μ

μ

초콩의제조중기능적특성비교 173 Table 1. Changes in total polyphenol contents of Chokong as affected by soaking time Extracting solvents Chokong 1) Soaking time (days) 1 4 7 10 14 Water 70% ethanol solution 23.46±4.62 b2) 21.72±2.77 ab 28.59±2.52 b 35.16±1.83 b 26.61±2.96 c 40.35±4.06 b 19.48±3.08 b 18.63±2.75 b 22.38±3.19 c 28.70±3.25 c 30.29±1.64 b 34.07±3.11 c 20.13±3.41 b 19.51±3.77 b 25.65±4.89 bc 33.29±1.38 b 30.37±3.08 b 43.68±3.14 ab 26.22±3.39 ab 22.70±4.81 ab 30.83±3.64 b 35.86±2.32 b 38.99±3.79 a 42.27±4.30 ab (mg/g) 29.60±2.59 a 25.08±2.30 a 34.90±2.92 a 44.83±3.71 a 40.74±2.25 a 46.97±4.15 a Values are mean±sd (n=3). 1) I: chokong prepared through soaking black soybean in unpolished rice vinegar, : chokong prepared through soaking black soybean in apple vinegar, : chokong prepared through soaking black soybean in persimmon vinegar. 2) Different superscript letters within the same row are significantly different at 0.05 by Duncan's multiple range test. Table 2. Changes in total flavonoid contents of Chokong as affected by soaking time Extracting solvents Chokong 1) Soaking time (days) 1 4 7 10 14 Water 2.17±0.12 2.03±0.25 3.02±0.33 2.20±0.10 1.92±0.46 2.50±0.31 3.62±0.09 3.50±0.18 3.77±0.11 b 2.15±0.29 2.10±0.09 2.54±0.17 3.70±0.48 3.42±0.19 3.80±0.31 b 2.33±0.30 2.16±0.24 2.66±0.28 3.78±0.50 3.61±0.47 3.97±0.58 ab (mg/g) 2.30±0.40 2.19±0.27 2.75±0.42 3.93±0.63 3.87±0.76 4.15±0.32 ab 70% ethanol solution 3.73±0.51 3.59±0.42 4.39±0.29 a2) Values are mean±sd (n=3). 1) I: chokong prepared through soaking black soybean in unpolished rice vinegar, : chokong prepared through soaking black soybean in apple vinegar, : chokong prepared through soaking black soybean in persimmon vinegar. 2) Different superscript letters within the same row are significantly different at 0.05 by Duncan's multiple range test. 태 ) 의플라보노이드함량 ( 물추출 : 6.07 mg/g, 70% 에탄올추출 : 7.49 mg/g) 을감안해볼때, 식초에 1일간담금하는동안에크게감소하며그이후소폭증가경향을나타내었으나대부분유의적인차이가없었다. 플라보노이드는넓은의미에서 anthoxanthin류, tannin류, anthocyanin류등으로분류되며, 검정콩에는 anthoxanthin류에속하는 isoflavone 성분과 anthocyanin 색소가함유되어있다 (22,23). Isoflavone 은콩을식초에담금한기간이길수록증가하는것으로보고 (24) 되기도하였으나, Bang 등 (25) 은감식초를이용하여제조된초콩의플라보노이드함량이감소하였다고보고하여본연구결과와유사하였다. 이는초콩의플라보노이드 함량이검정콩의식초담금시 anthocyanin 성분감소에크게영향을받은결과로추측된다. 초콩의총폴리페놀과플라보노이드는물추출보다 70% 에탄올추출물에서좀더높은함량을나타내었다. 전자공여능및 ABTS 라디칼소거활성 Fig. 1은초콩의항산화활성을조사하기위하여전자공여능을측정한결과이다. 초콩의전자공여능은물추출물보다 70% 에탄올추출물에서전반적으로높은값을나타내었으며, 초콩제조시검정콩의식초담금기간이길수록증가하는경향이었다. 대조구로사용한 BHT 용액의전자공여능은 (A) (B) I II III I II III Fig. 1. Changes in electron donating activities of water extracts (A) and 70% ethanol extracts (B) for chokong as affected by soaking time. : chokong prepared through soaking black soybean in unpolished rice vinegar, : chokong prepared through soaking black soybean in apple vinegar, : chokong prepared through soaking black soybean in persimmon vinegar. Different letters (a-c) within the same group are significantly different at 0.05 by Duncan's multiple range test. Sample concentration is 100 mg of chokong per 1 ml.

174 서지형 정용진 Table 3. Changes in ABTS radical scavenging activity of Chokong as affected by soaking time Extracting solvents Chokong 1) Soaking time (days) 1 4 7 10 14 Water 70% ethanol solution 63.5±7.2 66.1±6.4 69.2±4.7 107.4±5.1 c2) 109.3±3.6 b 117.6±6.9 ab 61.7±8.3 62.1±6.8 70.5±7.0 105.6±2.6 c 106.6±5.5 b 110.8±4.4 b 65.2±4.8 69.3±5.7 72.6±5.3 115.0±4.9 b 114.8±9.1 ab 118.3±8.9 ab 67.6±3.7 70.9±8.1 74.1±9.4 121.9±2.9 a 119.5±8.3 a 122.6±5.8 a (mg VCE/g) 72.1±9.5 71.8±5.8 73.5±7.3 123.4±6.8 a 122.1±6.0 a 125.3±5.4 a Values are mean±sd (n=3). The level of ABTS radical scavenging activity is expressed as mg vitamin C equivalents (VCE)/g. 1) I: chokong prepared through soaking black soybean in unpolished rice vinegar, : chokong prepared through soaking black soybean in apple vinegar, : chokong prepared through soaking black soybean in persimmon vinegar. 2) Different superscript letters within the same row are significantly different at 0.05 by Duncan's multiple range test. 89.3% 였으며, 검정콩을감식초에 7일이상담금하거나, 현미식초및사과식초에 10일간이상담금하여제조한초콩의 70% 에탄올추출물에서 50% 이상의전자공여능을나타내었다. 검정콩의식초담금기간이 1~7일내외일때전자공여능은감식초로제조한초콩 () 에서높은경향이었으나, 초콩제조기간이길어짐에따라식초종류에따른초콩간전자공여능차이는근소해졌다. 콩에는항산화성분으로폴리페놀, isoflavone, tocopherol, peptide 등이함유되어있으며 (26), 검정콩에는이밖에도 anthocyanin 색소가존재하여항산화성분의작용에시너지효과를기대할수있다 (27). 식초또한폴리페놀, 플라보노이드등의함량에따라서다양한항산화활성을나타내며발사믹식초이외에석류식초, 홍삼식초, 감식초등의항산화효과가양호한것으로보고 (5,28) 되고있다. 한편 DPPH법에의한전자공여능은항산화능분석에폭넓게이용되고있으나 genistein이나 daidzein의활성측정에는효과가미미하다는보고 (29,30) 가있다. 이에초콩의항산화활성에대한부가적인평가로 ABTS 라디칼소거활성을측정하였다. 항산화능분석법의일종인 TEAC법 (18) 은 ABTS 라디칼의흡광도가항산화성물질에의해억제되는원리를이용하며 DPPH법과비교해볼때 isoflavone으로 인한항산화능측정에효과적인것으로보고 (29) 되었다. Table 3에서초콩의 ABTS 라디칼소거활성또한초콩의제조기간이길어짐에따라점차증가하는경향이었으며, 특히초콩의 70% 에탄올추출물은물추출물보다 ABTS 라디칼소거활성이 1.6~1.8배높았고검정콩의식초담금기간에따라유의적으로증가하였다. ABTS 라디칼소거능도전자공여능과유사하게초콩의제조기간이길어짐에따라식초종류에따른차이가감소하는경향이었다. 전자공여능과 ABTS 라디칼소거능에대한결과로볼때초콩제조시검정콩을식초에담금한기간이경과됨에따라식초에함유된항산화성분의유입과검정콩성분의산분해로인한항산화성분의증가등으로초콩의항산화효과가향상될것으로추측되며, 구체적인항산화성분의변화에대해서는부가적인연구가요망된다. 아질산염분해능 Fig. 2는초콩의아질산염분해능을조사한결과이다. 대조구 (ascorbic acid) 의아질산염분해능은 73.2% 였으며초콩의아질산염분해능은물추출조건에서 20.37~ 28.01%, 70% 에탄올추출조건에서 25.32~38.51% 를나타내었다. 각초콩에서물추출물은아질산염분해능의유의적인변화가 (A) (B) I II III I II III Fig. 2. Changes in nitrite scavenging abilities of water extracts (A) and 70% ethanol extracts (B) for chokong as affected by soaking time. : chokong prepared through soaking black soybean in unpolished rice vinegar, : chokong prepared through soaking black soybean in apple vinegar, : chokong prepared through soaking black soybean in persimmon vinegar. Different letters (a,b) within the same group are significantly different at 0.05 by Duncan's multiple range test. Sample concentration is 100 mg of chokong per 1 ml.