Biological thiols are important antioxidants, and recent studies showed that their contents vary depending on the groups of foodstuffs. Therefore, we investigated the levels of some biological thiols in various vegetables and fruits by using a sensitive high-performance liquid chromatography (HPLC) technique. Biological thiols measured in some vegetables and fruits include glutathione (L-glutamyl-L-cysteinly glycine, GSH), N-acetylcysteine (NAC), captopril [CAP (C9H15NO3S)], homocysteine (HCYS), cysteine (CYS), and -glutamyl cysteine (GGC). Our results show that biological thiol contents are between 3-349 nM/g wet weight in vegetables and 4-136 nM/g wet weight in fruits. CAP is only found in asparagus (28 nM/g wet weight). Furthermore, none of the biological thiols analyzed were found in cabbages, red grapes, blackberries, apples, and peaches. Therefore, various vegetables and fruits differ significantly in their thiol contents. Oxidation of these important thiols may occur and result in the production of toxic byproducts, if they are exposed to radiation and ozone treatment for sterilization purposes. Further studies should be performed to monitor the levels of these biological thiols.
O. Demirkol et al., "Biologically Important Thiols in Various Vegetables and Fruits," Journal of Agricultural and Food Chemistry, vol. 52, no. 26, pp. 8151-8154, American Chemical Society (ACS), Jan 2004.
The definitive version is available at http://dx.doi.org/10.1021/jf040266f
Keywords and Phrases
Thiol; Free radicals; Vegetables; Fruits
Library of Congress Subject Headings
Free radicals (Chemistry)
Article - Journal
© 2004 American Chemical Society (ACS), All rights reserved.