황금(Scutellaria baicalensis) 추출물을 이용한 김치의 숙성지연 및 골마지 효모 억제 효과 검증

다국어 초록 (Multilingual Abstract)

Fermentation-Delaying Potential and Inhibitory Effect Against White Colony-Forming Yeasts in Kimchi by Scutellaria baicalensis Extract

Kim, Eun hae
Advisor : Prof. Chung Mi Ja Ph.D.
Department of Food Science and Nutrition, Graduate School of Gwangju University

Kimchi is a naturally fermented food in which fermentation continues during storage and distribution, often resulting in over-ripening characterized by excessive acidification, textural softening, and off-flavor development, particularly under long-term storage and export conditions. This study investigated the effects of Scutellaria baicalensis hot water extract (SBE-HW) on kimchi fermentation and elucidated its fermentation-delaying mechanism through integrated microbiological, physicochemical, and metabolomic analyses. SBE-HW exhibited concentration-dependent antimicrobial and antifungal activities against key lactic acid bacteria (LAB) and white colony-forming yeasts associated with kimchi fermentation. Notably, SBE-HW selectively suppressed the excessive growth and metabolic activity of heterofermentative lactic acid bacteria (Leuconostoc mesenteroides) and surface-growing yeasts without eliminating fermentation. Physicochemical analyses revealed that SBE-HW treatment significantly delayed pH reduction and acidity increase during storage, which corresponded with concentration-dependent suppression of LAB growth. Salinity and total soluble solids remained unchanged among treatments, indicating that the observed fermentation delay was not attributable to physicochemical formulation differences. Targeted metabolite analyses demonstrated that SBE-HW markedly delayed the consumption of fermentable sugars (glucose and fructose) and reduced the accumulation of major fermentation products, including lactic acid, acetic acid, and mannitol. Importantly, heterofermentative metabolites were reduced but not eliminated, suggesting modulation rather than inhibition of heterofermentation. Microbial community analysis further revealed that SBE-HW delayed the typical microbial succession from Leuconostoc mesenteroides to Latilactobacillus indicating controlled fermentation progression. Untargeted GC–MS-based metabolomic analysis confirmed that SBE-HW induced global metabolic shifts in kimchi fermentation. Principal component and partial least squares–discriminant analyses showed that SBE-HW-treated samples maintained metabolomic profiles closer to early fermentation stages even after prolonged storage, reflecting preservation of fermentation substrates and suppression of excessive metabolite accumulation. Overall, this study demonstrates that SBE-HW functions as a fermentation modulator rather than a preservative, selectively regulating microbial growth, metabolic activity, and community succession while preserving the essential characteristics of kimchi fermentation. These findings highlight the potential of SBE-HW as a natural fermentation control agent for improving kimchi quality and stability during long-term storage and export distribution.

목차 (Table of Contents)

• 1. 서론 01
• 2. 재료 및 방법 07
• 2.1. 실험재료 07
• 2.2. 황금(Scutellaria baicalensis) 추출물의 제조· 07
• 2.3. 김치 제조 07
• 2.4. HPLC 분석에 의한 플라보노이드 정량 10
• 2.4.1 분석장비 및 조건 10
• 2.4.2 플라보노이드 정량 방법 12
• 2.5. DPPH 라디칼 소거활성 측정 14
• 2.6. 항균·항진균 활성 평가 14
• 2.6.1 시험균주 14
• 2.6.2 항균·항진균 활성· 14
• 2.7. 김치의 이화학적 품질특성 15
• 2.7.1 pH 및 적정산도 측정 15
• 2.7.2 염도 및 고형분 함량 측정 15
• 2.7.3 김치 양념 색도 측정 16
• 2.8. 유리당 분석 16
• 2.9. 유기산 분석 18
• 2.10. 미생물 분석 20
• 2.10.1 총균수 및 젖산균수 측정 20
• 2.10.2 미생물 군집 분석 20
• 2.11. 대사체 분석 21
• 2.12. 휘발성 유기화합물(VOC) 분석· 24
• 2.13. 골마지(WCFY) 형성 억제 실험 24
• 2.13.1 표면 분사 처리 24
• 2.13.2 혼합 처리 24
• 3. 통계처리· 25
• 4. 결과 및 고찰 19
• 4.1. 황금(Scutellaria baicalensis) 추출 방법에 따른 baicalin, baicalein, wogonin 분석 26
• 4.2. 황금 열수추출물(SBE-HW)의 주요 성분 분석 결과 30
• 4.2.1 황금 열수추출물(SBE-HW)의 DPPH 라디칼 소거 작용 33
• 4.3. 김치 발효에 관여하는 주요 젖산균과 골마지 효모에 대한 황금 열수 추출물(SBE-HW)의 항균, 항진균 활성· 35
• 4.4. 저장기간에 따른 황금 열수 추출물(SBE-HW)처리 김치의 이화학적 품질특성 41
• 4.4.1 pH 및 산도 41
• 4.4.2 염도 및 고형분 함량 44
• 4.4.3 김치 양념의 색도 46
• 4.5. 저장기간에 따른 SBE-HW처리 김치의 유기산 및 유리당 변화 48
• 4.6. 저장기간에 따른 SBE-HW처리 김치의 미생물 수 변화 57
• 4.7. 저장기간에 따른 SBE-HW처리 김치의 미생물 군집 변화 62
• 4.8. 대사체 분석을 통한 대사 경로 변화 65
• 4.9. 휘발성 유기화합물(VOCs) 변화 및 향미 특성· 71
• 4.10. SBE-HW처리 김치의 골마지 억제 효과 검증 74
• 5. 요약 77
• 6. 참고문헌 79