초록 ▼

○ 연구결과
∙ 4-α-glucanotransferase를 이용하여 맞춤형 쌀전분, 쌀가루 소재의 제조방법을 탐색, 최적화 하고, 그 구조 및 물성을 조사하였다. 또한 제조한 다양한 소재를 떡과 면 제조에 첨가하여, 저장중 품질과 조직감이 향상된 떡과, 냉해동 과정 후에도 조직감과 품질이 유지되는 면을 제조하여, 본 연구에서 제조된 맞춤형 쌀전분, 쌀가루 소재의 응용가능성을 확인하였다.
∙기계적인 텍스쳐 측정 방법과 관능검사를 이용하여, 유통기한내 조직감 향상 및 냉동안정성이 향상된 제품의 제조조건을 확인하였다.
∙

○ 연구결과
∙ 4-α-glucanotransferase를 이용하여 맞춤형 쌀전분, 쌀가루 소재의 제조방법을 탐색, 최적화 하고, 그 구조 및 물성을 조사하였다. 또한 제조한 다양한 소재를 떡과 면 제조에 첨가하여, 저장중 품질과 조직감이 향상된 떡과, 냉해동 과정 후에도 조직감과 품질이 유지되는 면을 제조하여, 본 연구에서 제조된 맞춤형 쌀전분, 쌀가루 소재의 응용가능성을 확인하였다.
∙기계적인 텍스쳐 측정 방법과 관능검사를 이용하여, 유통기한내 조직감 향상 및 냉동안정성이 향상된 제품의 제조조건을 확인하였다.
∙미생물로부터 다양한 탄수화물 효소를 클로닝하고 이의 특성을 밝혀 쌀전분 등 전분의 구조변형에 이용 하였다. 효소 수식 전분의 평균분자량 변화, 가지결합분포 변화 등 구조적 특징을 정밀하고 분석하고 그와 연관된 물성학적 특징을 밝혔다.
∙Amylosucrase를 이용한 효소적 방법 및 citric acid를 이용한 화학적 방법을 통하여 난소화성 및 지소화성 전분의 제조 방법을 탐색 및 최적화하고, 그 구조 및 물성을 조사하였다. 또한, 이를 떡에 적용하여 가공적성을 조사하고 난소화성분이 가공 이후에도 존재함을 확인하여, 본 연구에서 개발된 맞춤형 전분의 응용가능성을 확립하였다.

Abstract ▼

In this study, to develop value-added food materials from rice starch and flour by carbohydrate engineering, first, enzymatically-modified starch and flour depending on treatment conditions (substrate concentrations, enzyme concentrations, treatment time) were prepared. A thermostable 4-α -glucanotr

In this study, to develop value-added food materials from rice starch and flour by carbohydrate engineering, first, enzymatically-modified starch and flour depending on treatment conditions (substrate concentrations, enzyme concentrations, treatment time) were prepared. A thermostable 4-α -glucanotransferase (4αGTase) was used to modify the physical and structural properties of starch. The hysicochemical properties of the modified rice starch and flour were investigated. As enzyme treatment time increased, the weight average molecular weight of rice starch and flour decreased to around 2.28×10sup>4 and the obtained moisture sorption isotherm revealed that the equilibrium moisture contents of 4αGTase-treated rice starches and flours were higher than that of control especially at higher water activity values (Aw > 0.8). The amount of unfrozen water in rice starch and flourmeasured using differential scanning calorimetry increased when starch and flour were modified with 4 αGTase. This result indicated that the 4αGTase-treated starches and flours can be used in the food industry as cryoprotectants. In an attempt to produce high-quality rice cake with prolonged shelf life, rice cake was prepared by two different methods. The first method was to mix enzymes with other ingredients when rice cakes were produced. The second method was to substitute rice flour with the enzymatically-modified rice flours. From this study, results demonstrated that the treatment of rice starch and flour with amylolytic enzymes like TAαGTase, TSαGTase, and BSMA could be successfully applied to the production of Korean traditional rice cakes, Packsulki and Jeungpyun. Treatment of those enzymes resulted in the considerable retardation of starch retrogradation, maintaing desirable textural characteristics of rice cakes. Noodle was also prepared with 5% and 10% addition of enzymatically-modified rice flour, and an increase of the noodle weight gain after cooking resulted. During freeze-thaw cycles, the noodle containing modified rice flour exhibited higher values of hardness, cohesiveness, and chewiness than those of control. The result of this study implied that the modified rice flour could be an effective substituent for improving quality of starchy foods after repeated freeze-thaw cycling. The results of this research could contribute to food industry in several aspects including an increase in diversity of enzyme selection for food production, a unique modification of food texture somewhat specific to enzyme selected, and an expansion of enzyme application to other starchy food production.
Various kinds of carbohydrate-active enzymes from microorganisms were cloned, expressed, and purified. Properties of carbohydrate enzymes were analyzed for the purpose of starch modification. Structure of enzymatically modified starch was analyzed for understanding mechanism of the carbohydrate enzymes. The enzymes modified the structure of rice starch such as average molecular mass and side chain distribution. Relationship between structure and physicochemical properties of rice starch was investigated and could be applied for producing modified starch with desired properties using carbohydrate enzymes.
Starch can be classified into three major fractions, resistant starch (RS), slowly digestible starch (SDS) and rapidly digestible starch (RDS), in nutritional aspects. In this study, enzymatic and chemical means were employed to increase the RS and SDS fractions of rice starch. Amylosucrase (AS; E.C.2.4.1.4) from Neisseria polysaccharea was applied to waxy and normal rice starches. The AS-treated waxy rice starch showed increased SDS fraction (~25%) compared to control. The molecular weights of starches increased and the proportion of long side chains (>DP 20) also increased. The AS-treated starches demonstrated a B-type X-ray diffractogram and showed higher relative crystallinities than those of non-treated starches. The moduli for the gel of AS-treated starches were much larger than those of raw starches indicating increased gel strengths of AS-treated starches. The AS treatment conditions were optimized using response surface methodology. The optimum conditions established, which had the highest SDS and RS fractions, were the treatment with 18700 units of AS per 0.45 gram starch for 13 hours 40 minutes. The AS-treated starch produced under optimum conditions was applied to a rice cake (Baeksulki). Rice flour was partially substituted with AS-treated rice starches at levels of 20, 30 and 40% to prepare rice cakes. The enthalpy values of endothermic peaks of AS-treated rice cakes were lower than that of rice cake without AS-treated starch implying the delays in retrogradation. Citric acid was used to produce resistant starch. The optimum condition established for resistant citrate starch was the treatment with 0.4 g citric acid per gram starch for 6 hours at 150 C. ˚ FT-IR spectra showed C=O bending stretching of citrate starches, indicating the formation of cross-linking by esterification. Morphological characteristics depicted the destruction of granule structure in citrate starches, and loss of birefringence. The resistant citrate starch showed a loss of crystallinity, shortening in side chains, and a decrease in molecular weight. The citrate starch produced under optimum conditions was applied to a rice cake (Baeksulki). Rice flour was partially substituted by citrate waxy rice starch at levels of 10, 20, 30, and 40% to prepare rice cakes. The RS of rice cakes was kept relatively stable during cooking. The textural properties of rice cakes changed with storage time. The hardness and chewiness showed steep decreases with the increase in CS content. The degree of starch retrogradation determined by DSC suggested that the Baeksulki substituted with CS had a significantly lower retrogradation rate than the Baeksulki without CS (p<0.05). The result suggested that the use of CS could effectively inhibit the retrogradation of starch in rice cakes.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 보고서 요약서 ... 3
• 요약문 ... 4
• SUMMARY ... 7
• CONTENTS ... 10
• 목차 ... 16
• 제 1 장 연구개발과제의 개요 ... 22
• 제 1 절 연구개발의 필요성 ... 22
• 1. 기술적 측면 ... 22
• 2. 경제적, 산업적 중요성 ... 23
• 제 2 절 연구의 목적 및 범위 ... 23
• 1. 연구의 목적 ... 23
• 2. 연차별 연구개발의 목표 및 범위 ... 24
• 제 2 장 국내외 기술개발 현황 ... 27
• 제 3 장 연구개발수행 내용 및 결과 ... 29
• 제 1 절 연구내용 ... 29
• 제 2 절 세부과제별 연구수행 결과 ... 30
• 1. 제 1 세부과제 ... 30
• 가. 서론 ... 30
• 나. 연차별 연구방법 및 결과 ... 30
• (1) 1차년도 ... 30
• (가) 재료 및 방법 ... 30
• (나) 연구결과 ... 31
• (다) 1차년도 연구성과 고찰 및 결론 ... 41
• (2) 2차년도 ... 41
• (가) 재료 및 방법 ... 41
• (나) 연구 결과 ... 46
• (다) 2차년도 연구성과 고찰 및 결론 ... 67
• (라) 4αGTase처리쌀가루를 첨가한 떡의관능적특성 조사 ... 68
• (3) 3차년도 ... 75
• (가) 재료 및 방법 ... 75
• (나) 연구결과 ... 77
• 2. 제 2 세부과제 ... 82
• 가. 연차별 연구방법 및 결과 ... 82
• (1) 1차년도 ... 82
• ① 신규 α-GTase의 클로닝 및 발현 ... 82
• ②신규 α-GTase의 생산 ... 83
• ③신규 α-GTase의 특성 ... 83
• (2) 2차년도 ... 89
• ① PfαGT를 이용한 맞춤형 전분의 생산 ... 89
• ② E. coli K12 유래의 Branching enzyme(BE)의 클로닝 및 전분에 대한 효소 특성 연구 ... 94
• ③ BSMA 처리를 통한 찹쌀전분으로부터 맞춤형 전분의 생산 ... 99
• (3) 3차년도 ... 101
• ① 초내열성 말토제닉 아밀레이즈의 클로닝 및 특성 규명 ... 101
• ② 효소의 산업적 이용을 위한 대량생산 체제 구축 ... 111
• 3. 제 3 세부과제 ... 112
• 가. 서론 ... 112
• 나. 연차별 연구방법 및 결과 ... 113
• (1) 1차년도 ... 113
• (가) 재료 및 방법 ... 113
• (나) 결과 ... 114
• (2) 2차년도 ... 119
• (가) 재료 및 방법 ... 119
• (나) 결과 ... 122
• (3) 3차년도 ... 133
• 1) 효소적 방법을 이용한 난소화성 및 지소화성 쌀 전분 제조 조건의 최적화 및 백설기의 품질 특성 ... 133
• 2) 화학적 방법으로 제조한 난소화성 쌀 전분 대체 백설기의 제조 및 특성 규명 ... 140
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 153
• 1. 연구별 연구목표 및 평가착안점 ... 153
• 2. 당초 연구개발목표의 달성도 및 관련분야의 기술발전에의 기여도 ... 154
• 제 5 장 연구개발 성과 및 성과활용 계획 ... 158
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 159
• 제 7 장 참고문헌 ... 161
• 끝페이지 ... 167