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

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.

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.

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

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.

Incidence of microflora and of ochratoxin A in green coffee beans (Coffea arabica)

2003 ◽  
Vol 20 (12) ◽  
pp. 1127-1131 ◽  
Author(s):  
M. L. Martins ◽  
H. M. Martins ◽  
A. Gimeno
Keyword(s):  
Ochratoxin A ◽  
Coffea Arabica ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

Screening on the Occurrence of Ochratoxin A in Green Coffee Beans of Different Origins and Types

2000 ◽  
Vol 48 (8) ◽  
pp. 3616-3619 ◽  
Author(s):  
Santina Romani ◽  
Giampiero Sacchetti ◽  
Clemencia Chaves López ◽  
Gian Gaetano Pinnavaia ◽  
Marco Dalla Rosa
Keyword(s):  
Ochratoxin A ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Different Origins
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