Ochratoxins A and B, Xanthomegnin, Viomellein and Vioxanthin Production by Isolates of Aspergillus ochraceus from Green Coffee Beans

1983 ◽  
Vol 46 (11) ◽  
pp. 965-968 ◽  
Author(s):  
MICHAEL E. STACK ◽  
PHILIP B. MISLIVEC ◽  
TURGUT DENIZEL ◽  
REGINA GIBSON ◽  
ALBERT E. POHLAND
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Ochratoxin A ◽  
High Performance ◽  
Toxin Production ◽  
Aspergillus Ochraceus ◽  
Average Level ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

Isolates from Aspergillus ochraceus obtained from green coffee beans were cultured on rice and water. After 20 d of growth the cultures were extracted with chloroform and the extracts were analyzed by high performance liquid chromatography for ochratoxin A (OA), ochratoxin B (OB), xanthomegnin (X), viomellein (V) and vioxanthin (VX). Forty-three percent of the isolates produced OA at an average level of 397 μg of toxin/g rice, 17% produced OB at an average level of 312 μg/g, and 84% produced X, V, and VX at an average level of 281, 417 and 386 μg/g, respectively. The highest levels of toxin production were OA, 2088 μg/g; OB, 3375 μg/g; X, 1562 μg/g; V, 2514 μg/g; and VX, 2054 μg/g. VX has not previously been reported as an A. ochraceus metabolite.

Effect of roasting on ochratoxin A level in green coffee beans inoculated with Aspergillus ochraceus

1987 ◽  
Vol 97 (2) ◽  
pp. 111-115 ◽  
Author(s):  
Haruo Tsubouchi ◽  
Katsuhiko Yamamoto ◽  
Kazuo Hisada ◽  
Yoshio Sakabe ◽  
Shun- ichi Udagawa
Keyword(s):  
Ochratoxin A ◽  
Aspergillus Ochraceus ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

scholarly journals Standardization of an analytical method to quantify ochratoxin A in green coffee beans by high performance liquid chromatography

2020 ◽  
Vol 9 (8) ◽  
pp. e39985070
Author(s):  
Wilder Douglas Santiago ◽  
Alexandre Rezende Teixeira ◽  
Juliana de Andrade Santiago ◽  
Ana Cláudia Alencar Lopes ◽  
Rafaela Magalhães Brandão ◽  
...  
Keyword(s):  
Food Safety ◽  
Ochratoxin A ◽  
High Performance ◽  
Animal Health ◽  
Green Coffee ◽  
Fungal Contamination ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Green Coffee Beans ◽  
Coffee Beans

Nowadays, Brazil is the largest producer and exporter of coffee, also the second largest consumer of the beverage. The importance of ensuring food safety for consumers has influenced research to improve and monitor the final product quality. Coffee is a product that presents a high risk of fungal contamination, which can result in the presence of mycotoxins and poses risks to human and animal health. Therefore, this study aimed to standardize a chromatographic method to test and quantify ochratoxin A in 13 samples of green coffee beans. The green coffee beans were stored in sheds without temperature or humidity control. Samples were ground, and the analyte was extracted by a 3% methanol:sodium bicarbonate (1:2 v/v) solution. Ochratoxin A was quantified in a high performance liquid chromatograph. The method was validated by testing the selectivity, linearity, accuracy, limits of detection and quantification. The method presented robustness to the tested parameters and among the analyzed samples. Ochratoxin A was detected above the limit established by the legislation (75.19 µg kg-1) only in one sample. Overall, the storage of green coffee beans in these sheds was adequate, since 12 samples had a low content of ochratoxin A and they were within the limit established by legislation. Therefore, food safety was guaranteed without any severe mycotoxin contamination.

Study of the Occurrence of Ochratoxin A in Green Coffee Beans

1974 ◽  
Vol 57 (4) ◽  
pp. 866-870 ◽  
Author(s):  
Colette P Levi ◽  
Hugh L Trenk ◽  
Herman K Mohr
Keyword(s):  
Heat Treatment ◽  
Ochratoxin A ◽  
Room Temperature ◽  
Aspergillus Ochraceus ◽  
Green Coffee ◽  
Optimal Conditions ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Almost All

Abstract Moldy green coffee beans were found to contain Aspergillus ochraceus and detectable levels of ochratoxin A. The official first action method for the detection of ochratoxins in barley, 26.C15–26.C22, was modified for analysis of coffee beans and a number of survey samples of coffee beans were analyzed. A. ochraceus was found to be present in almost all samples but ochratoxin A was infrequently observed. Ochratoxin A production in sterile green coffee beans inoculated with A. ochraceus under optimal conditions was maximal at 13 days at room temperature but the total amount was low (450 μg/kg). Considerable destruction (approximately 80%) of ochratoxin A occurred during a heat treatment which simulated the roasting of coffee beans.

Effect of Water Activity and Temperature on Mycelial Growth and Ochratoxin A Production by Isolates of Aspergillus ochraceus on Irradiated Green Coffee Beans

2005 ◽  
Vol 68 (1) ◽  
pp. 133-138 ◽  
Author(s):  
E. PARDO ◽  
S. MARÍN ◽  
A. J. RAMOS ◽  
V. SANCHIS
Keyword(s):  
Ochratoxin A ◽  
Water Activity ◽  
Mycelial Growth ◽  
Marked Decrease ◽  
Limit Of Detection ◽  
Aspergillus Ochraceus ◽  
Primary Data ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

Aspergillus ochraceus as a fungal contaminant and ochratoxin A (OTA) producer plays an important role in coffee quality. Temperature and water activity (aw) significantly influence mycelial growth and OTA production by isolates of A. ochraceus on green coffee beans. Maximum mycelial growth was found at 30°C and 0.95 to 0.99 aw. A marked decrease in growth rate was observed when temperature and aw were reduced. At 0.80 aw, mycelial growth occurred only at 30 and 20°C for one isolate. Maximum OTA production was found at 20°C and 0.99 aw. At 10°C, OTA was not produced, regardless of aw. Similarly, no OTA was detected at 0.80 aw. OTA production ranged from the limit of detection (40 ng g−1 of green coffee) to 17,000 ng g−1 of green coffee. Significant intraspecific differences in mycelial growth and OTA production were found. Primary data for lag phases prior to mycelial growth under the influence of temperature and aw were modelled by multiple linear regression, and the response surface plots were obtained.

Development of a Flow-Through Enzyme Immunoassay and Application in Screening Green Coffee Samples for Ochratoxin A with Confirmation by High-Performance Liquid Chromatography

2001 ◽  
Vol 64 (10) ◽  
pp. 1597-1602 ◽  
Author(s):  
L. SIBANDA ◽  
S. DE SAEGER ◽  
T. G. M. BAUTERS ◽  
H. J. NELIS ◽  
C. VAN PETEGHEM
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Ochratoxin A ◽  
High Performance ◽  
Hplc Method ◽  
Coffee Bean ◽  
Green Coffee ◽  
Penicillium Species ◽  
Flow Through

A flow-through enzyme immunoassay has been developed for the screening of green coffee bean samples for ochratoxin A (OA) and was later used in a survey on OA in green coffee from different countries. The test has a sensitivity of 8 ng/g, and calculated recoveries ranged from 70 to 89% and from 86 to 95% for spiked and naturally contaminated samples, respectively. There were no significant differences in within-day and between-day assay performance (P > 0.05). Green coffee samples (15 Arabica and 7 Robusta) received from an international coffee trader were analyzed for intrinsic fungal contamination, screened for OA, and subsequently confirmed by high-performance liquid chromatography (HPLC). All 22 samples were contaminated by fungal species of the genus Aspergillus, while Penicillium species were isolated from a mere 13.6% of the total number of samples. Isolates were tested for their ability to produce OA, and only 3.9% were positive. There was no correlation between occurrence of OA-producing isolates and levels of OA in contaminated samples. Results of the screening procedure showed that 4 of the 22 samples were contaminated with 8 ng/g or higher. The HPLC method confirmed that the OA levels ranged from 27 to 168 ng/g. A fifth sample, which was shown to be negative during screening, had an OA concentration of 4 ng/g. There were no false negatives or positives recorded, and the flow-through enzyme immunoassay results correlated with those obtained by HPLC.

A new preparative method for simultaneous purification of ochratoxin A and ochratoxin B from wheat culture inoculated with Aspergillus ochraceus

2016 ◽  
Vol 9 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Z.Y. Zhao ◽  
N. Liu ◽  
L.C. Yang ◽  
A.B. Wu ◽  
Z.L. Zhou ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Ochratoxin A ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Preparative Method ◽  
Aspergillus Ochraceus ◽  
Potential Health ◽  
Ochratoxin B ◽  
Purity Analysis

Ochratoxins are a mycotoxin family frequently found in agricultural commodities worldwide and pose a potential health risk to humans and animals. To obtain large amounts of high-purity ochratoxins for food safety monitoring and toxicological research, a novel and effective method was established for simultaneous purification of ochratoxin A (OTA) and ochratoxin B (OTB) from a wheat culture inoculated with an ochratoxin-producing Aspergillus strain. The inoculated wheat culture was first extracted with methanol:water (80:20, v/v), followed by one or two cleanup procedures involving acid-assisted liquid-liquid extraction and gel permeation chromatography. Subsequently, target analytes were separated and collected using preparative high performance liquid chromatography. Finally, a combined approach of ultra-high performance liquid chromatography, ultraviolet spectrophotometry and mass spectrometry was applied for purity analysis and structural identification of the obtained toxins. As a result, 100 g of an inoculated wheat culture yielded 69 mg of OTA and 6 mg of OTB with purities greater than 98%. This proposed method might serve as a valuable reference to obtain expensive ochratoxin standards. To the best of our knowledge, this is the first report on simultaneous preparation of OTA and OTB from artificially inoculated wheat culture.

Occurrence of Ochratoxigenic Fungi and Ochratoxin A in Green Coffee from Different Origins

2004 ◽  
Vol 10 (1) ◽  
pp. 45-49 ◽  
Author(s):  
E. Pardo ◽  
S. Marin ◽  
A. J. Ramos ◽  
V. Sanchis
Keyword(s):  
Fungal Infection ◽  
Ochratoxin A ◽  
High Performance ◽  
Limit Of Detection ◽  
Aspergillus Ochraceus ◽  
Green Coffee ◽  
Agar Plug ◽  
Coffee Beans ◽  
Different Origins ◽  
Positive Results

Fungal infection and ochratoxin A (OTA) contamination were determined in green coffee samples from different origins, in which OTA-producing fungi were also identified. About 72% of the beans analysed by direct plating presented fungal infection, including species of Aspergillus, Penicillium and Rhizopus. The genus Aspergillus was presented in more than 90% of infected coffee beans. Aspergillus ochraceus and Aspergillus section Nigri isolates represented 2.8 and 65.4%, respectively from the total number of isolates from the coffee beans. The capacity to produce OTA was determined in 260 isolates of A. section Nigri and 19 of A. ochraceus by the agar plug method, giving positive results for 6% of the A. section Nigri isolates and 16% of the A. ochraceus. OTA production was analysed by high performance liquid chromatography. OTA contamination of green coffee beans was analysed by enzyme immunoassay. OTA levels in all samples analysed were above the limit of detection (0.6 mg/kg), with a mean OTA concentration of 6.7 mg/kg.

Caffeine degradation and increased ochratoxin A production by toxigenic strains of Aspergillus ochraceus isolated from green coffee beans

1985 ◽  
Vol 90 (3) ◽  
pp. 181-186 ◽  
Author(s):  
Haruo Tsubouchi ◽  
Hisaya Terada ◽  
Katsuhiko Yamamoto ◽  
Kazuo Hisada ◽  
Yoshio Sakabe
Keyword(s):  
Ochratoxin A ◽  
Aspergillus Ochraceus ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Caffeine Degradation ◽  
Coffee Beans ◽  
Toxigenic Strains
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