Evaluation of Antioxidant Activity of Australian Tea Tree (<i>Melaleuca alternifolia</i>) Oil and Its Components
Hyun‐Jin Kim, Feng Chen, Changqing Wu, Xi Wang, Hau Yin Chung, Zhengyu Jin
Journal of Agricultural and Food Chemistry
Abstract
Antioxidant activity of Australian tea tree (Melaleuca alternifolia) oil (TTO) was determined using two different assays. In the 2,2-diphenyl-1-picrylhydrazyl assay, 10 microL/mL crude TTO in methanol had approximately 80% free radical scavenging activity, and in the hexanal/hexanoic acid assay, 200 microL/mL crude TTO exhibited 60% inhibitory activity against the oxidation of hexanal to hexanoic acid over 30 days. These results were equivalent to the antioxidant activities of 30 mM butylated hydroxytoluene in both tests at the same experimental conditions. This indicated that the TTO could be a good alternative antioxidant. Inherent antioxidants, i.e., alpha-terpinene, alpha-terpinolene, and gamma-terpinene, in the crude TTO were separated and identified chromatographically using silica gel open chromatography, C(18)-high-pressure liquid chromatography, and gas chromatography-mass spectrometry. Their antioxidant activities decreased in the following order in both assays: alpha-terpinene > alpha-terpinolene > gamma-terpinene.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
Australian tea tree oil (TTO) has approximately 80% free radical scavenging activity at 10 microL/mL in methanol
“In the 2,2-diphenyl-1-picrylhydrazyl assay, 10 microL/mL crude TTO in methanol had approximately 80% free radical scavenging activity.”
alpha-terpinene, alpha-terpinolene, and gamma-terpinene have antioxidant activities in the following order alpha-terpinene > alpha-terpinolene > gamma-terpinene
“Their antioxidant activities decreased in the following order in both assays: alpha-terpinene > alpha-terpinolene > gamma-terpinene.”
Australian tea tree oil (TTO) exhibits 60% inhibitory activity against the oxidation of hexanal to hexanoic acid at 200 microL/mL over 30 days
“In the hexanal/hexanoic acid assay, 200 microL/mL crude TTO exhibited 60% inhibitory activity against the oxidation of hexanal to hexanoic acid over 30 days.”