جستجوی مقالات مرتبط با کلیدواژه « aflatoxin » در نشریات گروه « پزشکی »

This study aims to evaluate the levels of heavy metals and aflatoxins in Kermanshahi oil and grape pekmez (a concentrated grape product) from the central provinces of Iran, as well as to assess how processing affects their fatty acid profiles. Twenty samples of Kermanshahi oil and grape pekmez were randomly collected from production centers in Chaharmahal and Bakhtiari and Isfahan provinces in Iran. The aflatoxin levels in both Kermanshahi oil and grape pekmez were within acceptable limits. Lead (Pb) and cadmium (Cd) concentrations in Kermanshahi oil and grape pekmez ranged from 0.001 to 0.1 ppb and 0.001 to 0.04 ppb, respectively. Traditional butter and Kermanshahi oils were found to contain high levels of SFAs, including palmitic (C16) and myristic (C14) acids, as well as unsaturated fatty acids such as oleic acid (C18:1). The composition of saturated, unsaturated, and trans fatty acids in Kermanshahi oils derived from traditional butter was measured at 77.075%, 16.34%, and 4.82%, respectively. Following the addition of grape pekmez to Kermanshahi oil, a decrease in short-chain fatty acids was observed, while palmitic, stearic, oleic, and linolenic acid levels increased. Additionally, the concentration of TFAs decreased. The incorporation of grape pekmez into Kermanshahi oil positively influenced the fatty acid composition, enhancing its overall quality.

Contamination of locally formulated herbs with aflatoxins and pathogenic organisms poses major health concerns to humans and animals, especially in recent times when herbal mixtures are on the rise. This study aimed to determine the herbs' microbial profile and aflatoxin level. Two different herbal medicines (malaria and typhoid; each prepared with water and alcohol) were obtained at Itoku market, Ogun-state, Nigeria. The samples were isolated using the serial dilution technique and isolates were identified morphologically. Aflatoxin quantification was done on the herbal samples using High-Performance Liquid Chromatography (HPLC). The viable bacteria count ranged from 1.0×105 cfu/g to 20.0×105 cfu/mL with the typhoid herbs prepared with water recording the highest count. The microorganisms obtained in the herbs were confirmed as, Escherichia coli, Staphylococcus aureus, Micrococcus luteus, Salmonella sp, Proteus sp, Aspergillus flavus, Penicillium chrysogenum, Saccharomyces cerevisae and Fusarium sp. Typhoid herbs prepared with water showed high aflatoxin detection limits of 7.60 μg/mL. The result showed that the locally formulated herbs were highly contaminated with microorganisms and that consumption of the locally formulated herbs with aflatoxin could cause aflatoxicosis.

Controlling the occurrence of aflatoxins in foods must be accompanied by managing the fungi responsible for their production. The abundance and diversity of aflatoxin-producing Aspergillus flavus are responsible for the accumulation of these toxins in crops, posing a persistent threat to public health and the economy in tropical developing countries. A study was conducted to investigate the occurrence and level of A. flavus and relate them to aflatoxin levels in maize in Kenya and Tanzania. A total of 786 maize samples were collected during harvesting in selected areas of the two countries for analysis. The fungal abundance in the samples was measured as the amount of fungal DNA relative to maize DNA. This was accomplished by quantifying the fungal DNA using qPCR, targeting the internal transcribed spacer (ITS) gene, while the maize DNA was quantified through the alpha-tubulin gene, the two genes known to be conserved. Aflatoxins were quantified using ultra-high performance liquid chromatography, coupled with ultra-high sensitivity, ultra-fast triple quadrupole tandem-mass spectrophotometer. A. flavus was detected in 88.5% of the 786 tested samples, and the average fungal load for these samples (expressed as the log host/pathogen ratio) was 5.53. Aflatoxin occurrence was positive in 31.9% of the samples, with an average level of 2.3 ± 0.643 ppb. The study established a positive relationship between the occurrence and level of aflatoxin B1 and the presence and biomass of A. flavus, which was statistically proven. These findings emphasize the need to place substantial attention on preharvest control of A. flavus in cereal fields as an effort to control the accumulation of aflatoxin B1 in foods.

 Wheat grains are susceptible to mycotoxins, toxic natural secondary metabolites generated by certain fungi on agricultural produce in the field during growth, harvest, transportation, or storage. Therefore, wheat flour can be contaminated with mycotoxins, which seriously threaten human health.

 A rapid method for screening seven mycotoxins in wheat flour was validated in accordance with Commission Decision 2002/657/EC. With this multi-analytical screening method, 7 prevalent mycotoxins (fumonisin B1, ochratoxin A, aflatoxin G1, deoxynivalenol, T-2 toxin, aflatoxin B1, and zearalenone) can be determined simultaneously. The method’s applicability was demonstrated by screening 7 mycotoxins in 39 wheat flour samples collected from different bakeries in Tehran province, Iran.

 The validation results indicated that for all 7 mycotoxins, the positivity threshold (T) was above the cut-off value (Fm), and no false positive results were obtained for any of the mycotoxins. The screening results of 12 packaged and 27 bulk wheat flour samples indicated that the concentrations of all mentioned mycotoxins were higher than the cut-off (in the relative light unit [RLU]), and all the samples were compliant.

 The present study revealed that the biochip-based technique is valid for identifying and assessing the levels of 7 mycotoxins in grain samples, such as wheat flour, at the measured validation concentrations. The method was simple, fast, and able to screen 7 mycotoxins simultaneously. The test process of the kit is easy to conduct, and the results are straightforward to interpret.

 Pistachio is one of the most crucial exported agricultural products of Iran. Pistachio nut is susceptible to fungal contamination and aflatoxin production.

 This study examined the effect of some functional factors of the optimized rotational UV-C irradiation system on the prevention of aflatoxin production by Aspergillus flavus. The factors included lamp distance from the products (10, 20, and 30 cm), irradiation time (15, 30, and 45 minutes), and the number of UV lamps (3, 5, and 7).

 The best treatment was the lamp distance of 10 cm, 30 minutes of irradiation with three UV-C lamps. The results revealed that aflatoxin levels in the irradiated sample were significantly lower than in the control sample (p<0.05). Also, UV-C irradiation caused significant changes (p<0.05) in some fatty acid profiles, as the amount of linolenic acid in the control sample (0.85±0.07%) was higher than the value in the irradiated sample (0.15±0.07%). However, the values of other fatty acids such as palmitic acid, palmitoleic acid, stearic acid, oleic acid, and linoleic acid were not significantly different between the control and irradiated sample.

 This irradiation system can be installed in different pistachio processing lines to disinfect products, which is very useful in reduction and prevention of the aflatoxins.

Aflatoxins are classified as definitive or possible human carcinogens. Nuts and nutty products are among the most frequent aflatoxin-contaminated foodstuffs. The aim of this study was to assess the levels of aflatoxins (B1, B2, G1, G2, total) in different nuts, including pistachio, almond, cashew, hazelnut obtained from selected supermarket chains in Tehran city.

A total of 20 nut samples were collected from eight randomly selected chain stores, and the levels of aflatoxins in the samples were evaluated using an immunoaffinity column and quantified by high-performance liquid chromatography technique (HPLC).

Among 20 tested nuts, only one sample (roasted hazelnut) was contaminated with the aflatoxins (AG1) at a level of 0.34 µg/kg, while the tested mycotoxins were not detected in the other samples.

Our findings indicated that different parameters such as climatic conditions, implementing strict regulations, improvement in harvest and post-harvest practices alongside rigorous surveillance by the Department of Public Health and Preventive Medicine (AJA University of Medical Sciences) on the quality of food materials may explain the low incidence of aflatoxins in this study.

Consumption of aflatoxins contaminated foods has led to detrimental health effects worldwide, with even more severe cases in African countries including Tanzania. A cross sectional study was conducted to assess awareness and aflatoxins contamination of sesame seeds in Lindi and Mtwara regions. Subsequently, a total of 70 sesame seed samples were randomly purchased from local markets for aflatoxin determination using High Performance Liquid Chromatography (HPLC). Qualitative data were analyzed using SPSS 20 for descriptive and correlation analysis. Results show that 82.4% of the respondents were not aware of aflatoxin contamination of agricultural produce. Awareness was negatively correlated to the levels of education (p=-0.309) and positively correlated with gender whereby men were more aware than women (p=0.03). On the other hand, 37 out of 70 sesame seeds samples were contaminated with total aflatoxins at a range of 0.009 ng/g to 5.557 ng/g. Although none of these samples exceeded the Tanzania maximum limits of 10 ng/g for total aflatoxins, 2 samples exceeded the maximum limit of 4 ng/g set by the European Union. Furthermore, Aflatoxin B1 was detected in 13 samples moreover the concentration was below the Tanzania and EU maximum limit of 5 ng/g and 2 ng/g respectively. Though the contamination was below the national maximum limits and limited to one agro-ecological zone and season, these findings provide useful insights on aflatoxins contamination of sesames seeds from the two main growing regions in Tanzania.

To explore the presence of aflatoxin B1 (AFB1) and fungi in traditional drugs collected in Vietnam.

505 samples of 88 different traditional drugs were obtained from 10 hospitals in Nghe An, a central province of Vietnam. AFB1 contamination was determined by a high-performance liquid chromatography (HPLC) assay. Fungal contaminants were determined according to WHO regulations and the obtained Aspergillus strains were characterized via morphological and molecular identification.

24 samples (4.75% of the total samples) were contaminated with AFB1 and the average concentration was 0.062± 0.030 µg/kg (ranging from 0.009 to 0.097 µg/kg). Fungal isolates were detected from 174 samples (34.45%). The genus Aspergillus was predominant (82.76% of the isolates) but Rhizopus, Alternaria, Corynespora and yeast were also found in a few samples. Among 144 strains of Aspergillus recovered, A. niger (105 strains) was most frequently found, followed by A. tubingensis (31 strains), A. oryzae (4 strains) and A. flavus (4 strains).

This study suggests a low risk of aflatoxin B1 exposure to consumers of traditional drugs in Vietnam.

Aflatoxins are the most contaminant of various agricultural products, especially pistachios. Nowadays, biological control is one of the successful methods in aflatoxin mitigation. Yeasts can be used as a safe and efficient strategy to mitigate aflatoxin in pistachio. The present study screens the high tolerant yeast isolates to environmental stresses.

Soil and pistachio nut samples were collected from commercial pistachio orchards. A dilution series method and GPYA medium were used to isolate yeast species. The ability of yeast isolates to inhibit the growth of Aspergillus flavus was investigated through dual culture, volatile compound, and non-volatile compound assays. The ammonia vapor method was used to evaluate the effectiveness of yeast isolates on aflatoxin production in cultural assays. The tolerance of isolates to non-living stresses was measured in optical density (OD) using spectrophotometry assays at 600 nm in a TSB medium.

The highest inhibitions of mycelial growth in volatile and non-volatile compounds, as well as dual culture, belonged to 78-3-2, YP4-11, 58-15, and 47-8 isolates by 79%, 88%, and 75%, respectively. The highest tolerance to salinity, drought, and heat stresses in the TSB medium was measured for 9, 6-5, and 181yeast isolates by 1.84, 0.75, and 2.18 (OD), respectively.

Selected isolates can be suitable candidates for field testing after further assays and accurate identification.

Due to the fact that fungal species such as Aspergillus flavus and Aspergillus parasiticus produce carcinogenic and mutagenic aflatoxins and have the potential to produce fungal secondary metabolites, fungal contamination should be avoided. This study was conducted using the HPLC method and was aimed at examining the fungal contamination of Isfahan hazelnuts in order to identify the presence of Aflatoxins.

One hundred samples of hazelnuts were randomly collected from supermarkets in Isfahan. The samples were then cultured on Sabouraud dextrose agar (SDA) media and analyzed to determine fungal contaminations. The aflatoxin analysis was carried out using the HPLC method.

It was discovered that nine genera of fungi, namely Aspergillus, Penicillium , Rhizopus, Ulocladium, Alternaria, Drechselera, Trichothecium, Scopulariopsis, and Mucor were identified in 78% of the samples. Samples contaminated with Aspergillus flavus (22 samples) were studied to determine the presence of aflatoxin. The results showed that 16 (72.72%) of the samples were contaminated with AFB1, AFB2 and AFG2 and the mean concentrations were 0.926, 0.563 and 0.155ng/g, respectively.

Some parameters that affect mycotoxin production are temperature, food substrate, strain of the mold and other environmental factors. Due to the toxigenic quality of some of these fungi and their hazard to human health, it is crucial that fungal contamination and aflatoxin identification tests are carried out before certain products are made available to the mass market.

Aflatoxins are carcinogenic secondary metabolites that are mainly produced by several different species of Aspergillus in a variety of foods. The problem of pistachio contamination with A. flavus and aflatoxin is a serious health threat that affects the export and trade of pistachios in the world. This study assessed the susceptibility of 12 commercial pistachio cultivars (Pistacia vera) and 2 wild pistachio species (Pistacia atlantica) to the colonization of A. flavus in vitro.

In the present study, 40 pistachio kernels samples were prepared from each cultivar and inoculated in four replications with spore suspension of A. flavus IPRC30 isolate. After one week, the percentage of fungal colonization on the surface of pistachio kernels and its penetration into pistachio kernel tissue were measured. The experiments were performed with four replications in a completely randomized experimental design. The data were analyzed by SAS software and the means were compared using Duncan's new multiple range test at the significance level of 0.05.

The results indicated that the fungal colonization on most cultivars was equally 60-80%. The lowest rate of colonization was related to wild Pistacia atlantica species with less than 15%. The percentage of colonization of internal tissue of pistachio kernel was variable. The highest percentage of fungal penetration was found in Ohadi cultivar (70%) and no penetration was observed in Sarakhs cultivar.

The results of this study can have some implications for selecting resistant cultivars in seed breeding programs.

There is not sufficient information about the effect of neem extract on the growth, sporulation level, and production of aflatoxins by A. flavus. Therefore, the aim of this study was to further investigate the effect of neem seed extract on the production of aflatoxin AFB1 by A. flavus in culture medium and on pistachios infected with the fungus.

Neem seeds were collected from Bandar Abbas in Hormozgan province from August to October 2016. Consecutive ethyl acetate, water, and hexane methods were used to extract Azadirachtin from neem seeds. After drying, the powdered extract was formulated with Tween 20 and sunflower oil. To evaluate aflatoxin production, Potato dextrose broth (PDB) culture medium containing A. flavus (6 log CFU / ml) and 0.3 ml extract were prepared and placed in an incubator for 9 days.

The results showed that the amount of fungal mycelium increased in the presence of ethyl acetate extract from neem seed, but the amount of aflatoxin B1 of this fungus decreased around 17% compared to the control sample (free of the formulated extract using the formulation of 1% of this extract).

The effectiveness of the formulated extract is attributed to tetranortriterpenoid such as Azadirachtin A. The use of the obtained formulation showed that in addition to the previous properties reported about neem seed extract, which prevents the plants from Insect damage, it can reduce the damage caused by aflatoxin contamination in pistachio. The 1%formulated of this neem extract had no effect on fungal growth, but the most important difference between studies on neem extract and Azadirachtin extracted in this study is the reduction of aflatoxin production by fungi. In other studies, aqueous extract of neem producing aflatoxin was reduced significantly, while Azadirachtin purified in this study had little effect on reducing aflatoxins.

Mycotoxins are known to be one of the most important food contaminants that pose potential health risks to humans. This study aimed to investigate the changes in total aflatoxin (TAF) content during grape vinegar production. Different types of aflatoxins including aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) were spiked into washed grape samples in the level of 5 μg/kg. Then grape samples were converted to vinegar. After different stages of vinegar processing including juicing, alcoholic fermentation, acetic acid fermentation, and pasteurization, sampling was performed and the level of each aflatoxin was measured using high performance liquid chromatography with fluorescence detector (HPLC-FD). Among different processing steps, the pasteurization operation had the least effect on the removal of aflatoxin. After juicing, the amount of AFB1, AFB2, AFG1 and AFG2 decreased by 14%, 11.18%, 13.77%, and 18.56%, respectively. Alcoholic fermentation had the greatest effect on the removal of aflatoxin so that it could reduce the levels of AFB1, AFB2, AFG1 and AFG2 by 41.87%, 45.34%, 45.37%, and 46.52%, respectively. Overall, during processing and conversion of grapes to vinegar, the values of AFB1, AFB2, AFG1 and AFG2 were reduced by 76.20%, 71.06%, 69.26%, and 75.85%, respectively. Processing grapes to vinegar can have a significant effect on the aflatoxin reduction.

Aflatoxins are a group of fungal secondary metabolites generally produced by Aspergillus flavus and A. Parasiticus. The Aflatoxin contamination especially occurs during processing stages in dried fruits, after harvesting. Aflatoxin contamination of Iranian pistachios has caused an export reduction in the last years. Aflatoxins contribute to replacing thymidine with guanine at the codon 249 of P53 (tumor suppressor gene) in the human genome; this mutation in the DNA could cause liver cancer.

Methods to manage the reduction of aflatoxin contamination has great importance; the most effective treatments, including chemical (ozone and citric acid) and physical (UV-C and gamma radiation), are reviewed in this paper

In ozone (O3) treatments in which the sensitivity of aflatoxin B1 and G1 is more than aflatoxin B2 and G2, under UV-C radiation, the degradation of aflatoxin B2 and G2 to is higher than aflatoxin B1 and G1. Acidic and alkaline substances also are utilized to eliminate aflatoxins in some products.

Use of acids along with other detoxification methods such as ozone, UV- C radiation, and …, will be more effective to degrade aflatoxins in pistachio nuts.

Pistachios are good sources of some functional compounds that are essential for human health. In addition to consuming dried pistachios (salted/roasted) or used as ingredients in a variety of confectionery and cookery products, consuming fresh pistachios is also gaining a foothold in the market. This review presents pre- and postharvest operations to prevent microbial contamination and to preserve physicochemical properties of fresh and processed pistachios for extending their shelf life. There is a potential in pistachios to be contaminated with some undesirable microbes, especially aflatoxin-producing fungi, during pre- and postharvest operations. In this regard, strategies to the prevention of aflatoxin production and the decontamination of produced aflatoxin in pistachios have been of interest to researchers. Different practices including sorting, thermal processing, biological control, ozone treatment, gamma irradiation, ultraviolet irradiation, and cold plasma have been proposed for aflatoxin decontamination. Sorting out damaged pistachios is one of the most important postharvest strategies to reduce aflatoxin levels (up to 98%) that can be done manually or electronically. The majority of pistachios (~85%) are consumed as roasted form that combining roasting with lemon juice improves the elimination of aflatoxin (up to 93%). Drying and packaging are the most important methods to maintain quality and improve the shelf life of pistachios. Laminated and metallized films with vacuum or modified atmosphere are the proper packaging for pistachios.

It goes without saying that the most important problem of the country’ pistachio exports is the contamination of pistachios with Aspergillus flavus and aflatoxin. The liver and kidney are the tissues targeted by aflatoxin that leads to carcinogenic effects. The contamination of pistachios with this toxin can threaten the main source of foreign exchange earnings, and prevent the producers from competing in the global market. In Iran and other pistachio-producing countries, contamination by Aspergillus species occurs during the growth phase as well as during or after the processing phases. As much as 2.5% of the world’s agricultural products are contaminated with mycotoxins. At present, the maximum allowed levels for aflatoxin B1 and total aflatoxin are 1-20 ng g-1 and 0-35 ng g-1 , respectively. The Iranian Institute of Standard and Industrial Research has set the highest acceptable levels of aflatoxin B1 and total aflatoxin in pistachios at 5 and 15 ng g-1 , respectively. Mechanical separation techniques, thermal inactivation, and irradiation are among the methods of decontamination and fungus control after pistachio harvesting. Ionizing radiation decontamination is a highly efficient, safe and environmental-friendly process that can be used for decontamination.

Considerable attempts have been made for the complete elimination of aflatoxins (AFs), as potent health hazards to both humans and animals, or reduction of their content in foodstuffs with increasing the knowledge and awareness of these toxins. In spite of the fact that the most effective intervention is considered prevention, heating has been also applied for the inactivation of AFs in contaminated foodstuffs. In the present study, the adoption of response surface methodology was evaluated for the assessment of the effect of heating on the reduction of AFs. Despite various degrees of AF decrease in the samples by treatment, a significant reduction was observed in the heated samples at a temperature of 90°C for 240 min. According to the results of the current study, a 23.70 % reduction was reported in the amount of aflatoxin B1 (AFB1). Various treatment conditions demonstrated a significant difference in AFB1 decomposition (p < 0.05). In addition, AFB1 degrading was reported to be depending on both time and temperature. After the statistical analysis of the obtained data, the third-order equation for the reduction of AFB1 is presented as follows (A: Time; B:Heating): AFB1 = 12.28 + 6.24A + 4.95B + 1.12AB - 3.11A2 + 1.55B2

Mycotoxin contamination of rice has been introduced as a big challenge for public health in developing countries in numerous studies. Rice consumption is also considered the main source of secondary metabolites in Iran. Given the diversity of climatic conditions in this region as well as unsuitable storage conditions, including high temperature and humidity, rice can be extremely contaminated via various fungi. The current study is a review of the occurrence of mycotoxins in rice in Iran. In this regard, some investigations had revealed that rice could be contaminated by mycotoxins such as aflatoxins (AFTs) (B1, B2, G1, and G2), deoxynivalenol (DON), fumonisin (FM) (B1 and B2), ochratoxin A (OTA), T-2 toxin, and zearalenone (ZEN). Moreover, the amount of mycotoxins in rice was reported in varying ranges in different provinces and regions and normally less than Iranian maximum tolerated dose (MTD). Given the importance of rice in the Iranian diet, it was finally recommended to screen consumed rice to find about fungal contaminations and mycotoxins.

One of the best and most important foods in the human diet is milk. So, the presence of nutritional compounds and the absence of harmful components is very remarkable. Mycotoxins are an important toxin in food and feed, they are produced by molds. The presence of mycotoxins in food is an emerging issue in the world. Among different types of mycotoxins, aflatoxins are so considerable. Different methods are used to reduce them, but the usage of microbial methods such as Lactic acid bacteria, probiotics, and yeasts is a beneficial strategy. The most studied microorganisms are lactic acid bacteria due to their natural presence in milk and also are known as a GRAS (generally recognized as safe) substances. It is noteworthy to mention that the bacterial cell walls are so important in binding ability. Also, parameters such as pH, temperature of incubation, type of starter, which is used in the product, concentration of microorganisms in milk, and the level of toxin can affect the efficiency of microorganisms. Hence, this review was aimed to investigate the results of studies about the effectiveness of microbial methods on the adsorption and reduction of aflatoxin in milk. Also compares the effect of microorganisms, influencing factors, and mechanisms of these methods.