Characterization of chlorogenic acids and analysis of antioxidation activity in different coffee varieties using electrochemical methods

U ovoj disertaciji provedena je karakterizacija klorogenskih kiselina (CGAs) i analiza antioksidacijske aktivnosti u različitim vrstama kave (zelenim i prženim zrnima kave C. arabica i C. robusta, mljevenim kavama Franck Guatemala i Flatcher Olympia te instant kavama Nescafé Classic, Nescafé Espresso, Jacobs Monarch i Jacobs Intense). Prije karakterizacije CGAs, istražena su elektrokemijska svojstva kafeoilkina kiselina (CQAs), dikafeoilkina kiselina (diCQAs) i feruloilkina kiselina (FQAs) primjenom pravokutnovalne voltametrije (SWV), diferencijalne pulsne voltametrije (DPV) i protočne stripping kronopotenciometrije (FTSCP). Elektrokemijska mjerenja CGAs utvrdila su da se na površini radne elektrode odvijaju različite elektrokemijske reakcije različitim oksidacijskim mehanizmima, ovisno o kemijskoj strukturi CGAs. Karakterizacija CGAs provedena je primjenom metoda SWV, DPV, FTSCP i HPLC. Identifikacija i kvantifikacija CGAs u kavama pokazala je da najveći sadržaj ukupnih CGAs imaju zelena zrna kava. Antioksidacijska aktivnost CQAs i diCQAs istraživana je primjenom elektrokemijskog DNA biosenzora, dok je antioksidacijska aktivnost kave istraživana i primjenom DPPH i ABTS metode. Analiza antioksidacijske aktivnosti CQAs i diCQAs primjenom DNA biosenzora pokazala je ovisnost o kemijskoj strukturi ispitivanih klorogenskih kiselina. DNA biosenzor, ABTS i DPPH metode pokazale su da najveću antioksidacijsku aktivnost imaju uzorci zelenog zrna kave, zbog najvećeg sadržaja ukupnih CGAs. Istraživanjima je utvrđeno da postoji vrlo dobra do izvrsna korelacija između antioksidacijske aktivnosti kava i sadržaja ukupnih CGAs.In this study, the characterization of chlorogenic acid (CGAs) and the analysis of antioxidant activity in different brands of coffee (green and roasted beans C. arabica and C. robusta, ground coffee Franck Guatemala and Flatcher Olympia, and instant coffee Nescafé Classic, Nescafé Espresso, Jacobs Monarch and Jacobs Intense) were investigated. Before the characterization, the electrochemical properties of the caffeoylquinic acids (CQAs), dicaffeoylquinic acids (diCQAs) and feruloylquinic acids (FQAs) were analysed by the square-wave voltammetry (SWV), differential pulse voltammetry (DPV) and flow through stripping chronopotentiometry (FTSCP). The electrochemical measurements of the CGAs have shown that on the surface of the working electrode, the different electrochemical reactions via different mechanisms of oxidation proceeded, in connection with the chemical structure of CGAs. Characterization of CGAs was performed by SWV, DPV, FTSCP and HPLC methods. The identification and quantification of the CGAs in different brands of coffee were performed by the SWV, DPV, FTSCP and HPLC methods. The results have shown that the highest CGAs total content exists in the green coffee beans. The antioxidant activity CQAs and diCQAs were analysed by DNA-biosensor while the antioxidant activity of coffee was analysed also by DPPH and ABTS methods. Antioxidant analysis of CQAs and diCQAs using DNA-biosensors has shown the dependence on the chemical structure of investigated CGAs. The methods of DNA-biosensor, ABTS and DPPH have shown the highest antioxidant activity in the green coffee beans due to the highest content of the total CGAs. Very good to the excellent correlation between the antioxidant activity of coffee and the CGAs total content was observed in this study

Characterization of chlorogenic acids and analysis of antioxidation activity in different coffee varieties using electrochemical methods

U ovoj disertaciji provedena je karakterizacija klorogenskih kiselina (CGAs) i analiza antioksidacijske aktivnosti u različitim vrstama kave (zelenim i prženim zrnima kave C. arabica i C. robusta, mljevenim kavama Franck Guatemala i Flatcher Olympia te instant kavama Nescafé Classic, Nescafé Espresso, Jacobs Monarch i Jacobs Intense). Prije karakterizacije CGAs, istražena su elektrokemijska svojstva kafeoilkina kiselina (CQAs), dikafeoilkina kiselina (diCQAs) i feruloilkina kiselina (FQAs) primjenom pravokutnovalne voltametrije (SWV), diferencijalne pulsne voltametrije (DPV) i protočne stripping kronopotenciometrije (FTSCP). Elektrokemijska mjerenja CGAs utvrdila su da se na površini radne elektrode odvijaju različite elektrokemijske reakcije različitim oksidacijskim mehanizmima, ovisno o kemijskoj strukturi CGAs. Karakterizacija CGAs provedena je primjenom metoda SWV, DPV, FTSCP i HPLC. Identifikacija i kvantifikacija CGAs u kavama pokazala je da najveći sadržaj ukupnih CGAs imaju zelena zrna kava. Antioksidacijska aktivnost CQAs i diCQAs istraživana je primjenom elektrokemijskog DNA biosenzora, dok je antioksidacijska aktivnost kave istraživana i primjenom DPPH i ABTS metode. Analiza antioksidacijske aktivnosti CQAs i diCQAs primjenom DNA biosenzora pokazala je ovisnost o kemijskoj strukturi ispitivanih klorogenskih kiselina. DNA biosenzor, ABTS i DPPH metode pokazale su da najveću antioksidacijsku aktivnost imaju uzorci zelenog zrna kave, zbog najvećeg sadržaja ukupnih CGAs. Istraživanjima je utvrđeno da postoji vrlo dobra do izvrsna korelacija između antioksidacijske aktivnosti kava i sadržaja ukupnih CGAs.In this study, the characterization of chlorogenic acid (CGAs) and the analysis of antioxidant activity in different brands of coffee (green and roasted beans C. arabica and C. robusta, ground coffee Franck Guatemala and Flatcher Olympia, and instant coffee Nescafé Classic, Nescafé Espresso, Jacobs Monarch and Jacobs Intense) were investigated. Before the characterization, the electrochemical properties of the caffeoylquinic acids (CQAs), dicaffeoylquinic acids (diCQAs) and feruloylquinic acids (FQAs) were analysed by the square-wave voltammetry (SWV), differential pulse voltammetry (DPV) and flow through stripping chronopotentiometry (FTSCP). The electrochemical measurements of the CGAs have shown that on the surface of the working electrode, the different electrochemical reactions via different mechanisms of oxidation proceeded, in connection with the chemical structure of CGAs. Characterization of CGAs was performed by SWV, DPV, FTSCP and HPLC methods. The identification and quantification of the CGAs in different brands of coffee were performed by the SWV, DPV, FTSCP and HPLC methods. The results have shown that the highest CGAs total content exists in the green coffee beans. The antioxidant activity CQAs and diCQAs were analysed by DNA-biosensor while the antioxidant activity of coffee was analysed also by DPPH and ABTS methods. Antioxidant analysis of CQAs and diCQAs using DNA-biosensors has shown the dependence on the chemical structure of investigated CGAs. The methods of DNA-biosensor, ABTS and DPPH have shown the highest antioxidant activity in the green coffee beans due to the highest content of the total CGAs. Very good to the excellent correlation between the antioxidant activity of coffee and the CGAs total content was observed in this study

Chromatographic and Voltammetric Characterization of Chlorogenic Acids in Coffee Samples

The accurate and precise characterization of eight chlorogenic acids (CGAs) isomers, caffeoylquinic acids (5-CQA, 4-CQA, 3-CQA), dicaffeoylquinic acids (3,5-diCQA, 4,5-diCQA, 3,4-diCQA), and feruloylquinic acids (5-FQA, 4-FQA), was carried out using different brands of coffee. High-performance liquid chromatography (HPLC), differential pulse (DPV) and square-wave voltammetry (SWV) were applied for the investigation. HPLC proved to be an accurate and precise method for separation, identification and quantification of CGAs isomers in coffee extracts. DPV and SWV have shown that electrochemical behaviour of coffee extracts was very similar to that of CGAs isomers and DPV and SWV can be used for the correct characterization of CGAs in coffee. All three techniques have shown a very high correlation of CGAs content in all investigated coffee samples. Therefore, HPLC, DPV and SWV methods can be used in combination as very selective, sensitive and precise methods for characterization of CGAs isomers in coffee extracts. This work is licensed under a Creative Commons Attribution 4.0 International License

Validity of Neuroimaging in Juvenile Headaches

Aim: The objectives of this study are to evaluate the incidence of headache considering the type of headache, to define the types of headaches, to determine the difference in the status of diagnostic scanning in children with headaches, to establish a correlation between the psychological profile of the child and the incidence of headache, and to establish a correlation between socio-demographic characteristics and the type of headache. Patients and Methods: The study included 139 patients with headache symptoms up to the age of 18, hospitalized at the Pediatric Clinic of the University Hospital Center Osijek from 1/1/2017 to 31/12/2018. The data included demographic data, diagnosis, environmental factors, EEG findings, neuroimaging data processing and other indicated medical tests. Results: A headache usually occurs between the ages of 12 and 18 (69.8%). It is more common in girls (70.5%). The common localizations are frontal and occipital. Altered standard EEG findings were reported in 26.7% of patients. Additional neuroradiological processing (brain MRI) was indicated in 98 patients (70.5%), with changes found in 56 patients (57.1%). Psychological assessment indicated that patients with functional headaches predominantly suffer from anxiety, emotional instability and somatization, while patients with organic headaches reported high stress levels (82%). Conclusion: Headaches occur more frequently in pubescent girls. The most common concomitant symptoms include nausea and vomiting, while the most common localization is frontal. Patients also report emotional instability, cognitive deficits and somatization, as well as high stress levels. Headache as a result of psychological tension is the most common diagnosis in the observed group of patients. (Serdarušić I, Pušeljić S, Tomac V, Romić M. Validity of Neuroimaging in Juvenile Headaches. SEEMEDJ 2020; 4(2); 69-76

Adsorpcija diklofenaka na aktivnim ugljenima

The presence of pharmaceuticals in natural waters has been the subject of numerous studies in the last decade due to their potential negative effects on human health and the environment. Indeed, the intensive use of pharmaceuticals leads to their presence in municipal wastewater. Unfortunately, international and national regulations still do not require continuous monitoring of the presence of pharmaceuticals in natural waters and drinking water, so wastewater treatment plants do not focus on removing them from wastewater. Diclofenac, 2-[2-(2,6-dichloroanilino)phenyl]acetic acid (DCF), is a nonsteroidal compound used as an analgesic, anti-inflammatory, and antipyretic drug and is therefore commonly found in wastewater. Due to its properties, DCF remains biologically active in the aquatic environment and easily enters the food chain. Therefore, DCF should be removed from wastewater before it is discharged into water bodies. Adsorption is an efficient and simple method that can be used to remove DCF from water. In this study, the possibility of removing DCF by adsorption on activated carbon is investigated. Modified hazelnut shell (MHS), modified commercial activated carbon Cullar (MC) and unmodified commercial activated carbon Cullar (C) were batch tested as adsorbents. The tested adsorbents were characterised by FTIR, zeta potential and pHpzc, while the adsorbent efficiency was tested in the pH range from 2 to 10 and described by isothermal studies. Among the tested adsorbents, the maximum uptake of 48.7 mg g–1 was found when modified activated carbon Cullar was used, while both Freundlich and Langmuir isotherm models fitted well to the data. Modified activated carbon from hazelnut shells showed effective removal of DCF.Prisutnost farmaceutskih spojeva u prirodnim vodama tema je brojnih znanstvenih istraživanja tijekom prošlog stoljeća zbog njihova potencijalnog negativnog utjecaja na zdravlje ljudi i okoliš. Naime, česta i prekomjerna uporaba lijekova uzrokuje njihovu čestu pojavu u komunalnim otpadnim vodama. Nažalost, međunarodne i nacionalne regulative ne nalažu kontinuirano praćenje prisutnosti lijekova u prirodnoj i pitkoj vodi, pa stoga ni procesi pročišćavanja otpadnih voda nisu usmjereni na njihovo uklanjanje iz otpadnih voda. Diklofenak (DCF), 2-[2-(2,6-dikloroanilino)fenil]octena kiselina nesteroidni je spoj koji se upotrebljava kao analagetik, protuupalni i antipiretski lijek te se često može naći u otpadnim vodama. Zbog svojih karakteristika DCF ostaje biološki aktivan u vodenom okolišu i lako ulazi u hranidbeni lanac. Stoga je DCF nužno ukloniti iz otpadnih voda prije njihova ispuštanja u vodna tijela. Adsorpcija je učinkovita i jednostavna metoda kojom se DCF može učinkovito ukloniti iz vode. Cilj ovog istraživanja je ispitati mogućnost uklanjanja DCF-a adsorpcijom na modificirane ljuske lješnjaka, modificirani i izvorni oblik komercijalnog aktivnog ugljena Cullar (Cadriano, Italija). Svojstva adsorbensa ispitana su FTIR spektroskopijom, analizom zeta-potencijala i pHpzc. Učinkovitost adsorbensa ispitana je u području pH vrijednosti od 2 do 10 te opisana izotermnim modelima. Među ispitanim adsorbensima, najveća količina DCF-a od 48,7 mg g–1 adsorbirana je na modificirani aktivni ugljen Cullar, dok su dobiveni rezultati dobro opisani i Freundlichovom i Langmuirovom izotermom. Značajne količine DCF-a adsorbirane su i na modificirani aktivni ugljen iz ljuski lješnjaka

Utjecaj skladištenja kontroliranom atmosferom na kvalitetu hrvatskih tradicionalnih sorti jabuke

The aim of this work was to investigate the influence of cold storage at 2 °C for 180 days on water content, total acids, reducing and total sugar, antioxidant activity, polyphenol oxidase activity, and polyphenol profile of three Croatian traditional apple cultivars (‘Kanadska Reneta’, ‘Ilzer Rosenapfel’, ‘Wagener’). A significant variation in polyphenol profile of apple cultivars under investigation was noted. The most represented polyphenols in all apple cultivars were procyanidin B2 followed by chlorogenic acid, epigallocatechin, epicatechin, and phloridzin. After storage, the content of procyanidin B2 and chlorogenic acid was higher, while content of epigallocatechin after storage was lower in all investigated apple cultivars. Water content before storage ranged between 79.17 and 80.76 %, and after storage between 75.62 and 78.56 %. Total acids, polyphenol oxidase activity, and flavonoids had decreased during storage, while reducing and total sugar content was higher after storage. Moreover, after storage, cultivar ‘Kanadska Reneta’ had the highest antioxidant activity measured by both ABTS and DPPH methods, 1.65 and 0.70 mmol trolox kg–1, respectively. A significant variation in polyphenol profile of apple cultivars under investigation was noted. The most represented polyphenols in all apple cultivars were procyanidin B2, followed by chlorogenic acid, epigallocatechin, epicatechin, and phloridzin. After storage, the content of procyanidin B2 and chlorogenic acid was higher, while content of epigallocatechin after storage was lower in all investigated apple cultivars. Overall, it can be concluded that investigated apple cultivars, after storage, preserved most of the antioxidants and functional properties.Cilj ovog rada bio je istražiti utjecaj skladištenja kontroliranom atmosferom na 2 °C tijekom 180 dana na polifenolni profil, sadržaj vode, ukupne kiseline, reducirajuće i ukupne šećere, antioksidacijsku aktivnost i aktivnost polifenol oksidaze triju hrvatskih tradicionalnih sorti jabuke (´Kanadska Reneta’, ‘Ilzer Rosenapfel’, ‘Wagener’). Uočena je značajna varijacija u profilu polifenola ispitivanih sorti jabuke. Najzastupljeniji polifenoli kod svih sorti jabuke bili su procijanidin B2, zatim klorogenska kiselina, epigalokatehin, epikatehin i floridzin. Nakon skladištenja sadržaj procijanidina B2 i klorogenske kiseline bio je veći, dok je sadržaj epigalokatehina nakon skladištenja bio manji kod svih ispitivanih sorti jabuke. Sadržaj vode prije skladištenja kretao se između 79,17 i 80,76 %, a nakon skladištenja između 75,62 i 78,56 %. Tijekom skladištenja došlo je do smanjenja ukupnih kiselina, aktivnosti polifenol oksidaze i udjela flavonoida, dok je sadržaj ukupnih šećera bio veći nakon skladištenja. Štoviše, sorta ‘Kanadska Reneta’ nakon skladištenja imala je najveću antioksidacijsku aktivnost mjerenu ABTS i DPPH metodom, 1,65 odnosno 0,70 mmol trolox/kg–1. Uočena je značajna varijacija u polifenolnom profilu ispitivanih sorti jabuke. Najzastupljeniji polifenoli kod svih sorti jabuke bili su procijanidin B2, zatim klorogenska kiselina, epigalokatehin, epikatehin i floridzin. Nakon skladištenja sadržaj procijanidina B2 i klorogenske kiseline bio je veći, dok je sadržaj epigalokatehina nakon skladištenja bio niži kod svih ispitivanih sorti jabuke. Sveukupno se može zaključiti da su ispitivane sorte jabuka nakon skladištenja sačuvale najveći dio antioksidativnih i funkcionalnih svojstava

Etiology and the Genetic Basis of Intellectual Disability in the Pediatric Population

Intellectual disability/mental retardation (ID/MR) is defined as incomplete mental and cognitive development present before the age of 18. There are number of pre-natal and post-natal risk factors that can cause ID/MR but25 %-50% of all have genetic causes. In the general population,the prevalence of ID/MR is about 2 %-3%. Use of standard cytogenetic methods analysis of chromosomes (GTG banding) and FISH (Fluorescent in Situ Hybridization) reveals only a small number of causes, but when usingnew molecular genetics techniques (like chromosomal microarray and next generation sequencing), the rate of causes of ID/MR is increasedand new candidate genes for ID/MR have been discovered. Establishing a diagnosis of ID/MR is important for the patient and it provides genetic counseling for parents

Protection measures in the area of forestry authorities Ravna gora and Skrad in the period since 2008. by 2012.

U diplomskom radu prikazane su i obrađene mjere zaštite na području šumarija Ravna Gora i šumarija Skrad u razdoblju od 2008. do 2012. godine. Na osnovu podataka prikupljenih u odjelu za ekologiju u upravi šuma podruţnica Delnice prikazat će se glavne vrste biotskih čimbenika koje uzrokuju oštećenja u šumskim sastojinama kojima gospodare šumarija Ravna Gora i Skrad. Diplomski rad obuhvatit će analizu primjenjenih mjera zaštite u razdoblju od 2008. do 2012. godine. Glavni osvrt će se odnositi na zdrastveno stanje jele i njenu zaraţenost imelom (Viscum album var. Abietis Beck), jelinog moljca igličara (Argyresthia fundella F.R..) i praćenje jelovih potkornjaka

Protection measures in the area of forestry authorities Ravna gora and Skrad in the period since 2008. by 2012.

U diplomskom radu prikazane su i obrađene mjere zaštite na području šumarija Ravna Gora i šumarija Skrad u razdoblju od 2008. do 2012. godine. Na osnovu podataka prikupljenih u odjelu za ekologiju u upravi šuma podruţnica Delnice prikazat će se glavne vrste biotskih čimbenika koje uzrokuju oštećenja u šumskim sastojinama kojima gospodare šumarija Ravna Gora i Skrad. Diplomski rad obuhvatit će analizu primjenjenih mjera zaštite u razdoblju od 2008. do 2012. godine. Glavni osvrt će se odnositi na zdrastveno stanje jele i njenu zaraţenost imelom (Viscum album var. Abietis Beck), jelinog moljca igličara (Argyresthia fundella F.R..) i praćenje jelovih potkornjaka

Protection measures in the area of forestry authorities Ravna gora and Skrad in the period since 2008. by 2012.

U diplomskom radu prikazane su i obrađene mjere zaštite na području šumarija Ravna Gora i šumarija Skrad u razdoblju od 2008. do 2012. godine. Na osnovu podataka prikupljenih u odjelu za ekologiju u upravi šuma podruţnica Delnice prikazat će se glavne vrste biotskih čimbenika koje uzrokuju oštećenja u šumskim sastojinama kojima gospodare šumarija Ravna Gora i Skrad. Diplomski rad obuhvatit će analizu primjenjenih mjera zaštite u razdoblju od 2008. do 2012. godine. Glavni osvrt će se odnositi na zdrastveno stanje jele i njenu zaraţenost imelom (Viscum album var. Abietis Beck), jelinog moljca igličara (Argyresthia fundella F.R..) i praćenje jelovih potkornjaka