pH Effect on the Volatile Components in the Thermal Degradation of Cysteine

Chi Kuen Shu, Myrna L. Hagedorn, Chi Tang Ho, Braja D. Mookherjee

Research output: Contribution to journalArticlepeer-review

60 Scopus citations


The pH effect on the volatile components in the thermal degradation of cysteine was studied at pH's 2.2, 5.1, and 7.1, representing the pH values below, around, and above the isoelectric point of cysteine, with a Parr bomb model system. A vigorous degradation occurred at pH 5.1 and a very mild one at pH 7.1. At pH 2.2 the major components formed are l,2,3-trithia-5-cycloheptene and 2-thiophenethiol. The trithiacycloheptene compound was evaluated as roasted onion and roasted meat odor and was found for the first time in a model system. The mechanism of formation of these two major compounds is proposed. At pH's 5.1 and 7.1, 3,5-dimethyl-1,2,4-trithiolanes possessing a roasted odor are the major components.

Original languageEnglish (US)
Pages (from-to)442-446
Number of pages5
JournalJournal of agricultural and food chemistry
Issue number3
StatePublished - 1985

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

Fingerprint Dive into the research topics of 'pH Effect on the Volatile Components in the Thermal Degradation of Cysteine'. Together they form a unique fingerprint.

Cite this