LC-MS analysis of carbohydrate components in Porang tubers (Amorphophallus muelleri Blume) from the second and the third growth period

Abstract

The presence of carbohydrates, especially glucomannan, causes porang tuber to be important in some industries including food, cosmetics, medicines, and other industries. Porang has four growing periods (GP) in its life cycle. The GP1 until GP3 is the vegetative phase and GP4 is the generative phase. The tubers used as industrial materials generally were derived from GP2 and GP3 plants. The study aimed to analyse carbohydrate components in porang tubers from GP2 and GP3 plants using Liquid Chromatography Mass Spectrometry (LC-MS) method. The tubers produced from plants at GP2 and GP3 were extracted by maceration method using methanol solvent (pa) for 1 h. Liquid extracts obtained was further identified for the levels of carbohydrate components using LC-MS technique. The carbohydrate components identified with LC-MS were selected for quantifications. LC-MS analysis showed that both GP2 and GP3 tubers contained 67 types of chemical compounds. In the GP2 tubers 8 types of carbohydrate components were detected. Whereas in the GP3 tuber in addition to the 8 types of carbohydrate components that are the same as ini the GP2 tuber there is also 1 other type of component, namely trehalose. Glucomannan is the highest levels of the carbohydrate component in GP2 and GP3. However, glucomannan levels in GP2 tuber (58, 845.54µg/g) were lower than those in GP3 tuber (99, 436.85µg/g). Therefore, GP3 tubers are better than GP2 to be used as industrial materials.