Antioxidant activity of strawberries from organic and integrated production

Namen diplomske naloge je oceniti in primerjati antioksidativni potencial štirih sort jagod ‘St. Piere’, ‘Elsanta’, ‘Sugar Lie’ in ‘Thuchampion’ iz ekološke in integrirane pridelave. Antioksidativni potencial smo merili z ABTS ((2,2\u27-azino-bis(3-etilbenzotiazolin-6-sulfonska kislina)) metodo, ki temelji na redukciji ABTS•+ radikala in ga določimo spektrofotometrično pri valovni dolžini 734 nm. Umeritvena krivulja je bila v izbranem koncentracijskem območju linearna s korelacijskim koeficientom večjim od 0.99. Rezultate smo podali v µmol Trolox ekvivalenta (TE)/g sveže mase (SM). Najvišji antioksidativni potencial ekoloških jagod je bil ocenjen pri sorti ‘Elsanta’ (65.6 µmol TE/g SM), sledili sta sorti ‘Thuchampion’ (62.0 µmol TE/g SM) in ‘St. Piere’ (56.3 µmol TE/g SM). Najnižji antioksidativni potencial ekoloških jagod pa je bil ocenjen pri sorti ‘Sugar Lie’ (37.6 µmol TE/g SM). Pri integriranih jagodah je bil vrstni red sort enak kot pri ekoloških jagodah (54.0 µmol TE/g SM, 50.3 µmol TE/g SM, 48.4 µmol TE/g SM, 38.7 µmol TE/g SM). Pri sorti ‘Sugar Lie’ ni bilo statistično pomembnih razlik v antioksidativnem potencialu glede na način pridelave. Pri ostalih treh sortah je bil antioksidativni potencial statistično značilno višji pri jagodah iz ekološke pridelave v primerjavi z integrirano in se je v povprečju vseh sort razlikoval za 7,54 µmol.The purpose of the graduation thesis is to evaluate and compare the antioxidant activity of four strawberry varieties, i.e., ‘St. Piere’, ‘Elsanta’, ‘Sugar Lie’ and ‘Thuchampion’ from organic and integrated production. Antioxidant activity was measured by ABTS (2,2\u27-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) method, based on the reduction of ABTS•+ radical, which was determined spectrophotometrically at a wavelength of 734 nm. Calibration curve was linear in the chosen concentration range with a correlation coefficient higher than 0.99. The results were presented in μmol Trolox equivalent (TE)/g of fresh weight (FW). The highest antioxidant activity of strawberries from organic production was evaluated in the \u27Elsanta\u27 variety (65.6 μmol TE/g FW), followed by \u27Thuchampion\u27 (62.0 μmol TE/g FW) and St. Pierre\u27 (56.3 μmol TE/g FW), while the lowest value was evaluated in the ‘Sugar Lie’ variety (37.6 μmol TE/g FW). In the case of strawberries from integrated production, the results showed the same order as for organically produced varieties (54.0 μmol TE/g FW, 50.3 μmol TE/g FW, 48.4 μmol TE/g FW, 38.7 μmol TE/g FW). The comparison of the two production techniques showed that there were no statistically significant differences in antioxidant activity in \u27Sugar Lie\u27. However, in all other varieties studied, the antioxidant activity was statistically significantly higher in organically produced strawberries (by 7.54 µmol, on average)