Pilot survey of aflatoxin-albumin adducts in sera from Egypt.

Aflatoxins are potent liver carcinogens that frequently contaminate cereals in developing countries. Aflatoxin exposure has been predicted in Egypt but, to date, no studies have measured the level of aflatoxin-albumin (AF-alb) adducts as a validated biomarker to assess exposure. In this pilot survey, a limited number of sera samples, available from a hepatocellular carcinoma (HCC) case-control study in Egypt, were analysed. AF-alb was detected in 24/24 samples from HCC-negative individuals (geometric mean 9.0 pg mg(-1); range 3.5-25.8pg mg(-1)), while 7/22 samples from HCC-positive cases had detectable AF-alb (geometric mean 2.6 pg mg(-1); range: non-detectable-32.8 pg mg(-1)). These AF-alb data do not represent a case-control comparison due to inherent difficulties in comparing markers of dietary intake between controls and patients with disease. Although these data are limited, the potential health consequences of aflatoxin exposure in this region merit further investigation.     

Pilot survey of aflatoxin-albumin adducts in sera from Egypt

Aflatoxins are potent liver carcinogens that frequently contaminate cereals in developing countries. Aflatoxin exposure has been predicted in Egypt but, to date, no studies have measured the level of aflatoxin-albumin (AF-alb) adducts as a validated biomarker to assess exposure. In this pilot survey, a limited number of sera samples, available from a hepatocellular carcinoma (HCC) case-control study in Egypt, were analysed. AF-alb was detected in 24/24 samples from HCC-negative individuals (geometric mean 9.0 pg mg(-1); range 3.5-25.8pg mg(-1)), while 7/22 samples from HCC-positive cases had detectable AF-alb (geometric mean 2.6 pg mg(-1); range: non-detectable-32.8 pg mg(-1)). These AF-alb data do not represent a case-control comparison due to inherent difficulties in comparing markers of dietary intake between controls and patients with disease. Although these data are limited, the potential health consequences of aflatoxin exposure in this region merit further investigation.     

Deoxynivalenol exposure assessment in a cohort of pregnant women from Bradford, UK

Deoxynivalenol (DON) is a ubiquitous contaminant of cereal crops in temperate regions of the world. It causes growth faltering and immune suppression in animals. Limited information is available on DON exposure in UK subpopulations. The objective of this study was to provide DON exposure assessment in a subset of pregnant women scheduled for an elective caesarean in a large multi-ethnic mother/infant birth cohort from Bradford, UK. Women aged 16-44 years (n = 85) provided a urine sample for DON analysis in the last trimester of pregnancy, and concurrently completed a food-frequency questionnaire (FFQ). The urinary DON biomarker was detected in all measured samples (geometric mean (GM)?= 10.3 ng DON mg(-1) creatinine, range = 0.5-116.7 ng mg(-1)). Levels were higher in women classified as South Asian in origin (GM: 15.2 ng mg(-1); 95% CI = 10.7-21.5 ng mg(-1)) compared with non-South Asians (GM = 8.6 ng mg(-1); 95% CI = 6.6-11.8 ng mg(-1)), p = 0.02). Estimated DON intake from FFQ data and typical levels of DON contamination of food suggest that this was mainly due to higher levels of exposure from bread, particularly daily intake of DON from chapattis in South Asians (estimated mean = 2.4 μg day(-1); 95% CI = 1.2, 3.7 μg day(-1)) compared with non-South Asians (estimated mean = 0.2 μg day(-1); 95% CI = 0-0.4 μg day(-1)), p < 0.001. This is the first biomarker demonstration of DON exposure in pregnant women, and several urinary DON levels were the highest ever recorded in any study. A larger survey within this birth cohort is warranted to investigate any potential risk to mothers and their babies, from DON exposure during pregnancy.     

The presence of aflatoxin B₁-FAPY adduct and human papilloma virus in cervical smears from cancer patients in Mexico

The carcinogenic biomarker aflatoxin B(1)-formamidopyrimidine 2,3-dihydro-2-(N-formyl)-2',5',6'-triamino-4'-4'-oxy-N-pyrimidyl-3-hydroxy-AFB(1) called AFB(1)-FAPY adduct, and Human Papilloma Virus (HPV) types 16 and 18 were quantified from DNA cervical scrapes from 40 women with cervical cancer (CC) and 14 healthy women as controls. The relationship between the AFB(1)-FAPY adduct and HPV types 16 and 18 was determined. Competitive inhibitory indirect ELISA was validated with 94% inhibition to quantify the AFB(1)-FAPY adducts in picograms per milligram of DNA (limit of detection = 0.1 pg/mg, and limit of quantification = 10 pg/mg), polymerase chain reaction and DNA sequencing to identify HPV types. The average concentration of AFB(1)-FAPY adducts/mg DNA in the CC cases was 1025 pg, 1420 pg with HPV16 and 630 pg sharing HPV18 (p = 0.03). In comparison, healthy controls had ≤ 2.6 pg/mg DNA, a statistically significant difference (p = 0.00006). The presence of AFB(1)-FAPY adduct increased six-fold the risk for CC between cases and controls, the odds ratio was 6.1 (95% CI = 1.4-25.4). There was a close relationship between the AFB(1)-FAPY adducts and HPV16 in CC samples.     

Determination of aflatoxin M1 in breast milk as a biomarker of maternal and infant exposure in Colombia

Chronic exposure to aflatoxins, and especially to aflatoxin B₁ (AFB1), causes hepatocellular carcinoma with prevalence 16–32 times higher in developing compared with developed countries. Aflatoxin M₁ (AFM1) is a monohydroxylated metabolite from AFB1 that is secreted in milk and which can be used as a biomarker of AFB1 exposure. This study aimed to determine AFM1 levels in human breast milk using immunoaffinity column clean-up with HPLC and fluorescence detection. Breast milk samples were obtained from 50 nursing mothers. Volunteers filled in a questionnaire giving their consent to analyse their samples as well as details of their socioeconomic, demographic and clinical data. The possible dietary sources of aflatoxins were assessed using a food frequency questionnaire. A total of 90% of the samples tested positive for AFM1, with a mean of 5.2 ng l^?1 and a range of 0.9–18.5 ng l^?1. The study demonstrated a high frequency of exposure of mothers and neonates to AFB1 and AFM1 in Colombia, and it points out the need to regulate and monitor continuously the presence of aflatoxins in human foods. Further research is needed in order to determine the presence of other mycotoxins in foods and in human samples as well as to devise protection strategies in a country where mycotoxins in human foods are commonly found.     

Simultaneous detection of 12 mycotoxins in cereals using RP-HPLC-PDA-FLD with PHRED and a post-column derivatization system

A new method for the simultaneous quantification of 12 mycotoxins was developed and optimized using reverse phase high performance liquid chromatography (RP-HPLC) with a photodiode array (PDA) and fluorescence detector (FLD), a photochemical reactor for enhanced detection (PHRED) and post-column derivatization. The mycotoxins included aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB(1), FB(2), and FB(3)), T-2 and HT-2 toxins. A double sample extraction with a phosphate-buffered saline solution (PBS) and methanol was used for co-extraction of mycotoxins, and a multifunctional immunoaffinity column was used for cleanup. Optimum conditions for separation of the mycotoxins were obtained to separate 12 mycotoxins in FLD and PDA chromatograms with a high resolution. The method gave recoveries in the range 72-111% when applied to spiked corn samples. The limits of detection (LOD) were 0.025 ng/g for AFB(1) and AFG(1), 0.012 ng/g for AFB(2) and AFG(2), 0.2 ng/g for OTA, 1.5 ng/g for ZEA, 6.2 ng/g for FB(1), FB(3) and HT-2 toxin, 9.4 ng/g for FB(2) and T-2 toxin, and 18.7 ng/g for DON. In addition, the limits of quantification (LOQ) ranged from 0.04 ng/g for AFB(2) and AFG(2) to 62 ng/g for DON. The method was successfully applied to the determination of these mycotoxins in 45 cereal samples obtained from the Malaysian market. The results indicated that the method can be applied for the multi-mycotoxin determination of cereals.     

Excretion pattern of aflatoxin M1 in milk of goats fed a single dose of aflatoxin B1

The feedstuffs used in dairy animals must be able to give consumers confidence about the wholesomeness of milk with regard to aflatoxin contamination. The aim of this study was to determine the excretion patterns of aflatoxin M(1) (AFM1) in the milk of dairy goats fed a single dose of pure aflatoxin B(1) (AFB1), which can occasionally occur if feeds are infected by hot-spot growth of molds that produce aflatoxins. Five dairy goats in midlactation were administered 0.8 mg of AFB1 orally. Individual milk samples were collected for 84 h after AFB1 dosage. Aflatoxin M(1) was found in milk in the highest concentration. In all goats, AFM1 was not detected in milk before AFB1 administration, but was detected in the first milking following AFB1 administration. The excretion pattern of AFM1 concentration in milk was very similar in all goats even if the values of the concentration differed between animals. The peak values for AFM1 concentration in milk was observed in milk collected during the milking at 3 and 6h. After the peak, the AFM1 in milk disappeared with a trend that fitted well a monoexponential decreasing function, and the toxin was not detected after 84 h. Only about 0.17% of the amount of AFB1 administered was detected as AFM1 in milk, and about 50% of this was excreted in the first liter of milk yielded after AFB1 intake. Correct procedures to prevent growth of molds, and consequent AFB1 contamination, on the feedstuffs for lactating goats represent the key to providing consumers a guarantee that milk is not contaminated by AFM1.     

Co-occurrence of mycotoxins in commercial formula milk and cereal-based baby food on the Qatar market

The present study was conducted to explore the occurrence of mycotoxins in commercial baby foods in Doha-Qatar. LCMS/MS- and HPLC-based analysis of baby food (n = 67) for 12 mycotoxins confirmed the presence of aflatoxin M1 (AFM1, 33%), ochratoxin A (OTA, 31%), deoxynivalenol (DON, 27%), aflatoxin B1 (AFB1, 22%), fumonisin B2 (FB2, 10%), zearalenone (ZEN, 4%) and T-2 toxin (2%). Noodles exhibited the maximum contamination percentage, with 33% of the samples being contaminated above the EU maximum limits, for at least one mycotoxin. Among the multi-grain flake samples, up to 28% and for the milk and milk-based-cereal samples, 14% contained at least one mycotoxin above the EU maximum limits. From all cereal-based food samples, 22%, 5%, 2% and 2% were concurrently contaminated with 2, 3, 4 and 5 mycotoxins, respectively. The occurrence of toxicological important mycotoxins in Qatari market warrants the implementation of strict regulatory limits to protect human health.     

真菌毒素在赤霉病小麦研磨及其湿法加工中的分布研究

小麦赤霉病不仅会导致粮食减产,更会引起多种真菌毒素的高污染风险。将染病小麦进行实验室制粉并湿法分离统粉中的粗淀粉、谷朊粉,采用酶联免疫吸附测定法(Enzyme-Linked Immuno Sorbent Assay,ELISA)测定各系统的呕吐毒素(Deoxynivalenol,DON)、黄曲霉毒素B1(Aflatoxin B1,AFB1)、玉米赤霉烯酮(Zearalenone,ZEN)以及赭曲霉毒素A(Ochratoxin A,OTA)的含量,以探究赤霉病小麦在制粉及其湿法加工中四种常见真菌毒素的分布变化规律。结果显示:研磨制粉及湿法加工对真菌毒素的分布影响显著。制粉加工后,皮磨和心磨系统粉的DON、AFB1、ZEN和OTA含量比原粮显著降低,降低率分别为1.38~16.24%、20.47~71.77%及26.71~69.51%;湿法加工产物中,DON消减为相应统粉的4.88~12.11%,AFB1与OTA浓缩富集,富集率分别可达统粉的2.55、3.65倍,粗淀粉中ZEN消减为统粉的12.70~15.83%,谷朊粉则富集为统粉的4.11倍。研究表明,在工业生产中,可根据赤霉病小麦的感染类型及程度,适当选用研磨或湿法加工等合适的方法加工处理。     

基于金掺杂的锆基金属有机框架电化学适配体传感器检测玉米中黄曲霉毒素B1

目的 基于金掺杂的锆基金属有机框架(Gold-doped zirconium-based metal-organic framework, Au@Zr-MOF)的电化学适配体传感器建立检测玉米中黄曲霉毒素B1 (Aflatoxin B1,AFB1)的方法。方法 利用具有高比表面积、介孔结构的Zr-MOF作为骨架,通过原位还原生长的方法掺杂金纳米粒子(Au NPs),得到导电性良好、分散均匀的Au@Zr-MOF。并基于Au-S键共价结合黄曲霉毒素B1 适配体,构建电化学阻抗型适配体传感器,当AFB1存在时,适配体对其进行识别结合,引起电极表面电化学传质电阻增加,随着AFB1浓度的增大,阻抗值也随之增加,并根据阻抗值的变化实现对AFB1的定量检测。结果 在最佳的实验条件下,该传感器对AFB1检测的线性范围为10-4-10 ng/mL,检出限为0.19 pg/mL,对玉米样品的回收率为96-112%。结论 本研究建立的电化学适配体传感器可以实现对AFB1的定量检测,且具有良好的特异性和重现性,为准确、快速检测食品中的AFB1提供思路。     

Deoxynivalenol exposure assessment in a cohort of pregnant women from Bradford,UK

Deoxynivalenol (DON) is a ubiquitous contaminant of cereal crops in temperate regions of the world. It causes growth faltering and immune suppression in animals. Limited information is available on DON exposure in UK subpopulations. The objective of this study was to provide DON exposure assessment in a subset of pregnant women scheduled for an elective caesarean in a large multi-ethnic mother/infant birth cohort from Bradford, UK. Women aged 16–44 years (n?=?85) provided a urine sample for DON analysis in the last trimester of pregnancy, and concurrently completed a food-frequency questionnaire (FFQ). The urinary DON biomarker was detected in all measured samples (geometric mean (GM)?=?10.3?ng?DON?mg^?1 creatinine, range?=?0.5?116.7?ng?mg^?1). Levels were higher in women classified as South Asian in origin (GM: 15.2?ng?mg^?1; 95% CI?=?10.7?21.5?ng?mg^?1) compared with non-South Asians (GM?=?8.6?ng?mg^?1; 95% CI?=?6.6?11.8?ng?mg^?1), p?=?0.02). Estimated DON intake from FFQ data and typical levels of DON contamination of food suggest that this was mainly due to higher levels of exposure from bread, particularly daily intake of DON from chapattis in South Asians (estimated mean?=?2.4?µg?day^?1; 95% CI?=?1.2, 3.7?µg?day^?1) compared with non-South Asians (estimated mean?=?0.2?µg?day^?1; 95% CI?=?0?0.4?µg?day^?1), p?<?0.001. This is the first biomarker demonstration of DON exposure in pregnant women, and several urinary DON levels were the highest ever recorded in any study. A larger survey within this birth cohort is warranted to investigate any potential risk to mothers and their babies, from DON exposure during pregnancy.     

NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis: II. Reduction in biomarkers of aflatoxin exposure in blood and urine

The efficacy of NovaSil clay (NS) to reduce aflatoxin (AF) biomarkers of exposure was evaluated in 656 blood samples and 624 urine samples collected from study participants during a 3-month phase IIa clinical intervention trial in Ghana. NS was delivered before meals via capsules. Serum AFB (1)-albumin adduct was measured by radioimmunoassay and urinary AFM (1) metabolites were quantified by immunoaffinity-high-performance liquid chromatography (HPLC)-fluorescence methods. Levels of AFB (1) -albumin adduct in serum samples collected at baseline and at 1 month were similar (p = 0.2354 and p = 0.3645, respectively) among the placebo (PL), low dose (LD, 1.5 g NS day (-1)), and high dose (HD, 3.0 g NS day (-1)) groups. However, the levels of AFB (1)-albumin adduct at 3 months were significantly decreased in both the LD group (p < 0.0001) and the HD group (p < 0.0001) compared with levels in the PL group. Levels of AFM(1) in urine samples collected at baseline and at 1 month were not statistically different among the three study groups. However, a significant decrease (up to 58%) in the median level of AFM (1) in samples collected at 3 months was found in the HD group when compared with the median level in the PL group (p < 0.0391). In addition, significant effects were found for dose, time, and dose-time interaction with serum AFB(1)-albumin adduct and dose-time interaction with urinary AFM (1) metabolites. The results suggest that capsules containing NS clay can be used to reduce effectively the bioavailability of dietary AF based on a reduction of AF-specific biomarkers.     

NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis: II. Reduction in biomarkers of aflatoxin exposure in blood and urine.

The efficacy of NovaSil clay (NS) to reduce aflatoxin (AF) biomarkers of exposure was evaluated in 656 blood samples and 624 urine samples collected from study participants during a 3-month phase IIa clinical intervention trial in Ghana. NS was delivered before meals via capsules. Serum AFB (1)-albumin adduct was measured by radioimmunoassay and urinary AFM (1) metabolites were quantified by immunoaffinity-high-performance liquid chromatography (HPLC)-fluorescence methods. Levels of AFB (1) -albumin adduct in serum samples collected at baseline and at 1 month were similar (p = 0.2354 and p = 0.3645, respectively) among the placebo (PL), low dose (LD, 1.5 g NS day (-1)), and high dose (HD, 3.0 g NS day (-1)) groups. However, the levels of AFB (1)-albumin adduct at 3 months were significantly decreased in both the LD group (p < 0.0001) and the HD group (p < 0.0001) compared with levels in the PL group. Levels of AFM(1) in urine samples collected at baseline and at 1 month were not statistically different among the three study groups. However, a significant decrease (up to 58%) in the median level of AFM (1) in samples collected at 3 months was found in the HD group when compared with the median level in the PL group (p < 0.0391). In addition, significant effects were found for dose, time, and dose-time interaction with serum AFB(1)-albumin adduct and dose-time interaction with urinary AFM (1) metabolites. The results suggest that capsules containing NS clay can be used to reduce effectively the bioavailability of dietary AF based on a reduction of AF-specific biomarkers.     

超高效液相色谱-串联质谱法测定牛奶中24 种真菌毒素

运用基质分散固相萃取净化,建立牛奶中24 种真菌毒素（黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、黄曲霉毒素M1、赭曲霉毒素A、玉米赤霉烯酮、玉米赤霉酮、α-玉米赤霉烯醇、β-玉米赤霉烯醇、α-玉米赤霉醇、β-玉米赤霉醇、T-2毒素、HT-2霉素、伏马毒素B1、伏马毒素B2、伏马毒素B3、脱氧雪腐镰刀菌烯醇、3-乙酰脱氧雪腐镰刀菌烯醇、15-乙酰脱氧雪腐镰刀菌烯醇、交链孢霉单甲基醚、交链孢酚、腾毒素、细交链孢菌酮酸）多残留检测的超高效液相色谱-串联质谱检测方法。样品经80%乙腈溶液（体积分数）提取,通过基质分散固相萃取净化,氮吹至近干,1 mL 50%乙腈溶液（体积分数）复溶,采用超高效液相色谱-串联质谱进行测定。经ACQUITY UPLC HSS T3反相柱（2.1 mm×100 mm,1.8 μm）分离,梯度洗脱,采用电喷雾离子源-多反应监测模式采集。24 种目标物的相关系数（R2）均大于0.985,加标回收率为71.0%～123.0%,相对标准偏差均小于10%。该方法具有操作简单、重复性好、灵敏度高、杂质干扰小等特点,可以用于牛奶中24 种真菌毒素的检测。     

臭氧熏蒸对玉米胚中真菌毒素的降解消除作用

为探究臭氧熏蒸对玉米胚中真菌毒素消除效果,固定臭氧质量浓度为150 mg/L,以蒸馏水调节玉米胚水分至不同质量分数(5％、10％、15％、20％、25％、30％),并熏蒸不同时间(20、30、40、50、60、80min),分析熏蒸处理后玉米胚中真菌毒素含量以及玉米胚和玉米油品质的变化.结果表明:玉米胚水分质量分数为2...     

Prevalence of aflatoxins in blood and urine of Egyptian infants with protein-energy malnutrition

The aim of the present work was to study the presence of aflatoxins in blood and urine of infants with protein-energy malnutrition (PEM). The study was conducted on 60 infants, 30 with kwashiorkor and 30 with marasmus, with 10 age-matched healthy infants studied as a control group. Complete blood count, liver function tests, and determination of the level of aflatoxins (B1, B2, G1, G2, M1, M2, G2a, B3, GM1, P, and aflatoxicol R0) in blood and urine were carried out in all studied infants. Serum aflatoxins were detected in more infants with kwashiorkor (80%) than in those with marasmus (46.7%). The mean serum levels of total aflatoxins, AFB1, AFG1, and AFB2a, were significantly higher in infants with kwashiorkor (p <.001). Aflatoxin B1 (AFB1) was the most commonly detected type. The prevalence of aflatoxin excretion in the urine of infants with kwashiorkor was 80%, a higher value than that in infants with marasmus (46.7%). The mean urinary concentration of total aflatoxins followed the same pattern of distribution (p < .052). There were no significant differences between groups in the mean urinary concentrations of AFB1, AFG1, AFB2a, AFM1, and AFG2a. Aflatoxins were not detected in any of the serum or urine samples of the control group. Aflatoxins are highly prevalent in this study population and show a high degree of correlation with severe PEM.     

Urine metabolite analysis as a function of deoxynivalenol exposure: an NMR-based metabolomics investigation

Deoxynivalenol (DON) is a toxic fungal metabolite that frequently contaminates cereal crops including wheat, maize and barley. Despite knowledge of frequent exposure through diet, our understanding of the potential consequences of human exposure remains limited, in part due to the lack of validated exposure biomarkers. In this study, we interrogated the urinary metabolome using nuclear magnetic resonance (NMR) spectroscopy to compare individuals with known low and high DON exposure through consumption of their normal diet. Urine samples from 22 adults from the UK (seven males, 15 females; age range = 21–59 years) had previously determined urinary DON levels using an established liquid chromatography-mass spectrometry (LC-MS) assay. Urine samples were subsequently analysed using an NMR-based metabolomics approach coupled with multivariate statistical analysis. Metabolic profiling suggested that hippurate levels could be used to distinguish between groups with low (3.6 ng DON mg^?1 creatinine: 95% CI = 2.6, 5.0 ng mg^?1) and high (11.1 ng mg^?1: 95% CI = 8.1, 15.5 ng mg^?1) DON exposure, with the concentration of hippurate being significantly (1.5 times) higher for people with high DON exposure than for those with low DON exposure (p = 0.047). This, to our knowledge, is the first report of a metabolomics-derived biomarker of DON exposure in humans.     

基于表面增强拉曼光谱适配体传感器检测植物蛋白肉中的黄曲霉毒素B1

目的 随着生活水平的提高,经济社会的发展,面对丰富多样的食品种类,保证饮食安全已成为民众关注的重点。然而,食品中的黄曲霉毒素B1（Aflatoxin B1,AFB1）的存在对人类健康构成了极大的威胁。因此,开发一种快速、简单、灵敏的AFB1检测方法,对食品安全十分必要和迫切。方法 研发了一种检测AFB1的表面增强拉曼散射(surface enhancement of Raman scattering, SERS)适配体传感器,传感器由巯基适配体（SH-DNA）修饰的金包四氧化三铁磁性纳米粒子（Fe3O4@AuMNPs）作为捕获底物与巯基适配体互补链（SH-cDNA）修饰的金包二氧化硅纳米粒子（SiO2@Au-MBANPS）作为信号探针所组成。通过适配体与AFB1的特异性结合可以导致捕获底物释放信号探针,SERS信号强度随着AFB1的浓度的变化而发生变化,从而实现对AFB1的检测。结果 通过实验条件的优化,得到线性回归方程为Y= -222.07lgX+ 5723.12,r2= 0.9986的标准曲线,检出限为0.37 pg/mL。该SERS传感器成功应用于实际样品中AFB1的分析,得到回收率为98% ~ 110%,相对标准偏差值为3.9% ~ 5.7%。结论 本研究建立的SERS适配体传感系统可以实现对AFB1的定量检测,可以清楚识别AFB1与其他毒素的SERS信号强度差别,为AFB1的快速检测提供了新的检测方法,在实际样品植物蛋白肉中表现出优异的检测性能。     

Excretion of aflatoxin M1 in milk of dairy ewes treated with different doses of aflatoxin B1

Two experiments were conducted to study the amount of aflatoxin M1 (AFM1) in milk in response to feeding aflatoxin B1 (AFB1). In experiment 1, four dairy ewes in early lactation received a single dose of pure AFB1 (2 mg). Individual milk samples were collected during the following 5 d to measure AFM1 concentration. The average excretion of AFM1 in milk followed an exponential decreasing pattern, with two intermediate peaks at 24 and 48 h. No AFM1 was detected in milk at 96 h after dosing. The mean rate of transfer of AFB1 into AFM1 in milk was 0.032%, with a high individual variability (SD = 0.017%). In experiment 2, 16 dairy ewes in midlactation were divided into four groups that received different daily doses of AFB1 (0, 32, 64, and 128 microgram for control and groups T1, T2, and T3, respectively) for 14 d. Pure AFB1 was administered to each animal divided in two daily doses. Individual milk samples were collected at 12, 24, 36, 48, 72, 96, 144, 216, and 312 h after the first AFB1 administration, during the intoxication period, and every 24 h for 7 d after the withdrawal of AFB1. AFM1 was detected in the milk of all animals of the treated groups at 12 h after the administration of AFB1. In all treated groups, milk AFM1 concentration increased from 12 to 144 h after the beginning of administration. It then decreased, reaching a stable concentration at 216 and 312 h after the first administration. No AFM1 was detected in milk 3 d after the last administration of AFB1. Milk AFM1 concentration measured at steady-state condition was significantly affected by the AFB1 dose (0.031, 0.095, and 0.166 in T1, T2, and T3 groups, respectively), with a linear relationship between AFB1 dose and milk AFM1 concentration (R2 = 77.2%). The carryover (AFM1/AFB1 ratio) was not significantly affected by treatment, and its mean value was 0.112% (SE = 0.011). The carryover was lower than that reported for dairy cattle and goats, suggesting a better ability of sheep to degrade AFB1.