Occurrence Of Ochratoxin Research Articles

Occurrence of ochratoxin A in wine and grape juice marketed in Rio de Janeiro, Brazil

Ochratoxin A (OA) is receiving attention world-wide because of the hazard it poses to human health. The aim was to test the distribution of OA in grape juice, pulps of frozen grapes, and national and imported table wine obtained from markets in Rio de Janeiro, Brazil. Analytical methodology using immunoaffinity column for OA extraction and clean-up with a final separation on a reversed-phase (C18) column and fluorescence detection in high-performance liquid chromatography showed a detection limit of 21 ng l−1. The mean recovery was 91% for red wines and 82% for white wines; while the mean recoveries for juices and pulps of frozen grapes were 91.6 and 88%, respectively. Of 64 samples of grape juice and frozen pulps, 25% were positive for OA, being the mean content of 37 ng l−1 with a maximum concentration of 100 ng l−1. In wines, the mean concentration detected in 80 samples analysed was 34.4 ng l−1 with 28.75% of positive samples. Red wines showed the highest percentages and levels of contaminated samples: 38% and 37 ng l−1, respectively. The white wine contained levels above 26 ng l−1 in 17.75% of the analysed samples. The levels of contamination detected in red wine sold in Río de Janeiro were not enough to surpass the virtually safe dose established as 5 n g kg−1 body weight of daily intake.

Ochratoxin A in wines, musts and grape juices from Spain

AbstractA survey on the occurrence of ochratoxin A (OTA) in 240 grape‐based beverages was carried out. Red and white wines from four different Spanish Designations of Origin (n = 160), musts (n = 20), grape juices (n = 10), ordinary wines (n = 20), special wines (Malaga, muscatel, sherry, vermouth, etc) (n = 20) and sparkling wines (n = 10) were assayed for OTA content using immunoaffinity column clean‐up and high‐performance liquid chromatography with fluorimetric detection (detection limit 0.05 µg l−1). Forty‐three (17.9%) of the samples tested contained detectable levels of OTA. The overall mean OTA concentration in red and white wines of Designations of Origin was 0.30 and 0.18 µg l−1 respectively (ranges 0.05–3.19 and 0.05–1.13 µg l−1 respectively). The percentage of wine samples with detectable amounts of OTA was higher for red (18.3%) than for white (10%) wines. OTA was also found in two of 10 red ordinary wines (0.68 and 4.24 µg l−1), whereas none of 10 white ordinary wines contained OTA. The mean OTA amount detected in sparkling wines was 0.44 µg l−1 (range 0.14–0.71 µg l−1). Two of 20 must samples contained OTA at low levels (0.08 and 0.18 µg l−1), while none of 10 grape juice samples contained OTA. Highest amounts of OTA were found in special wines (45%), with a maximum of 15.25 µg l−1 in a muscatel sample. Copyright © 2004 Society of Chemical Industry

Occurrence of ochratoxin A and toxigenic potential of fungal isolates from Spanish grapes

AbstractThis paper reports the results from an extensive survey of filamentous fungi isolated from wine‐producing grapes and their capacity to produce ochratoxin A (OTA) on Czapek Yeast Autolysate agar (CYA), in order to assess their potential for producing this toxin in grapes. Grapes were sampled from four Spanish wine‐producing regions during 2001. The fungal infection in berries increased with time, reaching 100% at harvest. A total of 386 isolates of Aspergillus section Nigri and 10 of Aspergillus section Circumdati were isolated and tested for their ability to produce OTA in CYA. 21 strains produced OTA (18 Aspergillus section Nigri and 3 Aspergillus section Circumdati). Aspergillus section Circumdati isolates produced higher amounts of OTA than Aspergillus section Nigri ones, with means of 10.76 µg g−1 CYA and 1.42 µg g−1 CYA, respectively. Despite this, black aspergilli are believed to be highly responsible for the OTA levels found in musts and wines, as it is more widespread in grapes. Musts (n = 40) produced from the grapes collected were analysed. 15% were found to contain OTA, concentrations ranging from 0.091 to 0.813 ng ml−1 (detection limit: 0.07 ng ml−1), but no correlation was found with the ochratoxigenic moulds isolated from grapes. Copyright © 2004 Society of Chemical Industry

New data on the occurrence of ochratoxin A in human sera from patients affected or not by renal diseases in Tunisia

Ochratoxin A is often found in the sera of people exposed to this mycotoxin in their food (cereals such as barley, coffee, wines, fruit juices, spices, products of animal origin such as pig and poultry offal). Ochratoxin A is suspected of playing a role in the Balkan Endemic Nephropathy, a nephropathology described in Balkan areas where ochratoxin A is often found in cereals and in pork-derived products. In North Africa like Tunisia where high incidence of chronic interstitial nephropathies of unknown aetiology are pointed out, the involvement of ochratoxin A was suspected but contradictory studies on the degree of human exposure did not succeed in evidencing the role of ochratoxin A. In the present work, sera from 47 volunteers hospitalised for nephropathic damages including bladder tumours (21 people), and from 62 patients hospitalised for disorders other than nephropathic ones, were analysed for ochratoxin A contents. The determination of ochratoxin A in sera was done by a validated immunoaffinity-HPLC method. Sera from unaffected population exhibited percentages of 74.2%, 22.6% and 3.2% containing ranges of ochratoxin A as <0.10–0.5 μg/l, 0.51–1.0 μg/l and above 1.0 μg/l respectively. For patients affected with renal diseases, percentages were 59.5%, 25.5% and 14.9% on the same ranges of ochratoxin A levels respectively. The average ochratoxin A concentration for patients with urinary tract disease excluding cancer patients was 0.99±1.28 μg/l while that for the non-nephropathic patients was 0.53±1.00 μg/l. However the average levels in the cancer patients was only 0.26±0.20 μg/l. Those results are in line with most of previously published works and did not confirm very high ochratoxin A contents found in other reports from same regions.

Occurrence of ochratoxin A in Australian wine

A survey of 601 samples of Australian wine for the presence of ochratoxin A (OA) was undertaken. The study sampled predominantly bottled wines, approximately equal numbers of red and white wines, wines made from a range of grape varieties and wines from all the major producing areas and some of the minor ones. A validated HPLC assay that did not utilise expensive immunoaffinity columns was developed for quantifying OA in wine, with limits of detection and quantification of 0.02 and 0.05 μg/L respectively. OA was detected in 90 (15.0%) of the 601 samples, but at uniformly low levels, with 85% of positive samples containing less than 0.2 μg/L OA. Only one sample exceeded 0.5 μg/L OA and no sample exceeded 1.0 μg/L OA. No region of Australia appeared more or less likely to produce wines containing OA.

Occurrence of Ochratoxin A–Producing Fungi in Grapes Grown in Italy

A study was carried out to investigate fungi present on grapes grown in Italy. Aspergillus and Penicillium spp. isolates were identified and studied in vitro, and their ability to produce ochratoxin A (OA) was investigated. The survey involved nine vineyards, three located in northern Italy and six located in southern Italy. In 1999 and 2000, bunches of grapes at different growth stages were collected from all nine vineyards, and berry samples were placed in moist chambers and incubated. The resultant fungal colonies were then transferred to petri dishes containing Czapek yeast agar and incubated at 25°C for 7 days; the fungal isolates were identified and then cultivated in liquid Czapek yeast medium and evaluated for their ability to produce OA. During the survey, 508 isolates were collected, with 477 belonging to Aspergillus spp. and 31 belonging to Penicillium spp. Among the aspergilli, species of the Fumigati, Circumdati, and Nigri sections were identified, with species of the Nigri section (464 isolates) largely predominating; for species of the Nigri section, 108 isolates were uniseriate, 270 were biseriate, and 86 were identified as Aspergillus carbonarius. Black aspergilli isolated over the 2 years of the study showed a very similar pattern. On average, the biseriates represented about 60% of the isolates collected in both years and were followed by uniseriates (21%) and A. carbonarius (19%). The most toxigenic strains proved to be those of A. carbonarius; about 60% of these isolates were OA producers and produced the highest levels of OA. A. carbonarius was more frequent in the south, but in both areas the percentages of OA-producing isolates remained the same.

Effects of the botanical composition and weather conditions on mycotoxins in winter forage from grassland

The paper focuses on possible effects of the botanical composition and weather conditions on the extend of zearalenone and ochratoxin A concentrations in various grass swards in winter pasture systems. Zearalenone is only detectable in pure stands ofLolium perenne or inLolio-Cynosuretum plant communities, respectively. The occurrence of ochratoxin A is more frequent and less specific concerning the botanical composition. This mycotoxin was found in both,Lolium perenne andFestuca arundinacea in varying years. The incidence of ochratoxin A depends on year and is apparently related to the weather conditions in autumn and winter. There was no evidence that particular locatio8/22/2008 12:57PMns have a higher or a lower risk for high ochratoxin A or zearalenone concentrations than others. Peak values in individual swards are not intermittent over the years.

Occurrence of ochratoxin A in Greek wines

AbstractThe presence of ochratoxin A in foods and wines is of current interest owing to its toxic effects. Ochratoxin A is a widely distributed mycotoxin with nephrotoxic activity. It constitutes a new restrictive agent for the export of vinicultural products and is thus important from an economic as well as a scientific point of view. In this study the determination of ochratoxin A in Greek wines was made by means of commercial immunoaffinity columns for purification followed by HPLC with fluorescence detection for quantification of the toxin. The method was applied to 28 dry wines (14 red, 13 white, one rosé) and seven sweet wines (three red, four white) obtained by various viticultural and oenological practices. The levels of ochratoxin A ranged from &lt;0.02 to 3.2 ng ml−1, with sweet wines containing higher levels than dry wines. Most of the wines contained relatively low concentrations of ochratoxin A (0.02–0.5 ng ml−1), which do not represent a serious risk to consumer health.© 2003 Society of Chemical Industry

Occurrence of ochratoxin A in Danish wheat and rye, 1992-99

Ochratoxin A concentrations in rye and wheat in Denmark for 1992–99 are reported. The results show that the concentration of ochratoxin A is higher in rye than in wheat for both conventionally and organically grown rye and wheat. The levels in organically grown rye are higher than in conventionally grown based on multiyear mean contents. However, the difference between the two groups of cereals has decreased since the Danish food-monitoring system for ochratoxin A was started in 1986; 2.0% of all samples exceeded the Danish maximum limit of 5 μg kg-1 introduced in 1995. For rye samples, 3.2% exceeded the maximum limit, and for wheat samples, 0.5% exceeded the maximum limit.

On ochratoxin A and fungal flora in Polish cereals from conventional and ecological farms. Part 2: Occurrence of ochratoxin A and fungi in cereals in 1998

Over 200 samples of Polish cereal grain from the 1998 harvest obtained from conventional and ecological farms were investigated for the presence of ochratoxin A and for contamination by microscopic fungi. The frequency of contamination of rye and barley grains from conventional and ecological farms was similar in most cases; it varied from nearly 5 to 12%, respectively, for both types of farming. However, in samples from ecological farms, higher maximum concentrations of ochratoxin A were observed (35 μg kg-1, overall range 1.4–35.3 μg kg-1) for both cereals rye and barley in comparison with rye and barley from conventional farms (maximum levels of 8.8 and 9.7 μg kg-1, respectively). However, wheat grain from the conventional farms showed ochratoxin A concentrations in a very wide range from 0.6 to 1024 μg kg-1 and the average frequency of contaminated samples was about 48%. In contrast, in wheat samples from ecological farming, the presence of ochratoxin A ranged from 0.8 to 1.6 μg kg-1 (mean 1.2 μg kg-1) and the frequency of contamination was 23%. From samples containing detectable amounts of ochratoxin A, fungi producing ochratoxin A under laboratory conditions were isolated. They were classified as belonging to the species Penicillium cyclopium, P. viridicatum, Aspergillus ochraceus group, A. glaucus> and A. versicolor. Penicilliumstrains—species known to be producers of ochratoxin A—were isolated from 71% of the samples in 28% of samples, only Aspergillus strains (species known to be producers of this mycotoxin) were noted. These results have been compared with those obtained in 1997.

Raisins, ochratoxin A and human health

Raisins are one of the most nutritious dried fruits in the world. The occurrence of ochratoxin A (OTA) in raisins results from contamination and growth of ochratoxigenic fungi and short-term humid weather during drying. The estimation of the dietary exposure dose of OTA from raisins for the Czech population (children, adult) is presented. The risk of acute toxic effect of OTA was in the Czech Republic usually considered to be minimal. The risk of late toxic effects (particularly carcinogenic risk) after ingestion of very low single or repeated OTA doses from foodstuffs is very important.

On ochratoxin A and fungal flora in Polish cereals from conventional and ecological farms - Part 1: Occurrence of ochratoxin A and fungi in cereals in 1997

Over 200 samples of Polish cereal grain from the 1997 harvest obtained from conventional and ecological farms were tested for the presence of ochratoxin A as well as for contamination by microscopic fungi. Ochratoxin A contamination of rye from ecological farms was over six times more frequent than that from conventional cultivation. The ochratoxin A content in wheat and barley samples from ecological farms was also higher. No wheat sample from conventional farms contained the mycotoxin. In the group of ecological farms, there were differences in the percentage of cereal samples containing ochratoxin A. The ochratoxin A levels ranged from 0.2 to 57 µg kg−1. The mean concentration of ochratoxin A in investigated cereal grain was 5.7 µg kg−1. From samples containing detectable amounts of ochratoxin A, fungi producing ochratoxin A under laboratory conditions were isolated. They were classified as belonging to the species Penicillium cyclopium, P. viridicatum, P. chrysogenum and also Aspergillus alliaceus, A. versicolor, A. glaucus and A. flavus. Penicillium strains—producers of ochratoxin A—were isolated from 93% of the samples; in 7% of samples, only Aspergillus strains producing this mycotoxin were noted. Rye samples mainly from one farm with an ecological type of cultivation and from one conventional farm were contaminated with both Aspergillus and Penicillium mycotoxigenic strains.

Occurrence of ochratoxin A in black pepper, coriander, ginger and turmeric in India

Occurrence of ochratoxin A in black pepper, coriander, ginger and turmeric in India

Occurrence of ochratoxin A in black pepper, coriander, ginger and turmeric in India

Ochratoxin A (OA) contamination of black pepper, coriander seeds, powdered ginger and turmeric powder was estimated using indirect competitive ELISA. Samples (1 g) were extracted with 0.5% potassium chloride (KCl) in 70% methanol (5 ml) and diluted subsequently to give two-fold to ten-fold step-wise dilutions in phosphate-buffered saline containing 0.05% Tween 20 and 0.2% bovine serum albumin (PBS-T BSA). For extracts from the spices analysed, ELISA estimates of OA concentrations were compared with those made by HPLC. All estimates were within 1-2 standard deviation of the ELISA values. More than 90% of OA added to spice samples was recovered from samples containing between 5 and 100 microg/kg OA. Extracts of OA-free spice samples contained substances that interfered with ELISA, presumably because of non-specific reactions. This effect was avoided by preparing all the test solutions in extracts of OA-free spice samples. In 126 samples obtained from retail shops, OA was found to exceed 10 microg/kg in 14 (in the range of 15-69 microg/kg) of 26 black pepper samples, 20 (in the range of 10-51 microg/kg) of 50 coriander samples, two (23 microg/kg and 80 microg/kg) of 25 ginger samples and nine (in the range of 11-102 microg/kg) of 25 turmeric samples. This is the first record in India of the occurrence of OA in what are some of the most widely used spices in Indian cooking.

Occurrence of Ochratoxin A–Producing Fungi in Raw Brazilian Coffee

Ochratoxin A (OA)–producing fungi were identified in coffee at different stages of maturation. The toxin was quantified in coffee during terrace drying and in coffee stored in barns. By direct plating, a high level of contamination (100%) was found in the coffee beans studied, with the genus Aspergillus representing 33.2%, of which Aspergillus ochraceus and Aspergillus niger represented 10.3 and 22.9%, respectively, of the strains isolated from the coffee beans. The capacity to produce ochratoxin was determined in 155 strains of A. ochraceus and A. niger using both the agar plug method and extraction with chloroform, giving positive results for 88.1% of the A. ochraceus strains and 11.5% of the A. niger strains. Analysis for OA in the terrace and barn coffee samples showed that, independent of cultivar, year harvested, or production region, all except one of the samples analyzed showed mycotoxin levels below the limit suggested by the European Common Market (8 μg/kg), thus indicating that the problem is restricted and due to severe faults in harvesting and storage practices.

Residues of ochratoxin A in pet foods, canine and feline kidneys.

The occurrence of ochratoxin A (OTA) in canned (26 samples) as well as dry pet foods (17 samples) for cats and dogs was investigated. In addition, 26 feline kidney samples with or without kidney alterations were surveyed for OTA-residues. The separation and detection of OTA was carried out by an isocratic high-performance liquid chromatography system based on reversed phase with fluorescence detection. After homogenization and extraction steps, immuno-affinity columns were applied for sample clean up. OTA could be detected in 47% (n=40) of the pet food samples. Those found positive contained generally low amounts of OTA (0.1-0.8 microg/kg original substance). Higher levels were only detected in two pet food samples (3.2 and 13.1 microg/kg toxin, respectively). Low concentrations of ochratoxin A could also be found iIn tissue of cat kidneys, with 16 of the analysed kidneys (n=26) being positive. The concentration levels were between 0.35 and 1.5 microg/kg OTA in tissue. No relation between pathological findings and ochratoxin levels in feline kidneys could be assessed.

Occurrence of ochratoxin A in Italian wines

Occurrence of ochratoxin A in Italian wines

Occurrence of ochratoxin A in Italian wines

A total of 96 red wines and 15 white dessert wines produced mostly in the years 1995–97 in 19 Italian regions were analysed for ochratoxin A (OTA). The amount of OTA ranged from < 1 to 3856 ng/l, the median (mean) was found to be 90 (419)ng/l for the red wines and 8 (736)ng/l for the white dessert wines. Our survey shows that the geographic region of origin has a strong influence on OTA contamination, both for red and for dessert wines: in fact, wines produced in southern Italy were markedly more contaminated. The overall median (mean) OTA concentration in the red wines produced in the four Italian areas (northwest, northeast, centre and south) was 2 (11), 90 (81), 134 (295) and 1264 (1233)ng/l. The same trend was observed for the white dessert wines: OTA concentrations of over 1000ng/l were found in four out of five samples from southern Italy (1185, 2454, 3477, 3856ng/l), while central and northern samples showed very low contamination. The contribution of wine to mean daily OTA intake can be considered negligible in the case of people drinking wine manufactured in northern and central Italy; this is not true if a medium drinker constantly consumes red wine produced in southern Italy: in this case wine alone could supply the diet with an amount of OTA equal to or even above the tolerable daily intake of 5ng/kg body weight recommended by the Scientific Committee on Food of the European Commission.

Recent advances in ochratoxin research I. Production, detection and occurrence of ochratoxins

Ochratoxins are mycotoxins produced by Aspergillus and Penicillium species. Ochratoxin contamination of cereal grains and other plant products is a serious health hazard throughout the world since ochratoxins exhibit a range of pharmacological effects on animals and humans. This review deals with ochratoxin producing organisms, ochratoxin detection methods, and occurrence and legislation of ochratoxins in foods and feeds.

Occurrence of ochratoxin A (OTA) in wines: influence of the type of wine and its geographical origin

The results of more than 450 samples taken from the literature and 400 samples tested by our own investigations have been taken into account to quite extensively describe the situation of OTA contamination of wine. According to these data OTA is much more commonly detected in red wines than in rose and white wines and the OTA concentration is remarkably higher than in the last two. Thus OTA could be detected in 25% of white wine samples whereas it was detected in 40% of rose and 54% of red wine samples. The same result was found when comparing the wines from southern and northern regions. Here the red wine samples from the northern cultivating area showed a contamination of 12% in contrast to those from the southern area which showed a contamination of about 95%.