The aim of this work is to provide the fundamentals of extrusion. This includes an in-depth understanding of the structure and composition of plant proteins. Based on this, the production of the raw materials is discussed, as this has a great influence on the final product. In the last step, the difference between high moisture extrusion and low moisture extrusion is explained, as well as the general set-up of an extruder.
Table of Contents
1. Introduction and aim of the study
2. Soy protein as meat substitute
2.1. Structure and function
2.2. Protein fractions
2.3. Advantages of soy protein in extrusion
3. Manufacturing processes of protein isolates, concentrates and flours
4. Extrusion process
4.1. Basics of extrusion
4.2. Extruder construction
5. Conclusion and further considerations
Objectives and Topics
This thesis aims to provide a comprehensive understanding of the fundamentals of extrusion technology for the production of plant-based meat alternatives. It examines the structural and compositional properties of soy proteins, the impact of raw material processing on product quality, and the technical mechanisms of both low and high-moisture extrusion systems.
- Fundamentals of protein structure and the impact of denaturation
- Methods for manufacturing soy protein isolates, concentrates, and flours
- Technological differences between low-moisture and high-moisture extrusion
- Technical design, components, and operation of twin-screw extruders
Excerpt from the book
2.1. STRUCTURE AND FUNCTION
Proteins, as macromolecules, play a central role in the functionality of foods and in biological systems. They are composed of amino acids linked by peptide bonds. The sequence of the amino acids determines the unique three-dimensional structure of each protein and its specific function (Khan, Siddiqi, & Salahuddin, 2017). Above a certain molecular weight, or more than 100 amino acids, it is no longer called a polypeptide but a protein (Vasudevan, Sreekumari, & Vaidyanathan, 2011).
Protein molecules take over all important structural and functional work in the body. In addition, from a nutritional point of view, there are two further reasons for the relevance of proteins. On the one hand, a varied diet covers the need for essential amino acids that cannot be synthesized by the human organism itself. For example, a high concentration of vital lysine is found in legumes. On the other hand, the supply of nitrogen ensures the formation of non-essential amino acids. Other nitrogen-containing compounds, such as nucleic acids and creatine, also depend on a regular supply of nitrogen. (Young & Pellet, 1994)
The side groups of the individual amino acids are decisive for the multitude of protein structures with the most diverse properties and functions. These are responsible for the three-dimensional molecular structure of the proteins through various interactions with each other. The basis is the so-called primary structure, thus the linear sequence of amino acids and the position of existing disulfide bonds. (Khan et al., 2017)
Summary of Chapters
1. Introduction and aim of the study: This chapter contextualizes the rising global demand for sustainable protein sources and outlines the thesis's goal to explain the technical fundamentals of soy protein extrusion.
2. Soy protein as meat substitute: This section details the biological significance of proteins, their hierarchical structures, and how soy proteins serve as versatile functional ingredients for meat analogs.
3. Manufacturing processes of protein isolates, concentrates and flours: This chapter analyzes the three main purity grades of soy protein and the specific acid-wash or alcohol-wash methods used to achieve them, highlighting their impact on functional properties.
4. Extrusion process: This section provides a technical breakdown of extrusion technology, comparing low-moisture and high-moisture processes while explaining the mechanical and structural function of extruder components.
5. Conclusion and further considerations: This chapter synthesizes the findings, emphasizing the importance of understanding protein-protein interactions for future advancements in meat substitute production.
Keywords
Soy protein, Extrusion, Meat substitutes, Protein denaturation, Textured vegetable protein, High moisture extrusion, Isoelectric point, Food biotechnology, Plant-based diet, Protein functionality, Twin-screw extruder, Protein isolates, Protein concentrates, Food processing, Rheology
Frequently Asked Questions
What is the primary focus of this work?
The work focuses on the technical and structural fundamentals of using soy protein to produce meat substitutes via extrusion technology.
What are the central thematic fields covered in this thesis?
Key fields include protein biochemistry, industrial manufacturing of protein derivatives (isolates, concentrates), and the mechanical engineering aspects of extrusion processes.
What is the primary research objective?
The goal is to provide an in-depth understanding of how raw material properties and extrusion parameters interact to influence the quality and texture of the final meat substitute product.
Which scientific methods are analyzed in this work?
The thesis analyzes the "trial-and-error" industrial approach to food extrusion and examines the chemical and rheological principles behind protein denaturation and texturization.
What does the main body cover?
The main body covers the hierarchical structure of proteins, the chemical processes for isolating soy proteins, and the technical operation of extruders, including the role of cooling dies in high-moisture extrusion.
Which keywords best characterize this study?
Core keywords include Soy protein, Extrusion, Meat substitutes, Protein denaturation, and Protein functionality.
How does the alcohol-wash method compare to the acid-wash method?
The text notes that protein concentrates produced via acid-wash typically exhibit superior functional properties compared to those produced via alcohol-wash, as the latter utilizes a stronger denaturing agent.
Why is the isoelectric point significant in this study?
Knowledge of the isoelectric point (IEP) is critical for protein solubility analysis, as proteins demonstrate their lowest solubility at the IEP, which can interfere with accurate buffer-based testing.
What is the difference between low and high-moisture extrusion?
Low-moisture extrusion creates porous, expanded structures for rehydration, while high-moisture extrusion utilizes a cooling die to form fibrous, anisotropic structures that resemble muscle meat.
- Arbeit zitieren
- Naomi Albiez (Autor:in), 2021, Production of extruded meat substitutes based on textured soy protein, München, GRIN Verlag, https://www.grin.com/document/1193250
