Preparative separation of crocins and geniposide simultaneously from gardenia fruits using macroporous resin and reversed-phase chromatography.

Gardenia fruits contain valuable natural food colorants including crocins (gardenia yellow) and geniposide. In this study, a process for the enrichment of crocins and geniposide simultaneously from gardenia fruits was developed using macroporous resin and RP chromatography. The performance of eight different types of macroporous resins was evaluated. Static absorption/desorption experiments revealed that LX60 possessed optimal separating capacity. Further dynamic absorption/desorption experiments on LX60 columns were conducted to obtain the optimal parameters. After one run treatment with LX60, the content of crocin-1 in gardenia yellow reached 29.6%, while geniposide in another fraction reached 83.4%. An extract of crocins was obtained from gardenia yellow in a second-stage separation using RP medium-pressure LC, with its color value to be 756 and the content of crocin-1 reaching 60.8%. The separation process was highly efficient, low cost, and compact, which may be informative for purifications of other natural products from complex plant extracts.