Content of 4(5)-methylimidazole, caffeine and chlorogenic acid in commercial coffee brands

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F15%3A43874651" target="_blank" >RIV/70883521:28610/15:43874651 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.potravinarstvo.com/journal1/index.php/potravinarstvo/article/view/422" target="_blank" >http://www.potravinarstvo.com/journal1/index.php/potravinarstvo/article/view/422</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5219/422" target="_blank" >10.5219/422</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Content of 4(5)-methylimidazole, caffeine and chlorogenic acid in commercial coffee brands

Popis výsledku v původním jazyce

Content of 4(5)-methylimidazole (4-MeI), caffeine and chlorogenic acid in commercial coffee brands were determined using high-performance liquid chromatography (HPLC) with UV DAD and MS detectors. Positive ion ESI mass spectra of the 4-MeI standard yielded intense signals corresponding to [M+H]+ (83.0604) and [2M+H]+ ions (165.1115). Also, adducts of 4-MeI with acetonitrile from mobile were detected - [M+ACN]+ ions (124.0849). The LOD of 2.5 ng mL-1 and LOQ of 8.4 ng.mL-1 were calculated according to the following formulas: LOD = 3.SD/S, and LOQ = 10.SD/S, where S is the slope of the calibration curve and SD is the standard deviation of the noise. The caffeine content was compared to the results of the standard addition, 1st derivative and liquid-liquid extraction spectrophotometry. 4-MeI was in tens μg g-1 in the Vietnamese coffees while in units μg.g-1 in all Czech and Brazilian coffees (<2.4 μg.g-1 and <4.9 μg.g-1, respectively). The results for caffeine were within the documented range (0.31 - 2.20%) in all coffee samples. The lower content of caffeine and chlorogenic acid was observed in Vietnamese coffees. All the methods used for determination of caffeine in the Czech and Brazilian coffees gave acceptable precision and accuracy. However, there were significant differences in the results in Vietnamese coffees. The caffeine extractability (100 oC, 3 min brewing) almost reached 100% in Czech and Brazilian coffees, while it was less than 90% in Vietnamese coffees. The Czech and Brazilian coffees tend to produce more caffeine in brews than the Vietnamese coffee because of the different composition of blends and the particle size degree.

Název v anglickém jazyce

Content of 4(5)-methylimidazole, caffeine and chlorogenic acid in commercial coffee brands

Popis výsledku anglicky

Content of 4(5)-methylimidazole (4-MeI), caffeine and chlorogenic acid in commercial coffee brands were determined using high-performance liquid chromatography (HPLC) with UV DAD and MS detectors. Positive ion ESI mass spectra of the 4-MeI standard yielded intense signals corresponding to [M+H]+ (83.0604) and [2M+H]+ ions (165.1115). Also, adducts of 4-MeI with acetonitrile from mobile were detected - [M+ACN]+ ions (124.0849). The LOD of 2.5 ng mL-1 and LOQ of 8.4 ng.mL-1 were calculated according to the following formulas: LOD = 3.SD/S, and LOQ = 10.SD/S, where S is the slope of the calibration curve and SD is the standard deviation of the noise. The caffeine content was compared to the results of the standard addition, 1st derivative and liquid-liquid extraction spectrophotometry. 4-MeI was in tens μg g-1 in the Vietnamese coffees while in units μg.g-1 in all Czech and Brazilian coffees (<2.4 μg.g-1 and <4.9 μg.g-1, respectively). The results for caffeine were within the documented range (0.31 - 2.20%) in all coffee samples. The lower content of caffeine and chlorogenic acid was observed in Vietnamese coffees. All the methods used for determination of caffeine in the Czech and Brazilian coffees gave acceptable precision and accuracy. However, there were significant differences in the results in Vietnamese coffees. The caffeine extractability (100 oC, 3 min brewing) almost reached 100% in Czech and Brazilian coffees, while it was less than 90% in Vietnamese coffees. The Czech and Brazilian coffees tend to produce more caffeine in brews than the Vietnamese coffee because of the different composition of blends and the particle size degree.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

GM - Potravinářství

OECD FORD obor

—

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Potravinárstvo

ISSN

1338-0230

e-ISSN

—

Svazek periodika

9

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

SK - Slovenská republika

Počet stran výsledku

8

Strana od-do

31-38

Kód UT WoS článku

—

EID výsledku v databázi Scopus

2-s2.0-84983528037