Allium Discoloration: Color Compounds Formed during Pinking of Onion and Leek

作者：Kubec Roman^*; Urajova Petra; Lacina Ondrej; Hajslova Jana; Kuzma Marek; Zapal Jakub

来源：Journal of Agricultural and Food Chemistry, 2015, 63(46): 10192-10199.

DOI：10.1021/acs.jafc5b04564

• discoloration
• plant pigment
• pinking
• onion
• leek
• Allium
• thiosulfinate
• isoalliin
• dipyrromethane
• pyrrole

Structures and formation pathways of compounds responsible for pink discoloration of onion and leek were studied. A procedure was developed for the isolation and purification of the color compounds from various model systems and their identification by HPLC-DAD-MS/MS. In total, structures of 15 major color compounds were tentatively determined. It was found that the pigment is a complex mixture of highly conjugated species composed of two N-substituted 3,4-dimethylpyrrole-derived rings linked by either a methine or a propenylidine bridge. These two-ring units are further modified by various C1- and C3-side chains. Experiments with isotope-labeled thiosulfinates revealed that the methine bridge and C1-side chains originate from the methyl group of methiin, whereas the C3 units are derived from the propenyl group of isoalliin.

• 出版日期2015-11-25