In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum
oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale)
in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content
(TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined
in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol
contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and
Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically
significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying
and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been
found to have better antioxidant properties.