Comparison of Nutrient Composition of Yacon Germplasm

Abstract - The aim of this study is to provide the basic data for yacon [ Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson] in dietary food. The nutritional compositons, such as protein, ash, carbohydrate, dietary fiber, vitamin and fructooligosaccharide, were analyzed for 4 yacon germplasm lines. Yacon has low calories with only 46∼56 kcal/100 g. The contents of water, fat, ash, protein, carbohydrate and dietary fiber were ranged 85.9 ∼86.8%, 0.1∼0.2%, 0.2∼0.3%, 0.5∼0.7% , 12.2∼13.1% and 1.05∼1.14%, respectively. The iodine-starch test did not show any color or precipitation reaction, which indicates that yacon has no starch content. However, in the absence of starch, yacon is rich in fluctooligosaccharide, which is between 9.6 ∼11.1%. Maltose is present in the larger amount, followed by sucrose, glucose, and fructose in terms of free sugars. The analysis of mineral s revealed that yacon contains potassium in the larger amount of 141∼176 mg/100 g F.W., followed by magnesium at 8.2 ∼10.6 mg, calcium, and sodium representing the least present mineral. Yacon proved to have a total of 17 types of amino acids, which are between 404.0 ∼581.8 mg per 100 g of yacon. Glutamic acid, the main sweetening component, is present in the large amount of 94.0 ∼182.2 mg/100 g F.W., followed by aspartic acid, arginine, and alanine. The proportion of the essential amino acid was 24.8∼33.6%. Results of analysis also showed that yacon contains 0.001 ∼0.024 mg, 0.03 ∼0.11 mg, 0.02 ∼0.3 mg, 0.3 ∼0.4 mg and 14.1 ∼20.6 mg of β-carotene, thiamin, riboflavin, niacin, and ascorbic acid, respectively. It is also likely to be highly used as functional food material i n the future because it is abundant in both fluctooligosaccharide and antioxidants which are important functional components.