생두 가공법과 등급에 따른 커피의 관능적 품질 특성

다국어 초록 (Multilingual Abstract)

According to the percentage of defective coffee beans, the green coffee sample will be classified in conformity to the established standards in the New York Board of Trade(NYBOT). And one of the most important criteria used for assessing roasted coffee quality is based on sensory analysis and is referred to as cup quality. Therefore, the present study is aimed at an evaluation of physical and chemical attributes both green and roasted coffee and sensory characteristic of roasted coffees of different qualities and processing methods. Natural Coffee, pulped natural coffee and washed coffee samples classified as NY2, NY3/4 and NY4/5 were provide by the coffee farm located in Sul de Minas, Brazil.

1. Green Coffee
Defective beans were physically counted in a sample of 300g of each green coffee samples. The percentage of each type of defective beans increased as grade decreased. Black beans and sour beans were not found in the NY2 grade in all natural, pulped natural and washed coffee samples. Green(immature) and broken beans were found more in washed coffee than natural coffee samples. Insect damage beans were found more in natural coffee than washed coffee samples.
The optimum levels of moisture of the green coffee is 10 to 12 percent. In this study, moisture content of all green coffee samples were between 10 to 11%.
The lowest grade sample(NY4/5) presented the lowest values of density in all natural, pulped natural and washed coffee samples.
Washed coffee sample presented the highest values of lightness and natural coffee sample presented the highest values of redness and yellowness. In washed coffee samples, lightness decreased and redness and yellowness increased as green coffee grade decreased. In natural coffee samples, redness and yellowness decreased and lightness increased as green coffee grade decreased.

2. TDS and pH of the brewed coffee
Washed coffee sample present the lowest values of pH and natural coffee sample present the highest values of pH. It means washed coffee has more acidity than natural coffee.
Natural coffee samples present the highest values of TDS and washed coffee sample present the lowest values of TDS. TDS values of natural coffee sample decreased as green coffee grade decreased And TDS values of washed coffee samples increased as green coffee grade decreased.

3. Sensorial Evaluation
1) Cupping evaluation by expert tasters
Cupping testing was done by expert tasters to determine the actual sensory differences between the processing methods and grades of green coffees.
Natural coffee sample present the highest values of body. Pulped natural coffee sample present the highest values of sweetness and balance attributes. Washed coffee sample present the highest values of acidity and flavor attributes.
Flavor, cleanness, uniformity, aftertaste and overall attributes decreased as green coffee grade decreased in all natural, pulped natural and washed coffee sample.

2) QDA and acceptance of Espresso by trained panels
Espresso testing was done by trained panels to determine the sensory difference between the processing methods and grades of green coffees.
Natural coffee sample present the highest values of cherry-like, sweetness and body attributes. Washed coffee sample present the highest values of acidity and citrus attributes. And pulped natural coffee sample present average characteristics of natural and washed coffee samples.
Fruity, acidity, sweetness and aftertaste attributes decreased as green coffee grade decreased. Green, rio, bitterness, sour and astringency attributes increased as green coffee grade decreased.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1. 연구배경 1
• 2. 연구목적 5
• Ⅱ. 문헌연구 6
• 1. 커피 생두의 가공법 6
• 1.1. 내추럴 커피 6
• 1.2. 펄프드 내추럴 커피 6
• 1.3. 워시드 커피 7
• 2. 커피 생두의 품질 7
• 2.1 커피 생두의 등급 8
• 2.2 결점두 종류 10
• 3. 커피 로스팅 24
• 4. 커피 관능 평가 25
• 4.1 컵핑 25
• 4.2 에스프레소 관능 평가 27
• Ⅲ. 실험 재료 및 방법 28
• 1. 실험 재료 28
• 1.1 커피 생두 28
• 1.2 배전 커피 28
• 2. 이화학적 특성 29
• 2.1 결점두 함량 29
• 2.2 생두의 수분함량, 밀도와 색도 29
• 2.2.1 생두의 수분함량 29
• 2.2.2 생두의 밀도 29
• 2.2.3 생두의 색도 29
• 2.3 추출한 커피의 pH와 고형분 함량 30
• 2.3.1 pH 30
• 2.3.2 고형분 함량 (TDS) 30
• 3. 관능 검사 30
• 3.1 전문가 패널 30
• 3.1.1 패널 선정 30
• 3.1.2 시료 준비 및 방법 30
• 3.2 정량적 묘사분석 및 기호도 검사 37
• 3.2.1 패널 선정 및 훈련 37
• 3.2.2 묘사어 및 평가방법 37
• 3.2.3 시료준비 38
• 3.3 소비자 검사 43
• 3.3.1 패널 선정 43
• 3.3.2 시료 준비 및 방법 43
• 4. 통계방법 43
• Ⅳ. 결과 및 고찰 44
• 1. 이화학적 특성 44
• 1.1 결점두 함량 44
• 1.2 생두의 수분함량, 밀도와 색도 47
• 1.2.1 생두의 수분함량 47
• 1.2.2 생두 밀도 47
• 1.2.3 생두의 색도 50
• 1.3 추출한 커피의 pH와 고형분 함량 53
• 1.3.1 pH 53
• 1.3.2 고형분 함량 (TDS) 53
• 2. 관능 검사 57
• 2.1 전문패널의 컵핑 평가 57
• 2.1.1 가공법에 따른 관능 평가 57
• 2.1.2 등급 분류에 따른 관능 평가 60
• 2.2 정량적 묘사분석 64
• 2.2.2 가공법에 따른 묘사분석 64
• 2.2.3 등급분류에 따른 묘사분석 67
• 2.3 기호도 검사 69
• 2.3.1 가공법에 따른 기호도 69
• 2.3.2 등급분류에 따른 기호도 69
• 2.4 소비자 선호도 72
• 2.4.1 표본의 일반적인 특성 72
• 2.4.2 소비자 선호커피 73
• Ⅴ. 요약 및 결론 75
• 참고문헌 78
• Abstract 83
• 부록 88