배전 공정과 추출 방법이 커피의 이화학적 특성에 미치는 영향
Influence of roasting process and brewing method on the physicochemical characteristics of coffee
- 주제(키워드) 도움말 coffee , roasting process , brewing method , e-nose , physicochemical characteristics
- 발행기관 강릉원주대학교 일반대학원
- 지도교수 도움말 강윤한, 윤정로
- 발행년도 2020
- 학위수여년월 2020. 8
- 학위명 박사
- 학과 및 전공 도움말 일반대학원 식품과학과
- 실제URI http://www.dcollection.net/handler/kangnung/000000010740
- UCI I804:42001-000000010740
- 본문언어 한국어
초록/요약 도움말
In this study, the effects of roasting and extraction methods on the physicochemical and flavor characteristics of coffee extracts were analyzed. In addition to Light, Medium, and Dark roasting with different roasting degree, Scorched, Baked, and Underdeveloped roasting with different green bean input temperatures were analyzed for temperature profiles during roasting. Moisture content, apparent density, color, and weight loss ratio of the roasted beans were measured. In addition, acidity, pH, total phenol content, caffeine, chlorogenic acid, trigonelline, brownness, and antioxidant activity of the extract were investigated. During roasting, regardless of the roasting method, temperature cross-over was observed, which was presumed to occur when heat transfer by convection was insufficient. It was judged that the occurrence of this phenomenon after the first crack was better in terms of the quality of roasted beans than that before the first crack. Monitoring the temperature rise rate (ROR) and the development time ratio (DTR) in the roasting process was judged to be useful as a good indicator for determining whether the roasting proceeds well. As a measure of the degree of roasting, the weight loss ratio and the color of beans have been used traditionally. In this study, the roasting degree based on weight loss ratio or chromaticity was found to be increasing in the order of Light roasting, Scorched, Medium roasting, Underdeveloped, Baked, and Dark roasting. This order was consistent with the orders in which the pH of the coffee extract increased, the total acidity and trigonelline decreased, presumably because the stronger the heat treatment, the easier the decomposition of organic acid and trigonelline. When the correlation coefficient between the weight loss rate and other variables was obtained, the Agtron value of whole bean (-0.9984), and that of ground coffee (-0.9937), the concentration of trigonelline (-0.9641), and chlorogenic acid (-0.9453) were high. Meanwhile, DPPH antioxidant activity decreased in the order of Light roasting, Baked, Underdeveloped, and Medium roasting. Scorched and Dark roasting had the same lowest values. In addition, the order was significantly different from the order due to the increase in the weight loss rate, but was consistent with the brown color intensity of the extract. As a result of electronic nose analysis, extracts with different roasting methods on PCA were separated well except that Scorched overlapped with Medium roasting. In addition, Underdeveloped and Baked were positioned close to each other. Although Scorched and Medium roasting were roasted by different roasting procedures, similar values for various physicochemical properties were obtained. The aim of the present study on the extraction method was to investigate the physicochemical characteristics of hand drip, Aeropress, Espresso, Moka, Mukka and Brikka coffee brews. Espresso showed higher antioxidant activity, total solids, caffeine, chlorogenic acid, total phenolic compounds and trigonelline concentrations with respect to other coffee brews studied. In terms of extraction efficiency, Brikka and Mukka showed higher total solids, caffeine and chlorogenic acid contents whereas Drip coffee brew showed higher trigonelline content than other coffee brews. Based on the aroma profile by e-nose, principle component analysis (PCA) was conducted. Samples were well separated into distinct groups representing their brewing methods. Despite the similarity of brewing principle of Moka and other high temperature brewing methods, i.e., Mukka and Brikka, the location of Moka coffee brew was closer to that of Espresso in PCA, which was consistent with the PCA result conducted by e-tongue.
more목차 도움말
Abstract i
Contents iv
List of figures viii
List of tables x
Ⅰ. 연구 배경 1
Ⅱ. 문헌고찰 3
1. 생두 3
2. 배전 3
3. 추출방법 6
4. 화학적 변화 9
4.1. 카페인 9
4.2. 트리고넬린 9
4.3. 클로로겐산 9
4.4. 탄수화물 10
4.5. 단백질 10
4.6. 향기성분 11
5. 전자코, 전자혀 12
Ⅲ. 연구목적 13
Ⅵ. 배전 조건을 달리한 커피의 이화학적 특성 15
1. 서론 15
2. 재료 및 방법 17
2.1. 실험재료 17
2.1.1. 생두 17
2.1.2. 시약 17
2.2. 실험방법 17
2.2.1. 수분 17
2.2.2. 색도 17
2.2.3. 배전 및 분쇄 18
2.2.4. 중량 손실(Weight loss, %) 18
2.2.5. 발현 시간 비율(Development time ratio, DTR) 19
2.2.6. 겉보기 밀도 19
2.2.7. 추출물의 제조 19
2.2.8. pH, 적정 산도 19
2.2.9. 갈색도 20
2.2.10. 총 페놀 함량 20
2.2.11. DPPH 라디칼 소거능 20
2.2.12. 카페인, 클로로겐산 및 트리고넬린 21
2.2.13. 전자코분석 23
2.2.14. 통계처리 25
3. 결과 및 고찰 25
3.1. 배전 온도 프로파일 25
3.1.1. Turning point 25
3.1.2. 온도 역전 현상 28
3.1.3. 1차 크랙 28
3.1.4. ROR 분석 29
3.1.5. 발현시간 비율 33
3.2. 배전중의 물리적 성질 35
3.2.1. 수분 함량 35
3.2.2. 겉보기 밀도 35
3.3. 원두의 물리적 성질 38
3.3.1. 수분 함량 38
3.3.2. 겉보기 밀도 38
3.3.3. 색도 38
3.3.4. 중량 손실율 40
3.4. 원두 추출물의 이화학적 성질 41
3.4.1. pH 41
3.4.2. 총산도 41
3.4.3. 총페놀 함량 43
3.4.4. 카페인 43
3.4.5. 클로로겐산(5-CQA) 43
3.4.6. 트리고넬린 44
3.4.7. 갈색도 44
3.4.8. DPPH 라디칼 소거능 45
3.4.9. 전자코 45
Ⅴ. 추출 방법을 달리한 커피의 이화학적 특성 52
1. 서론 52
2. 재료 및 방법 54
2.1. 커피 원두 54
2.2. 시료의 제조 54
2.3. 모카포트, Mukka, Brikka의 추출온도 55
2.4. 총고형분 56
2.5. pH, 적정 산도, 색도 56
2.6. 총 페놀 함량 56
2.7. DPPH 라디칼 소거능 57
2.8. 카페인, 트리고넬린 및 클로로겐산 57
2.9. 전자코와 전자혀 분석 57
2.10. 통계처리 58
3. 결과 및 고찰 58
3.1. 원두 분말의 입도분포 58
3.2. 추출온도 및 시간 60
3.3. 총고형분 63
3.4. 총산 66
3.5. pH 66
3.6. 총 페놀 함량 67
3.7. 카페인 67
3.8. 클로로겐산(5-CQA) 68
3.9. 트리고넬린 69
3.10. 색도 69
3.11. DPPH 라디칼 소거능 70
3.12. 전자코 70
3.13. 전자혀 75
Ⅵ. 결론 78
Ⅶ. 참고문헌 80
