A Study on the Physicochemical Properties and the Nitrite Scavenging Ability of Japanese Sumac Extracts

Abstract

Japanese sumac (Rhus javanica) is one of the common herbaceous plants growing over the country. This study was conducted to investigate the extraction characteristics and physiological activities inluding nitrite scavenging ability of the water extracts from leaf, fruit and bark of Japanease sumac. Extraction yield was 6.62~13.84%, free amino acids were detected as 24 kinds with 37.9 mg/100g in leaf extract, 23 kinds with 27.0 mg/100g in fruit extract and 27 kinds with 39.0 mg/100g in bark extract, respectively, and seven kinds essential amino acids were detected. Total contents of flavonoids equivalent to naringin were 587.2 mg/100g in bark extract, 557.3 mg/100g in fruit extract and 379.9 mg/100g in leaf extract, respectively. Total contents of phenolics equivalent to gallic acid were 111.2 mg/100g in leaf extract, 108.4 mg/100g in fruit extract and 80.4 mg/100g in bark extract, respectively. The nitrite scavenging ability of extracts was order of 61.93% in bark extract>57.38% in fruit extract>55.49% in leaf extract, and was 78.1~100% of those of BHT (butylated hydroxytoluene) equivalents at pH 1.2. The electron donating ability was order of 47.38% in fruit extract>43.06% in leaf extract>38.55% in bark extract, and was compared to 65.6%, 58.8% and 53.6% of those of BHT equivalents, respectively. The reduction power was evaluated to 37% higher in leaf extract, 43% higher in fruit extract and 46% higher in bark extract than those of BHT equivalents. The metal chelating ability of extracts was considerably low and was order of 27.3% in bark extract>20.6% in leaf extract>11.2% in fruit extract.