Biologically important thiols in various organically and conventionally grown vegetables

Biothiols are well-known beneficial antioxidants that protect cells from oxidative damage that potentially leads to cancer and Alzheimer's disease. This study investigated and compared the levels of important biological thiols including glutathione (L-glutamyl-L-Cysteinyl glycine, GSH), N-acetylcysteine (NAC), captopril (CAP), cysteine (CYS), and gamma-glutamyl cysteine (GGC) in a variety of organic versus conventional (industrially-produced) asparagus, spinach, green beans and red peppers, using a sensitive high-performance liquid chromatography (HPLC) technique. Only the contents of CYS, or CYS with NAC, were detected as significantly higher in organic green beans or organic asparagus, respectively. However, conventional spinach contained significantly higher amounts of all investigated thiols than contained the organic spinach. Results also showed that conventional or organic production methods did not significantly affect the contents of CAP, GSH or CYS in asparagus, green beans or red poppers. In conclusion, production methods do not appear to be the only factor affecting the thiol contents in vegetables