항산화 및 Beauty food 활성을 가지는 천연발효종을 이용한 건강기능성 빵 제조 = Functional Properties and Baking Application of a Natural Sourdough Starter for Antioxidant and Beauty Food-Oriented Bread

다국어 초록 (Multilingual Abstract)

This study aimed to elucidate the functional properties of a natural sourdough starter and to provide fundamental data for its application in bread making. Fermentative microorganisms were isolated from the natural sourdough starter and identified using molecular biological techniques. The physiological activities of freeze-dried starter extracts and the quality and sensory characteristics of bread supplemented with the starter were comprehensively evaluated. Based on 16S and 28S rRNA gene sequence analyses, two representative isolates were identified as Saccharomyces cerevisiae and members of the genus Acetobacter . Hot water and 80% ethanol extracts of the freeze-dried natural sourdough starter were prepared at concentrations of 12.5—100 mg/mL to evaluate antioxidant activities. The 80% ethanol extract exhibited significantly higher DPPH and ABTS radical scavenging activities, protection factor (PF), and TBARS inhibitory activity than the hot water extract. To compare skin-related enzyme inhibitory activities, both extracts were prepared at concentrations of 12.5–200 mg/mL. The 80% ethanol extract showed stronger astringent effects, whereas the hot water extract demonstrated greater inhibitory activities against elastase and collagenase. In contrast, hyaluronidase inhibitory activity was comparable between the two extracts. Bread supplemented with 0-30% natural sourdough starter was produced to evaluate its baking applicability. As the starter addition level increased, the pH of the bread decreased, indicating enhanced acid production during fermentation. Texture profile analysis revealed that hardness and springiness were maintained at levels comparable to the control up to 10% starter addition; however, breads containing 20%or more starter exhibited partial softening and reduced textural quality. Sensory evaluation showed that the bread containing 10% starter achieved the highest overall acceptability score (6.92±1.41), and increasing starter levels generally resulted in favorable evaluations of appearance, texture, and flavor attributes. In conclusion, the natural sourdough starter used in this study, characterized by a microbial ecosystem dominated by yeast and acetic acid bacteria, exhibited notable antioxidant activity and inhibitory properties against skin-related enzymes. Considering both physicochemical and sensory qualities, an additional level of approximately 10% was determined to be optimal for bread making. These findings suggest that natural sourdough starters have strong potential as functional ingredients for health-oriented bakery products.

목차 (Table of Contents)

• Ⅰ. 서 론 1
• Ⅱ. 재료 및 방법 3
• 1. 실험 재료 3
• 1.1 천연발효종 실험 재료 3
• 1.2 천연발효종의 제조 3
• 2. 천연발효종 미생물 분석 5
• 2.1. 천연발효종 내 미생물 순수 분리 및 배양 5
• 2.2. 천연발효종 미생물 동정 6
• 3. 천연발효종의 생리활성 검정 7
• 3.1. 천연발효종 동결건조물을 이용한 추출물 제조 7
• 3.2. 천연발효종 동결건조물의 항산화력 측정 8
• 3.2.1. DPPH radical 소거능 8
• 3.2.2. ABTS radical decolorization 8
• 3.2.3. Antioxidant protection factor (PF) 효과 9
• 3.2.4. TBARS 저해 효과 9
• 3.3. 천연발효종 동결건조물의 피부 관련 효소 저해 활성 측정 10
• 3.3.1. Astringent 효과 10
• 3.3.2. Elastase 저해 효과 11
• 3.3.3. Collagenase 저해 효과 12
• 3.3.4. Hyaluronidase 저해 효과 13
• 4. 천연발효종을 함유하는 기능성 빵 제조 및 품질 특성 14
• 4.1. 농도별 천연발효종을 함유하는 식빵의 제조 14
• 4.2. 천연발효종 농도별 제조된 빵의 형태학적 변화 17
• 4.2.1. 천연발효종 농도별 빵의 외관 변화 17
• 4.2.2. 천연발효종 농도별 빵의 발효력 변화 17
• 4.3. 천연발효종 농도별 제조된 빵의 이화학적 변화 18
• 4.3.1. 천연발효종 농도별 빵의 pH 변화 18
• 4.3.2. 천연발효종 농도별 빵의 색차 변화 18
• 4.3.3. 천연발효종 농도별 빵의 기계적 물성 변화 18
• 4.4. 천연발효종 농도별 제조된 빵의 관능평가 19
• 5. 통계처리 19
• Ⅲ. 결과 및 고찰 20
• 1. 천연발효종 미생물 분석 20
• 1.1. 천연발효종 미생물의 배양 관찰 20
• 1.2. PDA 배지를 이용한 미생물의 순수 분리 23
• 1.3 천연발효종 미생물 동정 24
• 2. 천연발효종의 생리활성 검정 비교 26
• 2.2. 천연발효종 동결건조물의 항산화력 비교 26
• 2.2.1. DPPH radical 소거능 비교 26
• 2.2.2. ABTS radical decolorization 비교 27
• 2.2.3. PF 효과 비교 28
• 2.2.4. TBARS 저해 효과 비교 29
• 2.3. 천연발효종 동결건조물의 피부 관련 효소 저해 활성 비교 31
• 2.3.1. Astringent 효과 비교 31
• 2.3.2. Elastase 저해 효과 비교 33
• 2.3.3. Collagenase 저해 효과 비교 34
• 2.3.4. Hyaluronidase 저해 효과 비교 36
• 3. 천연발효종을 함유하는 기능성 빵 제조 및 품질 특성 비교 38
• 3.1. 천연발효종 농도별 빵의 형태학적 변화 비교 38
• 3.1.1. 천연발효종 농도별 빵의 외관 변화 비교 38
• 3.1.2. 천연발효종 농도별 빵의 발효력 변화 비교 40
• 3.2. 천연발효종 농도별 빵의 이화학적 변화 비교 41
• 3.2.1. 천연발효종 농도별 빵의 pH 변화 41
• 3.2.2. 천연발효종 농도별 빵의 색차 변화 42
• 3.2.3. 천연발효종 농도별 빵의 기계적 물성 변화 44
• 3.3. 천연발효종 농도별 빵의 관능평가 47
• Ⅳ. 요 약 51
• Ⅴ. 참 고 문 헌 53
• Abstract 59