title: [Optimization for determination methods of alpha-, beta- carotene in vegetables].
abstract: OBJECTIVE
  To optimize the determination method of carotene in order to separate the alpha and beta carotene.
  
  
  METHODS
  The homogenized samples were extracted with ethanol before saponification, and then extracted with petroleum ether followed by wash, dry and concentration. At last, the separation was performed on the high performance liquid chromatographic with YMC Carotenoid C30 column (3 microm 4.6 mm x 150 mm). The mobile phase was consisted of A (methanol: acetonitrile: water = 73.5: 24.5:2) and B (methyl tert-butyl ether), with a linear gradient elution. The detection wavelength was 450 nm.
  
  
  RESULTS
  The C30-HPLC column was used throughout the experiment exhibiting a significant benefit for the separation of carotienes and isomers. Multifactor analysis of variance showed that heating by the anhydrous ethyl alcohol before the saponification was more suitable for extracting the carotenoids from vegetables. Under the optimal condition, the linear range of alpha-carotene was 0.495-9.90 microg/mL, and all-trans-beta-carotene was 0.552-10.4 microg/mL, with the linear correlation coefficient were above 0. 999. The relative standard deviation for the alpha and beta carotene were less than 10% (n = 6). The average spike recoveries for alpha and beta carotene in vegetables were 81.6%-93.3%. The detection and quantification limits for alpha and beta carotene were 0.5 microg/100 g and 1.5 microg/100 g, respectively, when taking 5g samples.
  
  
  CONCLUSIONS
  The method is accurate, reliable, and fit for analyzing alpha-carotene and beta-carotene in fresh vegetables.
authors.forename: Mengjin
authors.initials: M
authors.lastname: Cao
authors.forename: Xuesong
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaojiig
authors.initials: X
authors.lastname: Wang
authors.forename: Xiang
authors.initials: X
authors.lastname: Shen
authors.forename: Zhu
authors.initials: Z
authors.lastname: Wang
mesh_terms: D002338:Carotenoids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis / Q000379:methods*; D014675:Vegetables / Q000737:chemistry*; D019207:beta Carotene / Q000032:analysis*
chemical_list: D019207:beta Carotene; D002338:Carotenoids; C041635:alpha-carotene