꽃양배추 색소의 추출특성

Extraction Characteristics of Red Flower Cabbage Pigment

새로운 천연식용색소원으로서 꽃양배추(Brassica oleracea L. var. acephala)로부터 anthocyanin색소의 추출특성을 조사하였다. 추출된 색소는 $pH\;1{\sim}12$의 범위에서 pH가 높아질수록 ${\lambda}_{max}$가 장파장 쪽으로 이동하는 bathochromic shift 현상을 보였으며 추출용매의 citric acid의 농도가 증가수록 추출속도가 빨라지고 TOD가 증가하였다. 꽃양배추 색소의 추출용매에 $0.8{\sim}1.0%$ citric acid를 첨가하였을 때 최대 TOD값을 나타냈으며 추출용매인 증류수에 10-20% ethanol을 첨가하였을 때 색소의 추출효율이 높게 나타났다. 따라서 citric acid 0.8%를 함유한 10% ethanol 수용액이 꽃양배추 색소를 추출하기 위한 가장 적합한 용매로 결정하였다. 추출 온도가 높을수록 색소추출속도가 증가하였으나 고온에서 추출할 경우 추출시간이 길어지면 색소가 파괴되어 TOD값이 감소하였다. 추출온도 5, 20, 40 및 $60^{\circ}C$에서 TOD값이 2.1에 이르는 시간은 각각 24, 8, 4, 2시간으로 추출온도가 높을수록 추출속도가 증가하여 추출시간이 단축되었다.

Extraction characteristics of anthocyanin pigment from red flower cabbage(Brassica oleracea L. var. acephala) as a new source of natural food colorant were investigated. The pigment extracted from red flower cabbage showed the characteristic bathochromic shift of the maximum wavelength of light absorption(${\lambda}_{max}$) as pH of the solution changed from pH 1 to 12. As the concentration of citric acid in the extraction solvent increased, extraction rate and total optical density(TOD) of the extract increased. Maximum TOD was obtained by using the extracting solvent including $0.8{\sim}1.0%$ citric acid and stable pigment solution was obtained by using the extracting solvent including $10{\sim}20%$ ethanol in distilled water. As a result, 10% ethanolic solution with 0.8% citric acid was decided as the optimum extraction solvent for the anthocyanin pigment from red flower cabbage. Within the experimental ranges, the extraction rate increased and therefore extraction time decreased as the extraction temperature increased. The times to reach a certain value of TOD i.e., 2.1 were 24, 8, 4 and 2 hours at extraction temperature of 5, 20, 40 and $60^{\circ}C$, respectively.