67B-18 |
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D. NILUFER, Ö. Alkan, and E. Capanoglu. Food Engineering Department, Istanbul Technical University, Maslak, Istanbul, 34469, Turkey Despite of their potential health hazards, synthetic antioxidants are frequently used to prevent and retard lipid oxidation in foods. Natural antioxidants are known to have many positive effects on health, such as reducing the risk of chronic diseases in addition to their non-toxic characteristics. As a result, natural antioxidants and foodstuff containing these antioxidants, especially herbs, became an important concern for the researchers. The aim of this study was to investigate the antioxidative effects of intact thyme, bay leaves and garlic in olive oil. Dried thyme and bay leaves and fresh garlic (25 g/500 g olive oil) were added into olive oil and stored in glass bottles at two different temperatures (25oC and 50oC) for 4 weeks. The control sample was prepared with addition of Butylated Hydroxy Toluene (0.02%) and stored under the same conditions. Peroxide value, free fatty acid, and Rancimat analysis were performed to follow the rate of oxidation. The peroxide value of olive oil samples containing herbs and garlic were lower than the control and BHT added samples at room temperature. However, at elevated temperature, there was no difference in peroxide values of samples containing herbs, garlic and antioxidant, except for the control sample which had the highest value. Similar results were obtained for the FFA values during storage at elevated temperature. However, at room temperature, the lowest FFA values were observed from the samples having bay leave and BHT. According to the ransimat results thyme was found to be as effective as BHT at room temperature. Among the herbs used in the study thyme had the best antioxidative effect compared to that of others during storage of olive oil.
Session 67B, Food Chemistry: Antioxidants and bioactive agents
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