Abstract
This study was carried out to investigate the thermal stability of gingerol from Ginger and effect of its concentration on the oxidation of soybean oil. After Heating gingerol, the contents of remained gingerol was measured by HPLC. After heat treatment at $105^{\circ}C$ for 3 hours, 94.5% of gingerol was remained, whereas at $165^{\circ}C$ for 30 min., only 10% of gingerol was remained. Crude gingerol was also added to soybean oil at the concentration of 0.02%, 0.1% and 0.2% by weight of oil, respectively. The oils with crude gingerol were heat-treated at $105^{\circ}C$ for 5 hours and $165^{\circ}C$ for 30 minutes, respectively, and then the heat-treated oils were incubated at $45^{\circ}C$ for 25 days. The peroxide value of the oils was measured in order to estimate the antioxidant activity of crude gingerol compared with BHT. In the soybean oil heated at $105^{\circ}C$ for 5 hours, crude gingerol showed antioxidant activity at all concentration and the activity was more effective than 0.02% BHT. And during the storage of the heat-treated oils at $45^{\circ}C$, the antioxidant activity of crude gingerol increased in direct proportion to its concentration. In the soybean oil heated at $165^{\circ}C$ for 30 minutes and then stored at $45^{\circ}C$, the antioxidant activity of crude gingerol increased in direct proportion to its concentration.
본 실험에서는 생강에서 추출한 crude gingerol의 열 안정성 및 대두유의 산화에 미치는 crude gingerol의 농도에 따른 항산화 효과를 검토하였다. $105^{\circ}C$에서 3시간 가열된 crude gingerol에는 94.5%의 gingerol이 잔존하는 반면, $165^{\circ}C$에서 30분간 가열된 경우에는 10.2%의 gingerol이 잔존하였다. 0.02%, 0.1% 및 0.2%의 crude gingerol이 첨가된 대두유를 $105^{\circ}C$에서 5시간 또는 $165^{\circ}C$에서 30분간 열처리한 후 $45^{\circ}C$에서 저장하면서 과산화물가의 변화를 측정하여 crude gingerol의 항산화효과를 BHT와 비교하였다. 0.02%, 0.1% 및 0.2%의 crude gillgerol이 첨가된 대두유를 $105^{\circ}C$에서 5시간 열처리 후 crude gingerol 첨가군은 BHT 첨가군보다 항산화 효과가 높았으며, 이 대두유를 $45^{\circ}C$에 저장하는 경우 crude gingerol의 항산화 효과는 gingerol의 농도가 증가함에 따라서 증가하였다. $165^{\circ}C$에서 30분간 열처리 한 후 $45^{\circ}C$에 저장된 0.02%, 0.1% 및 0.2%의 crude gingerol이 첨가된 대두유에서 crude gingerol의 농도가 증가함에 따라 그 항산화 효과가 증가하였다.