|Opis:||The objective of this work was to study the nutritional composition and the antioxidant activity of tomato material from different parts of tomato fruit. We used lyophilized material, prepared from fresh tomatoes, extracts and juice. The material for extraction was prepared by lyophilization of fresh tomatoes. Varios organic solvents were used: methanol, ethanol, hexane, ethyl acetate. In case of carbohydrates extraction, water was used as a solvent, in addtion to the mixture of methanol and water. Saponification has also been performed in order to determine the contents of free fatty acids. In these sense, chemical analyzes using spectrophotometric, titration and chromatographic methods have been performed. The content of vitamin C, pigments (proanthocyanidins, betalaines and carotenoids), total carbohydrates, proteins and fatty acids have been determined. Antioxidant activity was determined using 1,1-diphenyl-2-picrylhydrazine (DPPH) free radical method.
The highest extraction efficiency was obtained by extraction with ultrasound as a mixture of methanol-water (1:1) was applied as extraction media. Despite the lowest yield, extracts obtained with ethyl acetate have been shown to have the highest antioxidant activity. The content of vitamin C and carotenoids in tomato juice is relatively high (0,2106 mg/mL for vitamin C in 57,7 mg/kg for carotenoids). The highest content of proanthocyanides was measured in the extracts obtained with ethyl acetate, and the highest content of total betalain was present in the extract obtained by the Soxhlet method and ethyl acetate as a solvent (1065,9 mg/100 g). The highest content of carbohydrates was present in the extract obtained with a mixture of methanol-water (1: 1) by extraction with mixing. The highest proportion of proteins was present in the extracts obtained with ethanol. In the saponified extract, among all tested fatty acids, linoleic acid was present in the highest content, followed by oleic acid and palmitic acid. The total content of saturated fatty acids is 23.77% and the total content of unsaturated fatty acids is 76.23%.
We found that extracts from tomatoes could represent potential dietary supplements and have a high potential replace synthetic preservatives.|