HERB EXTRACT INFLUENCE ON THE OXIDATIVE STABILITY OF SELECTED LIPIDS

Abstract

ABSTRACT The total polyphenol content and antioxidant activity of ethanol herb extract in different lipid systems was determined. For the purpose of this study, five representatives of spices were selected: garlic (Allium sativum L.), marjoram (Origanum majorana L.), peppermint (Mentha piperita L.), rosemary (Rosmarinus officinalis L.) and thyme (Thymus vulgaris L.). Lipid analyses showed different antioxidant potential of herbs extracts depending on the system used. Rancimat and Oxidograph tests showed that extract antioxidant potential in lard was higher than in sunflower oil. Thyme and marjoram extract exhibited the highest antioxidant activity but the lowest was recorded for garlic and mint one. Statistical Analysis showed a high correlation between total polyphenol content and antioxidant activity. Lipid oxidative stability in the Schaal oven test showed different trends, however, highest activity was observed in the samples of thyme and rosemary extract. Mint extract in sunflower oil and lard on cellulose matrix exhibited prooxidative activity. PRACTICAL APPLICATIONS Herbs are known for their medicinal properties, resulting from a wide range of bioactive compounds. Polyphenols are the potential antioxidants that would slow down or terminate oxidation processes. Lipids are very susceptible to oxidation that is why the present investigations aimed at finding herbs source of as strong antioxidant compounds to be used in lipids stabilization. Use of herb extracts efficiently increases the oxidative stability of examined lipids. Hence, their addition could enhance the nutritional value of the lipid products.