Analysis Of Aflatoxins Research Articles

The Effect of Rapid Detection Methods on the Minimization and Prevention of the Risk of Contamination with Aflatoxins in Peanut Products

The methods of analysis and control of aflatoxins in peanuts pursue three key objectives: prevent the entry of contaminated peanuts into ready-to-eat products where they are used as an ingredient; prevent and minimize the risk of cross-contamination from contaminated peanuts to fit-for-use raw materials; perform an appropriate incoming inspection through rapid analysis methods for real-time detection of the absence of or the degree of contamination with aflatoxins. The aim of this study was to analyze the effect of rapid detection methods on the minimization and prevention of the risk of contamination with aflatoxins during the incoming inspection in industries using peanut products in the composition of the finished products. The methods of detection of aflatoxins in peanut products are: Mass Spectrometry combined with High - Performance Liquid Chromatography (HPLC), the internal methodology VAL 92:2010 developed by an accredited laboratory and immunochromatographic rapid tests.

A facile extraction method followed by UPLC-MS/MS for the analysis of aflatoxins and ochratoxin A in raw coffee beans

ABSTRACT A UPLC-MS/MS method was developed and validated for the determination of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and ochratoxin A (OTA) in raw coffee samples. Mycotoxins were extracted using a modified QuEChERS method with little sample preparation excluding clean-up and enrichment procedures. Linearity was demonstrated for the five mycotoxins in the range 0.125–20 µg/kg. This method shows negligible matrix effect for individual concentrations, thus allowing the use of an external standard procedure. Limits of quantification (LOQ) ranged from 0.45 to 1 μg/kg. Recoveries between 63% and 89% were achieved. The intra- and inter-day precisions were lower than 15%. The applicability of the method was demonstrated, taking into account fitness for purpose, with simplicity, reliability, low costs and environmental friendliness. The results show that 3 out of 4 samples were contaminated with OTA.

Single-Laboratory Validation of an Immunoaffinity Column Cleanup LC Method for the Analysis of Aflatoxins and Ochratoxin A in Cannabis Plant Material, Resins, Vapes, Isolates, and Edible Products.

Potential fungal infection of cannabis plants during drying has raised concerns of resulting mycotoxin contamination in leaves and flowers and subsequent contamination of derived products including cannabis-containing edible products. Validated routine methods are essential to monitor cannabis and cannabis products to ensure consumer safety consistent with long-standing controls for mycotoxins such as aflatoxins and ochratoxin A in foodstuffs. To provide single-laboratory validation data to demonstrate the suitability of a method for determining aflatoxins and ochratoxin A in cannabis plant material, resins, vapes, isolates, and edible products such as chocolate. Extraction of solid and liquid matrixes with acetonitrile:water, centrifugation, and then dilution of an aliquot of supernatant with phosphate-buffered saline solution containing Tween 20 surfactant. Cleanup by passing through an immunoaffinity column containing antibodies to both aflatoxins and ochratoxin A and analyzing in a single LC chromatographic run with fluorescence detection. For within-day analysis, recoveries were in the range 77 to 99% with RSDs from 0.7 to 9.6% for aflatoxin B1. Similarly, ochratoxin A recoveries were from 64 to 94% and RSDs from 0.9 to 9.5% for mycotoxin mixtures spiked into cannabis flowers, resins, vapes, isolates, chocolate, gummies, edible oils, and beverages. A method for the determination of aflatoxins and ochratoxin A was successfully developed and single-laboratory validation data has been presented for cannabis plant material, resins, vapes, isolates, and edible products. A multi-mycotoxin immunoaffinity column cleanup with LC-fluorescence has been validated and shown to be suitable for routine control of aflatoxins and ochratoxin A in cannabis flowers and a diverse range of edible cannabis products.

Research on Mould and Aflatoxin Contamination Levels of Feeds Used in Trout Farms of Adana (Turkey)

This research was conducted to analyze the mould counts and aflatoxin contamination levels of different types and sizes of feed used in trout farms of Adana. Totaly 33 different feeds supplied from 15 trout farms of Adana (Turkey) were analysed for moulds and aflatoxins (AFB1, AFB2, AFG1 and AFG2) between July-December 2010. To identify mould counts; the samples were incubated in the aerobic conditions at 25 ± 1 °C for five days by using Dichloran Rose Bengal Chloramphenicol Agar (DRBC). Aflatoxins were determined by using liquid-solid extraction and recoveries were obtained 70.00% to 112.20%. The precision of measured values of mould and aflatoxin analysis methods was calculated with the results of repeatability and reproducibility. The bias, expressing the accuracy value, varies between 4.312 and 12.909. Although moulds were found in 12 of 33 analysed samples (36.30%): aflatoxins were determined 8 out of 33 analysed samples (24.25%). Positive sample’s range were 3.08-4.86 log10 kob g-1 moulds and 0.21–0.90 g AFB1 kg-1 (ppb) of trout feeds. As a result, this research showed that none of the trout feeds used in trout farms of Adana has aflatoxins above Turkey legal limits.

Determination of the Level of Aflatoxins Contamination in Maize (Zea mays L.) Produced in Five Regions of Côte d’Ivoire

Aims: The aim of this work is to assess the level of aflatoxins contamination in maize produced in five regions (Poro, Hambol, Gontougo, Gbêkê, Indénié-Djuablin) of Côte d'Ivoire.
 Place and duration of study: In this study 375 samples of maize (grains, cobs, spathes) were taken from February 2016 to January 2017 and the aflatoxin analyses were carried out at the Biotechnology Laboratory, Agriculture and Development of Biological Resources of the Félix Houphouët-Boigny University.
 Methodology: The aflatoxins (B1, B2, G1 and G2) were extracted and assayed by High Performance Liquid Chromatography (HPLC) according to the AOAC method.
 Results: The results indicate the presence of aflatoxins B1, B2, G1 and G2 in all forms of maize (grains, cobs, spathes) and in the five regions chosen for the study. The mean concentrations of aflatoxins B1 (AFB1) and the total aflatoxins (AFT) varied from 0.79 ± 0.04 µg/kg to 130.31 ± 22.56 µg/kg and from 2.63 ± 2,35 µg/kg to 169.13 ± 40.39 µg/kg respectively. samples from Indénié-Djuablin, Hambol and Gountougo regions showed the highest proportions of non-compliance with the european Union limit of 5 μg/kg and 10 μg/kg. Regarding AFB1, these proportions vary from 0% to 46% in the regions of Gbêkê, Poro and Hambol, while they are between 54% and 96% in the regions of Indénié-Djuablin and Gontougo. For total aflatoxins, the proportions of non-compliant samples were between 0% and 40% (Gbêkê and Poro), 12% and 56% (Hambol), 56% and 96% (Indénié-Djuablin and Gontougo).
 Conclusion: These results demonstrate a need for monitoring of maize production by stakeholders in the sector who should adopt good agricultural practices.

Aflatoxin, microbial contamination, sensory attributes, and morphological analysis of pistachio nut coated with methylcellulose.

Pistachio is a nut with high consumption that could be affected by aflatoxin contamination, which affects the consumption market; therefore, broad studies seem to be necessary for this area. In the current study, pistachio nuts (Abbasali variety) were coated with different concentrations (0.1%, 0.5%, 1%, and 2%) of methylcellulose (MC) by immersion method and then stored in the incubator (25°C) for four months. The inhibitory effect of hydrocolloid coating on microbial (mold, yeast, and total count) and aflatoxin (B1, B2, G1, G2, and total aflatoxin) contamination, as well as sensory attributes (flavor, color, crispiness, aroma, and total acceptability), was investigated during storage periods. Results showed that the storage period had a significant effect on yeast, mold, and total count. HPLC analysis results showed that coating with MC had a significant inhibitory effect on aflatoxin contamination, and the highest amount of aflatoxin contamination was related to the control sample (3.5%). All samples except sample coated with MC 0.5% had appropriate total acceptability. Regarding the inhibitory effect of MC edible coating on aflatoxin contamination, its application on pistachio nut could be a promising approach to control the fungus infection and reduce aflatoxin production in coated pistachio.

Aspergillus species and aflatoxin contamination in pepper (Capsicum annuum L.) in West Gojjam, Ethiopia

Pepper (Capsicum annuum L.) is an important spice and source of income for smallholder producers in Ethiopia. Since the larger proportion is for the market, it takes a significant share of the national income from export commodity. However, often the product was rejected by some of the European Union markets due to the maximum aflatoxin level accumulations beyond their acceptable limits. So, the present study was carried out to highlight the importance of Aspergillus species invasion in pepper, and levels of aflatoxin contamination at maturity in the field (pod form), farmers' storage and local market (powder form)in West Gojjam, Ethiopia. A total of 135 pepper samples were collected from three districts of West Gojjam(Burie, Jabitehnan, and Fnoteselam), Ethiopia for fungal and aflatoxin analysis.The producers used a pre-validated structured questionnaire to obtain information on pepper production practices. Aspergillus species isolates were recovered using potato dextrose agar (PDA) medium and counting was through dilution method (cfu g-1). The pepper pods were ground to a fine powder for aflatoxin analysis using Enzyme-Linked Immunosorbent Assay(ELISA). The prevalence of infected samples revealed that, pre-harvest samples(51%) were less infected by Aspergillus species, compared to local markets (65 %) and storage (79 %).Aspergillus flavus species were recovered in pre-harvest samples, whilst A.niger were found in local market samples. Aflatoxin contamination at pre-harvest, storage, and local market were 10, 47, and 42 % with levels which ranged from non-detected to 10.6, 0.3 -17.1 and 3.1 -19.2 ppb, respectively.The mean aflatoxin concentration detected from storage samples (10.6 ppb)and local market (12.6 ppb)were found to be above the tolerable limits set byEU (5 ppb) in pepper products.From the findings in this study, proper drying, physical separation of molded pods and use of clean storage structures should be implemented along the production chain in order to reduce aflatoxin contamination in pepper in Ethiopia.

Physicochemical, microbial, and aflatoxin analyses of selected high-quality cassava flour (HQCF) from the major markets of Zambia

Various quality grades of high-quality cassava flour (HQCF) are found in markets due to the rapid increase in its utilization for product development. Therefore, this study assessed the chemical, f...

Antifungal activities of lactic acid bacteria and yeast isolated from various types of Tempe

Mycotoxin-producing fungi are harmful contaminants in food and feed products. Lactic acid bacteria (LAB) and yeast groups are known to produce antifungals. Indonesia is known as a Tempe-producing country, an important functional fermented food. Soybean Tempe has been commonly known and well-studied, while other types of Tempe such as Tempe Gembus, Tempe Koro, Tempe Lamtoro and Oncom have not been well studied. This study aimed to determine LAB and yeast population in various types of Tempe and to select antifungal activity against mycotoxin-producing fungi. Research methods included total aflatoxin analysis in Tempe products, enumeration and isolation of LAB and yeast, and antifungal assay. The results showed that the total aflatoxins in all Tempe products were 1.99 - 3.84 ppb and it was qualified as food for consumption. The total LABs were 7.16 - 8.25 log10 cfu/g while the total yeast was 4.48 - 7.38 log10 cfu/gram. The highest antifungal activities in mycotoxin-producing fungi such as Aspergillus parasiticus and Penicillium citrinum, shown by LAB G1 isolates which were identified as Lactobacillus sp. and yeast G6K1 and G6K2 which were identified as Saccharomyces spp. All the selected isolates were isolated from Tempe Gembus. The clear zone diameter of antifungals was 15-20 mm and 3.5 mm respectively for LAB G1 and G6K1-G6K2. These selected LAB and yeast had the potential to be used as natural bio-preservatives in functional food products to prevent the growth of mycotoxin-producing fungi.

Inhibition analysis of aflatoxin by in silico targeting the thioesterase domain of polyketide synthase enzyme in Aspergillus ssp

The spread of fungal growth causes enormous economic, agricultural, and health problems for humans, such as Aspergillus sp., which produce aflatoxins. Thus, the inhibition of aflatoxin production became a precious target. In this research, the thioesterase (TE) domain from Polyketide synthase enzyme was selected to employ the in silico docking, using AutoDock Vina, against 623 natural compounds from the South African natural compound database (SANCDB), to identify potential inhibitors that can selectively inhibit thioesterase domain. The top ten inhibitors components were pinocembrin, typhaphthalide, p-coumaroylputrescine, dilemmaone A, 9-angelylplatynecine, 2,4,6-octatrienal, 4,8-dichloro-3,7-dimethyl-, (2e,4z,6e)-, lilacinobiose, 1,3,7-octatriene, 5,6-dichloro-2-(dichloromethyl)-6-methyl-, [r*,s*-(e)]-(-)- (9ci), lilacinobiose, 1,3,7-octatriene, 5,6-dichloro-2-(dichloromethyl)-6-methyl-, [r*,s*-(e)]-(-)- (9ci), 1,3,7-octatriene, 1,5,6-trichloro-2-(dichloromethyl)-6-methyl-, [r*,s*-(z,e)] and 9-angelylhastanecine and that depending on the lowest binding energy, the best chemical interactions and the best drug-likeness. The results of those components gave successful inhibition with the thioesterase domain. So, they can be used for inhibition and controlling aflatoxin contamination of agriculture crop yields, specially, pinocembrin which gave promising results. Communicated by Ramaswamy H. Sarma

Quantitative analysis and dietary risk assessment of aflatoxins in Chinese post-fermented dark tea

Recently, mycotoxins safety in Chinese post-fermented teas has attracted much attention because it is still controversial whether environmental fungi in the teas are able to produce aflatoxins. In this study, a rapid and selective analytical method based on immunoaffinity column (IAC) cleaning coupled with liquid chromatography-mass spectrometry (LC-MS) was developed to quantify four aflatoxins (B1, B2, G1 and G2) in post-fermented teas. Recoveries ranged from 80.8 to 92.2% with relative standard deviation less than 3%. The limits of detection and quantification were 0.109–0.348 μg kg−1 and 0.364–1.159 μg kg−1, respectively. Two out of 158 samples were positive for aflatoxins examination (occurrence rate 1.27%). The deterministic assessment for the maximal aflatoxins exposure under upper bound was 9.19 × 10−6 μg kg−1 day−1 from heavy exposure consumers (≥50 year age group), but the exposure was lower than the JECFA acceptable value of 1.0 ng kg−1 day−1 on liver risk. Probabilistic assessment showed that the upper bound 95th percentile carcinogenic risk value for the 318 consumers (Yunnan China and Ulan Bator Mongolia) was 1.75 × 10−7, and for heavy exposure consumers was 2.4 × 10−7, and the values equally below the acceptable carcinogenic risk level.

Qualitative and Quantitative Analysis of Aflatoxins in Dry Fruits and Nuts from Central India

In central part of India, dry fruits and nuts are mostly sold in loose conditions and hence may get fungal infections, and may have aflatoxins to the levels beyond the safe limits. The present study is an attempt to showcase the present scenario of aflatoxins in dry fruits and nuts from Central India, both qualitatively and quantatively. Out of 84 samples, 15 were found to have the presence of at least one aflatoxin. HPLC detection showed that AFB1 is the major aflatoxin. The total aflatoxins were found in the range of 25.4 - 393.51 μg kg-1, which is beyond the safe limit set by regulatory authorities. Further, dry figs were the most contaminated among tested dry fruits, and 5 out 12 samples (41.6%) were contaminated, followed by cashew nuts (33.3%). Samples sold in loose packing were found more contaminated with aflatoxins. The study advocates that selling of such dry fruits in loose form should be banned by the regulatory authorities.

Advances in Antibody Preparation Techniques for Immunoassays of Total Aflatoxin in Food.

Aflatoxin (AF) contamination is a major concern in the food and feed industry because of its prevalence and toxicity. Improved aflatoxin detection methods are still needed. Immunoassays are an important method for total aflatoxin (TAF) analysis in food due to its technical advantages such as high specificity, sensitivity, and simplicity, but require high-quality antibodies. Here, we first review the three ways to prepare high-quality antibodies for TAF immunoassay, second, compare the advantages and disadvantages of antigen synthesis methods for B-group and G-group aflatoxins, and third, describe the status of novel genetic engineering antibodies. This review can provide new methods and ideas for the development of TAF immunoassays.

Development of Anti-Idiotypic Nanobody-Phage Based Immuno-Loop-Mediated Isothermal Amplification Assay for Aflatoxins in Peanuts.

Aflatoxin contamination in agricultural products has posed serious health hazards and brought huge economic loss in the food and feed industries. Monitoring aflatoxins in various foods and feeds has become a crucial means to protect public health. This study aimed to report an immuno-loop-mediated isothermal amplification (iLAMP) assay by using an anti-idiotypic nanobody-phage for on-site and rapid detection of aflatoxin in real samples. The iLAMP method was developed on the basis of a competitive immunoassay and LAMP reaction performed in a simple water bath. This method can provide visualized test results: violet color represents positive samples while sky blue represents negative. The visual detection limits of iLAMP for aflatoxin B1, B2, G1, and G2 in peanut samples were 1.6, 1.6, 3.2, and 16 μg/kg, respectively. The developed assay was verified with high performance liquid chromatography (HPLC) for the analysis of aflatoxins in peanuts, which demonstrated that the iLAMP method can be applied to the detection of aflatoxin in real samples. The novel iLAMP assay eliminates the need for aflatoxin conjugates, the antibody labeling process, and special equipment, and offers an alternative to existing methods with advantages of time-saving, cost-effectiveness, and ease-of-use.

A Review: Sample Preparation and Chromatographic Technologies for Detection of Aflatoxins in Foods.

As a class of mycotoxins with regulatory and public health significance, aflatoxins (e.g., aflatoxin B1, B2, G1 and G2) have attracted unparalleled attention from government, academia and industry due to their chronic and acute toxicity. Aflatoxins are secondary metabolites of various Aspergillus species, which are ubiquitous in the environment and can grow on a variety of crops whereby accumulation is impacted by climate influences. Consumption of foods and feeds contaminated by aflatoxins are hazardous to human and animal health, hence the detection and quantification of aflatoxins in foods and feeds is a priority from the viewpoint of food safety. Since the first purification and identification of aflatoxins from feeds in the 1960s, there have been continuous efforts to develop sensitive and rapid methods for the determination of aflatoxins. This review aims to provide a comprehensive overview on advances in aflatoxins analysis and highlights the importance of sample pretreatments, homogenization and various cleanup strategies used in the determination of aflatoxins. The use of liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE) and immunoaffinity column clean-up (IAC) and dilute and shoot for enhancing extraction efficiency and clean-up are discussed. Furthermore, the analytical techniques such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), capillary electrophoresis (CE) and thin-layer chromatography (TLC) are compared in terms of identification, quantitation and throughput. Lastly, with the emergence of new techniques, the review culminates with prospects of promising technologies for aflatoxin analysis in the foreseeable future.

Recent Advances in Aflatoxins Detection Based on Nanomaterials

Aflatoxins are the secondary metabolites of Aspergillus flavus and Aspergillus parasiticus and are highly toxic and carcinogenic, teratogenic and mutagenic. Ingestion of crops and food contaminated by aflatoxins causes extremely serious harm to human and animal health. Therefore, there is an urgent need for a selective, sensitive and simple method for the determination of aflatoxins. Due to their high performance and multipurpose characteristics, nanomaterials have been developed and applied to the monitoring of various targets, overcoming the limitations of traditional methods, which include process complexity, time-consuming and laborious methodologies and the need for expensive instruments. At the same time, nanomaterials provide general promise for the detection of aflatoxins with high sensitivity, selectivity and simplicity. This review provides an overview of recent developments in nanomaterials employed for the detection of aflatoxins. The basic aspects of aflatoxin toxicity and the significance of aflatoxin detection are also reviewed. In addition, the development of different biosensors and nanomaterials for aflatoxin detection is introduced. The current capabilities and limitations and future challenges in aflatoxin detection and analysis are also addressed.

Detection of Aflatoxins from Malt Barley Under Storage Conditions in Central Ethiopia

Aflatoxins are non avoidable highly poisonous and carcinogenic auxiliary metabolite produced by some molds belonging to Aspergillus genera on range of agricultural products including malt barley. This study was conducted with the aim to examine total aflatoxin (AFT) concentration in malt barley samples. A total of eighty seven malt barley samples collected from farmers' stores and seed enterprises' of Amhara and Oromia regions were employed for aflatoxin analysis through an ELISA test. Of these, 30 (34.48%) were positive whereas the remaining 57 (54.03%) were negative. The total aflatoxin levels in the positive samples layover in a range between 0.0005μgkg -1 and 0.04μgkg -1 .The existing results undoubtedly revealed insignificant contamination of malt barley samples in Ethiopia, suggesting that concentrations were low enough and ensure compliance with the Food and Agricultural Organization of the United Nations (FAO) 20 ugkg -1 , World Health Organization (WHO) 15 μgkg -1 and European Union (EU) 4-15ugkg -1 admitted levels depending on the raw material use of cereals. Fortunately, the result of this study may not lead to infer the urgent need to apply control measures against aflatoxigenic fungi and associated aflatoxins that could result adverse effects. The major factors for less contamination of malt barley by aflatoxin were expected to be pre- and post-harvest environmental factors, mechanized harvesting and proper management practices like drying before storage. Although the present status of aflatoxins is remarkably at lower concentrations, regular and accurate cereal quality testing is critical to reduce the risk of severe health problems as well as international trade repercussions. Keywords: Adverse effect, Auxiliary metabolite, Contamination, ELISA, Molds. DOI: 10.7176/JBAH/10-15-01 Publication date: August 31 st 2020

Residual Analysis of Aflatoxins in Spice by HPLC Coupled with Solid-Phase Dispersive Extraction and Solid-Phase Fluorescence Derivatization Method.

Aflatoxins (AFs) are carcinogenic mycotoxins. A simple, quick, and accurate method for the micro-analysis of AFs in foodstuffs, especially spices, is needed. A sophisticated pretreatment method that combines solid-phase dispersive extraction (SPDE) and solid-phase fluorescence derivatization using immunoaffinity (IA) gel as the solid phase was developed to analyze AFs in spices simply, quickly, and sensitively by liquid chromatography with fluorescence detection. White and black pepper samples were extracted with a mixed solution of methanol/water (4:1) and then diluted with 7% aqueous solution of Triton-X. The solution was subjected to cleanup by SPDE using IA gel. Trifluoroacetic acid was added to the IA gel for on-site solid-phase fluorescence derivatization. Chromatograms containing well-separated peaks and few interference peaks from contaminants were obtained. The method detection limit of AFs in white and black pepper was 0.15-0.29 ng/g. Repeatability and intermediate precision were <10% and <15%, respectively, and accuracy was 61.7-87.8%. In addition, inter-laboratory precision was <29% and mean recovery was 61.5-76.7%. A favorable z-score of |Z| ≦ 1 was obtained in seven laboratories, although one laboratory gave 2 < |Z| < 3. The validity, reliability, practicality, and robustness of the developed method were verified. By using SPDE and solid-phase fluorescence derivatization in combination for AF analysis, fluorescence derivatization during cleanup was realized, leading to simplification of the pretreatment operation.

Aflatoxin in raw peanut kernels marketed in Malaysia

The occurrence of aflatoxin in eighty-four samples of raw peanut kernels which are randomly collected from Malaysian supermarkets was examined. Analysis for aflatoxin was performed by solvent extraction and immunoaffinity clean-up followed by the determination using high performance liquid chromatography equipped with post-column photochemical reactor for enhanced detection and fluorescence detector. A detection limit of 0.01-0.09 ng/mL and a quantification limit of 0.04-0.30 ng/mL were obtained. The aflatoxin concentrations ranged from not detected to 97.28 ng/g in all samples investigated. About 78.57% of the samples were contaminated with aflatoxin, of which 10.71% exceeded the maximum tolerable limit of 15 ng/g set by the Codex. Average recoveries of the aflatoxin analysis were acceptable which were in the range of 74.85 ± 8.83% for AFG2 at the concentration of 0.15 ng/mL and 103.91 ± 6.45% for AFB2 at the concentration of 0.15 ng/mL. The average daily intake estimated for total aflatoxins was 10.69 ng/kg body weight. There was a significant difference (P < 0.05) in aflatoxin content between brands and locations.

Microbiological quality, fungal diversity and aflatoxins contamination in carob flour (Prosopis flexuosa)

Carob flour is obtained from pods of some species of Prosopis, leguminous trees that abound in many desert habitats worldwide. Currently, this product is available in healthy food stores in several countries, including Argentina, as a nontraditional meal of growing interest with multiple applications for the preparation of puddings, biscuits and snacks, among others. The objective of the present study was to evaluate the microbial quality of carob flour on basis of the presence of deteriorative and pathogenic microorganisms. Fungal diversity of the mycobiota was also studied with a special interest in toxigenic fungi. Eighteen samples of carob flour (Prosopis flexuosa) were analysed. Standard plate count of aerobic mesophilic bacteria showed levels of contamination ranging from <102 (estimative) to 6.8 × 105 CFU/g; total coliforms from <102 (estimative) to 4.7 × 105 CFU/g; moulds and yeasts from 2.1 × 102 to 8.1 × 104. In all samples, the absence of Salmonella sp. was verified in 25 g and counts of Bacillus cereus less than 102 were observed. These results indicate that from the safety point of view the carob flour studied does not have a significant microbial load. Regarding to fungal contamination, Aspergillus and Penicillium were the genera more diverse in species and were present in all the samples. Some of the species identified were potential mycotoxins producers. Among the most frequently detected species in the studied mycobiota were the Aspergillus of the Flavi section, well recognized as potential aflatoxin producers. The A. flavus species was one of the most widely distributed, since it was detected in almost all samples. A. parasiticus and A. arachidicola were found more sporadically. Aflatoxins analysis demonstrated that a high proportion of the samples were contaminated with aflatoxins in concentrations relatively low, ranging from 1.26 to 20.33 μg/kg of total aflatoxins. Type G aflatoxins are much less frequent contaminants than type B aflatoxins, which is consistent with the fact that A. parasiticus and A. arachidicola (producers of type B and G aflatoxins) were detected sporadically, while A. flavus, which produces aflatoxins B1 and B2, was present in a high number of samples. Results of the present work indicate that carob flour is susceptible to Aspergillus section Flavi and aflatoxin contamination and should be subjected to aflatoxin monitoring prior to marketing as required for other traditional crops.