engleski

Comparative study of bioactive composition of some nonrefined oils

The aim of this work was to compare the composition of fatty acids and bioactive components of five unrefined oil (cold pressed olive, rapeseed, linseed, sunflower and hazelnut) in order to provide additional information about nutritive value of these oils. The composition of fatty acids determines the properties of oil while bioactive components (chlorophylls, tocopherols, and phenols) act as antioxidants in oils but they also have biological effect. All samples of oil fulfil the basic quality parameters according to national regulations. The fatty acid composition in the analysed samples of olive, rapeseed and sunflower oil is in accordance with national regulations, while the fatty acid composition of linseed oil and hazelnut oil is in accordance with the literature. Flaxseed oil is rich in essential omega-3 fatty acids. In olive oil is established the highest amount of chlorophyll, followed by rapeseed oil. Hazelnut oil and sunflower oil are characterized with a high concentration of tocopherols and low concentration of phenols. Olive oil contains the highest amount of phenolic compounds, and it is the only oil that contains flavonoids and oleuropein. Rapeseed oil contains a high proportion of phenolic compounds with canolol as predominant phenolic compound. Antioxidant activity was determined by DPPH method and found that sunflower oil has the best ability to bleach DPPH radicals

antioxidant activity; fatty acid composition; non-refined oils; phenols; tocopherols

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