Newly developed inulin powders were prepared from roots of Asparagus falcatus (AF) and Taraxacum javanicum (TJ) plants grown in Sri Lanka. Inulin content, analyzed by enzymatic spectrophotometric as well as high-performance liquid chromatographic methods, showed that AF and TJ inulin powders contain 65.5% and 45.4% (dry wt) inulin, respectively, compared with 72% dry wt in the commercially available chicory inulin. Treating the AF and TJ inulin powders using ion exchange techniques significantly (P < 0.05) reduced their contents of micro (Zn, Cu, Mn, Fe) and macro (Na, K, Ca, Mg) elements. Enzymatic hydrolysis of inulin into fructose and glucose by fructanase, and FT-IR analyses proved that the developed AF and TJ inulins have characteristic molecular composition similar to commercial inulin. TJ inulin contained significantly (P < 0.05) greater amounts of total phenolics (4.37 mg GAE/g), total flavonoids (2.79 mg QE/g), and antioxidant capacity (833.11 mM TE/g) than AF inulin, which contained 1.33 mg GAE/g of total phenolics, 0.43 mg QE/g of total flavonoids, and 406.26 mM TE/g antioxidant capacity. The current study suggests that the newly developed inulin from AF and TJ roots could be used as an alternative commercial source of inulin for the food industry.
Keywords: FT-IR; HPLC; antioxidant capacity; inulin; phenolic compounds.
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