title: Enantiomeric distribution of chiral compounds in orange juices according to their geographical origins.
abstract: Chiral terpenes in nonprocessed orange juices of different geographical origins were examined by two different approaches: steam distillation-solvent extraction-gas chromatography-mass spectrometry (SDE-GC-MS) and solid-phase microextraction-gas chromatography (SPME-GC). The two sample preparation techniques were compared with regard to their effectiveness in determining the enantiomeric distributions of chiral compounds. Most target compounds exhibited constant enantiomeric ratios in all juices when either of the two approaches was used. Exceptions were found for terpinen-4-ol and beta-citronellol, whose of enantiomeric purity ratios varied significantly according to the geographical origin of the sample. These results may aid in guaranteeing the authenticity and thus the quality and safety of orange juice. A comparison between the two extraction procedures revealed SPME to be more reliable for stereochemical studies, since harsh experimental conditions that can bring about racemization are not required in such studies.
authors.affiliation: Instituto de Fermentaciones Industriales, Consejo Superior de Investigaciones Científicas, Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Ruiz del Castillo
authors.forename: M M
authors.initials: MM
authors.lastname: Caja
authors.forename: G P
authors.initials: GP
authors.lastname: Blanch
authors.forename: M
authors.initials: M
authors.lastname: Herraiz
mesh_terms: D001628:Beverages / Q000032:analysis*; D002849:Chromatography, Gas; D002957:Citrus / Q000737:chemistry*; D003257:Consumer Product Safety; D008401:Gas Chromatography-Mass Spectrometry; D005843:Geography; D013729:Terpenes / Q000032:analysis / Q000737:chemistry*
chemical_list: D013729:Terpenes