A simple production process of hydroxymethylfurfural (HMF) was developed by examining its reaction conditions in an ionic liquid, 3-methylimidazolium chloride ([OMIM]Cl). For this, effects of five parameters; extraction time, reaction time, HCl concentration, chromium dichloride (CrCl2) catalyst, and raw plant biomass sources (girasol as a source of inulin and potato tubers as a source of starch); on the yield of HMF were scrutinized. The results showed that HMF yield was significantly affected by each parameter or their combination. The best extraction time and reaction time were identified at 2 h and 60 mm, respectively. HCl concentration optima were determined at 0.3 M for girasol biomass and 0.5 M for potato tuber. The presence of CrCl2 in the reaction mixture prepared from potato tuber biomass exhibited approximately a 2-fold increase in the yield of HMF (54.4% +/- 5.1% dwt). In contrast, in girasol reaction mixture, its catalytic effect was not detected. The highest HMF yield (58.2 +/- 5.8% dwt) was achieved in the reaction mixture of 4g [OMIM]Cl, 1 ml ethyl acetate, and 5 ml girasol extract (prepared at 2 h extraction in 0.3 M HCl) without CrCl2 catalyst by undergoing the reaction at 120 degrees C for 60 min. (C) 2012 Elsevier Ltd. All rights reserved.