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Cilj dela je bil preučiti hranilno sestavo in antioksidativno aktivnost materialov iz različnih delov paradižnika. Pri delu smo uporabljali liofiliziran material, ekstrakte in sok, pripravljen iz svežega paradižnika. Material za ekstrakcijo smo pripravili z liofilizacijo svežega paradižnika. Ekstrakte smo pridobili z uporabo klasičnih konvencionalnih ekstrakcij in ultrazvočne ekstrakcije ob uporabi različnih organskih topil: metanol, etanol, heksan, etil acetat. Pri ekstrakciji ogljikovih hidratov smo kot topilo uporabljali vodo, poskusili pa smo tudi mešanico metanola in vode. Izvedli smo tudi sapofinikacijo ter določili vsebnost maščobnih kislin. Tako smo izvedli kemijske analize s pomočjo spektrofotometričnih, titracijskih in kromatografskih metod. Materialom smo določali vsebnosti vitamina C, pigmentov (proantocianidini, betalaini in karotenoidi), celokupnih ogljikovih hidratov, proteinov in maščobnih kislin. Antioksidativno aktvinost pa smo določali z uporabo prostega radikala 1,1-difenil-2-pikrilhidrazinom (DPPH). Najvišji izkoristek ekstakcije smo dobili pri ekstrakciji z ultrazvokom in mešanico metanol-voda (1:1). Kljub najnižjemu izkoristku so največjo antioksidativno aktivnost pokazali ekstrakti z etil acetatom (najvišja vsebnost je 12,97 %). Ugotovili smo, da je vsebnost vitamina C in karotenoidov v paradižnikovem soku visoka (0,2106 mg/mL za vitamin C in 57,7 mg/kg za karotenoide). Najvišjo vsebnost proantocianidov so pokazali ekstrakti pridobljeni z etil acetatom, najvišjo vsebnost skupnih betalainov pa je pokazal ekstrakt, pridobljen z metodo po Soxhletu in etil acetatom (1065,9 mg/100 g). Najvišjo vsebnost ogljikovih hidratov je pokazal ekstrakt, pridobljen z ekstrakcijo z mešanjem z mešanico metanol-voda (1:1) (0,43 %). Najvišjo vsebnost proteinov so pokazali ekstrakti pridobljeni z etanolom. V umiljenem ekstraktu je bilo prisotne največ linolne kisline (47,4 %). Sledita ji oleinska kislina (21,6 %) in palmitinska kislina (16 %). Skupna vsebnost nasičenih maščobnih kislin znaša 23,77 %, skupna vsebnost nenasičenih maščobnih kislin pa 76,23 %. Ugotovili smo, da so ekstrakti iz paradižnika potencialni prehranski dodatki oz. naravni prezervativi. 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. |
