TY  - JOUR
AU  - Pavun, Leposava
AU  - Uskokovic-Marković, Snežana
AU  - Jelikic-Stankov, Milena
AU  - Đikanović, Daniela
AU  - Durdević, Predrag
PY  - 2018
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1135
AB  - We propose a sensitive and selective spectrofluorimetric method for the determination of flavonoids as expressed in 'quercetin equivalent' in apple juices. The method is based on the strong emission of the aluminium(III)-quercetin complex at 480 nm with excitation at 420 nm, and it is successfully applied for the determination of flavonoids in commercial apple juices and compared with results obtained in reference spectrophotometric determination. The flavonoid content in commercial apple juices was found to range from 5.53 to 15.55 mg/l quercetin equivalent. The very good agreement between the two methods indicates the suitability of the proposed spectrofluorimetric method for the precise and accurate determination of flavonoids. In addition, the total polyphenol content was determined spectrophotometrically using the Folin-Ciocalteu (FC) method and the antioxidative activity of the tested juices was tested in a DPPH assay and these values were correlated with each other. The obtained profiles of compounds with antioxidative ability lead us to conclude that fruit juice labels based only on fruit % might sometimes misinform consumers.
PB  - Czech Academy Agricultural Sciences, Prague
T2  - Czech Journal of Food Sciences
T1  - Determination of Flavonoids and Total Polyphenol Contents in Commercial Apple Juices
EP  - 238
IS  - 3
SP  - 233
VL  - 36
DO  - 10.17221/211/2017-CJFS
ER  - 

@article{
author = "Pavun, Leposava and Uskokovic-Marković, Snežana and Jelikic-Stankov, Milena and Đikanović, Daniela and Durdević, Predrag",
year = "2018",
abstract = "We propose a sensitive and selective spectrofluorimetric method for the determination of flavonoids as expressed in 'quercetin equivalent' in apple juices. The method is based on the strong emission of the aluminium(III)-quercetin complex at 480 nm with excitation at 420 nm, and it is successfully applied for the determination of flavonoids in commercial apple juices and compared with results obtained in reference spectrophotometric determination. The flavonoid content in commercial apple juices was found to range from 5.53 to 15.55 mg/l quercetin equivalent. The very good agreement between the two methods indicates the suitability of the proposed spectrofluorimetric method for the precise and accurate determination of flavonoids. In addition, the total polyphenol content was determined spectrophotometrically using the Folin-Ciocalteu (FC) method and the antioxidative activity of the tested juices was tested in a DPPH assay and these values were correlated with each other. The obtained profiles of compounds with antioxidative ability lead us to conclude that fruit juice labels based only on fruit % might sometimes misinform consumers.",
publisher = "Czech Academy Agricultural Sciences, Prague",
journal = "Czech Journal of Food Sciences",
title = "Determination of Flavonoids and Total Polyphenol Contents in Commercial Apple Juices",
pages = "238-233",
number = "3",
volume = "36",
doi = "10.17221/211/2017-CJFS"
}

Pavun, L., Uskokovic-Marković, S., Jelikic-Stankov, M., Đikanović, D.,& Durdević, P.. (2018). Determination of Flavonoids and Total Polyphenol Contents in Commercial Apple Juices. in Czech Journal of Food Sciences
Czech Academy Agricultural Sciences, Prague., 36(3), 233-238.
https://doi.org/10.17221/211/2017-CJFS

Pavun L, Uskokovic-Marković S, Jelikic-Stankov M, Đikanović D, Durdević P. Determination of Flavonoids and Total Polyphenol Contents in Commercial Apple Juices. in Czech Journal of Food Sciences. 2018;36(3):233-238.
doi:10.17221/211/2017-CJFS .

Pavun, Leposava, Uskokovic-Marković, Snežana, Jelikic-Stankov, Milena, Đikanović, Daniela, Durdević, Predrag, "Determination of Flavonoids and Total Polyphenol Contents in Commercial Apple Juices" in Czech Journal of Food Sciences, 36, no. 3 (2018):233-238,
https://doi.org/10.17221/211/2017-CJFS . .

TY  - JOUR
AU  - Pavun, Leposava
AU  - Durdević, Predrag
AU  - Jelikic-Stankov, Milena
AU  - Đikanović, Daniela
AU  - Ciric, Andrija
AU  - Uskokovic-Marković, Snežana
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/799
AB  - A simple, accurate and precise method based on the fluorescence properties of the aluminum(III)-quercetin complex, for the determination of quercetin, has been developed and validated. The complex has strong emission at pH 3.30, lambda(em) = 480 nm, with lambda(ex) = 420 nm. The linearity range of quercetin determination was 1.5-60.5 ng ml(-1) with LOD 0.09 ng ml(-1) and LOQ 0.27 ng ml(-1). Recovery values in the range of 99.9-100.2% indicate a good accuracy of the method. The established method was applied for the determination of quercetin in capsules, with a recovery value of 98.3%, standard deviation of 0.22% and coefficient of variation of 0.09%. The reliability of the method was checked by the newly developed RP-HPLC/UV method for capsules with the direct determination of quercetin after separation. The good agreement between the two methods indicates the applicability of the proposed spectrofluorimetric method for quercetin determination in pharmaceutical dosage forms, with high reproducibility, and enables the direct and simple determination without its prior extraction from samples. The proposed spectrofluorimetric method has much better sensitivity and LOD and LOQ values that are about 1000 times lower than data reported in the literature.
PB  - Soc Chemists Technologists Madeconia, Skopje
T2  - Macedonian Journal of Chemistry and Chemical Engineering
T1  - Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms
EP  - 215
IS  - 2
SP  - 209
VL  - 33
DO  - 10.20450/mjcce.2014.496
ER  - 

@article{
author = "Pavun, Leposava and Durdević, Predrag and Jelikic-Stankov, Milena and Đikanović, Daniela and Ciric, Andrija and Uskokovic-Marković, Snežana",
year = "2014",
abstract = "A simple, accurate and precise method based on the fluorescence properties of the aluminum(III)-quercetin complex, for the determination of quercetin, has been developed and validated. The complex has strong emission at pH 3.30, lambda(em) = 480 nm, with lambda(ex) = 420 nm. The linearity range of quercetin determination was 1.5-60.5 ng ml(-1) with LOD 0.09 ng ml(-1) and LOQ 0.27 ng ml(-1). Recovery values in the range of 99.9-100.2% indicate a good accuracy of the method. The established method was applied for the determination of quercetin in capsules, with a recovery value of 98.3%, standard deviation of 0.22% and coefficient of variation of 0.09%. The reliability of the method was checked by the newly developed RP-HPLC/UV method for capsules with the direct determination of quercetin after separation. The good agreement between the two methods indicates the applicability of the proposed spectrofluorimetric method for quercetin determination in pharmaceutical dosage forms, with high reproducibility, and enables the direct and simple determination without its prior extraction from samples. The proposed spectrofluorimetric method has much better sensitivity and LOD and LOQ values that are about 1000 times lower than data reported in the literature.",
publisher = "Soc Chemists Technologists Madeconia, Skopje",
journal = "Macedonian Journal of Chemistry and Chemical Engineering",
title = "Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms",
pages = "215-209",
number = "2",
volume = "33",
doi = "10.20450/mjcce.2014.496"
}

Pavun, L., Durdević, P., Jelikic-Stankov, M., Đikanović, D., Ciric, A.,& Uskokovic-Marković, S.. (2014). Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms. in Macedonian Journal of Chemistry and Chemical Engineering
Soc Chemists Technologists Madeconia, Skopje., 33(2), 209-215.
https://doi.org/10.20450/mjcce.2014.496

Pavun L, Durdević P, Jelikic-Stankov M, Đikanović D, Ciric A, Uskokovic-Marković S. Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms. in Macedonian Journal of Chemistry and Chemical Engineering. 2014;33(2):209-215.
doi:10.20450/mjcce.2014.496 .

Pavun, Leposava, Durdević, Predrag, Jelikic-Stankov, Milena, Đikanović, Daniela, Ciric, Andrija, Uskokovic-Marković, Snežana, "Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms" in Macedonian Journal of Chemistry and Chemical Engineering, 33, no. 2 (2014):209-215,
https://doi.org/10.20450/mjcce.2014.496 . .