J Korean Soc Food Sci Nutr 한국식품영양과학회지 44(4), 579~585(2015) http://dx.doi.org/10.3746/jkfn.2015.44.4.579 오디 (Morus bombycis) 추출물침지커피의품질특성 임현화 1 지석근 1 곽한섭 1,2 엄태길 1,2 김미숙 1,2 이영승 1,2 도재욱 3 유성률 4 최근표 5 정진일 6 정윤화 1,2 1 단국대학교식품영양학과, 2 단국대학교글로벌식품산업연구소 3 Cafe Moi, 4 세명대학교임상병리학과, 5 강원도립대학식품가공제과제빵과 6 국립과학수사연구원식품의약품연구실 Quality Characteristics of Coffee Brewed from Green Beans Soaked in Mulberry (Morus bombycis) Extract Hyun Hwa Lim 1, Seokgeun Ji 1, Han Sub Kwak 1,2, Taekil Eom 1,2, Misook Kim 1,2, Youngseung Lee 1,2, Jae Wook Do 3, Sungryul Yu 4, Geun Pyo Choi 5, Jin Il Jeong 6, and Yoonhwa Jeong 1,2 1 Department of Food Science and Nutrition and 2 Institute of Global Food Industry, Dankook University 3 Cafe Moi 4 Department of Clinical Laboratory Science, Semyung University 5 Department Food Processing and Bakery, Gangwon Provincial College 6 Food & Drug Analysis Section, National Forensic Service ABSTRACT The objective of this study was to investigate the quality characteristics of coffee soaked in Morus bombycis extract. Green coffee beans were soaked in M. bombycis extract for 2, 4, and 6 hours (sample codes: 2H, 4H, and 6H) at 4 C. Soaked green beans were dried and roasted for coffee extraction. Two controls, roasted with the same amount of heat (C1) and showed the same weight after roasting (C2), were used. Physicochemical characteristics (ph, total acidity, color, browning index, and total soluble solids), DPPH free radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total polyphenol content (TPC), and total flavonoid content (TFC) were investigated. Lower ph and higher total acidity were observed in 2H, 4H, and 6H (P<0.05), supporting evidence of sour taste. There were significant differences in DPPH between the controls (45.51 47.02%) and samples (50.67 55.25%, P<0.05), although 2H and 6H did not show significantly higher DPPH than the controls. 2H, 4H, and 6H showed significantly higher FRAP values (0.320 0.331 FeSO 4 7H 2O mm FeSO 4/g) than controls (0.265 0.271 mm FeSO 4/g). ORAC values of samples [1,062.86 1,153.68 mm trolox equivalent (TE)/g] were significantly higher than those of controls (689.40 942.12 mm TE/g). 2H, 4H, and 6H showed significantly higher TPC [24.27 26.07 mg gallic acid equivalent (GAE)/g] and TFC [3. 4.28 mg quercetin equivalent (QE)/g] than controls (19.79 22.77 mg GAE/g and 1.07 1.95 mg QE/g, respectively) (P<0.05). M. bombycis extracts soaked into green coffee beans showed polyphenol compounds from green coffee beans. Consumer acceptance of 4H (5.12) was the highest, followed by C2 (4.92). C1 (4.14) showed the lowest consumer acceptance. Consumers were segmented into two groups, those who preferred M. bombycis extract-soaked coffee (approximately 61%) and controls (approximately 39%). Key words: coffee, Morus bombycis, antioxidant, polyphenol, consumer acceptance 서 우리나라는커피를매년 10만톤이상을수입하는세계 10대커피수입국중하나이다 (1). 커피는기호식품으로소비되고있으며, 다량의항산화물질을포함하고있는것으 Received 2 December 2014; Accepted 26 January 2015 Corresponding author: Yoonhwa Jeong, Department of Food Science and Nutrition, Dankook University, Yongin, Gyeonggi 448-701, Korea E-mail: yjeong@dankook.ac.kr, Phone: +82-31-8005-3176 론 로보고되어왔다 (2). 커피의향및향미성분뿐만아니라커피의기능성에관한다양한연구도전세계적으로진행되어오고있다. Hečimović 등 (3) 은로스팅정도에따른 Arabica 및 Robusta의총폴리페놀과카페인함량을비교분석하였고, Parras 등 (4) 은 14종의커피를 3가지추출법을이용하여항산화활성비교를하였다. Kim 등 (5) 은우리나라시판아메리카노한잔의총폴리페놀함량이 63.83~ 110.12 mg gallic acid 상당량이라고보고하였다. 한국의전통적인산업중하나였던양잠산업은시장이개방된이후중국등과의원가경쟁력에서밀려산업이축소
580 임현화 지석근 곽한섭 엄태길 김미숙 이영승 도재욱 유성률 최근표 정진일 정윤화 되었다. 그러나양잠산업의부산물로여겨지던뽕나무의열매인오디가최근에는웰빙식품으로주목을받으면서생산량이증가하고있다. 국내오디생산량은 2007년 2,050톤에서 2011년 6,2톤으로 4년사이에 3배이상생산량이증가하였고, 지속적인증가가예상되고있다 (6-8). 오디는 anthocyanin 함량이포도보다높고 (9), 혈소판응집억제, 항산화및항염증에효과가있는 resveratrol이다량함유되어있으며 (10), 또한오디추출액에알코올분해능이있다는연구가보고되었다 (11). Kim 등 (12) 은 10종의오디를이용하여발효주를제조한후그품질특성을보고하였고, Moon 등 (13) 은오디착즙액을젤리에적용하여오디착즙액의양이증가할수록젤리의총폴리페놀함량증가를보고하였다. Kim(14) 은오디착즙액을식혜에적용하여사용량이증가할수록높은항산화활성을보였다고보고하였으며, Lee와 Choi(15) 는오디농축액을머핀에적용하여물첨가량의 10~15% 를오디추출액으로대체시소비자기호도를높일수있다고보고하였다. 커피는대부분커피자체를추출하여마시거나설탕, 커피크림등을첨가하여마시는음료이다. 커피에추가적으로다른소재를이용하여기능성, 기호도를높인커피음료에관한연구는미비한편이다. Andueza 등 (16) 은설탕과커피를함께로스팅하여 Torrefacto coffee를제조하고항산화활성에관하여보고하였다. Kim 등 (17) 은커피를둥글레와함께로스팅하고커피양, 둥글레의양및로스팅온도를변수로사용하여반응표면분석법을적용한후최적의소비자기호도에맞는로스팅조건을보고하였다. 또한 Choi 등 (18) 은로스팅커피에홍삼분말을첨가하여추출한커피추출액의항균및항산화에관한연구를보고하였다. 본연구에서는커피음료의다양화와품질향상을위하여오디추출액을커피에적용하여커피의쓴맛을감소시키고신맛을높여커피의기호도를향상시키며항산화활성을가진기능성커피를제조하여품질특성을조사하였다. 재료및방법실험재료생두는브라질 Minas 지역에서수확된 Arabica 품종 (Brazil Ipanema Euro, 수입원 : Koiners International Co., Ltd., Bucheon, Korea) 을구입하여사용하였다. 오디는전북고창에서수확된냉동오디 (Gochangnonghyup, Gochang, Korea) 를대형마트 (Hanaro mart, Nonghyup, Seoul, Korea) 에서구입하여사용하였다. Folin-Ciocalteu reagent, gallic acid, aluminum nitrate, potassium acetate, quercetin, 1,1-diphenyl-2-picrylhydrazyl, ascorbic acid, FeCl 3, FeSO 4 7H 2O(iron(Ⅱ) sulfate heptahydrate), trolox, 2,2'-azobis(2-amidino-propane)dihydrochloride, fluorescein sodium은 Sigma-Aldrich사 (St. Louis, MO, USA) 에서구입하였고, 2,4,6-tri(2-pyridyl)-1,3,5-triazine은 Tokyo Chemical Industry Co.(Tokyo, Japan) 에서, ethanol, dimethyl sulfoxide는 Junsei Chemical Co. (Tokyo, Japan) 에서, sodium carbonate는 Showa Chemical Industry Co.(Tokyo, Japan) 에서구입하여사용하였다. 오디추출액및오디침지커피제조냉동오디를상온에서해동후에분쇄기 (BLIXER 5 Plus Blixer, Robot Coupe, Ridgeland, MS, USA) 로분쇄한후 1:10(w/v) 의비율로물을첨가하였다. 가열하여용액이끓기시작하면 5분후가열을중지하였다. 상온에서 60분간냉각후 150 150 μm 표준체로걸러진부분만을추출액으로사용하였다. 생두 200 g을오디추출액 500 ml에넣어 4 C에서침지하였다. 생두를 2, 4, 6시간동안오디추출액에침지한후체를이용하여생두와오디추출액을분리하였다. Dry oven(50 C) 을사용하여오디침지생두를건조하였으며, 초기생두무게 (200 g) 와비슷한수준의범위 (200 ~203 g) 까지건조하였다. 로스팅및추출건조가완료된생두를소형직화식로스터 (KN-8828P- 2K, Hottop USA, Cranston, RI, USA) 를사용하여로스팅을하였다. 로스터를가열하여 C에서생두를투입하고최대화력으로 12분간로스팅을한후, 2분간팬의강도를중간으로하여온도상승을억제하면서로스팅을하였다. 로스팅이완료된원두는상온에서냉각한후 3일간 15 C에서보관하였다. 대조군1(C1) 은오디침지원두와동일한로스팅조건에서로스팅을하였으며, 대조군2(C2) 는오디침지원두와최종무게를동일하게맞추기위해총로스팅시간을 30초줄여서로스팅하였다. 오디침지커피의시료번호는침지시간 (2, 4, 6시간 ) 에따라각각 2H, 4H, 6H로표기하였다. 대조군및실험군의로스팅조건, 최종무게, 배출온도는 Table 1과같다. 로스팅 3일후자동식커피용분쇄기 (KG79, DeLonghi, Milano, Italy) 로사용하여가장고운분쇄도로원두를분쇄한후 710 710 μm 표준체를통과한분쇄원두를추출에사용하였다. 추출은 solid-liquid ex- Table 1. Roasting conditions of two control and three Morus bombycis soaked green coffee beans Condition C1 1) C2 2H 2) 4H 6H Initial weight (g) Final weight (g) Roasting time (min) Initial temperature ( C) Final temperature ( C) 159.0 198 170.2 13.5 192 168.0 189 168.0 186 167.8 186 1) C1 and C2 meant control 1 and control 2, respectively. C1 was roasted with same condition of 2H, 4H, and 6H samples. C2 was roasted to the similar weight of 2H, 4H, and 6H with same heat capacity but 30 second shorter. 2) 2H, 4H, and 6H meant sample codes of 2, 4, and 6 soaking hours in Morus bombycis extract at 4 C.
오디 (Morus bombycis) 추출물침지커피의품질특성 581 traction 방법 (19) 으로하였다. 분쇄된원두 30 g에증류수 300 ml를넣은후 98 C 항온수조에서 10분동안 100 rpm 속도로교반을하여추출한후원심분리 (6,500 g) 하고, 상층액을여과지 (No 2, Advantec, Tokyo, Japan) 로감압여과하여사용하였다. ph 및총산함량측정여과된추출액을 ph meter(orion 3 star, Thermo Fisher Scientific Inc., Waltham, MA, USA) 로 ph를측정하였다. 총산함량은추출액 10 ml를 0.1 N NaOH로적정하고소비된 NaOH의 ml 수를 0.05% 초산상당량으로환산하였다. 측정하였다. Gallic acid를 0~1,000 μg/ml의농도로제조하여시료와동일한방법으로얻어진검량곡선 (R 2 =0.998) 을통해시료의총폴리페놀함량을 gallic acid 상당량 (mg gallic acid equivalent(gae)/g) 으로나타내었다. 총플라보노이드함량측정총플라보노이드함량은건강기능식품공전상의방법 (25) 을이용하여측정하였으며, quercetin을표준물질로사용하여 0~180 μg/ml의농도범위에서얻어진표준검량선 (R 2 = 0.997) 을사용하여 quercetin 상당량 (mg quercetin equivalent(qe)/g) 으로나타내었다. 색도측정색도는오디침지추출액 (3 ml) 을색도계 (JC-801S, Color Techno System Co., Tokyo, Japan) 를사용하여 L 값 ( 명도 ), a값 ( 적색도 ), b값 ( 황색도 ) 으로나타내었다. 갈색도 (browning index) 측정갈색도는여과한커피추출액을 40배로희석한후 spectrophotometer(ultrospec 2100 pro, Biochrom Ltd., Cambridge, UK) 를사용하여 420 nm에서흡광도로측정하였다 (20). 가용성고형분함량측정가용성고형분함량은굴절당도계 (Master-M, ATAGO Co., Tokyo, Japan) 를이용하여측정하였고 Brix로나타내었다. DPPH radical 소거활성측정 DPPH(1,1-diphenyl-2-picrylhydrazyl) radical 소거활성은 Blois(21) 방법을변형하여사용하였으며, 아래의식을이용하여활성도를나타내었다. DPPH radical scavenging activity (%)= control Abs-(sample Abs-blank Abs) 100 control Abs Ferric-reducing antioxidant power(frap) 측정 Benzie와 Strain(22) 의방법을변형하여 FRAP를측정하였다. FRAP는표준물질인 FeSO 4 7H 2O 표준곡선 (R 2 = 0.997) 을작성하여커피 1 g의환원력 (mm FeSO 4/g) 으로나타내었다. Oxygen radical absorbance capacity(orac) 측정 ORAC는 Ou 등 (23) 의방법을사용하여측정하였으며, ORAC value(µm trolox equivanent(te)/g) 로나타내었다. 총폴리페놀함량측정총폴리페놀함량은 Folin-Dennis 방법 (24) 을변형하여 소비자기호도조사소비자기호도조사는커피를월 1회이상마시는 51명의단국대학교학생 (19~27세, 남 10명, 여 41명 ) 을대상으로진행하였다. 패널은 9점척도 (1= 매우많이싫어함, 5= 좋지도싫지도않음, 9= 매우많이좋아함 ) 를정확하게이해하도록교육을받았으며, 전반기호도및색상기호도, 향기호도, 커피맛기호도, 쓴맛기호도, 신맛기호도를평가하였다. 시료의제시는 Wakeling과 MacFie(26) 의방법을사용하여 5개의커피시료간발생하는영향을최소화하였다. 추출은상업용에스프레소추출기 (Faema E98, Faema, Milan, Italy) 를이용하였다. 커피 14 g을포터필터에넣고, 약 10 kg의힘으로탬핑후 9기압 98 C의수증기로 60 ml 추출하였다. 추출된시료에정수된뜨거운물 (98 C) 을 5배가수후보온병에보관하였다. 패널에게시료를제공하기직전보온병에있는커피추출액을종이컵에옮겨제공하였다. 20 ml의시료를 190 ml 의종이컵에제공되었으며, 시료의온도변화를최소화하고자종이컵을두겹으로하였다. 시료의취식후생수 (Baeksansu, Nongshim, Seoul, Korea) 를제공하여시료를평가한후입안을헹구도록하였다. 소비자조사실의온도는 24 C로유지되었으며, 조명은형광등을이용하였다. 통계분석모든이화학분석은 3회반복하였으며통계분석은 XLSTAT(version 2012, Addinsoft, Paris, France) 를사용하였다. 이화학적특성, 항산화활성, 총폴리페놀함량, 총플라보노이드함량, 소비자기호도는시료를독립변수로하여일원분산분석 (1-way analysis of variance, ANOVA) 을실시하였다. 시료간의유의차 (P<0.05) 가나타날경우 Fisher s least significant different(lsd) test를실시하여어떠한시료사이에유의차가있는지를분석하였다. 소비자들이시료에대해서어떠한기호도경향성을보이는지군집으로나누어분석하고자소비자전반기호도를이용하여군집분석 (agglomerative hierarchical clustering analysis) 을실시하였다.
582 임현화 지석근 곽한섭 엄태길 김미숙 이영승 도재욱 유성률 최근표 정진일 정윤화 Table 2. Physicochemical characteristics of two control and three Morus bombycis soaked coffee bean extracts Sample 1) ph Total acidity (%) Brix Browning index C1 C2 2H 4H 6H 5.70 b2) 6.03 a 5.13 c 5.06 d 5.00 e 0.65 c 0.46 d 1.19 b 1.27 a 1.28 a 2.80 b 2.97 a 2.57 d 2.70 c 2.47 e 0.340 b 0.388 a 0.250 c 0.232 d 0.228 d Color L a b 12.92 c 11.87 d 15.10 b 15.36 a 15.18 ab -0.16 b -1.59 c 3.47 a 3.41 a 3.24 a 6.12 c 4.86 d 9.68 b 10.27 a 10.08 ab 1) C1 and C2 meant control 1 and control 2, respectively. C1 was roasted with same condition of 2H, 4H, and 6H samples. C2 was roasted to the similar weight of 2H, 4H, and 6H with same heat capacity but 30 second shorter. 2H, 4H, and 6H meant sample codes of 2, 4, and 6 soaking hours in Morus bombycis extract at 4 C. 2) Different letters within a column meant significant differences at P<0.05 by Fisher s least significant difference test. 결과및고찰이화학적특성대조군 (C1, C2) 및오디추출액침지커피 (2H, 4H, 6H) 의 ph, 총산함량, 가용성고형분함량, 갈색도및색도는 Table 2와같다. 오디추출액침지커피와동일한조건으로로스팅한 C1의 ph는 5.70, 유사한최종무게를가지는 C2 의 ph는 6.03이었다. ph는 2H에서 5.13, 6H에서 5.00으로오디추출액에생두침지시간이길어질수록낮아졌다. 이는생두침지시간이길수록생두에오디추출액의유기산이더많이흡수된것으로보인다. Kim(14) 은오디를첨가한식혜의품질특성에관한연구에서오디의함량이늘어날수록 (0~30%) ph가감소 (4.58~5.78) 하였다고보고하였으며, Lee(7) 는오디농축액을첨가한머핀에관한연구에서오디의함량이늘어날수록 (0~25%) ph가감소 (7.46~6.06) 됨을보고하여본연구결과와유사하였다. 총산함량은 ph와반비례하였으며 C2에서가장낮았다 (0.46%). 오디커피의총산함량은실험군인 2H에서 1.19 %, 4H에서 1.27%, 6H에서 1.28% 로 C1보다약 1.9배, C2 보다약 2.8배높았다. 2H의총산함량은 4H와 6H의총산함량보다유의적으로낮았다 (P<0.05). 오디추출액침지커피 ( 실험군 ) 가대조군보다 ph가낮고총산함량이높기때문에오디침지커피의신맛에영향을미쳤다고생각된다. 가용성고형분함량은오디침지커피 (2H, 4H, 6H) 가 2.47~2.57 Brix였으며, 대조군 (C1, C2) 보다유의적으로낮았다 (P<0.05). 커피생두를오디추출액에침지하는동안커피생두내의환원당, 아미노산등가용성고형분중일부가유출되었을가능성이있다 (27). 또한침지후건조과정에서커피생두의조직에변화가있어서로스팅후에오디침지커피내부의다공성정도가대조군보다낮아서추출시가용성고형분이덜추출되었을가능성이있다. 오디침지커피 (2H, 4H, 6H) 의 L, a, b 값은대조군보다유의적으로높았다 (P<0.05). 오디침지커피의색상의명도, 적색도, 황색도가더높은것으로나타났다. 오디침지과정에서오디추출액이커피생두내부로침투해들어가서커피의로스팅후에오디추출액색상의영향으로커피추출액의명도, 적색도, 황색도가높게나온것으로보인다. 갈색 도는대조군인 C1, C2가각각 0.340과 0.388이었으며오디침지커피는대조군보다유의적으로낮았다 (0.228~0.250) (P<0.05). 대조군과오디침지커피간의갈색도차이는커피생두의환원당, 아미노산등의성분이오디추출액에침지하는동안빠져나가커피로스팅시 Maillard 반응이덜일어나게되어오디침지커피의갈색정도가낮게나타난것으로보인다 (27). 항산화활성대조군 (C1, C2) 과오디침지커피 (2H, 4H, 6H) 의 DPPH 라디칼소거능, FRAP, ORAC 값은 Table 3과같다. DPPH 라디칼소거능은대조군 C1 및 C2에서각각 45.51% 와 47.02%, 실험군 2H, 4H 및 6H에서각각 55.25%, 52.88%, 50.67% 였다. 오디침지커피가대조군보다 DPPH 라디칼소거능이높았다 (F=8.22, P=0.003). C1과 C2의 FRAP는각각 0.265 및 0.271 mm FeSO 4/g이었으며, 오디침지커피는대조군보다유의적으로높았다 (0.320~0.331 mm FeSO 4/ g). 이는침지과정에서생두에오디의항산화물질이흡수되어항산화활성이높아진것으로판단된다 (F=79.96, P< 0.001). 그러나오디침지커피 (2H, 4H, 6H) 사이에침지 Table 3. DPPH radical scavenging activity, ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) of two control and three Morus bombycis soaked coffee bean extracts Sample 1) DPPH (%) C1 C2 2H 4H 6H 45.51±1.57 e2) 47.02±0.18 cd 55.25±0.95 a 52.88±0.96 ab 50.67±0.85 bc FRAP (FeSO 4 7H 2O μmol/g) 0.265±0.001 b 0.271±0.004 b 0.331±0.012 a 0.320±0.002 a 0.326±0.005 a ORAC (mm TE/g) 3) 689.40±17.59 d 942.12±21.68 c 1,062.86±10.26 b 1,153.68±7.39 a 1,124.89±36.20 a 1) C1 and C2 meant control 1 and control 2, respectively. C1 was roasted with same condition of 2H, 4H, and 6H samples. C2 was roasted to the similar weight of 2H, 4H, and 6H with same heat capacity but 30 second shorter. 2H, 4H, and 6H meant sample codes of 2, 4, and 6 soaking hours in Morus bombycis extract at 4 C. 2) Different letters within a column meant significant differences at P<0.05 by Fisher s least significant difference test. 3) TE meant trolox equivalent.
. 오디 (Morus bombycis) 추출물침지커피의품질특성 583 시간에따른항산화활성의유의적인차이는없었다 (P> 0.05). 오디침지커피의 ORAC 값이대조군보다높았다 (F= 203.11, P<0.001). 4H에서원두 1 g당 1,153.68 mm TE로가장높게측정되었으며, 6H에서 1,124.89 mm TE/g으로두번째로높은값을가졌으나두실험군간에유의적인차이는없었다 (P>0.05). C1의 ORAC 값이가장낮았으며, C2 는 942.12 mm TE/g으로 C1보다 ORAC 값은높았으나오디침지커피 ( 실험군 ) 와비교해서유의적으로낮았다 (P< 0.05). 위결과는오디추출액침지를통하여커피의항산화활성이증가되었다는것을보여준다. 기존의오디를첨가하여가공한식혜, 모닝빵, 젤리, 초콜릿, 샐러드드레싱에서의첨가량증가에따라서대조군대비항산화능력이증가한연구결과와유사하였다 (13,14,28-30). 그러나침지시간에따른항산화활성은일정한경향을나타내지는않았다. DPPH 라디칼소거능은침지시간이길어짐에따라감소하였으며, ORAC 값은 4H에서가장높은수치를보여주었다. 총폴리페놀함량및총플라보노이드함량대조군 (C1, C2) 과오디침지커피 (2H, 4H, 6H) 의총폴리페놀함량은 Fig. 1과같다. C1과 C2의총폴리페놀함량은 19.79 mg GAE/g 및 22.77 mg GAE/g으로오디침지커피보다낮았다 (P<0.05). 2H 및 4H의총폴리페놀함량은각각 26.06 및 26.07 mg GAE/g이었으며전체시료중가장높았다. 오디추출액을첨가한젤리의총폴리페놀함량이대조군보다유의적으로높은연구결과와유사하였다 (13). 그러나 6H의총폴리페놀함량은 24.27 mg GAE/g으로 2H 와 4H보다유의적으로낮았다 (P<0.05). 이는장시간침지시커피내부의폴리페놀이오디추출액으로빠져나가는것으로추측된다. 이러한경향은 4H와 6H의가용성고형분함량의변화와일치하였다. 대조군과오디침지커피의총플라보노이드함량은 Fig. Total flavonoid content (mg QE/g) 5 4 3 2 1 0 1.07d 1.95c 3.b 4.13a 4.28a C1 C2 2H 4H 6H Fig. 2. Total flavonoid contents of two control and three Morus bombycis soaked coffee bean extracts. Total flavonoid content of the coffee extract was presented as quercetin equivalent (mg QE)/g of roasted coffee. Roasting conditions and sample labels were referred to Table 1. Different letters meant significant differences at P<0.05 by Fisher s least significant difference test. 2와같다. C1과 C2의총플라보노이드함량은 1.07 mg QE/ g 및 1.95 mg QE/g 으로커피자체에도일정수준의총플라보노이드가함유되어있는것으로생각된다. 2H, 4H 및 6H 의총플라보노이드함량은각각 3., 4.13, 4.28 mg QE/g 이었다. 오디추출액의플라보노이드가생두에침투된것으로여겨진다. 소비자기호도조사소비자기호도조사결과는 Table 4와같다. 시료간에전반기호도는유의적인차이가있었다 (F=3.49, P=0.009). 4H에대한기호도가 9점만점중 5.12점으로가장높았으며, C2가 4.92로그뒤를이었고 C1이 4.14로가장낮았다. 색상에대한기호도는 2H, 4H, C2 순서로높았으며, 6H 및 C1보다유의적으로높았다 (F=0.86, P<0.001). 풍미에대한기호도는 C2가 5.16점으로가장높았으며, C1이 4.08 점으로가장낮았다 (F=3.78, P=0.005). 오디침지커피는 Total polyphenol content (mg GAE/g) 30 25 20 15 10 5 0 19.79d 22.77c 26.06a 26.07a 24.27b C1 C2 2H 4H 6H Fig. 1. Total polyphenol contents of two control and three Morus bombycis soaked coffee bean extracts. Total polyphenol content of the coffee extract was presented as gallic acid equivalent (mg GAE)/g of roasted coffee. Roasting conditions and sample labels were referred to Table 1. Different letters meant significant differences at P<0.05 by Fisher s least significant difference test. Table 4. Consumer acceptance ratings (n=51) of two control and three Morus bombycis soaked coffee bean extractss Acceptance Sample 1) C1 C2 2H 4H 6H Overall quality 2) 4.14 b 4.92 a 4.78 ab 5.12 a 4.59 ab Color Aroma Flavor Sourness Bitterness 4.39 c 5.43 ab 5. a 5.53 ab 4.90 bc 4.88 5.37 5.29 5.29 5.10 4.08 b 5.16 a 4.57 ab 4.80 ab 4. ab 4.65 5.06 4.65 4.57 4.67 3.69 b 4.69 a 4.69 a 5.25 a 4.61 a 1) C1 and C2 meant control 1 and control 2, respectively. C1 was roasted with same condition of 2H, 4H, and 6H samples. C2 was roasted to the similar weight of 2H, 4H, and 6H with same heat capacity but 30 second shorter. 2H, 4H, and 6H meant sample codes of 2, 4, and 6 soaking hours in Morus bombycis extract at 4 C. 2) Different letters within a column meant significant differences at P<0.05 by Fisher s least significant test.
584 임현화 지석근 곽한섭 엄태길 김미숙 이영승 도재욱 유성률 최근표 정진일 정윤화 Table 5. Consumer segmentation by agglomerative hierarchical clustering analysis (AHC) of overall quality ratings for two control and three Morus bombycis soaked coffee bean extracts Cluster Panelist C1 1) C2 2H 4H 6H 1 31 3.23 c2) 4.52 b 5.23 ab 5.39 a 4.65 ab 2 20 5.55 a 5.55 a 4.10 b 4.70 ab 4.50 ab 1) C1 and C2 meant control 1 and control 2, respectively. C1 was roasted with same condition of 2H, 4H, and 6H samples. C2 was roasted to the similar weight of 2H, 4H, and 6H with same heat capacity but 30 second shorter. 2H, 4H, and 6H meant sample codes of 2, 4, and 6 soaking hours in Morus bombycis extract at 4 C. 2) Different letters within a row meant significant differences at P<0.05 by Fisher s least significant difference test. 4.57~4.80으로 C2보다낮았으며유의적인차이는없었다 (P>0.05). 쓴맛에대한기호도 (F=7.53, P<0.001) 는시료사이에유의차가있었으며 C1이가장낮았다. 오디침지커피의쓴맛은커피생두를동일한조건에서로스팅하였을때보다낮았다. 그러나동일한무게 (C2) 로로스팅한시료와유의적인차이가없었다 (P>0.05). 이는동일한조건으로로스팅시오디침지커피의쓴맛기호도가높은것으로여겨진다. 향에대한기호도 (F=0.746, P=0.56) 와신맛에대한기호도 (F=1.186, P=0.32) 는시료간유의차가없었으며, 이는소비자기호도의차이가없는것으로여겨진다. 전반기호도를이용한군집분석결과는 Table 5와같다. 31명의패널로구성된군집1은오디침지커피에대한기호도 (4.65~5.39) 가대조군 (3.23~4.52) 보다높았다. 20명의패널로구성된군집2는대조군 (5.55) 의기호도가오디침지커피 (4.10~4.70) 의기호도보다높았다. 군집분석을통해서소비자는대조군을선호하는소비자와오디침지커피를선호하는소비자로나누어졌다. 오디침지커피를선호하는소비자가전체평가인원의약 61% 를차지하였다. 요 본연구에서는커피생두를오디추출액에 2~6시간침지시켜오디침지커피를제조하고이화학적특성, 항산화활성, 소비자기호도등의품질특성을조사하였다. 오디침지커피는대조군보다신맛이더강하였다. 가용성고형분함량및갈색도는오디침지커피가대조군보다낮았다. 오디침지커피는대조군보다높은 a값 ( 적색도 ) 및 b값 ( 황색도 ) 을보여일반커피색보다주황빛을띠었다. 항산화활성은오디침지커피가대조군보다유의적으로높았으나 (P<0.05), 침지시간에따라비례하지는않았다. 총폴리페놀함량은 2H 및 4H에서가장높았으며, 총플라보노이드함량은 4H 및 6H에서가장높았다. 통계적으로 4H에서 DPPH, FRAP, ORAC의항산화활성, 총폴리페놀함량, 총플라보노이드함량이가장높았으며, 이는 4시간침지오디침지커피 (4H) 가항산화활성이가장우수한커피로여겨진다. 소비자기호도조사에서 4H가가장높은전반기호도를보여주었으 약 며, 색, 향, 풍미, 쓴맛에서도높은기호도를가지는것으로평가되었다. 군집분석을통해서소비자는오디침지커피를좋아하는약 61% 의소비자와대조군을좋아하는약 39% 의소비자로나누어졌다. 군집분석결과는오디침지를통한기능성커피의시장성을보여준다. 이화학적특성, 항산화활성, 소비자조사결과를종합하여볼때, 4시간의침지시간이오디커피제조에가장적합한것으로판단된다. 감사의글 본연구는농림축산식품부고부가식품전문인력양성사업의지원에의해이루어졌습니다. REFERENCES 1. KCS. 2014. Statistics of import and export of coffee. http: //www.customs.go.kr/kcsweb/user.tdf?a=user.newtradestatistics.newtradestatisticsapp&c=1003&mc=stats_inqu _TRADE_020. Korea Customs Service, Daejeon, Korea (accessed Oct 2014). 2. Moreira DP, Monteiro MC, Ribeiro-Alves M, Donangelo CM, Trugo LC. 2005. Contribution of chlorogenic acids to the iron-reducing activity of coffee beverages. J Agric Food Chem 53: 1399-1402. 3. Hečimović I, Belščak-Cvitanović A, Horžić D, Komes D. 2011. Comparative study of polyphenols and caffeine in different coffee varieties affected by the degree of roasting. Food Chem 129: 991-1000. 4. Parras P, Martínez-Tomé M, Jiménez AM, Murcia MA. 2007. Antioxidant capacity of coffees of several origins brewed following three different procedures. Food Chem 102: 582-592. 5. Kim MJ, Park JE, Lee JH, Choi NR, Hong MH, Pyo YH. 2013. Antioxidant capacity and bioactive composition of a single serving size of regular coffee varieties commercially available in Korea. Korean J Food Sci Technol 45: 299-304. 6. Sung GB, Kim KY, Ji SD. 2013. Survey and analysis of mulberry tree for mulberry production. J Seric Entomol Sci 51: 48-55. 7. Lee JA. 2011. A study on recognition and preference for processed product developments of mulberry (Morus alba L) fruit products. Korean J Culinary Res 17: 231-243. 8. MIFAFF. 2012. Agricultural statistic on silkworm rearing and current state of sericulture in 2011. Ministry of Food, Agricultural, Forestry and Fishery, Sejong, Korea. p 1-56. 9. Chang SW, Kim HJ, Song JH, Lee KY, Kim IH, Rho YT. 2011. Determination of several phenolic compounds in cultivars of grape in Korea. Korean J Food Preserv 18: 328-334. 10. Kim HB, Kim JB, Kim SL. 2005. Varietal analysis and quantification of resveratrol in mulberry fruits. Korean J Seric Sci 47: 51-55. 11. Lee EJ, Bae JH. 2011. Study on the alleviation of an alcohol induced hangover and the antioxidant activity by mulberry fruit. Korean J Food & Nutr 24: 204-209. 12. Kim HR, Kwon YH, Kim HB, Ahn BH. 2006. Characteristics of mulberry fruit and wine with varieties. J Korean Soc Appl Biol Chem 49: 209-214. 13. Moon HK, Lee SW, Moon JN, Yoon SJ, Lee S, Kim GY. 2012. Quality characteristics of jelly added with mulberry juice. Korean J Food Cookery Sci 28: 797-804.
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