title: Determination of antioxidant potential of volatile extracts isolated from various herbs and spices.
abstract: Antioxidant activities of volatile extracts isolated from thyme, basil, rosemary, chamomile, lavender, and cinnamon were evaluated by two independent assays: the aldehyde/carboxylic acid assay and the conjugated diene assay. The volatile extracts were prepared from dried herbs and spices using liquid-liquid continuous extraction following steam distillation under reduced pressure (55 degrees C and 95 mmHg). The antioxidant activities of the extracts decreased in the following order in both of the lipophilic assay systems: thyme > basil > rosemary > chamomile > lavender and cinnamon. Thyme and basil extracts inhibited the oxidation of hexanal for 40 days at the levels of 10 microg/mL and 50 microg/mL, respectively. The extracts of thyme and basil were effective in retarding methyl linoleate deterioration at 40 degrees C, with activity increasing with concentration in the range 10-200 microg/mL. At a concentration of 50 microg/mL, thyme extract was similar in antioxidant activity to BHT and alpha-tocopherol in the conjugated diene assay. The antioxidant potentials of the volatile extracts used in this study were accurately measured by the lipophilic systems, such as the aldehyde/carboxylic acid assay and the conjugated diene assay.
authors.affiliation: Department of Environmental Toxicology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA. kwglee@ucdavis.edu
authors.forename: Kwang-Geun
authors.initials: KG
authors.lastname: Lee
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D020843:Chamomile / Q000737:chemistry; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D027523:Lavandula / Q000737:chemistry*; D018649:Ocimum basilicum / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis* / Q000494:pharmacology; D027542:Rosmarinus / Q000737:chemistry*; D017365:Spices / Q000032:analysis*; D046930:Thymus Plant / Q000737:chemistry*; D014835:Volatilization; D024502:alpha-Tocopherol / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D002084:Butylated Hydroxytoluene; D024502:alpha-Tocopherol