Myung Yul Lee

Physicochemical Composition and Antioxidative Effects of Yacon (Polymnia Sonchifolia)

This study was carried out to investigate the physicochemical and functional properties of Yacon (Polymnia Sonchifolia) powder. The proximate composition of Yacon powder as a dry matter basis was 3.53% moisture content, 1.13% crude protein, 0.40% crude fat, 0.79% crude ash, 1.63% dietary fiber and 92.52% carbohydrate. The major free sugars were identified as fructose and glucose. Analysing total amino acids, 18 kinds of components were isolated from Yacon powder. The essential amino acid contained in Yacon powder accounted for 28.40% of total amino acid, while the non-essential amino acid accounted for 73.61%. Analysing total fatty acids, only 2 kinds - palmitic acid and lauric acid - were detected. Oxalic acid was the major organic acid. The contents of vitamin A, vitamin C and vitamin E were 0.057 mg%, 0.670 mg% and 0.001 mg%, respectively. The mineral contents of Yacon powder were in the order of Zn＜Mg＜Ca＜Na＜K. Antioxidant index by Rancimat test and nitrite scavenging ability of ethylacetate fraction of Yacon ethanol extract were the highest among fractions and were less than that of BHT. These results suggest that Yacon is recommendable as a vegetable of high nutritional quality and possesses potential antioxidative capacity.

Chemical Components and Antioxidative Effects of Eriobotrya japonica Lindl. Leaf

This study was carried out to investigate the physicochemical compositions and antioxidative effects of Eriobotrya japonoca Lindl (Loquat). The proximate compositions of the loquat leaf on a dry matter basis were 8.78% moisture content, 6.74% crude protein, 7.87% crude fat, 6.99% crude ash, 43.61% dietary fiber and 26.01% carbohydrate. In analysis of free amino acids, 16 kinds total amino acid components, 17 kinds of components were isolated from loquat. The essential amino acids contained in loquat leaf accounted for 50.15% of total amino acids, while the non-essential amino acids accounted for 49.85%. In analysis of total fatty acids, only 5 kinds of acid were detected: lauric acid, myristic acid, pentadecanoic acid, stearic acid and oleic acid. The contents of vitamin A, vitamin E and vitamin C were 0.039 mg%, 0.096 mg% and 0.575 mg%, respectively. The mineral contents of loquat leaf were greater in order of Zn