Korean J. Breed. Sci. 49(4):359-368(2017. 12) https://doi.org/10.9787/kjbs.2017.49.4.359 Online ISSN: 2287-5174 Print ISSN: 0250-3360 수확시기에따른노랑찰옥수수의총카로티노이드함량및항산화활성변화 이진석 * 손범영 김정태 배환희 김상곤 백성범 농촌진흥청국립식량과학원중부작물부 Change of Total Carotenoid Contents and Antioxidant Activities of Yellow Waxy Corns (Zea mays L.) Depending on Harvest Time Jin-Seok Lee *, Beom-Young Son, Jung-Tae Kim, Hwan-Hee Bae, Sang-Gon Kim, and Seong-Bum Baek Central Area Crop Breeding Division, National Institute of Crop Science, RDA, Suwon 16429, Korea Abstract : This study was conducted to compare changes of total carotenoid contents and antioxidant activities in yellow waxy corns (Zea mays L.) depending on harvest time. The total carotenoid contents of yellow waxy inbred lines and hybrids increased from 19 days and then the highest content of total carotenoid contents was observed at 25 to 27 days after pollination. Thereafter, there was little change in total carotenoid contents. According to analysis total content of carotenoids on 23 days after pollination, which was the period of harvesting waxy corn, KY2 was the highest as 15.4 μg /g in inbred lines and KY2/KY39 was the hightest as 11.2 μg /g in hybrids, respectively. The total carotenoid contents of each hybrid were higher than mean that of their parent lines except for some hybrids. The total carotenoid contents of KY27/KY37 were significantly higher than those of their parental lines. Antioxidant activity of yellow waxy corn showed a tendency to increase after decrease depending on delaying harvesting time. Antioxidant activities of hybrids were higher than that of inbred lines. As a result of correlation analysis between total carotenoid contents and antioxidant activity, correlation coefficient of inbred lines and hybrids was as low as -0.12 and -0.13, respectively. When the harvest time was delayed, the lightness of yellow waxy corn decreased but the redness and yellowness increased. As a result of correlation analysis between Hunter s Lab value and total carotenoid contents, correlation coefficient of lightness, redness and yellowness were -0.22, 0.67, 0.53, respectively. Keywords : Yellow, Waxy, Corn, Carotenoid, Harvest time 서 옥수수는세계 3대식량작물로벼와밀보다단위면적당생산량이높으며세계적으로 10억톤이상생산되어사료용, 가공용, 간식용등으로이용되고있다 (FAOSTAT 2014). 우리나라의옥수수는대부분찰옥수수이며간식용으로이용하고있다. 찰옥수수는호숙기에풋상태로수확하여이용하기때문에재배기간이짧고타작물과작부체계운영이쉬우며단위면적당소득이높아재배면적이꾸준히증가하고있다 (Lee et al. 2011). 우리나라찰옥수수육종은 1970년대재래종을수집하여계통육성을시작하였고수량성이낮은재래종을대체하고자하였다 (Park et al. 1992). 2000년대에들어서는소비자의기호에맞춰 *Corresponding Author (E-mail: z9813139@korea.kr, Tel: +82-3 1-695-4043, Fax: +82-31-695-4029) (Received on September 18, 2017. Accepted on October 30, 2017.) 언 찰옥수수품질향상으로육종목표가전환되었으며 2000년대후반건강기능성에대한사회적관심이증가하고참살이문화가확산됨에따라찰옥수수의기능성향상에노력하였다 (NICS 2012). 소비자의식생활문화가건강기능성중심으로변화함에따라항암, 항산화등기능성이뛰어난컬러푸드에대한관심이증가하고있다 (Lee et al. 2012). 옥수수에색을나타내는기능성물질로는대표적으로안토시아닌과카로티노이드가있으며이들은항산화물질로잘알려져있다 (Kim et al. 1996). 안토시아닌은식물계에서가장큰수용성색소그룹으로오렌지색부터청자색까지다양한색을나타낸다 (Pietta 2000, Tanaka et al. 2008). 옥수수의안토시아닌은주로 cyanidin-3-glucoside, pelargonidin-3-glucoside, cyanidin-3-(6" malonylglucoside), cyanidin-3-(3",6"-dimalonylglucoside) 등으로구성되어있으며 cyanidin-3-glucoside가항산화활성이높은것으로알려져 Copyright c 2017 by the Korean Society of Breeding Science This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
360 韓育誌 (Korean J. Breed. Sci.) 49(4), 2017 있다 (Kim et al. 1999, Moreno et al. 2005). 카로티노이드는황색에서적색까지의색을나타내는지용성색소물질로옥수수에는주로 lutein, zeaxanthin, α-carotene, β-carotene 등으로존재한다 (Kandianis 2009, Tanaka et al. 2008). 카로티노이드는비타민A 합성의전구물질로이용되고면역력향상에도움을주며자체적으로항산화기능을가지고있다 (Cazzonelli 2011, Eldahshan & Singab 2013). 국내에서는미흑찰 (Park et al. 2007), 얼룩찰1호 (Lee et al. 2011), 흑진주찰 (Jung et al. 2009) 등안토시아닌을함유한다양한찰옥수수품종들이개발되어보급되고있지만카로티노이드를함유한찰옥수수품종개발은시작단계에있으며아직까지상용화되어있는품종은찾아보기힘들다. 따라서, 수확시기에따른노랑찰옥수수의카로티노이드함량및항산화활성의변화를구명하여노랑찰옥수수품종육성에기초자료를제공하고카로티노이드함량이높은유전자원탐색에활용하고자본연구를수행하였다. 재료및방법공시재료노랑찰옥수수 13 자식계통과 18 교잡계를농촌진흥청국립식량과학원시험포장에파종하여개화기에인공교배한후수확하여분석에이용하였다. 노랑찰옥수수시험구는재식밀도 60 25 cm (6,600본/10a) 로시험구크기는 4m, 3열로하였고 2립씩파종하여 3~5엽기에 1주만남도록솎아주었으며재배관리는농촌진흥청식용옥수수표준재배법에준하여실시하였다. 균일한분석시료를얻기위하여옥수수가출사되기전이삭에교배비닐을씌워다른옥수수의꽃가루혼입을방지하였고각각의시료별로 40주를인공교배한후교배일을표시하였다. 인공교배후 19일부터 27일까지 2일간격으로각각 3개이삭을수확하였고완숙되는 45일째 3개의이삭을수확하였으며수확한시료는 74 초저온냉장고에저장하여보관후분석에이용하였다. 총카로티노이드함량분석 Al-Farsi et al. (2005) 방법을응용하여측정하였다. 시료는동결건조하여분쇄한후 100 mesh 체로걸러분석에이용하였다. 총카로티노이드함량분석은 2 g의시료에아세톤 : 에탄올 1:1 (v/v) 을이용하여암조건에서추출하였다. 추출액은 10분간 4, 12,000 rpm에서원심분리하였으며상등액은 Whatman No.42 를이용하여분리한후 Spectrophotometer (U-2900, HITACHI) 를사용하여 470 nm에서측정하였다. 총카로티노이드함량은다음의계산식을이용하여계산하였다. 총카로티노이드함량 A 470 은 470 nm에서흡광도, V는추출물의총부피, A 1% 는카로티노이드 1% 혼합물에대한흡광계수, G는시료중량 (g) 을나타낸다. 항산화활성 (Diphenyl picryl hydrazyl, DPPH) 검정분쇄한시료 2 g에 80% 메탄올 50 ml 첨가하여 25 shaking water bath에서 24시간교반하여추출하였고 Whatman No.42 로여과하였다. 추출한시료여과액을 96 well plate에 100 μl씩분주하고 0.4 mm DPPH용액을동량첨가하여실온에서 10분간반응시킨후 Spectrophotometer (U-2900, HITACHI) 로 517 nm에서흡광도를측정하였다. DPPH 활성산소소거능은다음의식을이용하여계산하였고 DPPH의흡광도가 50% 감소할때나타나는시료의농도로표시하였다. 활성산소소거능 Ac 는시료대신메탄올을첨가하여흡광도를측정한것이고 As 는시료를첨가하여반응한반응액의흡광도를나타낸다. Hunter s Lab 값측정 노랑찰옥수수색차측정은인공교배후각시기별로수확한종실을이용하여수행하였으며수확한종자를탈립후실험용체를이용하여이물질을제거하였다. 이물질을제거한찰옥수수종자를색차계셀에옥수수종실의상단부가아래로향하게정열하여넣은후색차계 (Model CM-3500D, Minolta, Tokyo, Japan) 를이용하여명도값 L (lightness), 적색도값 a (redness), 황색도값 b (yellowness) 등 Hunter s Lab 값을측정하였다. 통계분석 통계분석은 SAS 9.2 (SAS Institute Inc, USA) 와 Microsoft Excel 2010 (Microsoft, USA) 을이용하여수행하였다. 조사값들간의평균비교는 SAS 9.2를이용하여 Duncan의다중범위검정 (Duncan s multiple range test, DMRT) 으로 5% 유의수준
수확시기에따른노랑찰옥수수의총카로티노이드함량및항산화활성변화 361 Fig. 1. Mean total carotenoid contents in yellow waxy corn inbred lines and hybrids depending on harvest time. Table 1. Total carotenoid contents of 13 yellow waxy corn inbred lines depending on harvest time. Inbred Total carotenoid contents at days after pollination ( μg /g) 19 days 21 days 23 days 25 days 27 days 45 days KY2 11.5±0.0a z 11.4±0.3b 15.4±0.2a 14.4±0.1a 15.9±0.5a 9.4±0.4b KY3 4.5±0.8e 5.3±1.1ef 4.8±0.5fg 4.9±0.0hi 5.2±0.1hi 5.8±0.9c KY13 7.8±0.4c 8.2±0.7d 7.6±0.3d 8.1±0.6e 8.4±0.2de 12.2±1.4a KY17 6.2±0.4d 8.2±0.7d 6.9±1.2de 6.5±0.3fg 6.6±0.7fg 8.1±0.7b KY27 3.2±0.7fg 4.4±0.1f 4.4±0.7g 3.7±0.0j 4.8±0.1i 3.3±0.0d KY30 11.0±0.1a 14.1±0.7a 9.8±0.5c 13.3±0.8b 13.8±0.7b 13.4±0.5a KY34 1.6±0.7h 0.6±0.2g 1.3±0.4i 1.9±0.8k 1.6±0.9j 1.2±0.6e KY36 2.8±0.4g 4.8±0.4ef 5.3±0.0fg 7.4±0.5ef 6.1±0.4gh 5.4±0.4c KY37 4.2±0.7ef 5.9±0.7e 5.8±0.2ef 7.0±0.4f 7.4±0.3ef 6.7±0.1c KY39 4.6±0.0e 4.6±0.0f 4.3±0.0g 5.6±0.4gh 4.4±0.7i 3.1±0.5d KY41 8.9±0.3b 9.7±0.2c 11.2±0.7b 11.0±0.2c 8.7±0.7cd 12.1±0.6a KY43 7.0±0.6cd 7.5±0.0d 5.8±0.1ef 9.5±0.1d 9.9±0.3c 8.9±0.7b KY45 4.2±0.3ef 4.2±0.3f 2.7±0.7h 4.3±0.4ij 5.1±0.7hi 5.3±0.4c z Means in the same column followed by the same letter are not significantly (p<0.05) different by Duncan s multiple range test. 에서비교하였고조사값들의표준오차는 Excel 함수 STDEV.S 를이용하여구하였으며상관분석은 CORREL 함수를이용하여구하였다. 결과및고찰수확시기에따른노랑찰옥수수의총카로티노이드함량변화수확시기에따른노랑찰옥수수의총카로티노이드함량변화를분석하기위하여노랑찰옥수수의자식계통과교잡계를인공교배후 19일, 21일, 23일, 25일, 27일, 45일에수확하여총카로 티노이드함량을분석하였다. 수확시기에따른총카로티노이드함량은자식계통과교잡계에서평균적으로인공교배후 19일부터증가하다가 25~27일경가장높은함량을나타내었고이후에는총카로티노이드함량에큰변화가없었으며각각의자식계통및교잡계의총카로티노이드함량의변화양상은유사하였다 (Fig. 1). 이것은단옥수수는출사후 25일, 일반옥수수는출사후 28일에총카로티노이드함량이가장높고, 찰옥수수의경우미성숙종자에서가장높은카로티노이드함량을나타내며, 이러한특성들은품종간차이가있다는기존의연구보고와유사한결과였다 (Hu & Xu 2011,
362 韓育誌 (Korean J. Breed. Sci.) 49(4), 2017 Table 2. Total carotenoid contents of 18 yellow waxy corn hybrids depending on harvest time. Hybrid Total carotenoid content at days after pollination ( μg /g) 19 days 21 days 23 days 25 days 27 days 45 days KY2/KY39 6.6±0.4b z 8.1±0.8d 11.2±0.3a 10.6±0.1b 9.5±0.7bc 6.8±0.1fgh KY3/KY13 6.6±0.0b 6.7±0.5efg 5.3±0.2fg 6.1±0.7fg 6.8±1.0fg 6.2±0.1h KY3/KY30 11.3±0.1a 10.9±0.7a 8.1±0.4bc 11.9±0.2b 10.7±0.7b 9.8±0.5c KY3/KY39 3.6±0.3e 4.2±0.7i 5.7±0.8f 7.2±1.2def 5.5±0.6h 6.7±0.3fgh KY13/KY17 4.1±0.7de 5.9±0.5fgh 7.3±0.7bcde 6.5±0.0ef 9.4±0.2cd 8.6±0.1de KY13/KY30 7.0±0.5b 8.7±1.0cd 9.9±0.8a 10.7±1.3b 10.0±0.9bc 10.5±0.4bc KY17/KY30 11.4±0.7a 8.6±0.1cd 10.9±0.5a 15.7±0.0a 16.4±0.9a 15.7±0.1a KY17/KY39 5.0±0.3cd 6.9±0.2ef 6.4±0.5def 7.9±0.3cde 7.4±0.2ef 6.2±0.6h KY27/KY30 5.9±0.6bc 10.6±0.3ab 8.5±0.9b 8.4±0.5cd 8.3±0.9de 6.4±0.5gh KY27/KY36 5.2±0.7cd 5.6±0.7gh 7.9±0.5bcd 7.1±0.4def 7.4±0.2ef 5.7±0.1h KY27/KY37 5.1±0.5cd 7.8±0.2de 6.5±0.3def 5.9±0.4fg 3.1±0.2i 5.8±0.2h KY30/KY39 4.7±0.6d 7.7±0.2de 7.8±0.2bcd 8.3±0.9cd 10.5±0.5bc 11.3±0.0b KY34/KY27 2.5±0.0f 2.8±0.2j 4.1±0.7g 3.7±0.1h 4.1±0.2i 3.6±0.1i KY34/KY36 5.0±0.4cd 5.6±0.5gh 5.6±0.9fg 9.0±1.3c 6.0±0.1gh 7.6±1.2efg KY34/KY37 5.9±0.2bc 5.0±0.2hi 5.9±1.1ef 6.3±0.4ef 7.7±0.2ef 7.8±1.2ef KY34/KY43 4.5±0.6de 3.9±0.8ij 6.8±1.1cdef 7.2±1.1def 7.9±0.2ef 9.6±0.2cd KY34/KY45 6.7±0.5b 6.7±0.5efg 4.1±0.3g 4.6±0.2gh 5.8±0.1gh 4.2±0.1i KY41/KY45 11.9±0.2a 9.7±0.5bc 6.7±0.4cdef 8.6±0.8cd 9.7±0.2bc 11.6±1.0b z Means in the same column followed by the same letter are not significantly (p<0.05) different by Duncan s multiple range test. Song et al. 2016). 또한, 출사후등숙기간이증가함에따라총카로티노이드함량은처음에는감소하다가증가한후성숙단계에서다시감소한다는기존의연구결과와는차이가있었다 (Xu et al. 2010). 수확시기에따른노랑찰옥수수 13 자식계통의총카로티노이드함량을분석한결과, KY17 등 2 계통은인공교배후 21일경에, KY34 등 3 계통은인공교배후 25일경에, KY2 등 4 계통은인공교배후 27일에, KY3 등 4 계통은인공교배후 45일에가장높은함량을나타내었다 (Table 1). 인공교배후 45일에총카로티노이드함량이높게나타난것은미성숙한종자보다성숙한종자에서총카로티노이드함량이높다는기존의보고와유사한결과였으며, 계통에따라카로티노이드가축적되는양상에차이가있는것으로생각되었다 (Khampas et al. 2013). 찰옥수수를수확하여이용하는시기인인공교배후 23일에는 KY2가 15.4 μg /g으로가장높은총카로티노이드함량을나타내었으며그다음으로 KY41, KY30 순으로높은함량을나타내었다 (Table 1). 수확시기에따른노랑찰옥수수교잡계의총카로티노이드함량은평균적으로 Fig. 1과같이자식계통보다높은함량을나타 내었다. 수확시기에따른노랑찰옥수수 18 교잡계의총카로티노이드함량을분석한결과, KY34/KY45 등 2 교잡계는인공교배후 19일에, KY27/KY30 등 2 교잡계는인공교배후 21일에, KY2/KY39 등 3교잡계는인공교배후 23일에, KY3/KY30 등 6 교잡계는인공교배후 25일에, KY3/KY13 등 2 교잡계는인공교배후 27일에, KY30/KY39 등 3 교잡계는인공교배후 45일에총카로티노이드함량이가장높았다 (Table 2). 노랑찰옥수수수확시기인인공교배후 23일에는 KY2/KY39가총카로티노이드함량이 11.2 μg /g으로가장높은함량을나타내었으며 KY13/KY30, KY17/KY30 등 2 교잡계와총카로티노이드함량에유의한차이는없었다 (Table 2). 인공교배후 23일에노랑찰옥수수교잡계와그들의부모계통간총카로티노이드함량을비교분석한결과, 교잡계의총카로티노이드함량은 KY3/KY13, KY41/KY45 등 2 교잡계를제외한대부분의교잡계에서부모계통의평균총카로티노이드함량보다높은함량을나타내었고 KY27/KY36의경우교잡계의총카로티노이드함량이그의부모계통보다유의하게높았으며부모계통의총카로티노이드함량이높으면그의교잡계역시총카로티노이드함량이높은
수확시기에따른노랑찰옥수수의총카로티노이드함량및항산화활성변화 363 Fig. 2. Comparison of total carotenoid contents between yellow waxy hybrids and their parent lines at 23 days after pollination. Fig. 3. Mean antioxidant activities in yellow waxy corn inbred lines and hybrids depending on harvest time. 경향을나타내었다 (Fig. 2). 옥수수에서카로티노이드합성에관여하는유전자는 y1, y9 등이있고그외에도다양한 QTL이존재하기때문에카로티노이드관련유전자들의조성에따라노랑찰옥수수부모계통과교잡계의총카로티노이드함량에차이가있는것으로생각되었다 (Wurtzel et al. 2012). 수확시기에따른노랑찰옥수수의항산화활성변화수확시기에따른노랑찰옥수수의항산화활성의변화양상을구명하기위하여수확시기별항산화활성을분석하였다. 노랑찰옥수수의항산화활성은자식계통과교잡계에서모두평균적으로수확시기가늦어질수록감소하다가다시증가하는경향을 나타내어총카로티노이드함량의변화와는차이가있었고자식계통은인공교배후 45일에, 교잡계는인공교배후 19일에가장높은항산화활성을나타내었으며평균적으로교잡계의항산화활성이자식계통보다높은경향을나타내었다 (Fig. 3). 노란색단옥수수류의활성산소소거능은미성숙한종자보다성숙한종자에서높다고보고되고있지만자식계통과교잡계간에활성산소소거능이가장높은시기에는차이가있었으며이것은각각의옥수수간에유전적배경이다르고페놀화합물등다른항산화물질들의발현양상의차이에기인한것으로생각되었다 (Hu & Xu 2011; Khampas et al. 2013). 수확시기에따른노랑찰옥수수자식계통의항산화활성을분석한결과, KY2 등 2 계통은
364 韓育誌 (Korean J. Breed. Sci.) 49(4), 2017 Table 3. Antioxidant activities of 13 yellow waxy corn inbred lines depending on harvest time. Inbred Antioxidant activity at days after pollination (%) 19 days 21 days 23 days 25 days 27 days 45 days KY2 42.5±2.7b z 38.5±1.7c 36.1±3.4bc 34.1±3.4bcd 32.2±1.5b 24.9±1.1h KY3 19.7±1.9f 17.7±1.5j 26.1±2.5f 19.7±2.7f 20.0±0.7e 20.1±2.2i KY13 17.2±2.2fg 22.5±0.8i 18.0±1.7h 11.0±0.8g 10.7±1.3f 23.7±1.2h KY17 30.4±1.4d 31.7±1.4g 26.6±2.4f 26.4±0.2e 29.2±1.6c 37.0±3.4cd KY27 43.3±1.6b 41.0±1.7b 38.4±0.7ab 37.6±1.0ab 32.8±0.8b 43.8±2.7b KY30 23.6±0.3e 25.1±1.2h 15.2±1.2h 19.0±1.1f 25.2±1.3d 43.8±2.3b KY34 16.5±1.4g 35.4±1.1de 40.4±0.2a 36.3±5.9abc 33.3±0.6b 34.7±0.4de KY36 19.6±2.2f 19.2±2.4j 22.8±2.1g 21.6±1.0f 20.7±0.5e 30.9±0.4fg KY37 28.9±0.9d 34.4±0.3ef 30.2±1.6e 31.3±0.8d 37.6±0.6a 29.2±1.5g KY39 36.1±0.4c 36.6±1.5cde 32.4±1.1de 34.2±1.9bcd 29.6±1.3c 38.5±1.2c KY41 37.0±0.3c 32.8±1.0fg 34.8±0.4cd 32.8±0.9cd 31.8±1.0b 35.1±0.5de KY43 34.6±1.6c 37.2±0.4cd 17.4±0.5h 32.0±0.3d 32.6±0.5b 33.2±1.2ef KY45 49.0±1.1a 43.7±1.7a 38.5±2.2ab 39.9±2.3a 38.6±1.4a 55.1±2.1a z Means in the same column followed by the same letter are not significantly (p<0.05) different by Duncan s multiple range test. Table 4. Antioxidant activities of 18 yellow waxy corn hybrids depending on harvest time. Hybrid Antioxidant activity at days after pollination ( μg /g) 19 days 21 days 23 days 25 days 27 days 45 days KY2/KY39 61.4±0.7c z 55.1±1.0b 62.5±1.3a 57.0±1.8a 53.1±1.3b 43.6±0.9ab KY3/KY13 84.3±0.3a 80.1±0.9a 56.0±1.4b 48.4±1.4c 49.7±1.7c 37.3±2.2c KY3/KY30 41.3±0.2g 37.9±1.5ef 27.9±1.7ij 40.2±2.0e 29.7±1.3gh 31.5±0.8de KY3/KY39 41.1±0.9g 40.4±1.9de 44.7±0.9de 38.2±0.6ef 38.0±1.0d 33.2±0.9d KY13/KY17 37.7±0.3h 42.4±0.9d 47.8±0.7cd 50.3±1.4bc 57.2±0.3a 45.3±3.2ab KY13/KY30 32.9±0.2jk 30.6±0.2g 40.4±1.4fg 29.8±1.1g 26.9±0.8ij 38.1±1.9c KY17/KY30 49.0±1.2ef 31.3±2.2g 55.6±2.6b 23.4±0.4h 27.8±0.1hij 28.9±0.7efg KY17/KY39 34.8±1.1ij 37.3±1.6f 33.8±0.1h 44.0±1.0d 39.8±1.3d 44.9±0.8ab KY27/KY30 79.4±0.4b 38.3±0.1ef 37.4±1.7g 31.8±1.3g 32.6±1.4ef 45.2±1.0ab KY27/KY36 40.8±1.6g 36.2±1.0f 29.6±3.9i 37.1±2.8f 28.9±1.4hi 45.0±0.8ab KY27/KY37 37.1±1.9hi 41.9±2.6d 51.4±0.8c 35.7±1.5f 38.4±1.6d 42.6±2.3b KY30/KY39 13.6±1.1n 25.7±2.0h 24.3±4.1jk 16.3±2.6i 14.7±2.4l 25.6±2.5gh KY34/KY27 31.9±1.9k 20.7±1.0i 29.7±4.5i 24.3±3.0h 32.8±1.2e 37.9±1.1c KY34/KY36 46.6±2.5f 49.0±2.0c 42.3±1.3ef 44.5±1.2d 27.2±1.5hij 29.5±2.7ef KY34/KY37 51.9±2.4d 53.5±2.2b 63.1±1.6a 53.0±1.8b 32.2±1.7efg 22.4±1.6h KY34/KY43 51.0±3.1de 32.2±2.2g 37.7±1.9g 30.0±1.6g 21.4±2.9k 27.6±2.9fg KY34/KY45 26.1±2.0l 23.7±1.6h 22.5±2.0k 18.5±2.2i 30.0±1.9fgh 46.4±1.6a KY41/KY45 20.7±1.5m 16.2±0.2j 13.5±1.2l 11.5±0.6j 25.8±0.9j 28.9±3.0efg z Means in the same column followed by the same letter are not significantly (p<0.05) different by Duncan s multiple range test. 인공교배후 19일에, KY43은인공교배후 21일에, KY3 등 2 계통은인공교배후 23일에, KY37은인공교배후 27일에, KY13 등 7 계통은인공교배후 45일에항산화활성이가장높았다 (Table 3). 특히, 총카로티노이드함량이상대적으로적었던 KY45가수확시기전체적으로유의하게높은활성을나타내었고인공교배후 23일에는 KY34가 40.4% 로가장높은활성을나타내었으며상대적으로총카로티노이드함량이많았던 KY30 이 15.2% 로가장낮은항산화활성을나타내었다 (Table 3). 수확시기에따른노랑찰옥수수교잡계의항산화활성을분석한결과, KY3/KY13 등 4 교잡계는인공교배후 19일에, KY30/KY39 등 2 교잡계는인공교배후 21일에, KY2/KY39 등 6 교잡계는인공교배후 23일에, KY13/KY17은인공교배후 27일에, KY17/KY39 등 4 교잡계는인공교배후 45일에가장높은항산화활성을나타내었다 (Table 4). 공시교잡계
수확시기에따른노랑찰옥수수의총카로티노이드함량및항산화활성변화 365 Fig. 4. Comparison of antioxidant activities between yellow waxy hybrids and their parent lines at 23 days after pollination. 중에서인공교배후 23일에는 KY34/KY37이 63.1% 로가장높은항산화활성을나타내었으며 KY2/KY39와항산화활성에유의한차이는없었다 (Table 4). 노랑찰옥수수교잡계의항산화활성은그들의부모계통의항산화활성에따라차이가있었고인공교배후 23일의항산화활성은 KY27/KY36, KY30/KY39, KY34/KY27, KY34/KY43, KY34/KY45, KY41/KY45 등 6 교잡계를제외한 12 교잡계가부모계통보다높거나부모계통중어느한계통과유사하였으며총카로티노이드함량이상대적으로적었던 KY3/KY13이항산화활성이상대적으로높은수준을나타내었다 (Fig. 4). 노랑찰옥수수의총카로티노이드함량에대한항산화활성에미치는영향을구명하기위하여상관분석을실시하였다. 자식계통과교잡계의총카로티노이드함량과항산화활성의상관분석결과, 자식계통과교잡계는상관계수 (r) 가각각 -0.12(p>0.05), -0.13(p>0.05) 으로낮은부의상관을나타내었으며총카로티노이드함량과항산화활성간에는상관이낮은것으로생각되었다. Ku et al. (2014) 은 ABTS 활성산소소거능분석과 FRAP(ferric reducing antioxidant power) 분석을통해총카로티노이드와항산화활성의상관관계를분석한결과, 항산화활성과총카로티노이드함량간의상관관계가없었지만이것은카로티노이드와같은비극성화합물에대한용매추출방법이적합하지않았기때문이라고하였다. Hexane을용매로이용하여총카로티노이드를추출하면총카로티노이드함량에따라항산화활성이직선적으로증가한다고보고되고있으나본연구에서카로티노이드 추출에사용한아세톤 1: 에탄올 1 (v/v) 은카로티노이드의항산화활성을검정하기에는부적합한추출용매로생각되었으며효과적인카로티노이드의항산화활성측정을위해서는 Hexane 등다른용매를이용하여추출하는것이좋을것으로생각되었다 (Kljak & Grbeša 2015). 수확시기에따른노랑찰옥수수의 Hunter s Lab 값의변화총카로티노이드함량과색차간의상관관계를분석하기위하여수확시기별노랑찰옥수수종실의 Hunter s Lab 값을분석하고총카로티노이드함량과의상관을분석하였다. 노랑찰옥수수의자식계통과교잡계의명도는수확시기가늦어질수록지속적으로감소하는경향을나타내었고적색도는증가하였으며황색도는증가하다가낮아지는경향을나타내었다 (Fig. 5). Hunter s Lab 값과총카로티노이드함량의상관분석결과, Hunter s Lab 값과총카로티노이드함량에는유의한상관이있었고명도는상관계수가 -0.22(p<0.05) 로부의상관관계, 적색도와황색도는각각 0.67 (p<0.05), 0.53(p<0.05) 으로정의상관관계였으며상대적으로적색도와황색도가명도보다높은상관을나타내었다 (Fig. 6). Hunter s Lab 값과총카로티노이드함량의상관분석결과, 명도는결정계수 (R 2 ) 가 0.05로이를이용하여총카로티노이드함량을설명하기는힘들것으로생각되었다. 적색도와황색도는값이증가함에따라총카로티노이드함량이증가하였고각각의결정계수가 0.46, 0.28로, 적색도와황색도를이용하여총카로티노이드함량이높은자식계통및교잡계선발이가능할
366 韓育誌 (Korean J. Breed. Sci.) 49(4), 2017 Fig. 5. Mean Hunter s Lab value of yellow waxy corn inbred lines and hybrids depending on harvest time. a) Lightness; b) Redness; c) Yellowness. Fig. 6. Correlation between Hunter s Lab and total carotenoid contents in yellow waxy corns. a) Lightness; b) Redness; c) Yellowness. 것으로생각되었다 (Fig. 6). 옥수수종실의색차를이용한선발방법은비파괴적인분석방법으로유전자원의소실을막을수있으며전문적인지식이없더라도쉽게이용이가능하므로총카로티노이드함량이높은자원탐색및계통선발에도유용하게이용할수있을것으로생각되었다. 적요본연구는노랑찰옥수수수확시기에따라종실의총카로티노이드함량과항산화활성의변화양상을구명하고노랑찰옥수수품종육성에활용할수있는기초자료를제공하고자수행하였으며그결과는다음과같다. 노랑찰옥수수자식계통과교잡계의총카로티노이드함량은
수확시기에따른노랑찰옥수수의총카로티노이드함량및항산화활성변화 367 평균적으로인공교배후 19일부터증가하다가 25~27일경가장높은함량을나타내었고이후에는총카로티노이드함량에큰변화가없었으며교잡계가자식계통보다평균적으로높은함량을나타내었다. 찰옥수수를수확하여이용하는시기인인공교배후 23일의총카로티노이드함량은자식계통의경우 KY2가 15.4 μg /g으로가장높은함량을나타내었고교잡계의경우 KY2/KY39가 11.2 μg /g으로가장높은함량을나타내었다. 교잡계와부모계통의총카로티노이드함량을비교분석한결과, 교잡계의총카로티노이드함량은일부교잡계를제외하고는부모계통의평균보다높은함량을나타내었고 KY27/KY36의경우교잡계의총카로티노이드함량이부모계통보다유의하게높았다. 수확시기에따른노랑찰옥수수의항산화활성은자식계통과교잡계에서모두평균적으로수확시기가늦어질수록감소하다가다시증가하는경향을나타내었고교잡계가자식계통보다높은경향을나타내었다. 총카로티노이드함량과항산화활성의상관분석결과, 자식계통과교잡계의상관계수가각각 -0.12, -0.13 으로낮았다. 수확시기가늦어질수록노랑찰옥수수의명도는감소하였고적색도와황색도는증가하였으며총카로티노이드함량과상관분석결과, 상관계수가명도는 -0.22, 적색도는 0.67, 황색도는 0.53으로적색도와황색도가명도보다높았다. 사사본논문은농촌진흥청공동연구사업의과제번호 : PJ01249702 ( 식용옥수수우량계통육성시험 ) 에의해이루어진것임. REFERENCES 1. Al-farsi M, Alsalvar C, Morris A, Baron M, Shahidi F. 2005. Comparison of antioxidant activity, anthocyanins, carotenoid, and phenolics of three native fresh and sun-dried date (Pheoenix dactylifera L.) varieties grown in oman. J Agric Food Chem 53: 7592-7599. 2. Cazzonelli CI. 2011. Carotenoids in nature: insights from plants and beyond. Functional Plant Biology 38: 833 847. 3. Eldahshan OA., Singab ANB. 2013. Carotenoids J Pharmacogn Phytochem 2: 225-234. 4. Hu Q. P., Xu J. G. 2011. Profiles of carotenoids, anthocyanins, phenolics, and antioxidant activity of selected color waxy corn grains during maturation. J Agric Food Chem 59: 2026-2033. 5. Jung T. W., Song S. Y., Son B. Y., Kim J. T., Baek S. B., Kim C. K., Kim S. L., Kim S. J., Kim S. K., Park K. J., Shin H. M., Huh C. S. 2009. A black waxy hybrid corn, Heukjinjuchal with good eating quality. Kor J Breed Sci 41: 599-602. 6. Kandianis C. 2009. Genetic dissection of carotenoid concentration and compositional traits in maize grain. Doctor of Philosophy, Illinois University at Urbana-Champaign, Crop Sciences. 7. Khampas S, Lertrat K, Lomthaisong K, Simla S, Suriharn B. 2013. Variability in phytochemicals and antioxidant activity in corn at immaturity and physiological maturity stages. Itnl Food Res J 20: 3149-3157. 8. Kim SL, Choi BH, Park SU, Moon HG. 1996. Functional ingredients of maize and their variation. Kor J Crop Sci 41(Special issue): 46-68. 9. Kim SL, Kim EH, Son YK, Song JC, Hwang JJ, Hur HS. 1999. Identification of anthocyanin pigments in black waxy corn kernels. Kor J Breed Sci 31: 408-415. 10. Kljak K, Grbeša D. 2015. Carotenoid content and antioxidant activity of hexane extracts from selected Croatian corn hybrids. Food Chem 167: 402-408. 11. Ku KM, Kim HS, Kim SK, Kang YH. 2014. Correlation an alysis between antioxidant activity and phytochemicals in K orean colored corns using principal component analysis. J Agri Sci 6: 1-9. 12. Lee JS, Jung TW, Song SY, Son BY, Kim JT, Kim SK, Kim SL, Baek SB, Seo JH, Lee JE, Kim SJ, Kwon YU, Kim WH, Park KJ, Shin HM, Huh CS, Kang DS. 2011. A bicolor waxy corn hybrid with high eating quality, Eolrukchal 1. Kor J Breed Sci 43: 554-558. 13. Moreno YS, Sánchez GS, Hernández DR, Lobato NR. 2005. Characterization of anthocyanin extracts from maize kernels. J Chromatogr Sci 43: 483-487. 14. National Institute of Crop Science. 2012. 50 years history of crop science in Korea. pp. 163-177. 15. Park KJ, Ryu SH, Min HK, Seo JS, Park JY, Goh BD, Jang JS, Kim NS. 2007. A new black waxy corn hybrid Cultivar, Miheugchal with good eating quality and high yield. Kor J Breed Sci 39: 106-107. 16. Park SU, Park KY, Cha SW, Son YH, Park RK, Song SH, Hong JK, Kim UH. 1992. A new early maturing and high quality single cross waxy corn hybrid "Chalok 1".
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