대추 열매와 잎을 기능성 식품 재료로 이용하기 위한 기초자료를 제공하기 위하여 화학성분 및 항산화 활성을 조사하였다. 열매와 잎의 가용성 무질소물의 함량은 각각 71.92% 및 41.51%로 나타났으며, 열매와 잎에 많이 함유되어 있는 무기성분으로는 Ca(72.14 and 3,252.09 mg/100 g), K(899.82 and 1,708.12 mg/100 g) 및 P(172.11 and 286.28 mg/100 g).이었다. 열매의 주요 유리당은 glucose(13.01%)와 fructose(7.35%)였으며, 잎에서는 sucrose(3.94%)와 fructose(0.75%)였고, 비타민 C 함량은 열매(135.73 mg/100 g)가 잎(100.43 mg/100 g)보다 높았다. Glutamic acid, aspartic acid, proline과 필수아미노산 중에서는 leucine이 상대적으로 높은 비율을 보였으며, methionine과 cystine은 낮은 함량을 보였다. 대추 열매와 잎의 용매 분획물을 이용하여 ABTS 라디칼 소거활성, 환원력 및 지질과산화 억제활성을 조사한 결과 농도 의존적인 경향을 보였으며, 특히 잎 부탄올 분획물에서 가장 높은 항산화 활성을 보였는데, 이는 rutin과 quercitrin과 같은 페놀성 화합물과 매우 높은 상관관계를 보였다. 따라서 대추 잎의 페놀성 화합물은 효과적이면서도 안전성이 입증된 천연항산화제와 같은 기능성 식품 재료로 활용가능성이 매우 높을 것으로 생각된다.
The nutritional components and antioxidative activities of jujube fruit and leaf were investigated and analyzed to provide basic data for functional food materialization and processing. The nitrogen-free extract contents of the fruit and leaf were 71.92% and 41.51%, respectively. The mineral components of the fruit and leaf were rich in Ca (72.14 and 3,252.09 mg/100 g), K (899.82 and 1,708.12 mg/100 g), and P (172.11 and 286.28 mg/100 g), respectively. The major free sugars of the fruit were glucose (13.01 %) and fructose (7.35%); and of the leaf, sucrose (3.94%) and fructose (0.75%). The ascorbic acid contents were higher in fruit (135.73 mg/100 g) than in the leaf (100.43 mg/100 g). The analysis of the component amino acid showed a relatively high ratio of glutamic acid, aspartic acid, proline, and essential amino acids of leucine, but a low methionine and cystine content. The ABTS and FRAP assays indicated that the butanol fraction of the leaf was a more potent radical scavenger and reducing agent than the other five solvent fractions. The butanol fraction of the leaf also presented inhibitory effects against lipid peroxidation in a dose-dependent manner. Therefore, this study verified that the butanol fraction of the leaf has strong antioxidative activities that are correlated with its high level of phenolics, particularly rutin and quercitrin. These phenolics of jujube leaf can be utilized as effective and safe functional food substances, i.e., natural antioxidants.
