Selected Sri Lankan food plants and other herbs as potential sources of inulin-type fructans

The objective of this study was to determine the inulin-type fructan content in 20 selected food plants and other herbs commonly found in Sri Lanka. The inulin content of the selected plants were determined qualitatively and quantitatively using thin layer chromatography (TLC) and enzymatic spectrophotometric (ES) methods, respectively. The ES results showed that the inulin-type fructan contents based on fresh weight was highest in Allium sativum (18.62 % ± 1.55), followed by Asparagus falcatus (17.74 % ± 2.92), Asparagus racemosus (11.8 3% ± 0.87), Allium cepa (8.60 % ± 0.88), Allium ampeloprasum (6.20 % ± 0.23), Taraxacum javanicum (5.77 % ± 1.53) and Vernonia cinerea (4.55 % ± 0.93), respectively. Taraxacum javanicum and Vernonia cinerea plant extracts developed distinct blue black spots with the detection reagent on TLC plates similar to chicory inulin standard. However, Allium ampeloprasum, Allium cepa, Allium sativum, Asparagus falcatus and Asparagus racemosus developed thicker blue black streaks on TLC plates due to their higher inulin concentration, which confirmed the ES results. Aloe vera, Alpinia calcarata, Amophophallus campanulatus, Beta vulgaris, Canna indica, Diascorea alata and Sonchus oleraceus contained low levels (1 ≤ 0.5 g/100 g FW) of inulin while Caryota urens, Ipomoea batatas, Lasia spinosa and Maranta arundinacea contained very low levels or no (< 0.4 g/100 g FW) inulin.

J.Natn.Sci.Foundation Sri Lanka 2015 43 (1): 35 – 43