A method for thermal conversion of raw organic waste (ROW) to a compost-like material (CLM) with higher levels of unsaturated carbohydrates, nitrogen- and oxygen-containing compounds was developed, in which rice bran and an organo-iron compound were employed as a model ROW and the accelerator, respectively. To evaluate the qualities of CLMs, organic substances of an acid insoluble fraction of alkaline extracts (AIAEs) from a CLM were structurally characterized by elemental analysis, pyrolysis-gas chromatography/mass spectrometry and FT-IR. The levels of unsaturated carbohydrates, and nitrogen- and oxygen-containing compounds in the CLM samples were increased by long-term treatment (60 degrees C for 5 days, 170 degrees C for 3 days). In particular, the high lipid content of the AIAEs, which was indicative of inadequate digestion of CLM components, was dramatically reduced in the presence of the accelerator. (C) 2010 Elsevier Ltd. All rights reserved.