Textural Engineering of Hybrid Meat Systems Using Cellulose Ether and Yeast Protein : 셀룰로오스 에테르와 효모 단백질을 이용한 하이브리드 미트 시스템의 물성 제어 및 공학적 설계

다국어 초록 (Multilingual Abstract)

Hybrid patties have emerged as a sustainable option to reduce meat intake while maintaining product quality. Achieving meat-like performance in such products requires precise control of the ratios and interactions among proteins, fats, and binders. Moreover, polysaccharide-based sources are critical in plant-based food systems because they regulate water/oil retention and viscoelasticity to build a stable matrix. Accordingly, this study aimed to enhance the structural completeness and sustainability of hybrid patties by integrating cellulose-ether–based materials across the protein, fat, and binder components.
In Chapter 1, the mechanical properties and rheological behaviors of HPMC and MC were characterized. HPMC exhibited higher viscosity, stronger structural recovery, and stable viscoelasticity under heating–cooling cycles compared to MC, yet still showed insufficient absolute viscosity and weak mechanical strength. Whereas MC exhibited high hardness, strong viscoelasticity, and solid-like flow behavior, and the MC–AG composite showed excellent thermal and mechanical stability, allowing it to function as a backbone matrix for yeast-protein systems.
In Chapter 2 and 3, yeast protein hydrolyzed by Alcalase and Prozyme 2000P through single and double enzymatic treatments exhibited markedly improved solubility, dispersibility, and structural reactivity. The hydrolysis increased β-sheet content, enhancing structural stability, and achieved high hydrolysis efficiency within a short reaction time. Functional properties were further improved, including higher water and oil retention, greater emulsion stability, and enhanced antioxidant capacity driven by reduced free sulfhydryl groups and increased antioxidant-related amino acids. Based on the WHO-referenced EAA/TAA ratio exceeding 50%, the hydrolysate qualifies as a high-quality protein, confirming its applicability as an alternative protein.
In Chapter 4, bigel emulsion technology was employed to address the low hardness caused by air-bubble formation and the temperature-induced loss of viscoelasticity observed in HPMC in Chapter 1. Incorporating solid coconut oil into the system effectively filled the internal gaps within the HPMC hydrogel, producing an elastic bigel with enhanced hardness and viscoelasticity. The bigel exhibited stable thermo-viscoelastic behavior and maintained mechanical integrity under high-temperature compression without melting. Thus, a heat-stable alternative fat capable of providing meat-like juiciness was successfully developed.
In Chapter 5, the development of a meat-binding adhesive required overcoming the functional limitations of HPMC, including its hydrophilic nature, low adhesion, and slow structural recovery. Inspired by the underwater adhesion mechanism of mussel adhesive proteins, a zein–tannic acid complex was selected to enhance hydrophobicity and interfacial binding through protein–polyphenol interactions. Incorporating this complex into HPMC improved water retention, reduced moisture loss, lowered degradation, and increased surface hydrophobicity, while also providing greater adhesion than neat HPMC even after immersion in water. Moreover, heat treatment dramatically increased the adhesive strength from the MPa to the GPa range, demonstrating that the binder can firmly reinforce meat matrices under high-temperature conditions without structural failure.
Finally, in Chapter 6, hybrid patties were produced by integrating yeast protein (Chapter 2 and 3) supported by an MC–AG backbone matrix (Chapter 1), along with alternative fat (Chapter 4) and binders (Chapter 5). As a result, hybrid patties formulated with 40% yeast protein and 10% alternative fat (50% total substitution) or 15% yeast protein and 5% alternative fat (20% total substitution) exhibited the most comparable mechanical properties to conventional patties, along with enhanced cooking yield and improved color stability. These findings demonstrate that yeast proteins and cellulose-ether-based materials strengthen the structural stability of hybrid patties and contribute to the sustainable development of alternative meat products.

목차 (Table of Contents)

• Background 1
• CHAPTER 1 Mechanical and Rheological Characterization of Hydroxypropyl Methylcellulose and Methylcellulose to Support Textural Design of Hybrid Patty 4
• 1. Introduction 5
• 2. Materials and methods 8
• 2.1 Materials 8
• 2.2 Sample preparation 8
• 2.3 Texture property analysis 9
• 2.4 Compression strength and modulus 9
• 2.5 Rheological properties 10
• 2.5.1 Strain amplitude sweep (LVR) 10
• 2.5.2 Frequency sweep (Viscoelasticity) 11
• 2.5.3 Shear rate sweep (Viscosity) 11
• 2.5.4 Temperature sweep 11
• 2.5.5 Creep and recovery test 12
• 2.5.6 Hysteresis loop test 12
• 2.5.7 Three-interval thixotropy test (3ITT) 12
• 2.6 Statistical analysis 14
• 3. Results and discussions 15
• 3.1 Texture profile analysis of hydroxypropyl methylcellulose (HPMC) and methylcellulose (MC) 15
• 3.2 Rheological analysis of HPMC and MC at varying concentrations under steady and dynamic conditions 18
• 3.3 Thixotropic and structural recovery behavior of HPMC and MC hydrogels 23
• 3.4 Texture profile analysis of HPMC-based composite hydrogels 27
• 3.5 Texture profile analysis of MC-based composite hydrogels 31
• 3.6 Comprehensive TPA evaluation of real processed meats and HPMC- and MC-based composite hydrogels 32
• 3.7 Compression properties of HPMC- and MC-based composite hydrogels 36
• 3.8 Rheological properties of HPMC–polysaccharide hydrogels 42
• 3.8.1 Frequency sweep test 42
• 3.8.2 Flow behavior and yield stress 42
• 3.8.3 Creep–recovery behavior 43
• 3.8.4 Thixotropic recovery (3ITT test) 43
• 3.9 Rheological properties of MC–polysaccharide hydrogels 47
• 3.9.1 Frequency sweep test 47
• 3.9.2 Flow behavior and yield stress 47
• 3.9.3 Creep–recovery behavior 48
• 3.9.4 Thixotropic recovery (3ITT test) 48
• 3.10 Heating–cooling cycle dependent viscoelastic behavior of HPMC- and MC-based composite hydrogels 52
• 4. Conclusion 55
• CHAPTER 2 Characterization of Yeast Protein Hydrolysates by Single Enzyme Treatment for Promising Alternative Protein Source 56
• 1. Introduction 57
• 2. Materials and methods 60
• 2.1 Materials 60
• 2.2 Enzymatic hydrolysis of yeast protein 60
• 2.3 Degree of hydrolysis (DH) 60
• 2.4 Determination of solubility 61
• 2.5 Particle size distribution (PSD) 62
• 2.6 Fourier-transform infrared spectroscopy (FTIR) 62
• 2.7 Composition of free amino acids (AA) 63
• 2.8 Statistical analysis 64
• 3. Results and discussions 65
• 3.1 Protein hydrolysis and pH measurements after protease treatment 65
• 3.2 Analysis of protein solubility 68
• 3.3 Effects of hydrolysis on the particle size 71
• 3.4 Structural changes in yeast protein treated with various enzyme 75
• 3.5 Effects of enzymatic hydrolysis on free Aas 79
• 4. Conclusion 83
• CHAPTER 3 Effects of Double Peptidase Treatment on Properties of Yeast Protein as an Alternative Protein Source 84
• 1. Introduction 85
• 2. Materials and methods 88
• 2.1 Materials 88
• 2.2 Preparation of yeast protein hydrolysate through proteolysis 88
• 2.3 Degree of hydrolysis (DH) 89
• 2.4 Determination of solubility 89
• 2.5 Particle size distribution (PSD) 90
• 2.6 Sodium dedecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) 90
• 2.7 Size exclusion chromatography 91
• 2.8 UV spectra analysis 92
• 2.9 SEM and FTIR 92
• 2.10 Molecular weight distribution 93
• 2.11 ABTS radical scavenging activity 93
• 2.12 Water holding capacity (WHC) and Oil binding capacity (OBC) 94
• 2.13 Emulsifying activity index (EAI) and emulsion stability index (ESI) 95
• 2.14 Protein surface hydrophobicity 96
• 2.15 Determination of SH group levels 96
• 2.16 Composition of free amino acids (AA) 97
• 2.17 Statistical analysis 98
• 3. Results and discussions 99
• 3.1 Analysis of yeast protein solubility and degree of hydrolysis (DH) 99
• 3.2 Gel electrophoretic examination of yeast protein hydrolysate profiles 102
• 3.3 Morphological examination of yeast protein hydrolysates 104
• 3.4 Effects of hydrolysis on the particle size and molecular weight 104
• 3.5 Structural and compositional changes in yeast protein hydrolysates 110
• 3.6 Functional properties yeast protein hydrolysates as an alternative source 117
• 4. Conclusion 122
• CHAPTER 4 Development of Mechanically and Thermally Reinforced HPMC-Based Bigels Incorporating Coconut Oil as Fat Analogues 123
• 1. Introduction 124
• 2. Materials and methods 127
• 2.1 Materials 127
• 2.2 Optimization of bigel composition 128
• 2.2.1 Sample preparation 128
• 2.2.2 Emulsion stability 129
• 2.2.3 3D printability 129
• 2.2.4 Surface lipid exration 130
• 2.2.5 Texture analysis properties (TPA) 130
• 2.2.6 Rheological properties 131
• 2.3 Characterization of optimized bigel compared with real fat 132
• 2.3.1 Rheological properties 132
• 2.3.2 Heating & compression-induced water and oil loss 132
• 2.3.3 TPA at various temperature condition 133
• 2.3.4 Fourier Transform Infrared Spectroscopy (FTIR) 133
• 2.3.5 Thermogravimetric Analysis (TGA) 133
• 2.3.6 Color stability during storage period 133
• 2.3.7 The cycling test of compression 134
• 2.3.8 Oxidative stability (Peroxidase value & TBARS) 134
• 2.4 Statistical analysis 135
• 3. Results and discussions 136
• 3.1 Effects of HPMC content and gel phase ratio on emulsion stability, lipid retention, and printability 136
• 3.2 Effects of HPMC content and gel phase ratio on TPA and rheological properties 142
• 3.3 Rheological properties of emulsion gel and bigel compared with real fats 148
• 3.4 Water and oil retention properties of fat analogues during thermal–compression processing 151
• 3.5 Texture profile analysis (TPA) of natural and HPMC-based fat analogues under the various temperature conditions 153
• 3.6 Fourier Transform Infrared Spectroscopy (FTIR) of HPMC–coconut oil systems 155
• 3.7 Thermal stability and decomposition characteristics of bigel in comparison with pure oils and animal fats 158
• 3.8 Color characterization of HPMC–coconut oil systems 161
• 3.9 Resistance to repeated compression in HPMC–coconut oil bigels 165
• 3.10 Changes in peroxide and TBARS values of HPMC–coconut oil systems during storage 167
• 4. Conclusion 170
• CHAPTER 5 High-Temperature and Moisture-Stable Bioadhesive Hydrogels Reinforced with Zein-Tannic acid Complexes in a HPMC Matrix 171
• 1. Introduction 172
• 2. Materials and methods 175
• 2.1 Materials 175
• 2.2 Preparation of the HPMC/zein-tannic acid composite hydrogels 175
• 2.3 Structural and thermal characterization 177
• 2.4 Water resistance and stability evaluation 177
• 2.4.1 Swelling index 177
• 2.4.2 Degradation behavior under PBS soaking conditions 177
• 2.4.3 Water retention under heating condition 178
• 2.4.4 Water contact angle 178
• 2.5 Mechanical and rheological properties 179
• 2.5.1 Gel strength measurement 179
• 2.5.2 Texture properties analysis (TPA) 179
• 2.5.3 Rheological characterization 179
• 2.5.4 Self-healing behavior 180
• 2.6 Adhesive and functional properties 181
• 2.6.1 Adhesive strength under various condition 181
• 2.6.2 Printability of composite hydrogel inks for 3D printing 181
• 2.6.3 ABTS radical scavenging activity 182
• 2.7 Statistical analysis 183
• 3. Results and discussions 184
• 3.1 Structural interactions in composite hydrogels 184
• 3.2 Enhanced physicochemical stability of composite hydrogels: Thermal resistance, water retention, and surface hydrophobicity 186
• 3.3 Mechanical reinforcement and self-healing behavior of the composite hydrogels 190
• 3.4 Printability characteristics of composite hydrogels 195
• 3.5 Adhesive strength and antioxidant functionality of the composite hydrogels 197
• 4. Conclusion 200
• CHAPTER 6 Application Study:The Formulation of Hybrid Patty 201
• 1. Introduction 202
• 2. Materials and methods 204
• 2.1 Materials 204
• 2.2 Preparation of alternative beef patties using structured adhesive, protein, and fat systems 205
• 2.2.1 Preparation of alternative protein 205
• 2.2.2 Preparation of alternative fat 205
• 2.2.3 Preparation of binder (adhesives) 205
• 2.2.4 Patty formulation and processing 206
• 2.3 Determination of pre-cooking quality characteristics 208
• 2.3.1 Water holding capacity and pH measurement 208
• 2.3.2 Thawing loss 208
• 2.4 Post-cooking properties of hybrid patties 209
• 2.4.1 Cooking loss (%) 209
• 2.4.2 Diameter and tickness change (%) 209
• 2.4.3 Juiciness (%) 209
• 2.5 Color measurement and visuality of patties before and after cooking 210
• 2.6 Texture analysis properties of patties before and after cooling 210
• 2.7 Statistical analysis 211
• 3. Results and discussions 212
• 3.1 Physicochemical properties of raw beef patties before cooking 212
• 3.2 Cooking-induced dimensional changes, cooking loss, and juiciness characteristics 212
• 3.3 Color characteristics of patties before and after cooking 217
• 3.4 Texture profile characteristics of the real patty and alternative patties before and after cooking 221
• 4. Conclusion 224
• Reference 225
• ABSTRACT IN KOREAN 278