Food Irradiation·Food Science
YANG Wei, ZHANG Beihong, LING Qingyan, ZHONG Qing, YU Jiamin, XIAO Zufei, JIN Zhinong, LIU Yuanqiu
In order to explore the antioxidant properties of eucalyptus and citral camphor essential oils and hydrosols, the eucalyptus and citral camphor essential oils were extracted by steam distillation. Chemical composition and relative content of extracted oils were analyzed by gas chromatography-mass spectrometry analyzer (GC-MS). A total number of 15 major compounds with a relative content of more than 0.1% was found in eucalyptus-type camphor essential oil, among which Eucalyptol had the highest content of 57.28%. At the essential oil concentration of 128 g·L-1, the scavenging rate of essential oil to 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) was 82.60%, which was higher than that of the positive control(77.85%). The half maximal inhibitory concentration (IC50) with the strongest scavenging capacity for DPPH· and 2,2-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) radical (ABTS·+) were 14.25 and 31.65 g·L-1 respectively. There were 30 major compounds with a relative content more than 0.1% in citral-type camphor essential oil, among which citral (neral and geranial) had the highest content of 42.32%. The IC50 with the strongest scavenging capacity for DPPH· and ABTS·+ were 44.45 and 34.46 g·L-1 respectively. The hydrosols of essential oil had a certain scavenging effect on DPPH and ABTS, and the optimum antioxidant properties of eucalyptus-type hydrosols (DPPH·: 53.24%, ABTS·+: 10.50%) was higher than citral-type hydrosols (DPPH·: 10.58%, ABTS·+: 9.06%). Both chemotypes of camphor essential oils and hrdrosols possessed antioxidant properties, and in a certain concentration range, the antioxidant properties of the essential oils were significantly stronger at higher concentration than the lower concentration. Essential oil of eucalyptus-type camphor had stronger antioxidant activity than citral-type. The research provide a theoretical basis for the development and utilization of camphor essential oil.