Changes in Color Intensity and Components during Browning Reaction of White Ginseng Water Extract

백삼 물추출물의 갈변반응중 갈색도 및 성분의 변화

Changes of color intensity and components during browning reaction of water extracts from white tail ginseng were investigated. Temperature dependence was described by the Arrhenius relationship with an activation energy of 16kcal/mole. Temperature sensitivities$(Q_{10}\;value)$ for water extracts of ginseng was 1.90 between $70^{\circ}C\;and\;80^{\circ}C$, 1.57 between $80^{\circ}C\;and\;90^{\circ}C$ and 1.46 between $90^{\circ}C\;and\;100^{\circ}C$. pH value of the solution treated at $90^{\circ}C\;and\;100^{\circ}C$ slightly increased with an increase in reaction time. Among ginseng saponins ginsenoside-Re was most unstable against heat-treatment, white diol group saponins were more stable against heat-treatment. Hydrogen donating activity (reducing activity for ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$) and 3,5-dinitrosalicylic acid(DNS) positive substances of browning reaction products increased in proportion to the length of browning reaction time and temperature, whereas folin positive substances decreased by heat-denaturation of ginseng protein at initial reaction time and then increased thereafter.

인삼갈변기작을 연구하기에 앞서 인삼갈변에 따른 갈색도 및 성분변화에 대해 조사한 결과는 다음과 같다. $100^{\circ}C$에서 120시간까지 열처리하여도 갈색화반응은 계속 지속되었으며 갈변에 대한 활성화에너지는 약 16kcal/mole, $Q_{10}$값은 평균치가 $70{\sim}80^{\circ}C$에서는 1.90, $80{\sim}90^{\circ}C$에서는 1.67, $90{\sim}100^{\circ}C$에서는 1.46이었다. 반응액의 pH는 $90^{\circ}C$와 $100^{\circ}C$의 경우 약간씩 증가하는 경향이었다. 인삼사포닌 중에는 ginsenoside-Re가 열에 불안정하였으며 diol계 사포닌은 비교적 열에 안정하였다. 항산화능과 DNA 양성물질량은 온도가 높을수록, 반응시간이 경과할수록 증가하였으며, folin 양성물질량은 반응초기에 단백질의 침전과 함께 감소했다가 서서히 증가하였다.