Original Research Article
Year: 2019 | Month: August | Volume: 6 | Issue: 8 | Pages: 399-404
Simple Determination of Inulin Polymerization Degree Average from Dahlia Tuber Using Spectrophotometer
Iren Gusni Yanti1, Minda Azhar2, Anni Faridah3, Budhi Oktavia2
1Chemistry Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Padang
2Jl. Prof. Dr. Hamka, Air Tawar, Padang, Indonesia
3Faculty of Tourism and Hospitality, Universitas Negeri Padang
Corresponding Author: Minda Azhar
ABSTRACT
Degree of polymerization (DP) of inulin is the number of monomer units in inulin polymer strand. DP of inulin can be determined simply using spectrophotometer. This study aims to determine DP of inulin from fresh dahlia tubers and dahlia tubers that stored for fifteen days. Inulin extraction from dahlia tuber was based on the solubility of inulin in hot water and precipitation in ethanol by adding ethanol to final concentration of 80% solution. Reducing sugars of inulin was determined using the DNS method. The absorbances were measured using spectrophotometer at maximum wavelength of 490 nm. Total sugar of inulin was determined using Phenol-sulphate method, the absorbance was measured at λmax 350 nm. Inulin from fresh dahlia tubers had higher DP than inulin from dahlia tuber that stored for fifteen days. Inulin that found in this research belongs to the fructooligosaccharide (FOS) group.
Keywords: Degree of polymerization (DP), dahlia tubers, DNS, phenol-sulphate, reducing sugars, spectrophotometer.
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