Determination of starch lysophospholipids in rice using liquid chromatography mass-spectrometry (LC-MS)

Acquisition of a complete understanding of rice starch lysophospholipids (LPLs), their biosynthetic pathways, genetic diversity, and the influence of genotype by environment interactions has been hampered by the lack of efficient high throughput extraction and analysis methods. We hypothesized a single-step aqueous n-propanol extraction combined with liquid chromatography mass spectrometry (LCMS) could be employed to analyze starch LPLs in white rice. Our investigation found different grinding methods showed little effect on the final LPL detected and a simple single-step extraction with 75% n-propanol (8mL/0.15g) heated at 100 oC for two hours was as effective as an onerous multi-step extraction method. A LCMS method was optimized to simultaneously quantify ten major LPLs in rice starch within 15 minutes. This method enables total and individual starch LPLs analysis of a large number of rice samples at little cost. This approach could be applied to starch LPLs in other cereals.