title: Drying effects on the antioxidant properties of tomatoes and ginger.
abstract: 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.
authors.affiliation: Gebze Institute of Technology, Department of Chemical Engineering, Cayirova, Gebze 41400, Kocaeli, Turkey.
authors.forename: Özlem Aktürk
authors.initials: ÖA
authors.lastname: Gümüşay
authors.affiliation: Department of Chemical and Process Engineering, Bilecik University, 11210 Gulumbe, Bilecik, Turkey.
authors.forename: Alev Akpınar
authors.initials: AA
authors.lastname: Borazan
authors.affiliation: Department of Chemistry, Missouri University of Science and Technology, 142 Schrenk Hall, Rolla, MO 65409, USA.
authors.forename: Nuran
authors.initials: N
authors.lastname: Ercal
authors.affiliation: Department of Food Engineering, Sakarya University, Esentepe, Sakarya 54187, Turkey. Electronic address: omcad@sakarya.edu.tr.
authors.forename: Omca
authors.initials: O
authors.lastname: Demirkol
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D003890:Desiccation / Q000295:instrumentation / Q000379:methods*; D005519:Food Preservation / Q000295:instrumentation / Q000379:methods*; D020939:Zingiber officinale / Q000737:chemistry*; D018551:Solanum lycopersicum / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D001205:Ascorbic Acid
keywords: Antioxidant properties; Drying; Ginger; Thiols; Tomatoes