Antioxidant enzyme activities and lipid peroxidation as biomarker for potato tuber stored by two essential oils from Caraway and Clove and its main component carvone and eugenol

To evaluate two essential oils from Caraway and Clove and its main component carvone and eugenol as sprout inhibitors on germination of potato tubers. The enzymes activities: catalase, glutathione-S-transferase, peroxidase, polyphenol oxidase and superoxide dismutase, in addition to lipid peroxidation level were tested in potato tubers stored for 3, 6 and 9 weeks. Essential oils; Caraway, Clove, carvone and eugenol with three concentration (100, 200 and 300 ppm) were used to control germination process of potato tubers. The results of enzyme activities varied depending on the function of enzymes involved. As general trend the activities of the enzymes recorded are significantly found on the range of enzyme control or less, which prevent of potato tuber from germination. Glutathione-S-transferase activity was significantly increased after treatment with essential oils and the activity of enzyme reached (23.3±5.15) (100 ppm) for Caraway, (18.8±0.00) (100 ppm) for carvone, (10.4±0.00) (100 ppm) for colve, and (14.1±0.0) (100 ppm) for eugenol respectively compared to control (7.86±3.26). Polyphenol oxidase and peroxidase activity increased in its activity and recovered to the level of control after treatment with essential oils which maintain potato tuber for 9 weeks. The pure essential oils especially carvone have more potent as suppressor of potato tuber germination.