Efficient determination of cysteine sulphoxides in <em>Allium</em> plants applying new biosensor and HPLC-MS² methods


  • K. Ziegert
  • W. Schütze
  • H. Schulz
  • M. Keusgen
  • F. Gun
  • E. R. J. Keller


Cysteine sulphoxide (CSO) contents of 16 different accessions of garlic (Allium sativum L.) and 15 varieties of onion (Allium cepa L.) were measured using two different rapid analytical methods: a biosensoric approach and a newly developed HPLC-MS2 technique. Both methods allow quantification of naturally occurring cysteine sulphoxides present in Allium plants without time-consuming sample pretreatment such as derivatisation of amino acid derivatives prior to HPLC-separation. It has been found that the amount of alliin, which is the predominant CSO occurring in garlic, varies between 0.2 and 2.2 g/100 g dry matter. Contrary to that, isoalliin representing the main CSO in onion has been detected in significantly lower amounts (0.3 to 1.25 g/100 g dry matter).