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

Tsubouchi, Haruo; Yamamoto, Katsuhiko; Hisada, Kazuo; Sakabe, Yoshio; Udagawa, S.

doi:10.1007/bf00436848

Cited by 84 publications

(75 citation statements)

References 12 publications

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“…Several studies have been published regarding the heat stability of OA during the roasting process. Tsubouchi et al (1987) reported a reduction of 0-12 % OA after roasting artificially inoculated beans contaminated in the range of 200 to 140,000 #g/kg, which corroborates our own findings. One can assume a relatively high homogeneity in artificially contaminated samples as indicated by the results presented here, although Tsubouchi et al (1987) did not report corresponding data.…”

Section: Discussionsupporting

confidence: 91%

“…While only isolated data exist regarding nuts, dates, soya beans and cocoa beans, the natural occurrence of OA in green and roasted coffee beans has been reported several times. However, inconsistent results have been published with respect to the influence of the roasting process on the OA content (Gallaz and Stadler, 1976;Micco et al, 1989;Tsubouchi et al, 1987) and the transfer of OA into the brew (Micco et al, 1989;Tsubouchi et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

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The occurrence of ochratoxin A in coffee

Studer-Rohr

Dietrich

Schlatter

et al. 1995

Food and Chemical Toxicology

183

116

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Abstract--Ochratoxin A (OA) is a nephrotoxic and nephrocarcinogenic mycotoxin which is predominantly produced by the two ubiquitous fungal genera, Aspergillus and Penicillium. OA is found in foodstuffs, predominantly in cereals but also in coffee beans. Inconsistent results have been published regarding the influence of roasting on the OA content in roasted beans and the transfer into the coffee brew. In the present study an HPLC method was used for the detection of OA in green and roasted coffee beans as well as in the coffee brew. For qualitative confirmation and quantification of low OA levels in roasted coffee beans and coffee brew an additional clean-up step by immunoaffinity column was applied before HPLC analysis. In green coffee beans OA was detected in 13 out of 25 commercial samples analysed (detection limit, 0.5/~g OA/kg). Roasting (250°C, 150 sec) of naturally contaminated green beans or beans inoculated with A. ochraceus resulted only in a small reduction in the OA level. OA was also found to be eluted into the brew. Of 40 coffee brews prepared from commercially available samples OA was detected in 18 brews by HPLC and/or additional immunoaffinity column clean-up in the range of 0.4 to 7.8 pg OA/kg equivalent ground coffee. Our preliminary results suggest, therefore, that regular coffee consumption may contribute to exposure of humans to OA.

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Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

The occurrence of ochratoxin A in coffee

Studer-Rohr

Dietrich

Schlatter

et al. 1995

Food and Chemical Toxicology

183

116

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“…Tsubouchi et al (1987) found thut after Inoculation with A.~, roasting green coffee beans for 20 min at 2lXJOC reduced the concentration ofOTA by a maximum of only 12% in whole beans and 18·22% in ground beans. They concluded that the mode of OTA contamination wa.~the reason for Ihis greater heat resistance.…”

Section: Stability Of Ota and Dfccts Of Food Processingmentioning

confidence: 92%

Effect of cytochrome P450 induction on the metabolism and toxicity of ochratoxin A

Omar

Gelboin

Rahimtula

1996

Biochemical Pharmacology

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The role of cytochrome P-450 in me stimulation of lipid peroxidation induccd by thc mycotoxin ochratoxin A (OTA) has been investigated. Purified cytochrome P-450 (liB I) could effectively replace EDTA in stimulating lipid pefOxidation in a reconstituted system l'Onsisling of phospholipid vesicles, NADPH-cYlochrome P-450rcduc!ase, FeJ+, EDTA and NADPll, suggesting that it could mediate the transfer of electrons from NADPH to foc3,. Microsomcs isolated from liven of cobalt protoporphyrin IX-treated rllts (in which cytochrome P-450 Wll" depletedj underwent OTA-dependent lipid peroxidation much more slowly tlmn control microsomes.The role of cytochrome P-450 in OTA met.1bolism was also investigated. To dClermine which cytochrome P·450 isoforms are involved in the metabolism ofOTA, we used different cytochrome P-450 inducers to induce the major isofonns of cytochrome 1'-450 in lhe rm liver.Microsomes from these livers were used to investigate their effect on OTA metabolism.Pretreatment ofmts with pregnenolone -16c(·carbonitrile (peN), phenobarbit.ll (PB), 3-ll1cthyl cholanthrene (3MC), and isosafrole (ISF) greatly induced 4(R)-4-0H-OTA fonmllion; 4(5)-4-011-OTA fonnation was also induced after pretreatment with PB, PCN, 3MC and ISr:. INII pretreaunem primarily induced me 4(5) isomer formation, The fonnation of the 4(R) .md 4 (5) isomeri showed significant differences with respect to pH optima, effect of antioKidants ami iron chelators, The 4(R) isomer fonnation showed a pH optimum of 6.0 using microsornes from rJIs treated with 3MC and ISF, and 6.5 using mierosomes from rats treated with PI] :tnd peN and Wi!S not inhibited by antioxidants or iron chelators. In contmst, both the 4(5) isomer fonmllion and lipid pcroxidation showed a pH optimum of 7.0 -7,5 and both activities were highly sensitive to inhibition by antioxidants and iron ehelators. Lipid peroxides were no: involved in the 4(5) isomer fonnation since addition of linoleic acid hydroperoxidc to microsomcs did not give rise 10 the 4(5) isomer, Cytochrome P-450 appeared to be essenlial since other hemoprolcins such as horseradish peroxidase and hemoglobin were ineffective in metabolizing OTA. Microsomes from rats pretreated with Co-protoporphyrin IX resulted in no metabolil,rn of ochratoxin A. 7-Ethoxy-and 7-pentoxyresorufin assays showed specificity towards cytochromes P-450 induced by 3MC (fA I/lA2) and PB (IIBI) respectively. Also, metyrapone (inhibitor of cytochrome P·450 IIBt) preferentially inhibited OTA mel1bolism by microsomes from rats treated with PB, and I(-naphthoflavone (inhibitor of cytochrome P-450 IAI/lA2) preferentially inhibited OTA metabolism by microwmes from 3MC and ISF treated rats_ Monoclonal antibodies (MAbs) 1-7-1 (against P-450 lA 1/lA2) and 2-66-3 (against P-450 liB I) showed preferential inhibition ofOTA metabolism by microsomes from 3MC and PB treated rats respectively.Excretion of renal enzymes in urine is a sensitive non-invasive index of renal dam:lge.Therefore. we examined the effect of cytochrome P-450 induction on the...

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“…The first report on the occurrence of OTA in coffee appeared in 1974 [98]. Since then, several reports have confirmed the presence of OTA in green coffee beans [99][100][101][102], roasted coffee [103,104] and instant coffee [105,106]. OTA has also been detected in the final coffee brew prepared under normal methods [107].…”

Section: Occurrence Of Ota In Coffeementioning

confidence: 99%

Mycotoxin Contamination of Beverages: Occurrence of Patulin in Apple Juice and Ochratoxin A in Coffee, Beer and Wine and Their Control Methods

Reddy

Abbas

Abel

et al. 2010

Toxins

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Abstract:Mycotoxins are toxic secondary metabolites produced under special conditions of moisture and temperature by aerobic, microscopic fungi that can colonize a variety of foods from before harvest up to consumer use. Contamination of beverages, including that of apple juice by patulin and coffee, beer and wine by ochratoxin A has gained worldwide interest in recent years with the revelation of the effect of these toxins on human health. Patulin and ochratoxin A, which are produced by species of Penicillium, Byssochlamys and Aspergillus, pose the greatest threat to human health and are subject to government regulation in juices and beverages worldwide. This review provides an overview of the prevalence of these mycotoxins in beverages and control methods which help in establishing and carrying out proper management strategies. A detailed investigation on OPEN ACCESSToxins 2010, 2 230 contamination of juices and beverages by toxic compounds helps to provide safe products for consumption and export, and they allow us to prioritize future research efforts.

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

Cited by 84 publications

References 12 publications

The occurrence of ochratoxin A in coffee

The occurrence of ochratoxin A in coffee

Effect of cytochrome P450 induction on the metabolism and toxicity of ochratoxin A

Mycotoxin Contamination of Beverages: Occurrence of Patulin in Apple Juice and Ochratoxin A in Coffee, Beer and Wine and Their Control Methods

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