Occurrence of aflatoxin M1 in dairy products in Brazil

The objective of this study was to investigate the incidence and occurrence of aflatoxin M₁ (AFM₁) in dairy products produced in Brazil. A total of 123 samples of three different groups of dairy products (cheese, yoghurt, and dairy drinks) consumed by Brazilians were collected during 2010. All samples including 58 cheese samples, 53 samples of yoghurt and 12 dairy drinks were purchased from grocery stores in the Ribeirão Preto-SP area. Cheese samples were classified into three categories depending on their moisture and fat contents: Minas Frescal cheese, Minas Frescal light cheese and Minas Padrão cheese. Samples were analyzed for AFM₁ by a published method. The method comprised aqueous methanol extraction, immunoaffinity column purification and isolation, reversed phase liquid chromatography separation and fluorescence detection. AFM₁ was detected in 84% of the analyzed cheese samples (>3 ng/kg) with levels ranging from 10 to 304 ng/kg in 67% of the samples. AFM₁ was detected in 95% of the yoghurt and dairy drink samples with levels ranging from 10 to 529 ng/kg in 72% of the samples. Despite the lack of a Brazilian regulatory limit for AFM₁ in yoghurt and dairy drinks the survey data of this study may offer information useful in the determination of whether the occurrence of AFM₁ in Brazilian dairy products may be considered as a possible risk for consumer health and whether Brazilian regulatory guidelines for AFM₁ in dairy products are needed.     

Occurrence of toxigenic fungi and ochratoxin A in Ethiopian coffee for local consumption

Information on the presence of ochratoxin A (OTA) in local Ethiopian coffee is scarce. Therefore, the objective of this study was to type the fungal and mycotoxin contamination levels in Ethiopian coffee consumed by the local community. Coffee samples were collected from six major coffee growing districts in Jimma zone of Oromiya regional state in Ethiopia. Total fungal incidence mounted up to 87% and Aspergillus (79%), Fusarium (8%) and Penicillium (5%) were the predominant toxigenic genera. OTA producing species A. westerdijkiae, Aspergillus ochraceus, and Aspergillus steynii were identified for the first time in Ethiopia and were shown to be the predominant species while aflatoxin (AF) producing Aspergillus species were scarce. Using an in vitro approach, the OTA production potential was assessed under standardized conditions. Based on this experiment, it was concluded that Aspergillus westerdijkiae isolates were clearly the most potent producers of OTA. The median OTA level in the locally sold Ethiopian coffee was 1.53 μg/kg. Notwithstanding this low median value, significant differences in fungal and toxin incidences were observed between the different coffee processing types, coffee sample types, and storage characteristics.     

Aflatoxin M1 in milk and traditional dairy products from west part of Iran: Occurrence and seasonal variation with an emphasis on risk assessment of human exposure

In the present study, a total of 358 samples consisting of raw milk of cow (n = 64), goat (n = 56) and sheep (n = 52); traditional cheese (n = 40), yoghurt (n = 42), Kashk (n = 40), Doogh (n = 44) and Tarkhineh (n = 20) were analyzed for aflatoxin M₁ (AFM₁) by using an enzyme linked immunosorbent assay (ELISA). Frequency of AFM₁ and its concentration ranges in the ELISA positive samples were determined by high performance liquid chromatography with fluorescence detection (HPLC-FD). AFM₁ contamination was 84.3%, 44.6% and 65.3% for cow, goat and sheep raw milks, respectively. Moreover, AFM₁ was in 65.5%, 23.8%, 14%, 13.6% and 35.0% of cheese, yoghurt, Kashk, Doogh and Tarkhineh samples, respectively. Percentages of cow milk, goat milk, sheep milk and cheese samples exceeding the EU limit were 35.9%, 11.1%, 26.9% and 10%, respectively. HPLC analyses confirmed the ELISA results although the percentages of AFM₁ contamination in raw milk and dairy products were lower than that of ELISA. There were significant differences (P < 0.05) between the mean AFM₁ contents of raw milk, cheese and yoghurt samples during winter and summer seasons. Our study demonstrated that there is a potential risk for liver cancer due to the consumption of milk and dairy products in Iranian consumers.     

Seasonal variation of aflatoxin M1 contamination in industrial and traditional Iranian dairy products

This study aimed to determine the occurrence of aflatoxin M₁ (AFM₁) contamination in 682 dairy product samples consisting of raw milk of cow, goat and sheep; Lighvan cheese; and industrial and traditional yoghurt, Kashk and Doogh samples collected from popular markets and dairy ranches in four large Iranian cities. Thin layer chromatography (TLC) technique was used for analysis of the samples. Results showed that the incidence and levels of AFM₁ contamination in raw cow milk and industrial products (manufactured from cow milk) were higher than raw goat or sheep milk, and traditional products (made from goat and sheep milk), respectively. Moreover, seasonal variations influenced the concentration of AFM₁ in most of the analyzed dairy products. Owing to the abundance and popularity of the industrial products, contamination of these products in such a level could be a potential hazard for public health.     

Screening of aflatoxin M1 occurrence in selected milk and dairy products in Terengganu,Malaysia

The study was conducted to screen the occurrence of aflatoxin M₁ (AFM₁) in 53 selected milk and dairy product samples (11 liquid milk, 12 powdered milk, 8 3-in-1 beverages, 6 condensed sweetened milk, 2 evaporated milk, 7 cultured milk drink, 5 yogurt and 2 cheese samples). These samples were purchased from selected markets in Terengganu, Malaysia in January 2014 based on a questionnaire survey among 212 respondents on the types and brands of milk and dairy products that were frequently consumed. Based on the responses, 53 milk and dairy products were purchased and the competitive enzyme-linked immune-absorbent assay (ELISA) method was used to determine the level of AFM₁ in the samples. Of 53 samples, 19 samples were positive with AFM₁ (35.8%) ranging from 3.5 to 100.5 ng/L. Although 4/53 (7.5%) of the tested samples had the contamination level greater than the European Commission (EC) limit (>50 ng/L), the contamination levels were still below the Malaysia Food Regulation 1985 limit (less than 500 ng/L). This study provided a pioneering data on the occurrence of AFM₁ in milk and dairy products in Malaysia.     

Prevalence and antimicrobial resistance of Listeria species isolated from milk and dairy products in Iran

The objective of this study was to determine the prevalence of Listeria spp. in milk and dairy products in Isfahan province, Iran. From March 2007 to September 2009, a total of 594 samples of various milk and dairy products were obtained from randomly selected retail stores. Using conventional bacteriologic method, 55 samples (9.3%) were positive for Listeria spp. The highest prevalence of Listeria was found in raw sheep milk samples (22.6%), followed by cheese samples (18.9%). The most species recovered was Listeria innocua (58.2%); the remaining isolates were Listeria monocytogenes (32.7%) and Listeria seeligari (9.1%). Overall, 54 Listeria isolates (98.2%) were resistant to one or more antimicrobial agents. Resistance to nalidixic acid was the most common finding (96.4%). All Listeria isolates were susceptible to vancomycin. The results of this study indicate the potential risk of infection with Listeria in people consuming raw and unpasteurized milk and dairy products.     

Ochratoxin A in cocoa and chocolate products from the Italian market: Occurrence and exposure assessment

Three hundred samples of cocoa and chocolate-based products were randomly collected in South, Center and North Italy. One hundred and seventy nine, out of the 300 samples analyzed, were positive for ochratoxin A (OTA) contamination, representing 60% of the purchased products. All 40 cocoa samples showed OTA contamination, while grouping all the chocolate products the positive samples accounted for 53%. The mean OTA concentration levels for cocoa and chocolate products were well below the corresponding Italian legal limits. Teenagers’ male age group resulted as the highest consumers for cocoa powder (2.9 g per day), while the OTA highest weekly intake was reported for the younger age groups (0.10 and 0.38 ng/kg bw/week, for infant and children respectively). With respect to chocolate products, the highest daily consumption and the highest intake are reported for children (7.3 g and 0.57 ng/kg bw/week, respectively). As far as single chocolate products are concerned, the highest weekly intake is referred to the consumption of Easter chocolate eggs by the infant/children age group (0.10 ng/kg bw/week). The overall analysis of the exposure assessment suggests that the very low value of body weight for infant and children categories drives the exposure calculations. On the basis of the risk assessment carried out in this study, the exposure to OTA, due to the consumption of cocoa and chocolate products, is to be considered not a major concern. Therefore, the Italian Superior Council of Health considered the data arising from this study, adequate to repeal the existing Italian legal limits and to align national legislation with the EU provisions.     

Occurrence of ochratoxin A in cereal-derived food products commonly consumed in Turkey

Ochratoxin A (OTA) is a mycotoxin that can be found in several food commodities including cereals, wine, coffee, cacao, spices or dried fruits, resulting in chronic human exposure. The aim of our study was to investigate the presence of OTA in widely consumed cereal-derived products commercialized in Turkey. A total of 142 samples were collected from different supermarkets and traditional bazaars in Istanbul during 2008-2010 years. The analytical methods used in our study involved the liquid/liquid extraction of OTA, immunoaffinity clean-up and high performance liquid chromatography determination with fluorescence detection. The frequencies of OTA contamination were 21.62%, 19.05% and 55.95% and the mean concentrations of positive samples were 0.32 μg/kg, 0.14 μg/kg, 0.41 μg/kg for breakfast cereals, cereal-based baby foods and tarhana samples, respectively. Our findings show that contamination levels of OTA in all cereal-derived products were lower than the permitted level by European Commission Regulation.     

A novel minisequencing test for species identification of salted and dried products derived from species belonging to Gadiformes

The aim of the present study is to develop an assay for the specific identification of Gadus morhua, Gadus macrocephalus, Gadus ogac, Molva molva and Brosme brosme targeting sequences of the cytochrome b (cyt b) gene of mitochondrial DNA. The primers used in the preliminary PCR were designed in well conserved regions upstream and downstream of the diagnosis sites. They successfully amplified a conserved 188 bp region from the cyt b gene of all the species taken into consideration. The sites of diagnosis have been interrogated using a minisequencing reaction and capillary electrophoresis. All the results of the test were confirmed by fragment sequencing.     

A survey of concentration of aflatoxin M1 in dairy products marketed in Turkey

The aim of this study was to examine the presence of aflatoxin M1 (AFM1) in dairy product samples by enzyme-linked immunosorbent assay (ELISA). Aflatoxin M1 were found in 135 (64%) out of 210 analyzed samples. Only 7% of dairy product samples were contaminated at levels above the legal limits. AFM1 was detected in 43 (86%) of milk samples (ranging from 1 to 30 ng/l), in 38 (63%) of cheese (ranging from 12 to 378 ng/kg), in 28 (56%) of yoghurt (ranging from 2.5 to 78 ng/kg) and in 26 (52%) of dairy dessert samples (ranging from 1.5 to 80 ng/kg). None of the raw milk samples contained levels above the Turkish legal limit. The AFM1 levels of 7(14%) yoghurt, 5 (10%) dairy dessert and 3 (5%) cheese samples were above the limits of the Turkish Food Codex. It is emphasized that the presence of AFM1 in dairy products may be regarded as a potential hazard for human health.     

Solid-phase extraction of staphylococcal enterotoxin A in dairy products using an ion exchange resin

In this study, we developed a solid-phase extraction method for staphylococcal enterotoxin (SE), especially SE type A (SEA), in milk and dairy products. Ion-exchange resin, a cation-exchanger, was applied for the extraction of SEA, which was then measured using a sensitive fluorescence immunoassay. First, the optimal pH for the binding of SEA to the cation exchanger was determined to be pH 4.0. Second, the optimal volume of elution buffer, consisting of phosphate buffer with 0.5 M sodium chloride at pH 8.0, was estimated to be 6 ml for a column containing 4 ml wet volume of the cation-exchanger. Food samples (10 ml each) were then studied for the application of the extraction method. High recovery of SEA was obtained from raw milk (approximately 90%), sterilized milk product (approximately 60%), and skimmed milk powder (approximately 60%), whereas the recovery from cheese (approximately 40%) was lower than from other samples. These recoveries were almost constant at different concentrations of spiked SEA. The minimum measurable level with this extraction method was very low, being 0.25 ng/g in skimmed milk powder for example. With a larger volume (60 ml) of sample, this level was as low as 0.025 ng/g SEA in skimmed milk powder. The present extraction method was very simple and time saving in comparison with the conventional method with chloroform and trichloroacetic acid. The results of this study indicate that this extraction method could be applicable for the measurement of SEA in milk and dairy products.     

Occurrence and Co-occurrence of Alternaria toxins in tomato-based products collected in China

A total of 174 tomato-based products collected in China in 2021 were analyzed for the natural occurrence of four Alternaria toxins: alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and tentoxin (TEN) by ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry. The results showed that TeA was the predominant toxin (average: 37.6 μg/kg and maximum: 770.1 μg/kg). The positive samples showed a decreasing order of average, maximum, and median concentrations of the four Alternaria toxins: TeA > AOH > AME > TEN. There was a significant correlation between AOH and AME in all analyzed samples (r = 0.785, p < 0.05). Almost 95% of samples were with Alternaria toxins, specifically, 16.1% with one kind of toxin, 24.7% with two, 12.1% with three, and 41.4% with four toxins. Higher concentrations of toxins were in dried tomatoes compared to other types of tomato-based products. Moreover, there was no significant difference in Alternaria toxins concentrations of products made in China, Europe, America, Asia, and Australia. This survey revealed that the co-contamination of the four Alternaria toxins in commercially tomato-based products was very common. Ongoing surveillance of tomato-based products from China is necessary to gather more data, so specific regulations for Alternaria toxins in tomato-based products can be set in the future.     

Occurrence,seasonal variation and risk assessment of exposure to aflatoxin M1 in Iranian traditional cheeses

A total of 360 traditional cheeses consisted of Lighvan (n = 62), Koozeh (n = 62), Siahmazgi (n = 58), Khiki (n = 58), Talesh (n = 58) and Lactic (n = 62) collected from different parts of Iran were analyzed for aflatoxin M₁ (AFM₁) using an enzyme linked immunosorbent assay (ELISA). Frequency of AFM₁ and its concentration ranges of all the ELISA positive samples were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FD). AFM₁ was detected in 60.3%, 75.8%, 72.4%, 43.5%, 38.7% and 35.4% of Siahmazgi, Khiki, Talesh, Lighvan, Koozeh and Lactic cheeses, respectively with concentration ranging from 50.5 to 308.7 ng/kg, respectively. HPLC analyses confirmed the ELISA results although the rates of contaminated cheese samples were lower than that of ELISA. There was significant difference in AFM₁ level between various cheese types and samples collected from summer and winter seasons (P < 0.05). By comparing our findings with the EU limit, about 10.5% of cheese samples had exceeding values for the toxin. The results of the present study indicates that there is no health risk in consumption of Iranian traditional cheeses due to the presence of AFM₁.     

The incidence and distribution of ochratoxin A in Daqu,a Chinese traditional fermentation starter

Daqu, a traditional starter culture mainly used to produce Chinese liquor and vinegar, is spontaneously fermented by diverse bacteria, yeasts and filamentous fungi under thermophilic condition. Therefore, mycotoxins may exist in Daqu, resulting in the contamination of end-foods. Ochratoxin A (OTA), a mycotoxin produced by certain species of Aspergillus and Penicillium, is not known whether existing in Daqu. However, specific method to detect OTA as well as OTA occurrence in Daqu has not been reported so far. With this in mind, a new method was developed to detect OTA in Daqu by the combination of ultrasound-assisted solid-liquid extraction (USLE), solid phase extraction (SPE) cleanup and UPLC-MS/MS. The USLE conditions of OTA from Daqu were optimized using Plackett-Burman (PB) design coupled with Box-Behnken (BB) design. Under the optimized conditions, no matrix effects were found, and the external standard method can be used to determine OTA in Daqu. The recoveries for spiked samples were 87–106% with the relative standard deviations (RSD) < 15%. The limits of detection and quantification were respectively 0.33 and 0.41 ppb. This approach was then applied to analyze 133 Daqu samples from different geographical regions in China, including 26 low temperature-, 33 medium temperature- and 74 high temperature-type Daqu. The results showed that OTA was detected in 66 samples with a maximum concentration of 28.87 ppb in low temperature Daqu, and the OTA incidence was on increase in the order of high temperature-, medium temperature- and low temperature-type Daqu. This implied that fermentation temperature is the key factor influencing OTA occurrence in Daqu. Moreover, there may be some fungi possessing the biosynthesis ability of OTA under high temperature environment (more than 45 °C).     

A high incidence of species substitution and mislabelling detected in meat products sold in South Africa

Due to their high market value, meat products are often targets for species substitution and adulteration. DNA-based methods are recognized as the most appropriate means to detect such fraudulent practices, however, these have not been extensively employed for the authentication of meat products available in South Africa. The aim of this study was to utilize a variety of molecular techniques to evaluate the extent of meat product mislabelling prevailing on the local market. A total of 139 processed meat products (minced meats, burger patties, deli meats, sausages and dried meats) were collected from retail outlets and butcheries in South Africa. The enzyme-linked immunosorbent assay (ELISA) was employed for the detection of undeclared plant proteins (soya and gluten) in the samples. A commercial DNA-based LCD array was used to screen the samples for the presence of 14 animal species, the results of which were confirmed by species-specific polymerase chain reaction (PCR) and in some cases also DNA sequencing. The results revealed that 95 of 139 (68%) samples contained species which were not declared on the product labelling, with the incidence being highest in sausages, burger patties and deli meats. Soya and gluten were identified as undeclared plant proteins in a large number of samples (>28%), while pork (37%) and chicken (23%) were the most commonly detected animal species. Unconventional species such as donkey, goat and water buffalo were also discovered in a number of products. Overall, this study confirmed that the mislabelling of processed meats is commonplace in South Africa and not only violates food labelling regulations, but also poses economic, religious, ethical and health impacts.     

The occurrence and effect of unit operations for dairy products processing on the fate of aflatoxin M1: A review

Mold contamination has challenged the safety of feed production and processing because of its undeniable role in the spoilage and the possible consequent toxicity impact on human health and the economy. Aflatoxin M₁ (AFM₁) is a hepatocarcinogenic derivative of aflatoxin B₁ excreted into the milk after ingestion of feed contaminated by certain molds. Because of the important role of dairy products, especially milk in the human diet, there is a huge concern about the presence of AFM₁ in milk and dairy products. In this article, the occurrence of AFM₁ and the fate of AFM₁ during processing of milk and dairy products, such as yoghurt and cheeses, since 1996 until today, was reviewed. The evaluation of mechanisms by which AFM₁ is affected by each processing step is of major importance to provide useful and accurate information to develop risk assessment studies and risk management strategies.     

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.