발효기간에 따른 재래누룩의 미생물 천이와 품질특성 변화 = Changes in microbial community analysis and quality characteristics during fermentation of nuruk

다국어 초록 (Multilingual Abstract)

Nuruk has been used as a fermentation starter When brewing alcoholic beverages. since nuruk grows various microorganisms, starch saccharification and other microbial metabolites are produced. Microorganism, saccharification, and other enzymes produced during nuruk production can be said to be the most important factor in the production of traditional liquor by affecting the quality or production of alcohol in the subsequent alcohol fermentation. To date, most studies on nuruk have focused on the quality characteristics of fermented liquor produced with nuruk, and studies on the fermentation characteristics of the nuruk have been insufficient. Therefore, in this study, the purpose of this study was to analyze microbial community and physicochemical properties during the fermentation period of traditional nuruk prepared by a general method.
The moisture content of traditional nuruk gradually decreased from 29.97% to 12.23% and the pH ranged from 6.17 to 6.71, and total acid increased during the fermentation period, showing 0.40%. The amino acid and saccharogenic power, α-amylase, α-glucosidase, and carboxy peptidase activities of traditional nuruk decreased gradually after showing the highest activity on the 7th day of fermentation, and lipase activity showed the highest activity on the 14th day of fermentation. Formic acid, malic acid, and citric acid are the major organic acids of traditional nuruk. As a result of analysis of free amino acid content, a total of 17 free amino acids were detected, and Glycine, Tryptophan, Ethanol amine, and Hydroxylysine were identified as major free amino acids. As a result of analysis of the fungal community according to the fermentation period of the traditional nuruk, the genus Rhizopus occupied 33.90% on the 30th day of fermentation and confirmed that the genus Rhizopus is the dominant species. As a result of analysis of bacterial community according to the fermentation period of traditional nuruk, Bacillus genus occupied 90.10% on the 7th day of fermentation, confirming that Bacillus genus is the dominant species.
Therefore, in this study, it is possible to select an appropriate fermentation date according to the use of the nuruk using the results of analyzing the microbial community and physicochemical properties of the fermentation process of traditional nuruk. In addition, it can be expected to develop indicator components for the quality change of nuruk and to use it for improving and controlling the quality of fermented foods.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 재료 및 방법 4
• 1. 사용 원료 4
• 2. 재래누룩 제조 4
• 3. 재래누룩의 품온 측정 6
• 4. 이화학적 특성 분석 6
• 4-1) 수분함량 6
• 4-2) pH 및 총산 6
• 4-3) 아미노산도 6
• 5. 효소활성 측정 6
• 5-1) 효소활성 분석용 시료조제 6
• 5-2) Saccharification power(SP) 7
• 5-3) α-amylase 7
• 5-4) α-glucosidase 8
• 5-5) Carboxy peptidase 8
• 5-6) Lipase 9
• 6. 유기산 성분 분석 10
• 7. 유리 아미노산 성분 분석 10
• 8. 메타게놈 시퀀싱 11
• 9. 시퀀싱 데이터 분석 11
• 10. 통계처리 12
• Ⅲ. 결과 및 고찰 13
• 1. 이화학적 특성 13
• 1-1) 수분함량 13
• 1-2) pH 및 총산 15
• 1-3) 아미노산도 17
• 2. 재래누룩의 품온 변화 19
• 3. 재래누룩의 효소활성 21
• 3-1) Saccharification power(SP) 21
• 3-2) α-amylase 23
• 3-3) α-glucosidase 25
• 3-4) Carboxy peptidase 27
• 3-5) Lipase 29
• 4. 유기산 성분 분석 31
• 5. 유리 아미노산 성분 분석 35
• 6. 재래누룩의 미생물 다양성 분석 38
• 6-1) 미생물 다양성 분석_진균류 38
• 6-2) 미생물 다양성 분석_세균류 40
• 7. 재래누룩의 미생물 군집 분석 42
• 7-1) 미생물 군집 분석_진균류 43
• 7-2) 미생물 군집 분석_세균류 46
• Ⅳ. 요약 및 결론 49
• Ⅴ. 참고문헌 52