Kor. J. Hort. Sci. Technol. 22(2):177-182, 24 오이의성숙단계별이화학적품질요인과관능검사의상관관계 박세원 1 이지원 2 김영철 2 김광용 2 홍지흔 3 이미림 4 홍세진 4 1 건국대학교원예과학과, 2 원예연구소채소재배과, 3 ( 주 ) 두산 Biotech 연구소, 4 강릉대학교식물응용과학과 Relationship between Physicochemical Quality Attributes and Sensory Evaluation during Fruit Maturation of Cucumber Se Won Park 1, Ji Won Lee 2, Young Cheol Kim 2, Kwang Yong Kim 2, Ji Heun Hong 3, Mi Rim Lee 4, and Sae Jin Hong 4 1 Department of Horticultural Science, Konkuk University, Seoul 143-71, Korea 2 Vegetable Cultivation Division, National Horticultural Research Institute, Suwon 44-31, Korea 3 Doosan Company, Biotech BU, Biotech Research Laboratory, Yongin 449-795, Korea 4 Department of Applied Plant Science, Kangnung National University, Gangneung 21-72, Korea (Corresponding author) Abstract. Suitable indices for the marketable quality of cucumber fruit were evaluated through the correlation study between instrumental and sensory quality attributes. Three cucumber cultivars,, and were harvested at five maturity to investigate relationship between quality factors and sensory test. Fruit maturity was simply judged by fruit size from extra small to extra large. The significant correlation coefficient values were determined (more than r=.55) between the sensory sweetness and the contents of soluble solids, soluble sugars, fructose, and glucose. The results suggested that content of all the sugars were suitable for the sweetness index of cucumber, especially soluble sugars for (r=.7823), soluble solids for content (r=.827), and glucose for (r=.48), respectively. The high coefficient value (r=-.7555) between dry matters and mouth-feel texture suggested that the dry matter was suitable as an indicator for the texture of. and cultivars showed significant correlation coefficient value more than r=.5 between firmness and texture. There were no significant correlations between Hunter values and chlorophyll content regardless of maturity stages. The cucumber quality was mainly dependent on sweetness and flesh texture, thus suggesting that the two factors are decisive quality factors for, while soluble solids content and soluble sugars for. For cultivar, the new standard of quality indices might should be developed and introduced since significant relationship between previous quality indices and panel test were low or not found. Additional key words: Cucumis sativus, sweetness, mouth-feel texture, firmness, color 서언국내에서소비되는대표적인과채류중하나인오이는그중요도에비해성숙중품질과관련된연구가의외로취약하다. 최근오이의성숙에관련된연구는거의없으며, 품질기준설정과관련된연구는컴퓨터를이용한품질평가, 분류, 그리고포장에대한연구결과가보고되어있다 (Sung 과 Lee, 199a, 199b). 그러나이에관한연구도외형특히과형과크기에따른평가방법만을제시하고있어과실의내부성분과조직감등과같은품질평가요인은배제되어있 는실정이다. 외국의경우재배조건에따른수량및품질의예찰 (Marcelis와 Gijzen, 1998), 품질평가를통한품종의특성을나타내거나 (Shetty와 Wehner, 1998), 오이의과색중 carotenoid 함량분석을통한품질평가 (Navazio, 21) 그리고색차에의한품질평가 (Lin과 Jolliffe, 199) 의가능성등을제시하고있다. 오이의수확후관리와저장력증진을위한연구에서오이의품질유지를위한연구는수확후열처리와칼슘처리가저장성에미치는영향 (Kwon 등, 1999), 오이의저장중품질유지를위한포장방법과열처리 (Kang과 Park, 1999), 오이저장에적합한포장용필름의선발 (Park과 Kim, Received 24 December 23; Accepted 31 March 24. This research was supported by Rural Development Administration in 1999-21. 177
2), 그리고유통기간중최적의품질을유지하기위한포장재의종류 (Park과 Kang, 1998; Park과 Kim, 2) 등이거의전부이다. 수확후관리및유통을위해서는규격화가필수이며, 이를위한품질기준이마련되어있다. 국내의품질기준으로국립농산물품질관리원, 농촌진흥청, 그리고농수산물유통공사등에서제시하고있는오이의품질은크기와외형, 그리고생리및병리장해에의한품질평가로이에의한등급과분류기준이마련되어있다. 선진화된물류체계를확립하기위해서는등급, 선별, 그리고포장등의자동화가필수적이며, 이를위해서는기존의외형에의한규격화와함께새로운품질기준과평가방법이마련되어야할것이다 (Ryu 등, 199). 이러한연구에는반드시관능검사가동반되는데, 이는품질을평가하는데분석되는항목들이실제오이의품질과인간이느끼는감각이일치하는가를중요시하기때문이다. 본연구는오이의품질평가의기준을마련하기위해수확후관리의체계를확립하고등급 선별 유통의자동화와규격화를위한기준을제시하며, 각각의품질인자와관능검사와상관관계를조사하여적절한품질평가요인을제시하고자수행하였다. 재료및방법본실험은전남광주지역의온실에서관행재배하여가을에수확한 백다다기, 청장, 그리고수출용인 품종을성숙단계 별로극소, 소, 중, 대, 극대의 5단계로분류하여품질을조사하였다 (Fig. 1, Table 1). 단만연구의결과제시는과실이유통되는크기인중과대를기준으로하여극대와소등 4단계의성숙단계과실로한정하였다. 단맛을나타내는품질요인조사로서가용성고형물함량은굴절당도계로, 가용성당은과육조직 5g을증류수 1mL에넣고균질화시킨후 11, g에서 1분간원심분리하여얻은상징액을.45μm-membrane filter로여과하여 HPLC로분석하였다. HPLC 의분석조건은 column은 Alltech 7CH(column 온도, 75 C), mobile phase는 double distilled deionized water, 그리고검출기는 RI detector로분석하였다. 과육의조직감은과실경도와건물함량을측정하여분석하였다. 과실경도는물성분석기 (EZ test/ce, Shimadzu Corp.) 를이용하여 φ3mm plunger와 mm min -1 crosshead speed 조건으로분석하였다. 오이의색소함량은시료 2g을아세톤 2mL에넣고 2 초간균질화, shaking 15분, 11, g에서원심분리후 2ml로정용하여엽록소는 42.5nm와 nm에서 spectrophotometer로측정하여 AOAC법 (1995) 으로환산하여정량하였다. 과피색은 Minolta Chroma Meter CR-3으로 Hunter L, a 및 b를조사하였다. 식미와성숙단계별또는내부품질요인함량별상관관계를알아보기위해관능검사를수행하였다. 조사는단맛, 착색도, 조직감, 그리고전체적인맛을 1부터 1까지의등급으로하였으며, 각 Fig. 1. Cucumber cultivars including,, and (A), and fruit maturities (B) according to fruit length. Table 1. Maturity stages for three cultivars of cucumber sorted by fruit size. Cultivar Size Length (cm) Weight (g) z 11-14 (39.2) Length (cm) Weight (g) Length (cm) Weight (g) Size Stage 1 (extra small) (small) (medium) (large) (extra large) 15-2 (51.) 18-19 (7.4) z Average fresh weight of cucumber fruit. 14-17 (95.) 25-29 (133.2) 19-2 (7.) 17-2 (128.) 23-25 (13.8) 2-21 (82.) 2-23 (18.8) 2-23 (21.) 21-22 (9.) >23 (197.) >29 (3.2) >22 (112.) 178
각의조사는 5개의과실을한그룹으로 4반복하였다. 단맛등급은단맛이없는오이를 1로하여보통정도는 5, 그리고단맛이강하면 1으로하였다. 오이의착색지수는착색이불량하거나착색이약한것을 1, 보통은 5, 그리고착색과광택이우수하면 1으로하였다. 조직감은씹히는맛이불량한것은 1, 보통이면 5, 그리고씹히는맛이신선하고우수하면 1으로하여조사하였다. 전체적인맛의선호도는생식용오이로품질이열악한것을 1, 보통이면 5, 그리고맛이극히우수하면 1으로등급을정하였다. 관능검사의결과는매우주관적으로조사되어남녀비율이대략 1:1인 25-3명의인원으로 1차조사후 5명의숙달된인원으로재수행하였다. 분석은 5반복을원칙으로하였으며, 통계는표준편차를구하였고 t-test를통하여통계적유의성을검정하였다. 결과및고찰성숙단계별가용성고형물과단맛의상관관계는 청장 품종은 r=.827로뚜렷한상관관계가있으나, 백다다기 와 품종은각각 r=-.5933과 r=.4으로유의성이약하거나전혀없었다 (Fig. 2). 오이과실의주요가용성당인 glucose와 fructose 의합과단맛의상관계수는 백다다기, 청장, 그리고 품종이각각 r=.7823, r=.794, 그리고 r=.289로상관관계가인정되었으며, 특히 백다다기 품종이높은유의수준을보여주었다 (Fig. 3). Fructose 함량과단맛의상관관계에서는 백다다기 와 청장 품종에서도각기 r=.5588과 r=.53으로상관관계를보였으나, 품종은 r=-.353으로부의상관계수를보였으며상관관계에대한유의성도인정되지않았다 (Table 2). 그러나 glucose 함량과단맛의상관계수는세품종모두 r=. 이상으로상관관계의유의성이인정되었다. 단맛과가용성고형물및가용성당과의상관관계는 백다다기 와 청장 품종에서모두유의성이인정되었으며, 특히 백다다기 는가용성당과 청장 은 가용성고형물함량과단맛에대한상관관계에서높은유의수준을보여주었다 (Table 2). 조직감에대한건물함량의상관관계 (Fig. 5) 는 백다다기 품종의경우 r=-.7555로높은상관계수를보였으며, 청장 품종은 r=.217으로유의성이없었다. 성숙단계별조직감에대한과실경도의상관관계는 Fig. 에서보는바와같이 청장 과 품종이각각 r=.51과 r=.531로낮은유의성이있으나, 백다다기 품종은 r=.388로상관관계에대한유의성이없었다. 생체중감소와경도저하는실온저장에서각각 1% 및 24% 이상발생하였다는보고가있어 (Kwon 등, 1999) 실제유통시소비자가느끼는건물함량과경도는차이가있을수있다. 단적절한모의유통조건에서가용성고형물함량, 경도, 그리고색택은변화가거의없다는연구결과 (Park 등, 1999) 를토대로오이의수확후관리로품질변화를억제시켜야할것으로생각된다. 색에대한분석에서엽록소함량과색택에대한상관계수는 백다다기, 청장, 그리고 품종이모두부의상관계수를보이며 r=-.2 이하로상관관계가전혀없었다 (Table 2). 밝기를나타내는 Hunter L 값과색택에대한상관관계는 백다다기 품종은정의그리고 청장 과 는부의상관계수를보이나색태선호도와 Hunter L값의상관관계에대한유의성도세품종모두인정되지않았다. Hunter L 값은품종별로각기상이한경향을나타내며품질평가요인으로이용하기에는부적절할것으로판단되었다. 푸른색에서붉은색정도를나타내는 Hunter a 값과색택에대한상관관계는오이세품종모두 r=.1 이하로유의성이전혀없는것으로조사되었다. 노란색을나타내는 Hunter b 값과색택에대한상관관계에서도 백다다기 품종은 r=.3125이며, 청장 과 품종은각각 r=-.3325와 r=-.14으로낮은상관계수를보였다. 오이의크기와 carotenoids 함량을비교한 Navazio와 Simon(21) 의실험에서색소와과피색도는밀접한관계가있으며, 과실의크기가크게생장할수록색소발현이안정한것으로보 Soluble Solids Content (%) 8 4 2 r=.4 Sweetness r=-.5933 r=.827 Soluble Sugars (mg. g -1 FW) 3 24 18 12 r=.289 Sweetnwss r=.7823 r=.794 Fig. 2. Relationship between sweetness and soluble solid contents during maturation of three kinds of cucumber cultivar. Fruits of each cultivar were harvested at four different maturity levels. Fig. 3. Relationship between sweetness and soluble sugar contents during maturation of kinds of cucumber cultivar. Fruits of each cultivar were harvested at four different maturity levels. 179
Table 2. Correlations between quality attributes and the sensory evaluation, and their confidence level of cucumbers during maturation from small to extra large length of fruit. Cultivar Panel test Quality factor Correlation coefficient (r) Statistical significance Sweetness Soluble solids content Sweetness Soluble sugars Sweetness Fructose Sweetness Glucose Mouth-feel acceptability Dry metters Mouth-feel acceptability Firmness Color acceptability Chlorophyll Color acceptability Hunter L Color acceptability Hunter a Color acceptability Hunter b Sweetness Soluble solids content Sweetness Soluble sugars Sweetness Fructose Sweetness Glucose Mouth-feel acceptability Dry metters Mouth-feel acceptability Firmness Color acceptability Chlorophyll Color acceptability Hunter L Color acceptability Hunter a Color acceptability Hunter b Sweetness Soluble solids content Sweetness Soluble sugars Sweetness Fructose Sweetness Glucose Mouth-feel acceptability Dry metters Mouth-feel acceptability Firmness Color acceptability Chlorophyll Color acceptability Hunter L Color acceptability Hunter a Color acceptability Hunter b,,, Nonsignificant, significant at P.5,.1, or.1, respectively. -.5933.7823.5588.747 -.7555.388 -.12.2221.7.3125.827.794.53.183.217.51 -.719 -.322.951 -.3325.4.289 -.353.48 -.552.531 -.119 -.771.938 -.14 Glucose (mg. g -1 FW) 12 9 3 r=.48 r=.747 r=.183 Dry Matters (%) 4 3 2 1 r=-.552 r=.217 r=-.7555 Sweetness Mouth-feel Fig. 4. Relationship between sweetness and glucose content during maturation of three kinds of cucumber cultivar. Fruits of each cultivar were harvested at four different maturity levels. Fig. 5. Relationship between preference of texture and dry matters content during maturation of three kinds of cucumber cultivar. Fruits of each cultivar were harvested at four different maturity levels. 18
Firmness (N) 3 24 18 12 r=.531 r=.51 Mouth-feel r=.388 Fig.. Relationship between preference of texture and firmness during maturation of three kinds of cucumber cultivar. Fruits of each cultivar were harvested at four different maturity levels. 고하였다. 각 Hunter 값의품질평가항목과색택비교에서오이는녹색으로의착색이덜되는 백다다기 와과실전체가녹색으로착색되는 청장 과 품종이서로상이한결과를보이나품질평가기준으로는부적합한것으로조사되었다. 이상의결과들을종합해보면오이과실은맛과조직감특히신선도가중요한품질평가요인인것으로판단되며품종에따라외관및품질의차이가심하기때문에품종별로서로다른품질평가기준이설정되어야한다. 이러한품질지표를이용하여오이의등급판정에영상처리시스템 (Sung과 Lee, 1999) 을적극활용하는것이선진유통체계확립에필요할것으로판단된다. 백다다기 품종은단맛과관련된성분특히가용성당과 glucose 함량그리고건물함량이, 청장 품종에서는단맛성분특히가용성고형물함량그리고과실경도를, 그리고 품종의경우는가용성당과 glucose 함량그리고조직감을나타내는건물함량과과실경도정도가과실품질평가요인으로서사용이적절하다고판단된다. 수출용품종인 품종은국내에서유통 소비되는오이품종과비교될수없는독특한맛을가지고있어성숙단계별로기존의과실품질평가요인에대한관능검사결과의상관관계가유의성이없었으며, 기존의품질평가요인이외의새로운품질평가기준의설정이필요하다고생각된다. 초 오이의품질평가의기준을마련하기위해 백다다기, 청장, 그리고 품종의오이를성숙단계별로 5단계로분류하여각각의품질인자와관능검사와상관관계를조사하였다. 단맛에대한가용성고형물, 가용성당, fructose, 그리고 glucose 함량과의상관계수는 백다다기 와 청장 품종이모든 r=.55 이상의정또는부의유의성이있는상관관계를보였다. 특히상관계수에서 백다다기 는가용성당함량이 r=.7823을 청장 은가용성고형물함량 록 이 r=.827로단맛에대한상관관계에서높은유의수준을나타냈고, 품종도 glucose 함량의상관계수가 r=.48으로유의성이높게인정되었다. 성숙단계별조직감에대한건물함량의상관관계는 백다다기 품종이 r=-.7555로매우높은상관계수를보였으며, 과실경도의상관계수는 청장 과 품종이 r=.5 이상으로유의성이있었다. 색에대한분석에서엽록소함량과 Hunter 값의오이에대한색택선호도평가에서세품종모두상관관계가없는것으로조사되었다. 이상의결과들을종합해보면오이과실은품종에따라외관및품질의차이가심하기때문에품종별로서로다른품질평가기준이설정되어져야하며, 백다다기 품종은단맛과관련된성분특히가용성당과 glucose 함량그리고건물함량이, 청장 품종에서는가용성고형물함량을포함한가용성당그리고과실경도가과실품질평가요인으로서사용이가능할것으로판단된다. 품종은기존의과실품질평가요인에대한관능검사결과의상관관계가유의성이낮거나없었으며, 기존의품질평가요인이외의새로운품질평가기준의설정이필요하였다. 추가주요어 : Cucumis sativus, 단맛, 조직감, 경도, 색택 인용문헌 AOAC. 1995. Chlorophyll in plants. Chap. 3. p. 2-28. AOAC Vol. 1. USA. Kang, H.M. and K.W. Park. 1999. Effects of packaging methods and handling temperatures on postharvest quality during storage of cucumber. J. Kor. Soc. Hort. Sci. 4:9-12. Kwon, H.R., K.W. Park, and H.M. Kang. 1999. Effects of postharvest heat treatment and calcium application on the storability of cucumber (Cucumis sativus L.). J. Kor. Soc. Hort. Sci. 4:183-187. Lin, W.C. and P.A. Jolliffe. 199. Light intensity and spectral quality affect fruit growth and shelf life of greenhouse-grown Long English cucumber. J. Amer. Soc. Hort. Sci. 121:118-1173. Marcelis, L.F.M. and H. Gijzen. 1998. Evaluation under commercial conditions of a model of prediction of the yield and quality of cucumber fruits. Sci. Hort. 7:171-181. Navazio, J.P. and P.W. Simon. 21. Diallel analysis of high carotenoid content in cucumber. J. Amer. Soc. Hort. Sci. 12:1-124. Park, H.W. and D.M. Kim. 2. Effect of packaging films on quality Chuichung cucumbers during storage. J. Korean Soc. Food Sci. Nutr. 29:248-251. Park, K.W. and H.M. Kang. 1998. Effects of the sources and thickness of plastic films on the shelf life and quality of cucumber during modified atmosphere storage. J. Kor. Soc. Hort. Sci. 39:397-41. Park S.W., Y. Kwon, S.H. Chi, S.J. Hong, Y.M. Park. 1999. Effects of shipping temperature on quality changes of cucumber, eggplant, melon, and cherry-tomato fruit during simulated export and marketing. Kor. J. Hort. Sci. Technol. 17:118-122. Ryu, B.S., C.H. You, J.S. Lee. 199. Studies on the standardization 181
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