밀기울의 압출성형과 효소처리에 의한 이화학적 및 항산화 특성과 제빵·제면에 미치는 영향 = Effects of extrusion and enzyme treatments of wheat bran on the physicochemical and antioxidative properties and its applications for bread and noodle making

다국어 초록 (Multilingual Abstract)

The characteristics of the extruded wheat bran by enzyme treatment were determined by analysis of physicochemical characteristics, rheology, and sensory evaluation. The moisture contents of extruded wheat bran and enzyme treated extruded wheat bran was decreased, water solublity index (WSI) values of which were increased to 20% and 250% as compared to the wheat bran without treatment as control, respectively. In scanning electron microscopy, structural deformation of the cell wall was found due to high pressure and high shear force in extruded wheat bran while untreated wheat bran was smooth. As treatment with enzyme, extruded wheat bran surface was changed to the porous structure. After extrusion and enzyme treatment, soluble dietary fiber was increased from 4.62% to 4.90%, whereas arabinoxylan was increased from 0.32% to 7.14%. DPPH and ABTS also significantly increased. Peak viscosity, trough viscosity, setback viscosity and final viscosity with increase in the addition of different levels of extruded wheat bran (XWB), and enzyme-treated wheat bran (EXWB) had a remarkable downtrend because extrusion and enzyme treatment is likely to be the cause of gradual decrease of value in RVA for XWB blends and EXWB blends. DPPH and ABTS also significantly increased.The springiness value was little bit increased as adding volume of XWB blends and EXWB blends. Hardness, gumminess and chewiness also increased in XWB blends and EXWB blends. Adhesiveness was decreased more values of EXWB blends for noodle (NEXWB) than XWB blends for noodle (NXWB). Volume of bread was decreased depending rate of blending with XWB for bread (BXWB) and EXWB blend (BEXWB) compared control. BEXWB had bigger height than BXWB. Even though, 5% blends of BXWB had acceptable quality for baking of white bread. Lightness of noodle decreased gradually depending on blending rate, and width of downward force in NXWB was greater than blends of NEXWB. As result of changing the physical properties of the bran by extrusion and enzyme treatment, contents of water-soluble dietary fiber content and, antioxidant activity was increased. Five percent (%) of blends for XWB, BEXWB, NXWB and NEXWB was shown to be acceptable compared to control for white bread and noodle. Contents of water-soluble dietary fiber and antioxidant activity of wheat bran was increased and rheological properties of wheat was changed by modified physical properties of wheat bran by extrusion and enzyme treatment

목차 (Table of Contents)

• List of Tables v
• List of Figures vii
• List of Abbreviation viii
• Abstract ix
• Introduction
• 1. Structure and composition of wheat bran 3
• 2. Nutritional benefits of wheat bran 9
• A. Dietary fiber in wheat bran 9
• B. Antioxidative properties of wheat bran 12
• 3. Applications of wheat bran in food processing 13
• A. Extrusion treatment of wheat bran 15
• B. Enzyme treatment of wheat bran 16
• 4. Effect of wheat bran in bread and noodle making 18
• Materials and Methods
• 1.Materials 20
• 2. Physicochemical and antioxidative properties of wheat bran 20
• A. Treatment of wheat bran 20
• 1) Extrusion 20
• 2) Enzyme treatment 21
• B. Physicochemical properties 21
• 1) Distribution of particle size 21
• 2) Water solubility indes (WSI) and water absorption index (WAI) 22
• 3) Scanning electron microscopy (SEM) 22
• 4) Soluble and insoluble dietary fiber 23
• 5) Water soluble arabinoxylan 24
• 3. Antioxidative properties of wheat bran 25
• A. Total flavonoid contents 25
• B. Total polyphenols 25
• C. DPPH radical scavenging activity 25
• D. ABTS radical scavenging activity 26
• 4. Bread and noodle formulated with wheat bran 26
• A. Dough rheology measurement of flour blends with wheat bran used for bread and noodle making 26
• B. Viscosity measurement of flour blends with wheat bran used for bread and noodle making 26
• C. Making bread formulated with wheat bran 27
• D. Making noodle formulated with wheat bran 27
• E. Color measurement of noodle formulated with wheat bran 28
• F. Texture measurement of bread and noodle formulated with wheat bran 28
• G. Sensory evaluation of bread and noodle formulated with wheat bran 29
• 5. Statistical analysis 29
• Results and Discussion
• 1. Physicochemical properties of wheat bran by different treatments 32
• A. WSI, WAI and Color difference of wheat bran by extrusion and enzyme treatment 32
• B. SEM characteristics using extrusion and enzyme treatment 36
• C. Dietary fiber of enzyme treated extruded wheat bran 40
• 1) Soluble and insoluble dietary fiber 40
• 2) Arabinoxylan 41
• 2. Antioxidant properties of enzyme treated extruded wheat bran 44
• A. Total polyphenols and flavonoids 44
• B. DPPH and ABTS 44
• C. Correlation of process parameter of extruded wheat bran 47
• 3. Properties of blend and bread formulated with XWB and EXWB 50
• A. Physicochemical properties of BXWB and BEXWB 50
• B. Bread formulated with wheat bran 54
• 1) Dough rheology measurement of BXWB and BEXWB 54
• 2) Viscosity measurement of of BXWB and BEXWB 57
• 3) Texture measurement of bread formulated with BXWB and BEXWB 60
• 4) Sensory evaluation of bread formulated with BXWB and BEXWB 62
• 4. Properties of blend and bread formulated with XWB and EXWB 67
• A. Physicochemical properties of NXWB and NEXWB 67
• B. Noodle formulated with wheat bran 70
• 1) Dough rheology measurement of NXWB and NEXWB 70
• 2) Viscosity measurement of BXWB and BEXWB 70
• 3) Texture measurement of noodle formulated with NXWB and NEXWB 74
• 4) Sensory evaluation of noodle formulated with NXWB and NEXWB 74
• Conclusion 80
• References 82