Two-Dimensional Thin-Layer Chromatographic Method for the Analysis of Ochratoxin A in Green Coffee

2005 ◽  
Vol 68 (9) ◽  
pp. 1920-1922 ◽  
Author(s):  
MERITXELL VENTURA ◽  
IVAN ANAYA ◽  
FRANCESC BROTO-PUIG ◽  
MONTSERRAT AGUT ◽  
LLUÍS COMELLAS
Keyword(s):  
Thin Layer ◽  
Formic Acid ◽  
Ochratoxin A ◽  
Chromatographic Method ◽  
Low Cost ◽  
Chlorinated Solvents ◽  
Sodium Bicarbonate Solution ◽  
Coffee Bean ◽  
Green Coffee ◽  
Two Dimensional

A low-cost thin-layer chromatographic method has been developed for the presumptive measurement of ochratoxin A (OTA) at 5 μg/kg in green coffee beans. The analytical method consisted of extracting OTA by shaking the beans with a mixture of methanol and aqueous sodium bicarbonate solution, which was then purified by liquid-liquid partition into toluene. OTA was separated by normal-phase two-dimensional thin-layer chromatography and detected by visual estimation of fluorescence intensity under a UV lamp at 365 nm. The chromatography solvents were toluene–methanol–formic acid (8:2:0.03) for the first development and petroleum ether–ethyl acetate–formic acid (8:10:1) for the second dimension development. This method was tested with uncontaminated green coffee bean samples spiked with an OTA standard at four different concentrations (5, 10, 20, and 30 μg/kg). The method is rapid, simple, and very easy to implement in coffee-producing countries. It is highly selective and does not involve the use of chlorinated solvents in the sample extraction step. This inexpensive method has been applied to different types of green coffee samples from various countries (Zimbabwe, Brazil, India, Uganda, Colombia, and Indonesia) and different manufacturers, and no OTA below the detection limit of 5 μg/kg was detected in any samples analyzed.

Collaborative Study of a Method for the Determination of Ochratoxin A in Green Coffee

1975 ◽  
Vol 58 (2) ◽  
pp. 258-262 ◽  
Author(s):  
Colette P Levi
Keyword(s):  
Thin Layer ◽  
Ochratoxin A ◽  
Collaborative Study ◽  
Green Coffee ◽  
Average Recovery ◽  
Semiquantitative Determination ◽  
Chromatographic Methods ◽  
Green Coffee Beans ◽  
Coffee Beans

Abstract A method for the semiquantitative determination of ochratoxin A in green coffee has been studied collaboratively by 11 laboratories. The average recovery for the 7 samples spiked at 3 levels of ochratoxin A was 69.1%, ranging from 60.5 to 85.6%. This is comparable to other visual thin layer chromatographic methods of mycotoxin detection. The method has been adopted as official first action for the determination of ochratoxin A in green coffee beans.

Rapid Thin Layer Chromatographic Method for Determining Aflatoxin Bi, Ochratoxin A, and Zearalenone in Corn

1978 ◽  
Vol 61 (3) ◽  
pp. 584-585
Author(s):  
Ivan Balzer ◽  
Čedo Bogdanić ◽  
Stjepan Pepeljnjak
Keyword(s):  
Sodium Bicarbonate ◽  
Thin Layer ◽  
Ochratoxin A ◽  
Ultraviolet Light ◽  
Aflatoxin B1 ◽  
Chromatographic Method ◽  
Limits Of Detection ◽  
Chloroform Extraction ◽  
Tlc Plates

Abstract A multimycotoxin thin layer chromatographic method is described for the analysis of corn. Aflatoxins are extracted from the samples with acetonitrile-water, and sodium bicarbonate is added to separate the acidic ochratoxin from zearalenone and aflatoxin B1. After chloroform extraction, 1/V NaOH is added to separate zearalenone and aflatoxin B1# The separated mycotoxins are spotted on TLC plates, which are then examined under ultraviolet light. The following recoveries ( % ) were obtained for corn samples: aflatoxin B1 71, ochratoxin A 87, and zearalenone 85. The limits of detection for the respective mycotoxins were 2, 40, and 200 ppb.

Two-dimensional mapping as a tool for classification of green coffee bean species

PROTEOMICS ◽  
2005 ◽  
Vol 5 (3) ◽  
pp. 710-718 ◽  
Author(s):  
Maria Teresa Gil-Agusti ◽  
Natascia Campostrini ◽  
Lello Zolla ◽  
Corrado Ciambella ◽  
Carlo Invernizzi ◽  
...  
Keyword(s):  
Coffee Bean ◽  
Green Coffee ◽  
Two Dimensional ◽  
Green Coffee Bean ◽  
Dimensional Mapping

Effect of Temperature and Relative Humidity during Transportation on Green Coffee Bean Moisture Content and Ochratoxin A Production

2007 ◽  
Vol 70 (1) ◽  
pp. 164-171 ◽  
Author(s):  
HECTOR A. PALACIOS-CABRERA ◽  
HILARY C. MENEZES ◽  
BEATRIZ T. IAMANAKA ◽  
FREDERICO CANEPA ◽  
ALDIR A. TEIXEIRA ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ochratoxin A ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Coffee Bean ◽  
Green Coffee ◽  
Final Destination ◽  
Coffee Beans ◽  
Environmental Variations

Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).

scholarly journals Extraction of soluble sugars from green coffee beans using hot water and quantification by a chromatographic method without an organic solvent

2020 ◽  
Vol 32 (4) ◽  
pp. 242-246 ◽  
Author(s):  
Leonel Vinicius Constantino ◽  
Douglas Mariani Zeffa ◽  
Alessandra Koltun ◽  
Mariana Ragassi Urbano ◽  
Alisson Wilson Santos Sanzovo ◽  
...  
Keyword(s):  
High Performance ◽  
Chromatographic Method ◽  
Limit Of Detection ◽  
Low Cost ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Hot Water ◽  
Green Coffee ◽  
Limit Of Quantification ◽  
Assisted Extraction

An optimal condition for extraction of soluble sugars from green coffee using water and a validated chromatographic method for its separation and quantification were proposed in this research. An orbital incubator shaker (OIS) and microwave-assisted extraction (MAE) were the 2 techniques used to extract soluble sugars. In such experiments, the variables: sample amount (300, 400, and 500 mg), time (30, 60, and 90 min), and temperature (30, 45, and 60 °C) were tested. The separation of sugars was performed in a chromatographic system (high-performance liquid chromatography refractive index detector [HPLC-RID]), which presented the selectivity for the analytes, a limit of detection of 0.020 g/L, a limit of quantification of 0.0625 g/L, and recovery rates greater than 95%. The repeatability and inter-day precision had low dispersion, RSD < 2.0% and < 3.0%, respectively. Sucrose content ranged from 0.65 to 2.39 g/L using an OIS and from 1.19 to 2.72 g/L by MAE, while glucose and fructose concentration varied from 0.08 to 0.12 g/L using both methods. The OIS technique is preferably indicated for extraction of soluble sugars at the following conditions: 500 mg of grounded green coffee, 90 min, and 60 °C. The proposed method for soluble sugar extraction and quantification may be applied in research laboratories and food industries since it is a low-cost and environment-friendly technique.

A two-dimensional thin-layer chromatographic method for screening carbohydrate anomalies

1974 ◽  
Vol 95 (1) ◽  
pp. 51-58 ◽  
Author(s):  
M. Ghebregzabher ◽  
S. Rufini ◽  
G. Ciuffini ◽  
M. Lato
Keyword(s):  
Thin Layer ◽  
Chromatographic Method ◽  
Two Dimensional
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