J Korean Soc ood Sci Nutr 한국식품영양과학회지 43(12), 1964~1968(2014) http://dx.doi.org/10.3746/jkfn.2014.43.12.1964 연구노트 시설및노지재배한오디의품질특성 이지영 1 황인국 1 김하윤 1 유선미 1 박종태 2 1 농촌진흥청국립농업과학원농식품자원부 2 충남대학교식품공학과 Quality haracteristics of Mulberry ultivated under and Open ield onditions Ji Young Lee 1, In Guk Hwang 1, Ha Yun Kim 1, Seon Mi Yoo 1, and Jong Tae Park 2 1 epartment of grofood Resources, National cademy of gricultural Science, Rural evelopment dministration 2 epartment of ood Science and Technology, hungnam National University STRT This study investigated the quality characteristics of mulberry cultivated under greenhouse and open field conditions. Quality characteristics such as the number of aerobic bacteria, ph, acidity, soluble solid content, and contents of free sugar, polyphenol, and anthocyanin were investigated. The number of aerobic bacteria in mulberry cultivated in open fields was higher than that of mulberry cultivated in the greenhouse. The average ph was significantly higher in greenhouse mulberry whereas acidity was higher in mulberry grown in open fields. The average soluble solid content of mulberry cultivated in open fields was slightly higher than that of mulberry cultivated in the greenhouse, although the difference was not significant. ructose and glucose were detected in mulberry as free sugar. The free sugar content of mulberry was not affected by cultivation conditions. The average polyphenol contents of mulberry cultivated in the greenhouse and open fields were 393.36 and 514.47 mg%, respectively. The average anthocyanin contents of mulberry cultivated in the greenhouse and open fields were 205.00 and 265.56 mg%, respectively. The average polyphenol and anthocyanin contents of mulberry cultivated in open fields were significantly higher than those of mulberry cultivated in the greenhouse. Key words: mulberry, free sugar, polyphenol, anthocyanin, quality characteristics 서 오디 (mulberry) 는뽕나무과 (Moraceae) 에속하는낙엽교목인뽕나무 (Morus alba L.) 의열매로서온대에서아열대에이르기까지널리분포하고있으며, 우리나라에서는 5월부터 6월에걸쳐과실의색이검은색또는자홍색을나타낼때채취하여주로식용하거나건조후한약재로사용하고있다 (1,2). 오디에는당, 유기산, 무기질 ( 칼륨, 칼슘, 인등 ), 비타민 (, 1, 2) 등을비롯하여안토시아닌성분이풍부하고 (2-5) 항암, 항염증, 항산화, 항당뇨및항고혈압등에효과가있는것으로보고되면서 (2-5) 건강기능성식품원료로관심이높아지고있으며, 이에따라오디를활용한음료 (6), 발효주 (7,8), 젤리 (9), 빵 (10) 및절편 (11) 등다양한가공식품개발연구가활발히진행되고있다. 오디의여러가지유효성분및기능성이확인되면서국내 Received 4 September 2014; ccepted 14 October 2014 orresponding author: In Guk Hwang, epartment of grofood Resources, National cademy of gricultural Science, Rural evelopment dministration, Jeonbuk 565-851, Korea -mail: ighwang79@korea.kr, Phone: +82-63-238-3568 론 오디생산용뽕나무면적및그생산량은 2009년부터 2012 년까지각각 1,544 1,878 ha 및 5,613 6,752톤으로지속적으로증가하였다. 또한 2012년도기준오디의주생산지역은전북 ( 약 4,057톤 ) 및전남 ( 약 1,019톤 ) 지역으로총생산량의 80% 이상생산되고있으며그다음으로경북, 경기, 경남등의순으로생산되고있다 (12). 과수의시설하우스재배는동해, 서리, 강풍, 장마및가뭄등의자연재해및병해충예방으로과실의안정적인생산과보온또는가온에의한수체의생육과과실의숙기를촉진하는등의이점으로농가소득증대효과가높다 (13). 특히오디의경우수확기가장마기간과맞물려생산성및품질저하의원인으로작용하고있다. 최근시설하우스재배법이농가에보급확대되고있으며시설재배농가와생산량도꾸준히증가하는추세이지만, 시설재배한오디의품질특성에관한연구는부족한실정이다. 따라서본연구에서는지속적으로재배면적과생산량이증가할것으로기대되는시설재배오디의품질특성을노지재배한오디와비교분석하여오디재배농가, 식품업체및소비자등에게기초자료로제공하고자하였다.
시설및노지재배한오디의품질특성 1965 재료및방법재료및시약본실험에사용한오디는과상 2호품종으로 2013년 6월에전라북도부안지역에서시설및노지재배한것을각각세곳의농가에서수확하여시료로사용하였다. 수확한오디는즉시아이스팩을채운보냉상자에넣어밀봉후실험실로이송하였다. ructose, glucose, olin-iocalteu reagent, gallic acid 등은 Sigma-ldrich(St. Louis, MO, US) 에서구입하였고, 그밖의시약은 analytical 및 HPL 등급을사용하였다. 총균수측정시료 25 g을멸균팩에넣고멸균수 225 ml를첨가하여스토마커 (agmixer 400, Interscience, Saint-Nom-la- retèche, rance) 로 1분간처리한후여과액 1 ml를취하여멸균수로각시료를 10배희석법으로희석하였다. 총균수의측정은희석액 1 ml를건조필름배지 (Petrifilm TM, aerobic count, 3M, St. Paul, MN, US) 에접종하여 37, 36시간동안배양한다음형성된콜로니수를계수하여 log U/g으로나타내었다 (14). ph, 총산도및당도측정오디의 ph, 총산도및당도는 Park 등 (14) 의방법을변형하여측정하였다. 즉오디 100 g을 2겹의거즈를이용하여착즙, 여과한후그여과액을사용하여 ph, 총산도및당도를측정하였다. ph는 ph meter(orion 4 STR, Thermo Scientific, everly, M, US) 로측정하였고, 총산도는여과액 5 ml를취하여 0.1 N NaOH로 ph 8.3까지적정하여소비된 NaOH 용액의 ml 수를 citric acid 함량 (%) 으로환산하였으며, 당도는디지털당도계 (TGO, Tokyo, Japan) 로측정하여 rix로나타내었다. 유리당함량분석유리당함량은동결건조된시료 0.50±0.05 g에증류수 50 ml를가하여 200 rpm, 3시간진탕추출한후 Whatman No. 2 여과지 (Whatman International Ltd., Maidstone, Kent, UK) 로감압여과하여 50 ml로정용하였다. 추출물은 0.20 μm membrane filter(millipore orporation, illerica, M, US) 로여과하여 gilent Technologies 1200 series HPL system(palo lto,, US) 으로분석하였다. HPL 분석조건은 column으로 Shodex sahipak NH2P-5-4(5 μm, 4.6 250 mm, Tokyo, Japan) 를사용하였고, 검출기는 LS를사용하였으며, 이동상은 70% acetonitrile를 1.2 ml/min 속도로흘려주었고 10 μl를주입하여분석하였다 (15). 표준물질로는 fructose 및 glucose 를사용하였다. 총폴리페놀함량측정동결건조된시료 0.50±0.05 g에 70% ethanol 100 ml 를가하여 40 에서 40분간초음파추출한다음 Whatman No. 2 여과지 (Whatman International Ltd.) 로감압여과하여 100 ml로정용한후총폴리페놀측정용시료로사용하였다. 총폴리페놀함량은 olin-enis의방법을이용하여측정하였다 (16). 각추출물 100 μl에 2% Na 2O 3 용액 2 ml를가한후 3분간방치하여 50% olin-iocalteu reagent 100 μl를가하였다. 30분후반응액의흡광도값을 750 nm에서측정하였고표준물질로 gallic acid를사용하였다. 검량선을작성한후총폴리페놀함량은시료 g 중의 mg gallic acid로나타내었다. 안토시아닌함량측정오디의안토시아닌함량은 ph differential method에따라측정하였다. 동결건조된시료 0.50±0.05 g에 1% Hlmethanol 50 ml를가하고 40분간초음파추출한후원심분리 (12,000 rpm, 15 min) 하여얻어진상층액을시료로사용하였다. 각추출물 0.5 ml에각각 0.025 M potassium chloride buffer(ph 1.0) 와 0.4 M acetate buffer(ph 4.5) 4.5 ml를혼합한다음 510 nm 및 700 nm에서흡광도를측정하였다. 안토시아닌함량은 cyanidin-3-glucoside의몰흡광계수 (ε=26,900 M -1 cm -1 ) 를이용하여다음식에따라산출하였다 (14). nthocyanin content (mg/l)= MW 1000 ε V (absorbance value)=( 510-700)pH 1.0-( 510-700) ph 4.5 MW (molecular weight of cyanidin-3-glucoside)=449.2 =dilution factor ε (cyanidin-3-glucoside molar absorbance)=26,900 M -1 cm -1 V=volume of extract 통계분석통계분석은 SPSS 통계프로그램 (Statistical Package for the Social Science, Ver. 12.0, SPSS Inc., hicago, IL, US) 을이용하여각측정군의평균과표준편차를산출하고처리군간의차이유무를 one-way NOV(analysis of variation) 로분석한뒤 uncan's multiple range test를이용하여 P<0.05 수준에서유의성을검정하였다. 또한재배방법별차이를알아보기위하여 t-test를실시하였다. 결과및고찰 총균수, ph, 총산도및당도시설과노지재배한오디의총균수를측정한결과는 Table 1과같이시설및노지재배한오디의총균수는각각
1966 이지영 황인국 김하윤 유선미 박종태 Table 1. erobic bacteria of mulberries cultivated under greenhouse and open field conditions Samples erobic bacteria (log U/g) 6.49±0.35 c1)2) 5.27±0.55 d 6.70±0.47 c Mean±S 6.15±0.63 * 7.98±0.26 a 7.28±0.57 b 7.55±0.39 ab Mean±S 7.60±0.35 1) Values are mean±s (n=3). difference (P<0.05) by uncan's multiple range test. * P<0.05 indicate significant differences between greenhouse and open field by t-test. 5.27 6.70 및 7.28 7.98 log U/g 수준으로시설재배시총균수가유의적으로 (P<0.05) 적었다. 이는시설재배시비, 바람, 먼지등외부오염원에대한노출이적어나타난결과로생각된다. 과일류의 ph, 총산도및당도등은생과용이나가공용으로활용시중요한품질평가요소이다. 이전연구결과를살펴보면오디의 ph, 총산도및당도는각각 4.08 5.10, 0.26 0.73% 및 5.83 15.34% 수준이고, 품종, 재배법, 재배환경, 수확시기등에따라차이를보이는것으로보고되어있다 (2,17). 시설과노지재배한오디의 ph, 총산도및당도를측정한결과는 Table 2와같다. 오디의 ph 및총산도는각각 4.28 5.31 및 0.30 0.62% 범위로재배농가에따라유의적인 (P<0.05) 차이를보였다. 시설및노지재배한오디의평균 ph 및총산도를비교해보면시설재배한오디가 ph는유의적으로 (P<0.001) 낮고총산도는높은것으로나타났다. 오디의당도도 10.35 13.35% 범위로재배농가에따른유의적인 (P<0.05) 차이를보였으며, 재배방법별평균당도는노지재배가다소높은경향을보였지만유의적인차이는없는것으로나타났다. Kim 등 (13) 의노지와하우스재배에따른블루베리의과실특성을분석한연구에서는산함량은발육기간중에는하우스재배시노지재배에비해 Table 3. ree sugar contents of mulberries cultivated under greenhouse and open field conditions Samples ructose (%) Glucose (%) Total (%) 5.82±0.14 b1)2) 4.30±0.02 e 6.01±0.07 a 5.56±0.14 a 4.08±0.02 d 5.70±0.06 a 11.38±0.27 b 8.38±0.04 e 11.72±0.07 a Mean±S 5.38±0.82 5.12±0.78 10.49±1.60 5.04±0.17 d 5.65±0.02 bc 5.58±0.10 c 4.64±0.07 c 5.31±0.08 b 5.33±0.07 b 9.67±0.24 d 10.95±0.08 c 10.90±0.17 c Mean±S 5.42±0.30 5.09±0.35 10.51±0.65 1) Values are mean±s (n=3). difference (P<0.05) by uncan's multiple range test. 높은것으로나타나본연구결과와유사한경향을보였다. 또한당도의경우에는하우스재배시노지재배에비해유의적으로낮은것으로보고하여본연구결과와차이를보였으며, 이는시설재배시노지재배에비해낮은광량으로인한광합성의차이에서비롯한결과인것으로보고하였다. 유리당함량시설과노지재배한오디의유리당함량을분석한결과 Table 3과같이 fructose 및 glucose 함량이각각 4.30 6.01 및 4.08 5.70% 범위로재배농가에따라유의적인 (P<0.05) 차이를보였다. 오디의주요당으로는 fructose와 glucose만이검출되어 Lee와 hoi(17) 및 Kim 등 (18) 의연구결과와일치하였으며각각의당함량은 1.86 7.34 및 2.15 7.33% 범위수준으로계통간함량차이가큰것으로보고하였다. 반면에 Yang과 Rho(6) 의연구에서는 fructose, glucose 이외에소량의 sucrose 검출된것으로보고하여본연구결과와차이를보였다. 대체로광량이낮을경우광합성작용이원활하지않아당의축적이적은것으로알려져있고 (19), Kim 등 (20) 의연구에서뽕나무를시설재배시노지재배에비해광량은피복재의투광율로인해적은것으로보고되어있어당의축적이적을것으로예측하였으나본연구에서시설및노지재배한오디의평균유리당 Table 2. ph, total acidity, and soluble solids of mulberries cultivated under greenhouse and open field conditions Samples ph Total acidity (%, as citric acid) Soluble solids ( o rix) 4.28±0.13 c1)2) 4.33±0.04 c 4.72±0.01 b 0.58±0.05 a 0.62±0.03 a 0.30±0.01 c 11.50±0.75 b 10.35±0.29 c 12.93±0.05 a Mean±S 4.44±0.22 *** 0.50±0.15 *** 11.59±1.21 5.31±.016 a 5.27±0.04 a 4.83±0.04 b 0.25±0.01 d 0.30±0.04 c 0.36±0.01 b 12.93±0.78 a 13.35±0.29 a 11.08±0.32 bc Mean±S 5.13±0.25 0.30±0.05 12.45±1.13 1) Values are mean±s (n=3). difference (P<0.05) by uncan's multiple range test. *** P<0.001 indicate significant differences between greenhouse and open field by t-test.
시설및노지재배한오디의품질특성 1967 Table 4. Total polyphenol and anthocyanin contents of mulberries cultivated under greenhouse and open field conditions Samples Total polyphenol (mg%) 426.08±11.97 c1)2) 334.60±11.15 d 419.40±13.52 c Total anthocyanin (mg%) 236.08±8.28 c 184.49±1.86 d 194.43±13.17 d Mean±S 393.36±45.42 *** 205.00±24.97 *** 483.09±4.41 b 577.89±16.43 a 482.42±6.51 b 266.44±14.09 b 282.26±4.77 a 247.97±0.25 c Mean±S 514.47±48.43 265.56±16.62 1) Values are mean±s (n=3). difference (P<0.05) by uncan's multiple range test. *** P<0.001 indicate significant differences between greenhouse and open field by t-test. 함량은유의적인차이는없는것으로나타났다. 총폴리페놀및안토시아닌함량폴리페놀화합물은식물계에널리분포되어있는대표적인기능성물질로다양한구조를가지고있고항암, 항염증, 항산화, 항고혈압등다양한생리활성을갖고있으며, 특히오디에는안토시아닌화합물이다량존재하는것으로알려져있다 (2). 오디의총폴리페놀및안토시아닌함량은뽕나무품종, 재배환경등에따라차이를보이고, 각각 144.5 543.7 및 57.45 206.60 mg% 범위수준인것으로보고되어있다 (2,21). 시설과노지재배한오디의총폴리페놀및안토시아닌함량을측정한결과는 Table 4와같이각각 334.60 577.89 및 184.49 282.26 mg% 범위로재배농가에따라유의적인 (P<0.05) 차이를보였다. 또한노지재배한오디의총폴리페놀및안토시아닌함량이시설재배한오디에비해유의적으로 (P<0.001) 높은것으로나타났다. 이는노지재배시강한자외선과높은광환경조건으로인해폴리페놀화합물의축적이많아나타난결과로생각된다. Kim 등 (13) 의연구에서는노지와비가림하우스재배한블루베리의총폴리페놀함량은광포화점이높았던노지재배한블루베리가높아본연구결과와유사하였지만안토시아닌함량의경우에는재배방법에따라일정한경향을보이지않는것으로나타났다. 이상의결과를종합해보면오디의항산화성분인총폴리페놀및안토시아닌함량은시설재배시노지재배에비해낮았지만 ph, 총산도, 당도와유리당함량등품질특성은재배방법에따른큰차이가없었고총균수는시설재배오디에서적게검출된것으로조사되었다. 따라서장마철과수확시기가겹치는오디의경우장마에따른과실의품질저하를줄이고주변환경으로부터의오염원차단효과를기대할수있는시설재배가바람직할것으로판단된다. 요 본연구에서는시설및노지재배한오디의총균수, ph, 총산도, 당도, 유리당, 총폴리페놀및안토시아닌함량을비교분석하였다. 총균수는시설재배한오디가노지재배한오디에비해유의적으로 (P<0.05) 적게검출되었다. 시설재배한오디의평균 ph 및총산도는각각 4.44 및 0.50% 였고, 노지재배시각각 5.13 및 0.30% 로시설재배한오디가 ph는유의적으로 (P<0.001) 낮고총산도는높은것으로나타났다. 당도의경우노지재배시시설재배에비해다소높은경향을보였지만유의적인차이는없는것으로나타났다. 오디의주요유리당으로는 fructose와 glucose가검출되었고, 시설재배한오디의평균 fructose 및 glucose 함량은각각 5.38 및 5.12% 였고, 노지재배시각각 5.42 및 5.09% 로재배방법에따른유의적인차이는없었다. 시설과노지재배한오디의평균총폴리페놀함량은각각 393.36 및 514.47 mg%, 안토시아닌함량은각각 205.00 및 265.56 mg% 로노지재배시시설재배에비해유의적으로 (P< 0.001) 높았다. 약 감사의글 본연구는농촌진흥청공동연구사업 (PJ009426) 및 2014년도농촌진흥청국립농업과학원박사후연수과정지원사업에의해이루어진것임. RRNS 1. Teng H, Lee SH, Lee WY. 2013. Sterilization effects on mulberries (Morus alba L.) washed with electrolyzed water and chlorine dioxide. J ast sian Soc ietary Life 23: 654-661. 2. Kim O, Lee YJ, Leem HH, Seo IH, Yu MH, Kang H, hoi SW. 2010. omparison of nutritional and functional constituents, and physicochemical characteristics of mulberrys from seven different Morus alba L. cultivars. J Korean Soc ood Sci Nutr 39: 1467-1475. 3. Ju MJ, Kwon JH, Kim HK. 2009. Physiological activities of mulberry leaf and fruit extracts with different extraction conditions. Korean J ood Preserv 16: 442-448. 4. Lee J, ae JH. 2011. Study on the alleviation of an alcohol induced hangover and the antioxidant activity by mulberry fruit. Korean J ood & Nutr 24: 204-209. 5. hae JW, Park HJ, Kang S, ha WS, hn H, ho YJ. 2012. Inhibitory effects of various mulberry fruits (Morus alba L.) on related enzymes to adult disease. J Life Sci 22: 920-927. 6. Yang HS, Rho JO. 2012. Physiochemical characteristics and sensory evaluation of mulberry fruit beverages for rural food process. J ast sian Soc ietary Life 22: 246-254. 7. Kim HR, Kwon YH, Kim H, hn H. 2006. haracteristics of mulberry fruit and wine with varieties. J Korean Soc ppl iol hem 49: 209-214. 8. Kim MW, Kim J. 2007. The quality characteristics of mulberry fruit wine by two different manufacturing methods.
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