title: Localisation of antinutrients and qualitative identification of toxic components in Jatropha curcas seed.
abstract: BACKGROUND
  Jatropha curcas seed oil is a promising feedstock for biodiesel production. The seeds contain major toxic (phorbol esters, PEs) and antinutritional (phytate and trypsin inhibitor) factors. In the present study the localisation of antinutrients and a rapid qualitative method for detecting the presence of PEs were investigated.
  
  
  RESULTS
  Kernels were separated into cotyledon, hypocotyl, kernel coat and endosperm. The majority of phytate (96.5%), trypsin inhibitor (95.3%) and PEs (85.7%) were localised in the endosperm. Based on PEs, a qualitative method was developed to differentiate between toxic and non-toxic Jatropha genotypes. In this method, PEs were easily detected by passing methanol extracts of kernels (Jatropha toxic and non-toxic genotypes) through a solid phase extraction (SPE) column and measuring the absorption of the resulting eluates at 280 nm. For raw kernels, SPE eluates with absorbance ≥ 0.056 were considered as toxic and those with absorbance ≤0.032 as non-toxic. For defatted kernel meals, SPE eluates with absorbance ≥ 0.059 were considered as toxic and those with absorbance ≤0.043 as non-toxic.
  
  
  CONCLUSIONS
  The majority of antinutrients/toxic compounds are localised in the endosperm of the kernel. The qualitative method developed for rapid identification of toxic PEs could be useful in screening the toxicity of Jatropha-based products in the biodiesel industry. Further confirmation of PEs should be established by high-performance liquid chromatography.
authors.affiliation: Institute for Animal Production in the Tropics and Subtropics, University of Hohenheim, D-70593 Stuttgart, Germany.
authors.forename: Rakshit K
authors.initials: RK
authors.lastname: Devappa
authors.forename: Harinder P S
authors.initials: HP
authors.lastname: Makkar
authors.forename: Klaus
authors.initials: K
authors.lastname: Becker
mesh_terms: D000042:Absorption; D056804:Biofuels; D056625:Endosperm / Q000737:chemistry*; D005838:Genotype; D031286:Jatropha / Q000737:chemistry* / Q000235:genetics; D010703:Phorbol Esters / Q000032:analysis* / Q000633:toxicity; D010833:Phytic Acid / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D012016:Reference Values; D012639:Seeds / Q000737:chemistry*; D014116:Toxicology / Q000379:methods*; D014361:Trypsin Inhibitors / Q000032:analysis*
chemical_list: D056804:Biofuels; D010703:Phorbol Esters; D010936:Plant Extracts; D010938:Plant Oils; D014361:Trypsin Inhibitors; D010833:Phytic Acid