as well as undesirable texture and microstructure. The results suggested that the properties of SPI-based TVP are directly influenced by the extrusion process parameters, screw speed and die temperature. [ABSTRACT FROM AUTHOR]

Texturized vegetable protein (TVP) from a blend of faba bean protein concentrate and an oat beta-glucan rich fraction was produced by low-moisture extrusion to combine nutritional benefits of both ingredients. The effect of extrusion conditions (temperature in zone 6 (HZ6), feed rate (FR) and moisture content (MC)) on physicochemical, nutritional, textural, and sensory attributes was studied. Overall, effect of the FR and MC of the blend showed greater impact on TVP properties rather than the temperature. TVPs produced at 28.5%, 5 Kg/h and 150⁰C and at 30.8%, 4 Kg/h and 160⁰C for MC, FR and HZ6, respectively, presented improved properties to be further formulated into a meat analogue product. The beta-glucan content of TVP (5.6g/100g dm) was high enough to reach >1 g beta-glucan per serving in a final food product (e.g., vegan burger), which qualifies for the health claim “reduces low-density lipoprotein (LDL)-cholesterol” approved by the European Food Safety Authority. The combination of these ingredients resulted simultaneously in an improved composition of essential amino acids and increased the protein quality of the blend as the calculated digestible indispensable amino acid score (DIAAS) improved from 72.2 (beta-glucan rich fraction alone) or 76.1 (faba bean protein concentrate alone) to 90.2 (blend).

Low-moisture extruded products provide excellent shelf-life and stability, making the exploration of new formulations with various proteins highly valuable. This study prepared and compared products with different ratios of mung bean protein isolate (MPI) to wheat gluten (WG) (10:0, 9:1, 8:2, 7:3, 6:4, and 5:5). Results showed significant improvements (P < 0.05) in L∗-value and product quality with increasing WG ratios, peaking at an MPI/WG ratio of 7:3. Increased WG also enhanced protein cross-linking aggregation, as evidenced by changes in particle size, secondary structure, and fluorescence spectra. However, excessive WG (MPI/WG = 6:4) adversely affected product structure and techno-functional characteristics. Rehydration kinetics were best described by the Peleg model, with rehydrated products showing decreased hardness (291.25 N) and chewiness (227.45 N), but increased tensile resistance (P < 0.05). Eleven quadratic polynomial equations were developed to predict color and techno-functional characteristics based on WG percentage (0–50%). The findings provide a theoretical basis for expanding the application of MPI in new low-moisture extruded products. • The use of MPI and WG produces low-moisture extruded products with improved textures. • WG promoted the transition of proteins from disordered to ordered structures. • The Peleg model fitted the rehydration process of low-moisture extruded products. • Covalent and non-covalent bonds played important roles in maintaining the fiber structure of extruded products. [ABSTRACT FROM AUTHOR]

This study investigated meat analogs produced using low-moisture extrusion from oat and pea protein blends at ratios 20:80, 30:70, 50:50, and 70:30. Response surface methodology was used to assess the effect of blend composition, screw speed (200–1200 rpm), barrel temperature (135–160 °C), and moisture content (25–35%) on the properties of extruded meat analogs. Blend composition had a relatively stronger effect on water holding capacity, water solubility index, bitterness, cohesiveness, and springiness, while extrusion conditions had more influence on hardness, fibrousness, and moistness. As the oat content increased from 20% to 70% the maximum sensory fibrousness increased from 7.2 to 8.6 on a scale of 0–9. Although the mean water holding capacity decreased from 2.1 to 1.4 g g−1, the mean sensory moistness remained around 4.1. Cereal taste dominated over legumes with the mean intensities 3.9 and 2.0, however, the differences between oat-pea blends were small. In general, the extruded meat analogs had a mild flavor and high fibrousness, and the developed response surface models can be used to tune the properties further. This confirms that oat protein in combination with pea is a practical alternative to soy and gluten proteins for the production of meat analogs.

Low-moisture extrusion (LME) can modify starch structures and enrich their functionality. These LME-made starches may efficiently form inclusion complexes (ICs) with hydrophobic guest molecules, which is profoundly impacted by the guest molecule concentration. In this work, the influence of glycerin monostearin (GMS) concentration on the structure and in vitro digestibility of pre-extruded starch-GMS complexes was investigated. The results showed that LME pretreatment increased the complex index of high-amylose starch with GMS by 13 %. The appropriate GMS concentrations produced ICs with high crystallinity and excellent thermostability. The presence of IC retarded amylose retrogradation and dominated bound water in starches. In addition, highly crystallized ICs were resistant to enzymolysis and had a higher proportion of resistant starch. The acquired knowledge would provide a better understanding of the LME-modified starch and GMS concentration-regulated IC formation. • Low-moisture extrusion promoted complexation of starch with GMS. • Inclusion complex formation was GMS concentration-dependent. • V -type complexes increased the crystallinity and heat resistance of starch. • IC-rich starches were slow-digesting and had a high RS content. [ABSTRACT FROM AUTHOR]

Rapeseed press cake (RPC), an oil pressing side product rich in protein and fiber, can be combined with starch and valorized into directly expanded products using extrusion technology. The mechanism of starch expansion has been studied in detail, but the impact of RPC on expansion behavior is poorly understood. However, it can be linked to rheological and physicochemical properties and is a key product quality parameter. Blends with different amounts of RPC (0, 10, 40 g/100 g) were extruded at different barrel temperatures (100, 120, 140 °C) and moisture contents (24 or 29 g/100 g). The initial, intermediate and final sectional, longitudinal and volumetric expansion indices (SEI, LEI, VEI) were monitored directly, 10 s and 24 h after die exit to measure extrudate growth and shrinkage. The viscous and elastic properties of the extruded blends were investigated in a closed cavity rheometer. Starch and blends with 10 g/100 g RPC achieved a high initial SEI followed by significant short-term shrinkage. Blends containing 40 g/100 g RPC did not show any initial expansion. With increasing RPC content, the intermediate SEI decreased, but all samples reached a similar final SEI due to time-dependent swelling of the RPC blends. With increasing RPC content, the elasticity of the starch-based extruded samples significantly increased. Our study shows that comprehensive control and understanding of expansion mechanisms can be achieved only by investigating all stages of extrudate growth and shrinkage. We also found that the closed cavity rheometer is a powerful tool to correlate the rheological properties and expansion mechanisms of biopolymers.

[Display omitted] • Meat analogues in which partial or complete soy protein was replaced with rice protein were developed via low-moisture extrusion. • Meat analogues had the U-shaped fibrous structuring due to the velocity gradient of the mixture during the extrusion created by the Hagen-Poiseuille flow. • Incorporation of rice protein led to decreases in porosity and water absorption capacity of the meat analogues. • Incorporation of rice protein caused an increase in hardness and a decrease in springiness of the meat analogues. • Weibull model was best fitted for the rehydration kinetics of the meat analogues. Meat analogues are garnering significant attention as future food and a sustainable diet. This study demonstrates the possibility of using rice protein (RP) to create new meat analogues. Various RP substitution ratios [0, 25, 50, 75, and 100 % (w/w)] for soy protein (SP) were used to prepare the meat analogues based on a low-moisture extrusion cooking. The effect of its ratio on the meat quality characteristics was investigated via specific mechanical energy, expansion ratio, piece density, true density, porosity, water absorption capacity, rehydration kinetics, and texture profile (hardness, springiness, cohesiveness, chewiness, and resilience). The use of RP decreased some values (specific mechanical energy, porosity, expansion ratio, water absorption capacity, springiness, cohesiveness, chewiness, and resilience) while increasing others (piece density, true density, and hardness) depending on its substitution ratio. Three different models (Peleg, Weibull, and exponential) were used to describe the rehydration kinetics of the samples, and the Weibull model was the best-fitted one. Finally, twelve polynomial equations with RP mixing ratios (0–100 %) as variables were developed to predict the quality characteristics of meat analogues. These results suggested that RP can substitute the typical SP as an expansion or texture modifier in the production of SP-based meat analogue products, and a portion of SP (≤75 %, w/w) can be substituted with RP in the production of meat analogue products. Still, the full RP substitution was impossible due to the low porosity of the resulting meat analogue. [ABSTRACT FROM AUTHOR]

In this study, textured vegetable protein (TVP) based on soy protein isolate, wheat gluten, and corn starch was prepared at a 5:3:2 (w/w) ratio using a low-moisture extrusion process. To evaluate the effects of extrusion parameters, die temperature and screw rotation speed, on the properties of TVP, these two parameters were manipulated at a constant barrel temperature and moisture content. The results indicated that increasing the die temperature increased the expansion ratio while decreasing the density of the extrudates. Simultaneously, increasing the screw rotation speed clearly increased the specific mechanical energy of the TVP. Furthermore, mathematical modelling suggested that the expansion ratio increases exponentially to the die temperature. However, extreme process conditions bring about a decrease in water absorption capacity and expansion ratio, as well as undesirable texture and microstructure. The results suggested that the properties of SPI-based TVP are directly influenced by the extrusion process parameters, screw speed and die temperature., Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01207-8., Competing Interests: Conflict of interestThe authors declare no conflict of interest., (© The Korean Society of Food Science and Technology 2022, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Rapeseed press cake (RPC), an oil pressing side product rich in protein and fiber, can be combined with starch and valorized into directly expanded products using extrusion technology. The mechanism of starch expansion has been studied in detail, but the impact of RPC on expansion behavior is poorly understood. However, it can be linked to rheological and physicochemical properties and is a key product quality parameter. Blends with different amounts of RPC (0, 10, 40 g/100 g) were extruded at different barrel temperatures (100, 120, 140 °C) and moisture contents (24 or 29 g/100 g). The initial, intermediate and final sectional, longitudinal and volumetric expansion indices (SEI, LEI, VEI) were monitored directly, 10 s and 24 h after die exit to measure extrudate growth and shrinkage. The viscous and elastic properties of the extruded blends were investigated in a closed cavity rheometer. Starch and blends with 10 g/100 g RPC achieved a high initial SEI followed by significant short-term shrinkage. Blends containing 40 g/100 g RPC did not show any initial expansion. With increasing RPC content, the intermediate SEI decreased, but all samples reached a similar final SEI due to time-dependent swelling of the RPC blends. With increasing RPC content, the elasticity of the starch-based extruded samples significantly increased. Our study shows that comprehensive control and understanding of expansion mechanisms can be achieved only by investigating all stages of extrudate growth and shrinkage. We also found that the closed cavity rheometer is a powerful tool to correlate the rheological properties and expansion mechanisms of biopolymers. [ABSTRACT FROM AUTHOR]