Incidence of aflatoxins in commercial nuts in the holy city of Mekkah

The incidence of aflatoxins contamination in different nuts has been studied. Two hundred and sixty four samples of nuts were collected randomly from the main outlets across seven municipalities of the holy city of Mekkah. The samples were first screened for total aflatoxins using Aflatest immunoaffinity column (IAC) technique. The IAC results showed that 70 samples (26.5%) were contaminated with AFT in levels ranged between 1.0 and 110 μg/kg. The percentages of contamination of AFT in groundnuts were (18.4%), Pistachio (34%), walnuts (50%), cashew (15%), hazelnut (43%) and almond (17%). Only 23 samples (8.7%) had levels equal or exceeded the maximum tolerable limit for AFT in EU (4 μg/kg), and only 7 samples (2.65%) had exceeded the MTL in Saudi Arabia (20 μg/kg). The samples that exceeded MTL of Saudi Arabia were five pistachio sample (110, 45, 43, 34 and 30 μg/kg) and two peanut samples (100 and 28 μg/kg). Quantitative testing of total and individual AFs was conducted in selected samples from the IAC results with contamination levels exceeded the MTL of EU (23 samples) by using HPLC and fluorescence detection. AFB1 was detected in 22 out of 23 samples with contamination level in most of the positive samples exceeded the MTL set by EU regulations (2 μg/kg). The highest levels of AFB1 were detected in two sample of pistachio (411 and 126 μg/kg) and one sample of peanut (73.9 μg/kg). Aflatoxin G2 is detected in 5 out of 23 samples, pistachio (2), walnut (2) and hazelnut (1). While, B2 and G1 were detected in 17 samples in levels ranged between ND–10.7 μg/kg and ND–12.9 μg/kg, respectively.     

Two year survey on the occurrence and seasonal variation of aflatoxin M1 in milk and milk products in Serbia

The incidence of contamination of aflatoxin M1 (AFM1) in milk and milk products samples collected in Serbia was investigated by using the competitive enzyme linked immunosorbent assay (ELISA) technique. A total of 1438 samples composed of 678 raw milk, 438 heat treated milk and 322 milk product samples that were analyzed during the period of 2013–2014, including all seasons. The AFM1 levels exceeded the European Union maximum residue permitted amount (EU MRL) in 56.3% raw milk, 32.6% heat treated milk and 37.8% of milk product samples. Milk powders had the highest mean AFM1 concentration (0.847 μg/kg) of all types of milk products examined. Mean concentration of AFM1 in raw milk samples during the period of winter in Serbia was 0.358 μg/kg and did not significantly differ from the mean concentrations of 0.375 μg/kg during the spring. However, the AFM1 raw milk concentration in the summer (0.039 μg/kg) and autumn season (0.103 μg/kg) was significantly lower. Seasonal variation of AFM1 concentrations in heat treated milk samples followed the trend observed in raw milk. Mean raw milk AFM1 concentration has dropped down by 10 fold from 0.314 μg/kg in 2013 to 0.035 μg/kg in 2014. The fraction of raw milk samples exceeding the EU MRL has decreased from 62.3% to 11.5% by the end of 2014.     

Survey of aflatoxin B1 and ochratoxin A occurrence in traditional meat products coming from Croatian households and markets

The aim of this study was to investigate the occurrence of aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in different traditional meat products circulating on Croatian markets, produced by a large number of households situated in different Croatian regions. The study involved a total of 410 samples of traditional pork meat products in terms of hams (n = 105), dry fermented sausages (n = 208), bacon (n = 62) and cooked sausages (n = 35), collected over four years period (2011–2014). Mycotoxin concentrations were quantified and confirmed using validated immunoassay method (ELISA) and high performance liquid chromatography with fluorescence detection (HPLC-FLD), respectively. The maximal observed OTA level in the fermented sausages and hams was around 5 times (5.10 μg/kg) to 10 times (9.95 μg/kg) higher than the maximal recommended level (1 μg/kg) stipulated for pork products in some EU countries. AFB₁ levels found in any given meat product analysed within this frame were not significantly higher (p > 0.05) than the applied method limit of detection. The results showed an occasional mycotoxin contamination of traditional meat products, especially that by OTA, pointing that to avoid such contamination meat and meat products on households should be produced and processed under standardised and well-controlled conditions.     

Occurrence of patulin in various fruit products and dietary exposure assessment for consumers in China

A quantitative method with broad applicability was developed and validated for patulin determination in fruit products by high-performance liquid chromatography (HPLC) with UV detection. Sample pretreatment was optimized for patulin extraction. 4.0 g of fruit products was extracted for patulin determination with acetonitrile and purified with a mixture of 1.0 g PSA and 3 g MgSO₄ plus a multifunctional cartridge to remove interferences. Under optimized conditions, the recoveries ranging from 75.6% to 118.5% were obtained at different spiking concentrations in various fruit products. The correlation coefficient of patulin from 5 to 1000 μg/L was approximately 1.00. The limits of detection (LODs) were from 2.6 to 7.5 μg/kg, and the limits of quantification (LOQs) were from 8.0 to 15.0 μg/kg for patulin in various fruit products. A total of 137 fruit products (97 dried fruits, 20 fruit juice and 20 jams) marketed and consumed in China were investigated. The incidence of patulin in fruit products was 30.7% (42/137) with a concentration ranging from 10.0 to 276.9 μg/kg. This study revealed that the dried figs, dried longans (seedless) and dried hawthorn products showed an average of patulin contamination of 87.6 μg/kg, 68.4 μg/kg and 5.1 μg/kg, respectively; the fruit juice of 5.4 μg/kg; the fruit jams of 5.0 μg/kg. The highest levels of patulin were found mostly in dried longans (seedless) and dried figs. Overall, 17.5% of total samples exceeded the maximum limit of 50 μg/kg set by the EU regulation. Chronic intake assessment indicated that only 0.29% (Hazard Quotient) acceptable daily intake (PMTDI, 0.4 μg/kg bw/day) was consumed through dried fruits, fruit juice and jams. Individual dietary risk assessment indicated patulin contamination in fruit products doesn't pose public health risks, but combined additive or synergistic toxic effects caused by multiple mycotoxin contaminations should not be ignored.     

Occurrence of patulin in various fruit juice marketed in Tunisia

Patulin (PAT) is a secondary metabolite, which is mainly produced by certain species of Aspergillus and Penicillium fungi. The objective of this study is to investigate the presence of Patulin in various fruit products marketed and consumed in Tunisia. A total of 214 samples (30 concentrated juice samples, 42 apple juice samples, 42 pear juice samples, 34 mixed juice samples, 35 compote samples, 15 apple jams samples and 16 pear jam samples) were analyzed. The incidence of PAT contamination was 50% with a concentration ranging from 2 to 889 μg/l with an average of 89 μg/l and a median of 41 μg/l. Twenty two percent (22%) of total analyzed samples exceeded the limit recommended by the European Union. Our results showed that PAT seems to be a problem in fruit products marketed in Tunisia, which required and recommended a hard and fast surveillance of this toxin.     

Listeria monocytogenes in ready-to-eat vacuum and modified atmosphere packaged meat and fish products of Estonian origin at retail level

The prevalence, counts and genetic diversity of Listeria monocytogenes in ready-to-eat (RTE) vacuum and modified atmosphere packaged meat and fish products was studied in Estonia. Within two consecutive years 370 RTE food samples were collected at retail level from which 11% were found to be positive for L. monocytogenes. Contamination was higher among RTE fish products (17%) than in RTE meat products (6%). Generally, the counts of L. monocytogenes in positive products remained under ten colony forming units (CFU) per gram of product. Only 1.6% of the RTE meat and fish products contained L. monocytogenes in range of 10–100 CFU/g and 0.3% more than 100 CFU/g at the end of shelf-life. The food category containing highest L. monocytogenes prevalence was RTE lightly salted fish products with the prevalence of 32%. Only one (0.3%) RTE food sample exceeded the 100 CFU/g food safety criterion set out in the EU Regulation 2073/2005. Pulsed-field gel electrophoresis (PFGE) characterization of the isolates showed an overall similarity higher than 70%, and nine clusters based on 100% similarity were revealed. PFGE genotyping revealed that the few predominant pulsotypes were associated with particular food plants.     

Co-exposures of aflatoxins with deoxynivalenol and fumonisins from maize based complementary foods in Rombo,Northern Tanzania

Children consuming maize based foods in Tanzania may be exposed to multiple mycotoxins. We estimated co-exposures of aflatoxins with Deoxynivalenol (DON) and fumonisins for children in rural Tanzania. Food consumption by the children was estimated by twice administering a 24 h dietary recall questionnaire to mothers of 18–24 months old children in Kikelelwa village. Each mother also, provided a sample of maize based flour used for feeding her child in the previous day. Each child's body weight (bw) was measured by following standard procedures. Aflatoxins, DON and fumonisins were determined in each sample using validated HPLC methods. Exposures for a mycotoxin were estimated by multiplying flour consumption (g/child/kgbw/day) by its contamination (μg/kg). Complete data were obtained for 41 children. Maize flour consumption ranged from 16 to 254 g/child/day. Thirteen (32%) of the 41 children consumed flour with detectable aflatoxin levels (range, 0.11–386 μg/kg), resulting in exposures from 1 to 786 ng/kg bw/day. All these children exceeded the aflatoxins exposure of concern (0.017 ng/kg bw/day). Eighteen (44%) of the children consumed flour with detectable DON levels (57–825 μg/kg) and 34 (83%), detectable fumonisins levels (63–2284 μg/kg), resulting in respective exposure ranges of 0.38–8.87 μg/kg bw/day and 0.19–26.37 μg/kg bw/day. Twelve (66%) of the DON exposed children and 56% of the fumonisins exposed children exceeded the respective provisional tolerable daily intakes of 1 μg/kg bw and 2 μg/kg bw. Co-exposures for aflatoxins with both DON and fumonsins were determined in 10% of the 41 children. Co-exposures of aflatoxins with fumonisins alone were found in 29% and of fumonisins with DON alone in 41% of the children. The study showed that children consuming maize based complementary foods in Northern Tanzania are at a risk of exposure to multiple mycotoxins. We recommend adoption of appropriate measures to minimize exposures of multiple mycotoxins in Tanzania.     

Occurrence of patulin in apple-based-foods largely consumed in Tunisia

Patulin (PAT) is a toxic metabolite produced by several filamentous fungi of the genera of Penicillium, Aspergillus and Byssochlamys, principally by Penicillium expansum. A total of 85 samples of apple products largely consumed by Tunisian population were analyzed for PAT content, including apple juice, baby food and mixed juice collected during 2011 from the major supermarkets and stores located in Tunisia. The aim of this study was to investigate the presence of PAT in the widely-consumed apple products in Tunisia, to compare the levels of PAT contamination with the European norms and to suggest some factors that can promote the production of this mycotoxin in our country. To perform this study, we developed and validated, in our laboratory conditions, an HPLC method for a quantitative analysis of PAT in apple products. Our results showed that the incidence of PAT contamination was 35%. The levels of contamination determined in the total samples ranged between 0 and 167 μg/l with a mean value of 20 μg/l and a median of 13 μg/l. Eighteen percent (18%) of the total juice samples (apple juices and mixed juices) and twenty-eight percent (28%) of the baby food samples exceeded the tolerable limit recommended by the European Union, which are respectively 50 μg/l and 10 μg/l.     

Studies on contamination level of aflatoxins in some cereals and beans of Pakistan

The occurrence of aflatoxins in some cereals and beans was surveyed in this study. One hundred and sixty samples of cereals and beans were purchased from retail shops and local markets of different locations in Pakistan. The samples were analyzed for total aflatoxins to using immune affinity (IAC) clean up with liquid chromatography and fluorescence detection. The results showed the percentage of contamination for total aflatoxins in the samples such as in; rice (25%), broken rice (15%), wheat (20%), maize (40%) barley (20%) and sorghum (30%), while in red kidney beans (20%), split peas (27%), chick pea (10%), cow pea (20%), and soybean (15%). The highest contamination levels of aflatoxins were found in one wheat sample (15.5 μg/kg), one maize sample (13.0 μg/kg) and one barley sample (12.6 μg/kg). Among all the contaminated samples, two rice, one rice broken, two wheat, three maize, two barley, one sorghum, one red kidney beans, one split peas and two soybeans were above the suggested limit for total aflatoxins (4 μg/kg), set by EU regulations.     

A survey of the incidence and level of aflatoxin contamination in a range of locally and imported processed foods on Malawian retail market

Samples of locally (Malawian) processed and imported maize- and groundnut-based food products (peanut butters, roasted groundnuts, peanut based therapeutic foods, instant baby cereals, maize puffs and de-hulled maize flour) were collected from popular markets of Lilongwe City, Malawi. The samples were analysed in order to determine the frequency and extent of aflatoxin contamination, using immuno-affinity column and reversed-phase liquid chromatography with post-column photochemical derivatization and fluorescence detection. No aflatoxins were detected in all samples of imported baby cereal and locally processed de-hulled maize flour. However, all locally processed maize based baby foods had aflatoxins above EU maximum tolerable level of 0.1 μg/kg. In 75% of locally processed maize puffs, aflatoxins were detected at levels of up to 2 μg/kg. Peanut based therapeutic foods had aflatoxin level between 1.6 and 2.9 μg/kg, exceeding the EU tolerable maximum level (0.1 μg/kg) set for food for health purposes. Locally processed peanut butters had aflatoxins levels in the range of 34.2–115.6 μg/kg, which was significantly higher than their imported counterparts (<0.2–4.3 μg/kg). Samples of locally processed skinned and de-skinned roasted groundnuts had aflatoxins in range of 0.5–2.5 μg/kg and 0.6–36.9 μg/kg, respectively. These results highlight the need for rigorous monitoring of aflatoxins in commercially available processed products in order to reduce likely health risks associated with dietary aflatoxin intake.     

Occurrence of mycotoxins in commercial infant formulas locally produced in Ouagadougou (Burkina Faso)

Cereals products enriched with leguminous or oleaginous are used in Burkina Faso as food complement or to avoid infant malnutrition. Infant formulas from cereals are consumed as food supplements after the weaning age. They are produced in Burkina Faso with a mixture of several cereals (maize, millet, rice, or sorghum), leguminous (bean), oleaginous (peanut, soya or sesame), sugar or salt and sometimes milk powder. The production is artisanal or semi-industrial. These infant foods from cereals should be free from mycotoxins and pathogenic bacteria. The objective of this work was to determine the occurrence of mycotoxins like aflatoxins, ochratoxin A and fumonisins in infant formulas and grains in Ouagadougou (Burkina Faso). The mycotoxins (aflatoxins, ochratoxin A and fumonisins) were determined by HPLC-FLD in 248 samples of infant formulas produced by the Recovery and Nutrition Education Centers (CRENs) and sold on the market places in Burkina Faso.Results showed that the majority of samples of infant formulas presented high levels of mycotoxins. The frequency of contaminated samples by aflatoxin B1, ochratoxin A and fumonisins in analyzed samples were 83.9% (167/199), 7.5% (15/199) and 1.5% (3/199), respectively. The highest values registered in infant formulas were 900, 6 and 3 times higher for aflatoxin B1 (EU limit: 0.1 μg/kg), ochratoxin A (EU limit: 0.5 μg/kg) and fumonisins (EU limit: 200 μg/kg), respectively, than the EU regulation limits (1881/2006). This study presents the first results concerning the safety assessment of infant formulas regarding mycotoxins in Burkina Faso.     

A survey of aflatoxin M1 of raw cow milk in China during the four seasons from 2013 to 2015

In the present study, a total of 1550 raw cow milk samples were collected from Southern, Northern, Northeast, and Western regions of China during the four seasons from 2013 to 2015. Samples were analyzed for aflatoxin M1 (AFM1) using high performance liquid chromatography (HPLC). In 2013, AFM1 was detected in 21% of 366 raw cow milk samples with levels ranging between 0.01 and 0.24 μg/L. In 11.7% of samples, AFM1 levels were >0.05 μg/L, which is the legal limit in the European Union. The mean and median of positive samples were 0.069 ± 0.052 μg/L and 0.056 μg/L, respectively. In 2014, AFM1 was detected in 28.5% of 624 raw cow milk samples, with levels ranging from 0.01 to 0.25 μg/L. Of these samples, 7.7% had AFM1 levels exceeding 0.05 μg/L, with a mean of 0.042 ± 0.039 μg/L and median of 0.028 μg/L. AFMI was detected in 14.1% of 560 raw cow milk samples in 2015, with levels ranging from 0.01 to 0.144 μg/L. In 1.8% of these samples, AFM1 levels were above 0.05 μg/L, with a mean of 0.026 ± 0.024 μg/L and median of 0.017 μg/L. Our results demonstrate that AFM1 levels of the samples did not exceed the legal limit of 0.5 μg/L in China, the United States, and Codex Alimentarius Commission. Geographically, AFM1 contamination was more predominant in raw cow milk samples from Southern China than in those from other regions, with a higher number of samples containing AFM1 levels above 0.05 μg/L in 2013, 2014, and 2015. AFM1 levels were higher in autumn than in the other seasons during the entire study period. According to our survey, AFM1 contamination has been well-controlled in China during recent years; however, some samples still exceeded the European Union (EU) legal limit. Better prevention and management of aflatoxins in both feed and milk should be considered especially in Southern regions of China and in autumn.     

Occurrence of aflatoxin M1 in pasteurized and UHT milks in China in 2014–2015

This survey was performed to assess the safety of milk in China, specifically by assessing the presence of aflatoxin M1 (AFM1) residues in pasteurized and ultra high temperature (UHT) milk. In 2014–2015, 193 samples of UHT milk were collected from different cities in China. In 2015, 38 samples of pasteurized milk were collected from different cities in China. AFM1 was detected using an enzyme-linked immunosorbent assay (ELISA). AFM1 positivity was defined as a concentration exceeding the detection limit of the assay (0.005 μg/kg). Other cut-offs that were used were the legal AFM1 limits in the European Union (EU) and China (0.05 and 0.5 μg/kg, respectively). In 2014 and 2015, 88.6% and 59.6% of UHT milk samples were AFM1-positive, respectively. The pasteurized milk samples were less frequently AFM1-positive (47.4%). In 11.9% of the 2014–2015 UHT milk samples, the AFM1 levels exceeded the EU limit. This is lower than the frequency we recorded in 2010 (20.3%). None of the pasteurized milk samples exceeded the EU limit in 2015. The UHT milk samples from the north of China were less likely to be contaminated than the samples from the south in both 2014 and 2015. None of the samples exceeded the Chinese legal limit.     

Ethyl carbamate in alcoholic beverages from China: Levels,dietary intake,and risk assessment

A national survey of ethyl carbamate (EC) in alcoholic beverages from the fourth and fifth Chinese total diet study (TDS) performed in 2007 and 2009 was conducted for the first time. Alcoholic beverages samples were collected from 16 provinces representing the average dietary patterns of various provinces of China and covering about 60% of the total Chinese population. The results showed that the average EC level in alcoholic beverages (19.8 μg/kg) in the fifth TDS was higher than that of the fourth TDS (8.5 μg/kg). The dietary intake of EC from the Chinese population was estimated to be 8.27 ng/kg bw per day for average population and 45.67 ng/kg bw per day for high consumers (the 97.5th percentile) in the fifth TDS. The average and high-end estimated daily intakes of EC for the alcoholic beverages were both lower than estimated daily intake (EDI) value (80 ng/kg bw per day) suggested by JECFA, indicating low health risk of EC dietary exposure among Chinese adults at present.The Chinese rice wines, as a kind of traditional fermented alcoholic beverages in China, has a high level of EC and an obvious consumption regional disparity, thus the health risk of EC in Chinese rice wines should be of concern. To estimate the daily intake of EC from Chinese rice wines consumed in China, 890 Chinese rice wines samples including 468 commercial wines and 422 base wines were collected from various regions. The distribution of EC varied significantly among 468 commercial wines, ranging from 6.3 to 775.8 μg/L (mean: 232.9 μg/L). Based on the intake data for Chinese rice wines from the food consumption survey, the daily intake of EC was estimated to be 290.6 ng/kg bw per day for average consumers and 1848.4 ng/kg bw per day for high consumers (the 97.5th percentile). In this study, the estimated daily intake of EC for Chinese rice wines in China was far higher than EDI value suggested by JECFA indicating that Chinese rice wines were the main exposure origin of EC in alcoholic beverages. Health risk assessment of EC using a margin of exposure (MOE) approach recommended by the European Food Safety Authority (EFSA) suggested unlikely health concern with respect to current dietary intake of EC for alcoholic beverages in China. However, a relatively high health risk of EC dietary exposure in Chinese rice wines was observed in some provinces. Therefore, some adapted strategies should be developed and used in industrial scale to control the level of EC for Chinese rice wines.     

Polycyclic aromatic hydrocarbons in vegetable oils from unconventional sources

The levels of 4 compounds from the group of light PAHs listed by the US EPA and 15 PAHs listed by the EU Scientific Committee on Food were determined in selected unconventional oils. PAHs determination was performed by high-pressure liquid chromatography with fluorescent and diode array detectors (HPLC-FLD/DAD). Similar quality profiles of PAHs, with light PAHs being predominant, were stated. Total content of 19 PAHs varied from 23.41 (poppy seed oil) to 234.30 μg/kg (pumpkin seed oil). In most analyzed products, from the group of 15 PAHs benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[k]fluoranthene were detected. Benzo[a]pyrene was detected in amaranth, pumpkin, sesame, blackseed and borage oil, whereas in pumpkin seed oil its concentration was about 8 times higher than the maximum tolerable limit (2 μg/kg) stated in Commission Regulation (EU) No. 835/2011. The sum of benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene, for which the maximum tolerable limit has been set in Commission Regulation (EU) No. 835/2011 at the level of 10 μg/kg, were found in the range from 0.00 (linseed oil) to 35.03 μg/kg (pumpkin seed oil).     

Sushi commercialized in Brazil: Organic Hg levels and exposure intake evaluation

The presence of organic mercury (methylmercury) in tuna, salmon and kani sushis marketed in restaurants specialising in Japanese foods (Campinas, São Paulo, Brazil), was investigated by atomic absorption spectrometer with thermal decomposition and amalgamation. Total mercury was analyzed directly, whilst organic mercury was quantified after a previous extraction with toluene in an acid solution, assisted by microwaves. Under these analytical conditions there was no interconversion between the inorganic and organic mercury. High sensitivity was observed for organic mercury, with limits of detection and quantification of 2.0 and 6.6 μg kg⁻¹. The organic mercury contents ranged from 12 to 583 μg kg⁻¹, 6.6 to 8.2 μg kg⁻¹ and no detected values, for the tuna, kani and salmon sushi, respectively. The mean proportion of organic Hg/total Hg for tuna sushi was 88%, indicating that the most toxic form of mercury, organic Hg, predominate in this food. The estimated exposure to methylmercury was made by taking into account the Provisional Tolerable Weekly Intake (PTWI 1.6 μg/kg) considering the daily consumption of 150 g and 20 g per adults (60 kg) and children (15 kg), respectively. Our results demonstrated that the consumption of tuna sushi may exceed 100% of PTWI.     

High contents of cadmium,lead, zinc and copper in popular fishery products sold in Turkish supermarkets

Selected toxic (cadmium, lead) and essential (zinc and copper) trace metals were determined by means of differential pulse stripping anodic voltammetry (DPSAV) in some different brands and kinds of fishery products purchased from the popular supermarkets of Turkey. Among the fishery products, the highest concentration of cadmium, lead, zinc and copper were found in the frozen anchovy (494.2 μg/kg, 314.2 μg/kg, 566 mg/kg, 45.7 mg/kg, respectively). While the canned anchovy fillet had the lowest cadmium (25.1 μg/kg), zinc (33.8 mg/kg) and copper (7.1 mg/kg) concentrations, canned tuna fish (Brand A) had the lowest lead (76.1 μg/kg). The concentrations of all toxic and essential elements in the selected products were high and often exceeded legal limits set by health authorities. Therefore these products must be monitored more often.     

Determination of nitrofuran metabolites in shrimp muscle by liquid chromatography-photo diode array detection

The use of nitrofurans on any animal in the European Union (EU) and any animal or animal food products intended for export to the EU was banned in 1993 (except furazolidone which was banned in 1995) due to the carcinogenicity of the parent drugs and their metabolites. Thereafter, the screening of food of animal origin for nitrofurans and their metabolites became mandatory for all exports to the EU. This paper describes a High Performance Liquid Chromatography – Diode Array Detection (HPLC-DAD) method to detect tissue bound nitrofuran metabolites, namely 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholino-methyl-1,3-oxazolidinone (AMOZ), semicarbazide (SEM) and 1-aminohydantoin (AHD). The bound residues were hydrolysed and derivatized into the corresponding nitrophenyl derivatives (NPAOZ, NPAMOZ, NPSEM and NPAHD) with 2-nitrobenzaldehyde and analysed by HPLC-UV at 275 nm. The linearity of the photometric detector response to the four derivatized nitrofuran metabolites was verified using matrix-matched calibration standards in the range of 1–20 μg/kg and the average correlation coefficients for NPAOZ, NPAMOZ, NPSEM and NPAHD were 0.9960, 0.9951, 0.9984 and 0.9993, respectively. The decision limit of the method was below the Minimum Required Performance Limit (MRPL) of 1 μg/kg, for all four nitrofuran metabolites, which makes it compatible with the EU requirements. The average recoveries for (fortified samples between 1 and 5 μg/kg) AOZ, AMOZ, SEM and AHD were 107%, 107%, 115% and 114%, respectively. This is the first report of a HPLC-DAD method detecting nitrofuran metabolites below the MRPL according to our understanding. This method has been successfully used with aquaculture and poultry products; however, currently it is validated according to EU guidelines only for shrimp muscle tissue.     

Aflatoxin contamination and exposure in processed cereal-based complementary foods for infants and young children in greater Accra,Ghana

In the study, aflatoxin levels were assessed in thirty five (35) cereal-based food products intended for infants and young children. Additionally, the results showed that 71% of the processed foods intended for infants contained AFB₁ (0.18 ± 0.01 to 36.10 ± 0.32 μgkg⁻¹) levels higher than the European Union permissible limits of 0.1 μg kg⁻¹. Aflatoxin intake was estimated using aflatoxin levels in the food products and the estimated individual consumption rates. The study also revealed mixed cereals as having the highest intake of aflatoxin B₁ contaminants (0.005–0.852 μgkg⁻¹bw d⁻¹; 0.004–0.657 μgkg⁻¹bwd⁻¹) with mean estimated daily intake (EDI) of 0.23 ± 0.16 μgkg⁻¹bwd⁻¹ and 0.153 ± 0.13 μgkg⁻¹bwd⁻¹ for infants and young children respectively. The estimated AFT intake recorded for infants and young children for all the cereal-based food ranged from 0.005 to 1.054 μgkg⁻¹bwd⁻¹ and 0.004–0.838 μgkg⁻¹bwd⁻¹ respectively.     

Aflatoxins and fumonisins in rice and maize staple cereals in Northern Vietnam and dietary exposure in different ethnic groups

Mycotoxins in food are increasingly a food safety hazard concern in particular in developing countries. This study was performed to determine the occurrence and determinants of aflatoxin and fumonisin contamination in rice and maize and to assess health risks through dietary intake exposure among ethnic minority groups in northern Vietnam. A total of 111 rice and 102 maize samples, were tested for occurrence of fungi and mycotoxins, i.e. aflatoxins (AF’s) and fuminisin B (FB). Results showed that 107 (96.4%) rice and 84 (82.4%) maize samples were contaminated by fungi. Aspergillus flavus was found in 68 (61.3%) rice and 30 (29.4%) maize samples, Aspergilus parasiticus in 40 (36.0%) rice and 27 (26.7%) maize samples. AF’s - were detected in 27 rice (24.3%) and 27 maize samples (26.4%) at minimum and maximum levels in rice of 2.06 and 77.8 ng/g and 20.5 and 110 ng/g in maize, respectively. Nine (8.1%) rice and 24 (23.5%) maize samples contained FB at ranges of 2.3–624 ng/g in rice and 5.6–89.8 ng/g in maize. Data collected through interviews and observations in households showed that type of crop, storage duration and presence of fungi, particularly mycotoxigenic fungi were important risk factors for AF’s and FB contamination. Based on daily food consumption data, the estimated average exposure dose of aflatoxin B₁(AFB₁) from rice was 21.7 ng/kg bw/day for adults and 33.7 ng/kg bw/day for children. For FB, the rice based average exposure amounted to 536 ng/kg bw/day for adults and 1019 ng/kg bw/day for children. The calculated excess risk of liver cancer incidence by ingestion of cereals containing AFB₁ was 1.5 per 100,000 adults and 2.3 per 100,000 children per year. The average intake of FB was calculated to be lower than the tolerable diet intake (TDI). Our findings highlight that rice and maize are contaminated with mycotoxins at levels representing actual health hazards for the ethnic minority groups consuming these stable cereals. Proper drying and storage conditions in households are likely to reduce the mycotoxin contamination.