title: Identification of betalains from yellow beet (Beta vulgaris L.) and cactus pear [Opuntia ficus-indica (L.) Mill.] by high-performance liquid chromatography-electrospray ionization mass spectrometry.
abstract: Betaxanthins, the yellow-orange water-soluble pigments from yellow beet (Beta vulgaris ssp. vulgaris cv. Bejo Zaden) and cactus pear (Opuntia ficus-indica cv. Gialla) have been investigated using an HPLC system compatible with mass spectrometry. Five novel betaxanthins were found and characterized as the immonium adducts of betalamic acid with serine, gamma-aminobutyric acid, valine, isoleucine, and phenylalanine. To enable concentration of betalain samples, desalting was performed by solid-phase extraction. With this technique, betacyanins could be separated from the betaxanthins using the pH-dependent retention characteristics of red and yellow betalains. The betaxanthin fraction was taken for the preparation of betalamic acid as a precursor for semisynthetic standards. The HPLC method was applied to yellow beet and cactus pear, revealing a more complex betalain profile than described earlier, thus proving its suitability for screening of betaxanthin-containing plants as potential sources for natural food colors.
authors.affiliation: Institute of Food Technology, Section Plant Foodstuff Technology, Hohenheim University, Garbenstrasse 25, D-70599 Stuttgart, Germany.
authors.forename: Florian C
authors.initials: FC
authors.lastname: Stintzing
authors.forename: Andreas
authors.initials: A
authors.lastname: Schieber
authors.forename: Reinhold
authors.initials: R
authors.lastname: Carle
mesh_terms: D027461:Beta vulgaris / Q000737:chemistry*; D050859:Betacyanins; D050858:Betalains; D002851:Chromatography, High Pressure Liquid; D005505:Food Coloring Agents; D007211:Indoles / Q000302:isolation & purification; D029747:Opuntia / Q000737:chemistry*; D010860:Pigments, Biological / Q000302:isolation & purification; D011725:Pyridines / Q000302:isolation & purification; D000644:Quaternary Ammonium Compounds / Q000032:analysis* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D050859:Betacyanins; D005505:Food Coloring Agents; D007211:Indoles; D010860:Pigments, Biological; D011725:Pyridines; D000644:Quaternary Ammonium Compounds; C000252:betalamic acid; D050858:Betalains; C020228:betanin