Title
Analiza katehina, procijanidina, makro i mikroelemenata u crnoj, mlečnoj, i beloj čokoladi i kakaou u prahu i njihov antioksidativni potencijal
Creator
Mrmošanin, Jelena
Copyright date
2019
Object Links
Select license
Autorstvo-Nekomercijalno-Bez prerade 3.0 Srbija (CC BY-NC-ND 3.0)
License description
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Language
Serbian
Cobiss-ID
Theses Type
Doktorska disertacija
description
Datum odbrane: 25.10.2019.
Other responsibilities
mentor
Tošić, Snežana
član komisije
Pavlović, Aleksandra
član komisije
Kaličanin, Biljana
predsednik komisije
Mitić, Snežana
član komisije
Mitić, Milan
Academic Expertise
Prirodno-matematičke nauke
Academic Title
-
University
Univerzitet u Nišu
Faculty
Prirodno-matematički fakultet
Group
Odsek za hemiju
Alternative title
Analysis of catechins, procyanidins, macro, and microelements in dark, milk and white
chocolate and cocoa powder and their antioxidant potential
Publisher
[J. M. Mrmošanin]
Format
302 str.
description
Biografija sa bibliografijom: str. 295-302;
Bibliografija: str. 275-294.
description
Analytical Chemistry
Abstract (en)
The aim of this doctoral dissertation was то determinе the chemical
composition, as well as то investigatе of the antioxidative activity of
white, milk, dark chocolate and cocoa powder samples. The total
polyphenols, flavonoids, as well as total and monomer anthocyanins,
were determined using UV/Vis spectrophotometry.
Spectrophotometric methods (ABTS, DPPH, FRAP, and PFRAP) and
electrochemistry method – cyclic voltammetry (CV) were used to test
antioxidant activity. Тhere were three anode peaks оn cyclic
voltammograms. The first and the third anodic current peaks can be
ascribed to the oxidation of catechin-type flavonoids, while the
second peak can be ascribed to the oxidation of phenolic acids.
Procyanidins did not show any visible waves. The highest antioxidant
activity was present in dark chocolate and cocoa powder samples,
followed by milk and white chocolate samples. This is in agreement
with the total content of polyphenols and flavonoids in the tested
samples. The identification and quantification of polyphenolic
compounds (protocatechuic acid, (+)-catechin, (-)-epicatechin,
procyanidins B1, B2, B3 and B4, cyanidin-3-O-galactoside and
cyanidin-3-O-arabinoside) and alkaloid theobromine were carried out
using HPLC chromatography. The influence of storage temperature (4
°С – 35 °С) and thermal processing (95 °С – 125 °С) on the stability
of catechin-type flavonoids, total flavonoids, and anthocyanins in
dark chocolate and cocoa powder samples was also studied. During
storage and heating, the cocoa powder and dark chocolate flavonoids
and anthocyanins degraded more quickly with an increase in
temperature. To determine macro and microelements, the ICP-OES
methods were optimized and validated. Among macroelements, K is
most abudant in the samples of cocoa powder, followed by samples of
dark, milk and white chocolate. This suggests that the content of K is
directly related to the contribution of cocoa parts. After K, the content
of P, Ca, Na, Mg is highest in white chocolate, followed by the milk
chocolate, dark chocolate, and cocoa powder samples. Among the
microelements, the most abundant are Fe, Si, and Zn. The content of
potentially toxic metals, Pb and Cd, is below the maximum
permissible levels (MPL) prescribed by national and world
regulations. The differentiation of the tested samples based on the
content of metals and polyphenol compounds, as well as based on
their antioxidative activity, was done using principal component
analysis (PCA) and cluster analysis (CA).
Authors Key words
Kakao u prahu, crna čokolada, mlečna čokolada, bela čokolada,
polifenoli, metali, antioksidativna aktivnost, ciklična
voltametrija, UV/Vis spektrofotometrija, HPLC, ICP-OES,
analiza glavnih komponenata, klaster analiza
Authors Key words
Cocoa powder, dark chocolate, milk chocolate, white chocolate,
polyphenols, metals, antioxidant activity, cyclic voltammetry, UV/Vis
spectrophotometry, HPLC, ICP-OES, principal component analysis,
cluster analysis
Classification
547.56(577.118+663.91)(043.3)
542.943ʼ78(577.118+663.91)(043.3)
Subject
Р 003, Р 300
Type
Tekst
Abstract (en)
The aim of this doctoral dissertation was то determinе the chemical
composition, as well as то investigatе of the antioxidative activity of
white, milk, dark chocolate and cocoa powder samples. The total
polyphenols, flavonoids, as well as total and monomer anthocyanins,
were determined using UV/Vis spectrophotometry.
Spectrophotometric methods (ABTS, DPPH, FRAP, and PFRAP) and
electrochemistry method – cyclic voltammetry (CV) were used to test
antioxidant activity. Тhere were three anode peaks оn cyclic
voltammograms. The first and the third anodic current peaks can be
ascribed to the oxidation of catechin-type flavonoids, while the
second peak can be ascribed to the oxidation of phenolic acids.
Procyanidins did not show any visible waves. The highest antioxidant
activity was present in dark chocolate and cocoa powder samples,
followed by milk and white chocolate samples. This is in agreement
with the total content of polyphenols and flavonoids in the tested
samples. The identification and quantification of polyphenolic
compounds (protocatechuic acid, (+)-catechin, (-)-epicatechin,
procyanidins B1, B2, B3 and B4, cyanidin-3-O-galactoside and
cyanidin-3-O-arabinoside) and alkaloid theobromine were carried out
using HPLC chromatography. The influence of storage temperature (4
°С – 35 °С) and thermal processing (95 °С – 125 °С) on the stability
of catechin-type flavonoids, total flavonoids, and anthocyanins in
dark chocolate and cocoa powder samples was also studied. During
storage and heating, the cocoa powder and dark chocolate flavonoids
and anthocyanins degraded more quickly with an increase in
temperature. To determine macro and microelements, the ICP-OES
methods were optimized and validated. Among macroelements, K is
most abudant in the samples of cocoa powder, followed by samples of
dark, milk and white chocolate. This suggests that the content of K is
directly related to the contribution of cocoa parts. After K, the content
of P, Ca, Na, Mg is highest in white chocolate, followed by the milk
chocolate, dark chocolate, and cocoa powder samples. Among the
microelements, the most abundant are Fe, Si, and Zn. The content of
potentially toxic metals, Pb and Cd, is below the maximum
permissible levels (MPL) prescribed by national and world
regulations. The differentiation of the tested samples based on the
content of metals and polyphenol compounds, as well as based on
their antioxidative activity, was done using principal component
analysis (PCA) and cluster analysis (CA).
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