Change of Antioxidant Activities in Preparing Freeze Dried Wild Vegetable Block for the Long-term Storage

The antioxidant activities of water extracts from wild vegetables such as Ligularia fischeri (GC), Capsicum annuum L. (GCY), Aster scaber (CNM), Petasites japonicus S. et Z. Max (MYD), Ipomoea batatas L. (Lam) (GGM) were evaluated and compared with water extracts from freeze dried block. The antioxidant properties of water extracts from wild vegetables and their freeze dried block were evaluated using different antioxidant tests; 2.2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and nitrite scavenging activities. The water extracts from wild vegetables were found to have a higher total phenolic content than water extracts from freeze dried block. Total phenolic contents of water extracts from GC, GCY, CNM, MYD, and GGM were $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;{\mu}g/mg\;and\;122.67{\pm}3.51\;{\mu}g/mg$, respectively. At the concentrations of 1000 ppm, water extracts from GC, GCY, CNM, and GGM showed higher activities than water extracts from their freeze dried block on DPPH radical scavenger activity. The activity of water extracts from CNM, GC, GCY, MYD, and GGM were 90.9%, 89.9%, 76.6%, 71.1%, and 57.4%, respectively. When 10000 ppm of GC, GCY, CNM, MYD, and GGM water extracts tested for hydroxyl radical scavenging activity, activities were increased by 38.8%, 33.4%, 35.9%, 34.3%, and 33.8%, respectively and a similar effect was found with water extracts from GCY, CNM, and GGM freeze dried block at 10000 ppm concentration. However, the water extracts from GC and MYD was slightly more effective than freeze dried block extracts. The water extracts from wild vegetables and their freeze dried block had effective DPPH radical scavenger activity and hydroxyl radical scavenging activity at all tested concentrations. Nitrite scavenging activity of GC water extract significantly increased in a dose-dependent manner and the extract had higher nitrite scavenging activity than extracts freeze dried block extracts. We found that freeze dried block maintained antioxidant activities of the wild vegetables.

장기저장을 위해 제조한 동결건조 산채 블록의 항산화 활성 변화

곰취(Ligularia fischeri, GC), 고추잎(Capsicum annuum L., GCY), 취나물(Aster scaber, CNM), 머위대(Petasites japonicus S. et Z. Max, MYD) 및 고구마순(Ipomoea batatas L. (Lam), GGM)과 같은 산채들의 물 추출물의 항산화능력을 평가하고 이들 동결건조 블록 물 추출물들의 항산화력과 비교하였다. 산채 물 추출물들과 그들의 동결건조 블록물 추출물들의 항산화력 측정은 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical 소거작용, hydroxyl radical 소거작용 및 아질산염 소거작용과 같은 방법에 의해 알아보았다. 산채 물 추출물은 그들의 동결건조 물 추출물보다 총 페놀함량이 더 높았다. GC, GCY, CNM, MYD 그리고 GGM 물추출물들의 총 페놀 함량은 각각 $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;\mu}g/mg\;그리고\;122.67{\pm}3.51\;{\mu}g/mg$이었다. 1000 ppm GC, GCY, CNM 그리고 GGM 물 추출물의 DPPH radical 소거작용은 그들의 동결건조 블록 물 추출물보다 더 높았고, 1000 ppm CNM, GC, GCY, MYD 그리고 GGM의 물 추출물의 DPPH radical 소거작용은 각각 90.9%, 89.9%, 76.6%, 71.1% 그리고 57.4%였다. 10000 ppm GC, GCY, CNM, MYD 그리고 GGM 물 추출물들은 hydroxyl radical 소거작용을 각각 38.8%, 33.4%, 35.9%, 34.3% 그리고 33.8%까지 증가시켰고, GCY, CNM 그리고 GGM의 물 추출물은 동결건조 블록 물 추출물과 유사한 활성을 나타내었으나 GC와 MYD의 물 추출물이이들 동결건조 블록들의 물 추출물의 hydroxyl radical 소거작용보다 약간 더 영향력이 있었다. 산채 물 추출물들과 이들 동결건조 블록 물 추출물들은 실험된 모든 농도에서 DPPH radical 소거작용 및 hydroxyl radical 소거작용을 나타내었다. GC 물 추출물의 아질산염 소거작용은 현저하게 농도 의존적으로 증가하였고, GC 물 추출물의 아질산염 소거작용이 그것의 동결건조 블록 물 추출물의 아질산염 소거작용보다 높았다. 이상의 결과들로부터 동결건조블록이 산채와 비교하여 산채가 가지고 있는 항산화력을 유지하고 있다는 것을 알수 있었다.