Browsing by Author "Bošković-Rakočević, Ljiljana"

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Effect of processing on vitamin C content, total phenols and antioxidative activity of organically grown red beetroot ('Beta vulgaris' ssp. 'Rubra')
(Centre for Evaluation in Education and Science (CEON/CEES), 2021) Pavlović, Nenad; Mladenović, Jelena; Stevović, Vladeta; Bošković-Rakočević, Ljiljana; Moravcevic, Djordje; Poštić, Dobrivoj; Zdravković, Jasmina
The demand for organic food is rising since consumers want food from reliable, highest quality sources originating from the environment, undisturbed by cultivation and processing. It is necessary to determine to what extent there is a scientific basis for the claims that organic food is of high quality. In this study, beetroot from an organic production system originating from 6 certified organic food producers from different geographic locations was examined. The organic beetroot samples were processed by pasteurization at 70 ºC and 90 ºC into beet juice or by drying at 55 ºC. The following samples were tested and compared: fresh beetroot, pasteurized beet juice and dried beetroot slices. The concentration of vitamin C, level of total phenol compounds (TPC) and antioxidative activity (TAA) in beetroot were influenced by the geographic origin and the applied processing method. The highest degradation for all analysed parameters was found in the samples treated by drying or pasteurisation at 90 ºC. The lowest losses of studied phytochemical components were observed during juice pasteurisation at 70 ºC. The correlation coefficient between TPC and TAA was high and significant (r2 = 0.966).
Heredity mode of duration of vegetative stage in onion (Allium cepa L.)
(University of Banja Luka Faculty of Agriculture, 2022-05-26) Pavlović, Nenad; Marjanović, Miloš; Mladenovic, Jelena; Tomić, Dalibor; Bošković-Rakočević, Ljiljana; Moravcevic, Djordje; Zdravković, Jasmina
The duration of the vegetation period is a very important biological property of onion. In order to determine the ways of inheriting the duration of the vegetation period, the method of full diallel without reciprocals was applied, in order to obtain offspring of F1 and F2 generation. The field experiment with parents and hybrids of F1 and F2 generation was set up according to a random block system with five repetitions at the Institute for Vegetable Crops, Smederevska Palanka. The mode of inheritance of early maturity in this experiment was superdominance, observing all crossing combinations. The best general combiner in both generations was the AC 101 line. The highest significant value for SCA in both the F1 and F2 generations had the hybrid created by crossing Piroška x AC 101.
Yield and quality of lettuce (Lactuca sativa L.) depending on variety and type of nitrogen fertilizer
(Faculty of Food and Agriculture, United Arab Emirates University, 2023-06-01) Bošković-Rakočević, Ljiljana; Pavlović, Nenad; Mladenovic, Jelena; Marjanović, Miloš; Zdravković, Jasmina; Tošić
The aim of this research was to determine the effect of the application of different types of nitrogen fertilizer in five different varieties of lettuce on yield. The experiment was performed in the open field, in the spring cycle of growing during 2018 and 2019. The size of the base plot was 3 m2, and the trial was set up in a random block system. The trial covered the application of various forms of nitrogen fertilizers: ammonium sulphate, ammonium nitrate and urea. The applied nitrogen dose is 100 kg/ha (May 10th 2018 and May 8th 2019). Samples for the analysis of vitamin C and nitrate content, as well as yield determination, were carried out at the stage of the technological maturity of lettuce (60-62 days after seedling). The average weight of lettuce, depending on the variety, varied in the range of 211.3 g to 258.7 g. The use of ammonium nitrate resulted in the highest average weight of lettuce head (246.7 g), followed by the use of urea (238.9 g) and the lowest by the use of ammonium sulphate (221.0 g). The nutritional value of lettuce (vitamin C content) shows that depending on the applied form of nitrogen in the fertilizer, the highest content of vitamin C was determined by urea (10.86 mg/100 g), then ammonium sulphate (9.61 mg/100 g), and the lowest by ammonium nitrate (7.38mg/100g). The lower content of vitamin C was found in varieties of lettuce with red leaves compared to varieties with green leaves. The accumulation of nitrate in lettuce leaves directly depends on the variety and the applied fertilizer. The highest nitrate content was with ammonium nitrate (2355.6 mg/kg). The accumulation of nitrate in lettuce varieties with red leaves was higher compared to varieties with green leaves. Keywords: Lettuce, Nitrate, Vitamin C, Yield, Open field