Effects of High Hydrostatic Pressure Treatment on Physicochemical Properties of Rice Flour at Different Moisture Levels

다국어 초록 (Multilingual Abstract)

High hydrostatic pressure(HHP) is one of the non-thermal treatment techniques and can be used to gelatinize starch at a certain pressure. This study investigated the effect of high hydrostatic pressure(HHP) treatment on the physicochemical properties of rice, and investigated the quality characteristics of rice noodles made by HHP treated rice flour according to moisture levels in order to develop new materials for rice processed foods. Rice variety used were Samkwang variety at normal type and Shingil, Misiru, and Hangaru variety at processing type. The moisture content of rice flour was adjusted to 35-55% and treated with HHP treatment at 400-600 MPa. The water absorption capacity, solubility, and swelling power of rice flour according to the moisture levels and HHP treatment tended to increase as the moisture content and pressure increased. The 55% moisture content and 600 MPa treated rice flour of enzymatic hydrolysis and iodine blue value showed similar results for heat treatment. Scanning electron microscope(SEM) was observed low cavity, resulting in a dense structure when the moisture content or pressure is low and that the starch granules collapsed and gelatinized as the moisture content and pressure increased. X-ray diffraction was confirmed that the 23° peak indicating degree of gelatinization decreased with increasing moisture content and pressure. The HHP treated rice noodles made by the Shingil variety had the lowest moisture absorption, volume, cooking loss, and turbidity, so the cooking properties were excellent, but it was not suitable for making noodles due to its low tensile strength and hardness. Misiru and Hangaru was suitable for making noodles due to its improved cooking properties and excellent tensile strength and texture during HHP treatment. The HHP treatment of rice flour were changed that physicochemical properties according to the moisture content and pressure and affects the quality of rice noodles. This changes in properties is thought to be applicable to various foods.

목차 (Table of Contents)

• Contents
• List of tables ⅳ
• List of figures ⅴ
• Abstract ⅶ
• Ⅰ. Introduction 1
• 1. Rice(Oryza sativa.) 1
• 2. Strarch 4
• 3. Gelatinization 8
• 4. High hydrostatic pressure 10
• 5. Objectives 13
• Ⅱ. Materials and Methods 14
• 1. Evaluation of rice flour characteristics treated by HHP 14
• 1.1. Preparation of rice flour 14
• 1.2. High hydrostatic pressure(HHP) treatment 14
• 1.3. Measurement of HHP treated rice flour characteristics 14
• 1.3.1. Measurement of water absorption capacity 14
• 1.3.2. Measurement of solubility 15
• 1.3.3. Measurement of swelling power 15
• 1.3.4. Measurement of reducing sugar 16
• 1.3.5. Measurement of total sugar 16
• 1.3.6. Measurement of α-amylase hydrolysis 17
• 1.3.7. Measurement of iodine blue value 17
• 1.3.8. Measurement of resistant starch 18
• 1.3.9. Scanning electron microscope(SEM) 19
• 1.3.10. Measurement of X-ray diffraction 19
• 1.3.11. Measurement of rapid viscosity analysis(RVA) 19
• 2. Quality characteristics of noodle made by rice flour treated with HHP··· 20
• 2.1. Preparation of rice noodle 20
• 2.2. Measurement of rice noodle characteristics 20
• 2.2.1. Measurment of water absorption 20
• 2.2.2. Measurment of volume 21
• 2.2.3. Measurment of cooking loss 21
• 2.2.4. Measurment of turbidity of soup 21
• 2.2.5. Measurment of tensile strength 22
• 2.2.6. Measurment of texture 22
• 3. Statistical analysis 23
• Ⅲ. Results and Discussions 24
• 1. Characteristics of rice flour treated with HHP 24
• 1.1. Water absorption capacity 24
• 1.2. Solubility 26
• 1.3. Swelling power 28
• 1.4. Reducing sugar 30
• 1.5. Total sugar 32
• 1.6. α-amylase hydrolysis 34
• 1.7. Iodine blue value 36
• 1.8. Resistant starch 39
• 1.9. Scanning electron microscope(SEM) 41
• 1.10. X-ray diffraction 47
• 1.11. Rapid viscosity analysis(RVA) 49
• 2. Characteristics of rice noodle made by rice flour treated with HHP 53
• 2.1. Cooking properties 53
• 2.2. Tensile strength and texture 59
• Ⅳ. Conclusions 63
• Ⅴ. References 65
• SUMMARY IN KOREAN 75