scholarly journals Enzymatic modification of oat protein concentrate with trans- and protein glutaminase for increased fibrous structure formation during high-moisture extrusion processing

LWT ◽  
2021 ◽  
pp. 113035
Author(s):  
Pinja Pöri ◽  
Anni Nisov ◽  
Emilia Nordlund
Keyword(s):  
Structure Formation ◽  
Fibrous Structure ◽  
Protein Concentrate ◽  
Enzymatic Modification ◽  
High Moisture ◽  
Extrusion Processing ◽  
High Moisture Extrusion

scholarly journals High Moisture Extrusion of Soy Protein: Investigations on the Formation of Anisotropic Product Structure

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 102
Author(s):  
Patrick Wittek ◽  
Nicole Zeiler ◽  
Heike P. Karbstein ◽  
M. Azad Emin
Keyword(s):  
Structure Formation ◽  
Protein Interactions ◽  
Soy Protein ◽  
Plant Proteins ◽  
High Moisture Content ◽  
Protein Protein Interactions ◽  
High Moisture ◽  
Anisotropic Structures ◽  
Protein Rich ◽  
High Moisture Extrusion

The high moisture extrusion of plant proteins is well suited for the production of protein-rich products that imitate meat in their structure and texture. The desired anisotropic product structure of these meat analogues is achieved by extrusion at high moisture content (>40%) and elevated temperatures (>100 °C); a cooling die prevents expansion of the matrix and facilitates the formation of the anisotropic structure. Although there are many studies focusing on this process, the mechanisms behind the structure formation still remain largely unknown. Ongoing discussions are based on two very different hypotheses: structure formation due to alignment and stabilization of proteins at the molecular level vs. structure formation due to morphology development in multiphase systems. The aim of this paper is, therefore, to investigate the mechanism responsible for the formation of anisotropic structures during the high moisture extrusion of plant proteins. A model protein, soy protein isolate, is extruded at high moisture content and the changes in protein–protein interactions and microstructure are investigated. Anisotropic structures are achieved under the given conditions and are influenced by the material temperature (between 124 and 135 °C). Extrusion processing has a negligible effect on protein–protein interactions, suggesting that an alignment of protein molecules is not required for the structure formation. Instead, the extrudates show a distinct multiphase system. This system consists of a water-rich, dispersed phase surrounded by a water-poor, i.e., protein-rich, continuous phase. These findings could be helpful in the future process and product design of novel plant-based meat analogues.

scholarly journals High-moisture extrusion with insect and soy protein concentrates: cutting properties of meat analogues under insect content and barrel temperature variations

2019 ◽  
Vol 5 (1) ◽  
pp. 29-34 ◽  
Author(s):  
S. Smetana ◽  
C. Pernutz ◽  
S. Toepfl ◽  
V. Heinz ◽  
L. Van Campenhout
Keyword(s):  
Soy Protein ◽  
Dry Matter ◽  
Meat Products ◽  
Protein Concentrate ◽  
High Moisture ◽  
Protein Sources ◽  
Protein Concentrates ◽  
Insect Biomass ◽  
High Moisture Extrusion ◽  
Matter Basis

Insect biomass production is recognised as one of the potential solutions for the problem of a lack of traditional protein sources (most feed protein sources are imported in Europe). It is perceived to be utilised as a more suitable source of proteins for food and feed in Western countries within the next decades. High-moisture extrusion of protein concentrate and water mixtures results in the development of fibrous intermediates, suitable for the development of meat analogues. Hardness and protein composition of such intermediates were comparable to meat. Inclusion of 15-40% of insect protein concentrates (both Alphitobius diaperinus and Tenebrio molitor) could imitate the meat texture and resulted in a similar hardness compared to a standard sample composed of 100% soy protein concentrate (dry matter basis). Extruder barrel temperature and soy-insect ratio were found to affect the physical properties of the extrudates: an increase in temperature (alternatively decrease in water input) improved the hardness of the intermediates from 6.5-8 N (barrel temperature 160 °C) to 8-11 N (barrel temperature 170 °C). An optimal meat-like texture with the highest inclusion of insect biomass (40% dry matter basis) was achieved when using a maximal temperature of barrel extruder of 170 °C. The results demonstrated the potential of insect protein incorporation in a mixed (‘invisible’) form to generate high-protein texturized intermediates, presenting a viable alternative to the fresh meat products.

scholarly journals Effect of Oil Content and Oil Addition Point on the Extrusion Processing of Wheat Gluten-Based Meat Analogues

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 697
Author(s):  
Christina Kendler ◽  
Arvid Duchardt ◽  
Heike P. Karbstein ◽  
M. Azad Emin
Keyword(s):  
Tensile Strength ◽  
Oil Content ◽  
Wheat Gluten ◽  
Complex Viscosity ◽  
Process Conditions ◽  
High Moisture ◽  
Extrusion Processing ◽  
Common Process ◽  
Material Temperature ◽  
High Moisture Extrusion

High-moisture extrusion is a common process to impart an anisotropic, meat-like structure to plant proteins, such as wheat gluten. The addition of oil during the process promises to enhance the sensory properties of the meat analogs. In this study, the influence of oil on extrusion-relevant parameters as well as the structure-related characteristics of extruded wheat gluten was investigated. Oil was added directly to the extruder at different contents (0, 2, 4, 6%) and addition points (front/end of the extruder barrel). Process conditions, complex viscosity, Young’s modulus and oil phase morphology were determined as a function of oil content and oil addition point. With increasing oil content, material temperature, die pressure, and complex viscosity decreased. The addition of oil at the end of the extruder barrel reduced this effect compared to the addition of oil in the front part of the extruder. It was observed that the extrudate’s tensile strength is a function of material temperature, resulting in an increase in tensile strength with increasing material temperature. The oil was dispersed in the gluten matrix as small droplets with irregular shape. As the oil content increased, the size of the oil droplets increased, while the addition of oil at the end of the extruder resulted in a decrease in droplet size.

scholarly journals Morphology Development and Flow Characteristics during High Moisture Extrusion of a Plant-Based Meat Analogue

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1753
Author(s):  
Patrick Wittek ◽  
Felix Ellwanger ◽  
Heike P. Karbstein ◽  
M. Azad Emin
Keyword(s):  
Transition Zone ◽  
Flow Characteristics ◽  
Phase System ◽  
Shear Stresses ◽  
High Moisture ◽  
Tensile Stresses ◽  
Morphology Development ◽  
A Minor ◽  
Multi Phase ◽  
High Moisture Extrusion

Plant-based meat analogues that mimic the characteristic structure and texture of meat are becoming increasingly popular. They can be produced by means of high moisture extrusion (HME), in which protein-rich raw materials are subjected to thermomechanical stresses in the extruder at high water content (>40%) and then forced through a cooling die. The cooling die, or generally the die section, is known to have a large influence on the products’ anisotropic structures, which are determined by the morphology of the underlying multi-phase system. However, the morphology development in the process and its relationship with the flow characteristics are not yet well understood and, therefore, investigated in this work. The results show that the underlying multi-phase system is already present in the screw section of the extruder. The morphology development mainly takes place in the tapered transition zone and the non-cooled zone, while the cooled zone only has a minor influence. The cross-sectional contraction and the cooling generate elongational flows and tensile stresses in the die section, whereas the highest tensile stresses are generated in the transition zone and are assumed to be the main factor for structure formation. Cooling also has an influence on the velocity gradients and, therefore, the shear stresses; the highest shear stresses are generated towards the die exit. The results further show that morphology development in the die section is mainly governed by deformation and orientation, while the breakup of phases appears to play a minor role. The size of the dispersed phase, i.e., size of individual particles, is presumably determined in the screw section and then stays the same over the die length. Overall, this study reveals that morphology development and flow characteristics need to be understood and controlled for a successful product design in HME, which, in turn, could be achieved by a targeted design of the extruders die section.

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