Aflatoxin contamination of consumer milk caused by contaminated rice by‐products in compound cattle feed

BACKGROUND: Elevated levels of aflatoxin M1 were observed in routine checks of consumer milk in southern Sweden in early 2006. A trace‐back study revealed contaminated milk from several farms, and a total of 68 farms were banned from delivering milk to dairies for shorter or longer periods. The maximum level of aflatoxin M1 in a single sample from an individual farm was 257 ng kg^?1 fresh milk. RESULTS: Aflatoxin analyses of commercial compound feed revealed that the contamination originated from the ingredient rice feed meal, a by‐product from the preparation of Basmati rice for human consumption. Up to 56 µg kg^?1 of aflatoxin B1 was found in rice feed meal at one feed mill. CONCLUSION: The present example shows that an aflatoxin‐contaminated minor feed ingredient included at less than 10% (w/w) of compound cattle feed can significantly contaminate the milk produced. This emphasises the need for effective monitoring of the feed chain of food‐producing animals in order to prevent food contamination. Copyright © 2008 Society of Chemical Industry     

Aflatoxins in sunflower and safflower seeds from Iran

Aflatoxin content of 173 sunflower and safflower seeds was determined by HPLC with immunoaffinity column (IAC) clean-up and fluorometric detection. Aflatoxin B₁ contamination was found in 111 samples: in 8 of the sunflower seed samples (16%) at a mean level of 40.68?ng?g^?1 and in 103 safflower seed samples (83.7%) at a mean level of 2.81?±?0.44?ng?g^?1. In 5 sunflower seed samples and 1 safflower seed sample, aflatoxin B₁ levels were higher than the maximum levels of AFB₁ under Iran regulations (5?ng?g^?1). Aflatoxin B₁ levels in 5 sunflower and 2 safflower seed samples were higher than the European Union maximum limit (2?ng?g^?1).     

Risk assessment of aflatoxin-related liver cancer in Bangladesh

Aflatoxins are mycotoxins (fungal toxins) produced by Aspergillus species in variety of food commodities. Consumption of aflatoxin-contaminated food can cause adverse health effects, including liver cancer. Aflatoxin exposure is usually higher in hot and humid countries. Previous biomarker-based studies have indicated significant exposure to aflatoxins among the Bangladeshi population. Recently, high aflatoxin levels were reported in dates, which are consumed in large quantities during the month of Ramadan in Bangladesh and other Muslim countries. Bangladesh has recently enacted aflatoxin regulation in foods. In this study, we determined the risk of aflatoxin-related liver cancer among the Bangladeshi population based on the average dietary intakes of different aflatoxin contaminated foods, accounting for the synergistic impacts of aflatoxin with chronic hepatitis B viral infection in inducing cancer. We also determined whether the new aflatoxin regulations in Bangladesh could significantly reduce the risk of liver cancer. The mean number of cancer cases per year caused by dietary aflatoxin exposure in Bangladesh was estimated at about 1311, or 43.9% of the total annual liver cancer cases in Bangladesh. The new aflatoxin regulations do not appear likely to significantly reduce the risk of liver cancer in the country.     

Evaluation of total aflatoxin,nitrate and nitrite levels in layer feed samples of companies producing their own feed in Edincik and Bandırma province of Turkey

Feed contamination by fungi can lead to nutrient losses and detrimental effects on animal health and production. The presence of nitrates and nitrites in food can be harmful to both people and animals. The aim of this study was to determine total aflatoxin, nitrate and nitrite levels in layer feed samples from companies producing their own feed in Edincik and Band?rma provinces in Turkey and to discuss the potential risk to animal health. The results of the analyses indicated that mean total aflatoxin (AFT) ranged from 0.4 to 36.8?µg?kg^?1 and from 0.45 to 47.0?µg?kg^?1 in the year 2007 and the year 2008 samples, respectively. It was determined that nitrate levels were 2.4–10 and 1.7–13?µg?kg^?1 and that nitrite levels were 0–2.4?µg?kg^?1 and 0–2.6?µg?kg^?1 in these years, respectively. The levels of total aflatoxin, nitrate and nitrite in the layer samples could not be considered a risk to poultry health and productivity.     

酶联免疫法测定食品和饲料中的黄曲霉毒素

本实验应用酶联免疫方法对食品和饲料中的黄曲霉毒素进行测定,奶粉中黄曲霉毒素M1的多次重复测定的结果的变异系数小于12%,回收率接近90%。说明本试剂盒测定结果比较精确,重现性较好。食品辅料及饲料中的黄曲霉毒素B1的测定结果的变异系数小于15%,说明实验结果的重现性较好。     

Aflatoxins in black tea in Iran

Aflatoxins (AFs) are highly toxic, and carcinogenic secondary fungal metabolites and have been detected in various food commodities. In this regard, 40 black tea samples including domestic and imported black tea were analysed for aflatoxin contamination by high-performance liquid chromatography using a post-column derivatisation procedure (Kobra cell) with fluorescence detection. Samples were randomly collected in 2010 from Tehran markets. The results revealed that 30 among 40 samples were contaminated with aflatoxins (27.5% of the total). Mean AFB1 content was 10.0 ng/g and mean of aflatoxin total was 12.07 ng/g for the 11 contaminated samples.     

Occurrence of aflatoxin in commodities imported into Qatar, 1997-2000.

The occurrence of aflatoxin in commodities imported into Qatar was investigated from 1999 to 2000. During the 4 years, 351 samples of susceptible commodities were analysed. Aflatoxin was detected in 71 (20%) samples in the range 0.1-20 microg kg(-1) and in 50 (14%) samples above the permitted level of 20 microg kg(-1). The highest incidence and levels of aflatoxin contamination were recorded in pistachio without shell followed by pistachio with shell. Aflatoxin levels >20 microg kg(-1) in the pistachio samples varied from 8.7 to 33%. The highest level of total aflatoxin found in pistachio without shell was 289 microg kg(-1). A few samples of corn and corn products (three of 54 analysed), peanut and peanut products (nine of 42 analysed) and other nuts like almond, walnut and cashew (one of 40 analysed) were found contaminated with low levels (0.1-20 microg kg(-1)) of aflatoxins. Only one sample of custard powder and one sample of roasted peanut were found with aflatoxin >20 microg kg(-1)     

Fungal Profile and Aflatoxin Contamination in Poultry Feeds Sold in Abeokuta,Ogun State,Nigeria

Aflatoxin contamination of animal feeds is common and widely spread, especially in the tropics, due to the ubiquity of the producing fungi. The detection of aflatoxin in five samples of animal feed was carried out; using enzyme linked immunosorbent assay (ELISA). Samples were taken from five different areas in Abeokuta. The aflatoxin level was observed to be the highest in the poultry feed from Lafenwa with the value 93.1 μg/kg; and lowest in the feed from Idi-Aba with the value 13.5 μg/kg. Fungal counts are between 4 × 10³ and 42 × 10³ cfu/g, with highest count occurring in the feed from Lafenwa and lowest in Idi-Aba. The fungal growth was on potato dextrose agar (PDA), and Aspergillus flavus, A. oryzae, Rhizopus oryzae and Penicillum notatum were isolated and identified, with Aspergillus flavus predominating. Comparison statistical analysis using ANOVA showed a significant mean difference 95% confidence interval. In conclusion, aflatoxin was present in all the samples, which even at low concentration is of great concern to human and animal health. Maize was the main ingredient in all the contaminated feed.     

Occurrence of aflatoxins in layer feed and corn samples in Konya province, Turkey

The natural occurrence ofaflatoxin was investigated in layer feed and corn samples brought to Konya Veterinary Control and Research Institute Laboratory between 15 April and 15 December 2002. Seventy-eight samples (52 feeds, 26 corn samples) were analysed for total aflatoxin (B₁ + B₂ + G₁ + G₂) by an ELISA screening method. Aflatoxin contamination was determined in 37 feed samples (71.1%) and 15 corn samples (57.7%), with a range of1.5-133 μg kg^-1. However, a majority ofthe aflatoxin contamination was less than 5 μg kg^-1 (50% within the positive samples). Two feed samples and two corn samples exceeded the maximum tolerated levels in feed (20 μg kg^-1) and feedstuffs (50 μg kg^-1) for total flatoxin.     

Assessment of exposure of broiler chicken in Brazil to mycotoxins through naturally contaminated feed

The objective of the present study was to assess the degree of exposure of broiler chicken to mycotoxins through naturally contaminated feed and the hygienic quality of feeds. For this purpose the total fungal count and occurrence of fumonisins and aflatoxins were evaluated in four feed types intended for broilers (n?=?158), collected from a poultry breeding farm in northern Paraná State, Brazil. In most feed samples (94 % pre-starter, 91 % starter, 99 % grower and 97 % finisher feeds) the total mould and yeast counts were below 1.0?×?10⁴ CFU/g, the maximum limit established to assure a good hygienic quality of the product. Fumonisins were detected in 94.9 % feed samples at mean levels ranging from 0.52 mg/kg (finisher) to 0.68 mg/kg (pre-starter and grower), while aflatoxins were detected in 72.1 % feed samples at mean levels ranging from 0.0022 mg/kg (pre-starter) to 0.0064 mg/kg (grower). The maximum estimated daily intake of fumonisin B₁ for broilers (0.057 mg/kg body weight/day) was below the Lowest Observed Adverse Effect Level (2 mg/kg bw/day). Concerning aflatoxins, most of the positive samples (97 %) showed aflatoxin levels below the maximum limit allowed by the European Commission 0.02 mg aflatoxin B₁/kg. Nevertheless, a rigorous monitoring program of the feed producing chain is essential in order to minimize human health hazards. To our knowledge, this is the first report on the degree of exposure of broilers to mycotoxins through naturally contaminated feed in Brazil.     

Fungal and bacterial metabolites in commercial poultry feed from Nigeria

Metabolites of toxigenic fungi and bacteria occur as natural contaminants (e.g. mycotoxins) in feedstuffs making them unsafe to animals. The multi-toxin profiles in 58 commercial poultry feed samples collected from 19 districts in 17 states of Nigeria were determined by LC/ESI-MS/MS with a single extraction step and no clean-up. Sixty-three (56 fungal and seven bacterial) metabolites were detected with concentrations ranging up to 10,200?μg?kg(-1) in the case of aurofusarin. Fusarium toxins were the most prevalent group of fungal metabolites, whereas valinomycin occurred in more than 50% of the samples. Twelve non-regulatory fungal and seven bacterial metabolites detected and quantified in this study have never been reported previously in naturally contaminated stored grains or finished feed. Among the regulatory toxins in poultry feed, aflatoxin concentrations in 62% of samples were above 20?μg?kg(-1), demonstrating high prevalence of unsafe levels of aflatoxins in Nigeria. Deoxynivalenol concentrations exceeded 1000?μg?kg(-1) in 10.3% of samples. Actions are required to reduce the consequences from regulatory mycotoxins and understand the risks of the single or co-occurrence of non-regulatory metabolites for the benefit of the poultry industry.     

Determination of some specific isomers of polychlorinated biphenyl congeners in fatty foods of the Canadian diet

A total of 93 fatty food composites from the cities of Ottawa and Halifax (Canada) were analyzed for 34 selected isomers of polychlorinated biphenyls (PCBs). All fatty foods contained some PCB isomers with the 2,3,4,2',4',5'- and 2,4,5,2',4',5'-hexachlorobiphenyls present in all samples, except in skim milk and some dehydrated soups. The overall lowest PCB residues of all food commodities were found in skim milk, lamb, margarine and soups. Among the dairy products the highest PCB isomer levels were found in cheese and butter. The sum of all PCB isomers in these two commodities gave residue levels on a wet basis of 2.0 and 3.4 ng/g respectively. In the meat, fish and poultry class the highest specific PCB isomer levels were found in fish, especially freshwater fish, which contained a total of 21.0 ng PCB/g fish. In addition 28 out of the 34 selected PCB isomers were present in freshwater fish. Residue levels in canned fish were the second highest of all food commodities. The observed total PCB residue levels were below the Canadian guidelines for fish, dairy products, poultry, eggs and beef. A comparison of the percentage distribution of PCB isomers in fatty foods and human milk was difficult to evaluate due to the large variation of the fatty food data. However out of 31 PCB isomers reported in fatty foods, 25 were also found in human milk, although not to the same extent.     

Occurrence of aflatoxins (B1, B2, G1, G2) in herbal tea consumed in Turkey

Aflatoxin contents in 12 types of herbal teas were determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Forty eight samples were collected from four local herbal shops in Manisa, Turkey. Of the 48 samples analyzed, 43 were aflatoxin positive. The highest concentration of aflatoxin (34.18 µg/kg) was determined in a sample of camomile tea. The occurrence of AFB1, B2, G1 and G2 was found in samples at levels of 54, 29, 71 and 46 %, respectively. Aflatoxin B1, B2, G1 and G2 contamination levels varied from 0 to 14.2, 0 to 12.4, 0 to 13.5 and 0 to 28.7 µg/kg, respectively. Aflatoxin was not detected in five samples consisting of linseed, lime and fennel tea.     

Effect of microwave heating during alkaline-cooking of aflatoxin contaminated maize

To evaluate the effectiveness of maize detoxification achieved with a modified tortilla-making process (MTMP), maize contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) at levels of 22.46, 69.62, and 141.48 ng/g (AFB(1)+ AFB(2)) was processed into tortillas. Aflatoxin content was determined according to the 991.31 AOAC official method. Based on the results obtained with spiked samples (0.78 to 25 ng/g), the mean recovery was 92%, with a standard error of 1.2, and a coefficient variation value of 4.4%. The MTMP caused 68, 80, and an 84% decrease in aflatoxin content, respectively. Extract acidification (as occurs during digestion) prior to mycotoxin quantification caused some reformation of the aflatoxin structure in tortillas (up to 3%). According to these results, the MTMP seems to be safe for decontamination since a low percentage of the initial aflatoxin concentration can be reverted to the original fluorescent form upon acidification. PRACTICAL APPLICATION: The potential presence of aflatoxins in maize destined for human consumption is a serious problem to the Mexican food supply, as these toxic compounds may persist during the traditional alkaline-process for tortilla elaboration. Consequently, new detoxification procedures are needed that eliminate or at least minimize the aflatoxin risk, through lowering aflatoxin concentration in maize-based products. Under these considerations, the use of MTMP is recommended, since it has definite advantages including non-production of wastewater and reduced energy/time consumption.     

Determination of aflatoxin B1 in dried figs by visual screening, thin-layer chromatography and ELISA

Aflatoxin B1-contaminated fruits were sorted out from 250 kg dried figs (five Turkish and three Greek batches) by bright-greenish-yellow fluorescence under UV light. The aflatoxins of the fluorescent figs were extracted by simple soaking in methanol. Aflatoxin B1 was determined by thin-layer chromatography. Parallel to this, an extraction for the determination of aflatoxin B1 was developed by a competitive ELISA and the two methods were compared with each other. In a highly contaminated batch of Turkish figs, statistically there was one fig among 350 which had a high aflatoxin content (greater than 100 ng/g fig) and one fig amongst 140 fruits with an aflatoxin B1 content of greater than 10 ng B1/g fig.     

Fungal and bacterial metabolites in commercial poultry feed from Nigeria

Metabolites of toxigenic fungi and bacteria occur as natural contaminants (e.g. mycotoxins) in feedstuffs making them unsafe to animals. The multi-toxin profiles in 58 commercial poultry feed samples collected from 19 districts in 17 states of Nigeria were determined by LC/ESI–MS/MS with a single extraction step and no clean-up. Sixty-three (56 fungal and seven bacterial) metabolites were detected with concentrations ranging up to 10,200?µg?kg^-1 in the case of aurofusarin. Fusarium toxins were the most prevalent group of fungal metabolites, whereas valinomycin occurred in more than 50% of the samples. Twelve non-regulatory fungal and seven bacterial metabolites detected and quantified in this study have never been reported previously in naturally contaminated stored grains or finished feed. Among the regulatory toxins in poultry feed, aflatoxin concentrations in 62% of samples were above 20?µg?kg^?1, demonstrating high prevalence of unsafe levels of aflatoxins in Nigeria. Deoxynivalenol concentrations exceeded 1000?µg?kg^?1 in 10.3% of samples. Actions are required to reduce the consequences from regulatory mycotoxins and understand the risks of the single or co-occurrence of non-regulatory metabolites for the benefit of the poultry industry.     

Monitoring and identification of aflatoxins in wheat, gram and maize flours in Bihar state (India).

The occurrence of aflatoxins in some common food commodities: wheat, gram and maize flours is reported. Of the total 416 collections during three years (1987-1989) 162 were recorded to be aflatoxin-positive. The incidence of aflatoxins was maximum in the samples of 1987. Most of the contaminated samples contained aflatoxins at levels above 20 micrograms/kg. The environmental conditions and traditional agronomic and storage practices relating to aflatoxin incidence are discussed.     

Aflatoxins in spices marketed in Portugal

Seventy-nine prepackaged samples of 12 different types of spice powders (five cardamom, five cayenne pepper, eight chilli, five cloves, seven cumin, five curry powder, five ginger, five mustard, 10 nutmeg, 12 paprika, five saffron and seven white pepper) were selected from supermarkets and ethnic shops in Lisbon (Portugal) for estimation of aflatoxins by immmunoaffinity column clean-up followed by HPLC. Aflatoxin B (AFB) was detected in 34 samples of prepackaged spices (43.0%). All of the cayenne pepper samples were contaminated with levels ranging from 2 to 32 µ g AFB / kg. Three nutmeg samples contained levels ranging from 1 to 5 µ g/kg, three samples had levels ranging from 6 to 20 µ g/kg, and there were two with 54 µ g/kg and 58 µ g/ kg. Paprika contained levels of aflatoxin B₁ ranging from 1 to 20 µ g/kg. Chilli, cumin, curry powder, saffron and white pepper samples had levels ranging from 1 to 5 µ g/kg. Aflatoxins were not detected in cardamom, cloves, ginger and mustard. None of the samples analysed contained aflatoxins B₂, G₁ and G₂.     

Occurrence of aflatoxins in milk thistle herbal supplements

Milk thistle (MT) dietary supplements are widely consumed due to their possible liver-health-promoting properties. As botanicals they can be contaminated with a variety of fungi and their secondary metabolites, mycotoxins. The aflatoxigenic fungus Aspergillus flavus has been previously isolated from these commodities. Currently, there is no published method for determining aflatoxins (AFs) in MT. Therefore, a liquid chromatography (LC) method validated for aflatoxin analysis in botanicals was evaluated and applied to MT. The method consisted of acetonitrile/water extraction, immunoaffinity column clean-up, LC separation, post-column photochemical reaction derivatisation and fluorescence detection. The average recoveries for AFs added to MT seeds, herb, oil-based liquid extract and alcohol-based liquid extract were 76% or higher. The mean relative standard deviation was <10%. The limit of detection (LOD) was 0.01?µg kg^?1 and the limit of quantification (LOQ) was 0.03?µg kg^–1. The method was used to conduct a small survey. A total of 83 MT samples from the US market were analysed. AFs were detected in 19% of the samples with levels ranging from 0.04 to 2.0?µg kg^–1. Additionally, an aflatoxigenic A. flavus strain from ATTC and an A. parasiticus strain isolated from MT herb powder were found to produce high amounts of aflatoxins (11,200 and 49,100?µg kg^–1, respectively) when cultured in MT seed powder. This is the first study reporting on aflatoxin contamination of MT botanical supplements and identifying methodology for AF analysis of these commodities.     

AFLATOXIGENIC ASPERGILLI IN FOODS AND FEEDS IN UGANDA

Studies conducted during the sixties and the seventies on food crops in Uganda showed that the populace was exposed to consumption of aflatoxin-contaminated foods. These studies also linked the highest incidence of liver cancer in the world to the presence of high levels of aflatoxins in the food and beverages. After a lapse of a decade, it was of interest to investigate the occurrence of aflatoxins and aflatoxigenic fungi in staple Ugandan food crops and poultry feeds derived from these foodstuffs. A simple, rapid and reproducible procedure was used. The procedure consisted of growing or culturing feed grains on a selective medium, Aspergillus flavus/parasiticus agar (AFPA) followed by screening for aflatoxin producing fungi on a coconut agar medium (CAM) under UV light with a subsequent confirmatory screening method for aflatoxin production by the fungi in pure culture. Fifty-four samples consisting of corn and peanuts, soybean and poultry feed were analyzed for content of aflatoxigenic. A. flavus/parasiticus and 25 of the samples were also screened for aflatoxins B₁ and G₁, zearalenone, sterigmatocystin, ochratoxin A, citrinin, vomitoxin, and diacetoxyscirpenol (DAS). Aflatoxigenic A. flavus/parasiticus was detected from the majority of corn (77%), peanuts (36% human food and 83.3% animal feed) and poultry feed (66.6%). but not from soybean samples. Two samples out of 25 contained detectable levels of aJatosin B, (20 ppb). For the jirst time other mycotoxins, zearalenone (3 samples) and vomitoxin (2 samples) were detected in corn from Uganda.