Analysis of nonstructural carbohydrates in storage organs of 30 ornamental geophytes by high-performance anion-exchange chromatography with pulsed amperometric detection

A comprehensive analysis of nonstructural carbohydrates in storage organs (bulbs and corms) of 30 ornamental geophytes was conducted by employing a variety of extraction techniques followed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). Among species, starch, fructan, glucomannan and soluble sugars accounted for 50-80% of storage organ dry weight (DW). Starch ranged from 24 to 760 mg g(-1) DW, fructan (commonly occurring with starch) from 25 to 500 mg g(-1) DW, and glucomannan from 15 to 145 mg g(-1) DW. An acid hydrolysis protocol for concurrent determination of fructan and glucomannan was developed. The average degree of polymerization (DP) of ethanol and water-soluble fructan and the man : glu ratio of glucomannan also varied between species. The 80% ethanol fraction contained soluble sugars and short-chain fructans (< 25 DP), whereas water extracts contained soluble sugars, fructans (both short- and long-chain,