Ochratoxin A in red paprika: relationship with the origin of the raw material

Occurrence of Chemical Contaminants in Peruvian Produce: A Food-Safety Perspective

The presence of chemical contaminants in agricultural products is a continued food-safety challenge in Peru. This country has robust agriculture potential, but its output of fruits and vegetables is severely impacted by massive mining activities, as well as poor farming practices, including the use of polluted irrigation water, misuse of pesticides, and inadequate postharvest conditions. This review examines the current scientific knowledge on the levels of pesticide residues, heavy metals, and mycotoxins on crops produced in Peru. The available data shows that several crop varieties are contaminated with these classes of chemical contaminants, and at levels that exceed the national and international permissible limits. The abundance of chemical contaminants in produce indicates a relevant food-safety issue, which increases the risks of chronic human diseases, like cancer—a leading cause of death in Peru. Finally, this review presents recommendations to address these contamination problems in produce grown in the Andean country.

Mycobiota in Chilean chilli Capsicum annuum L. used for production of Merkén

This work aims to provide the first study on the mycobiota present in Chilean pepper Capsicum annuum L. cv. "Cacho de Cabra" throughout the early production stages. Two hundred and forty berry fruits were sampled: 1) at the ripe fruits harvest day; 2) during drying; and 3) smoking processes. A total of 192 strains, encompassing 11 genera and 44 species, were identified through analysis of β-tubulin (benA) gene and internal transcribed spacer of ribosomal DNA (ITS) region. All collection points showed samples with high fungal contamination, but the mycobiota composition varied as a result of different environmental conditions. Alternaria spp. and Fusarium spp. were predominantly isolated from fresh fruits of C. annuum. Penicillium spp. was the most frequent genus in all analysed points. Penicillium brevicompactum and P. crustosum were the most abundant species. Among Aspergillus, A. niger and A. flavus were dominant after the drying phase. In our study, none of the analysed strains of Penicillium (113) and Aspergillus (35) produced Ochratoxin A at detectable levels. The broad characterization of the fungal community of C. annuum carried out in this study, could be a guideline for future mycotoxin analyses performed directly on the pod. Understanding the role and dynamics of mycobiota and its relationship with the toxins present in this substrate, will be useful to establish and improve control measures considering the specificities of each point in the C. annuum production chain.

Inhibition of growth and ochratoxin A production in Aspergillus species by fungi isolated from coffee beans

Ochratoxin A (OTA) is a mycotoxin found in several agricultural commodities. Produced by Aspergillus spp., it is nephrotoxic and hepatotoxic and can be carcinogenic. Preventive measures are preventing fungal growth and OTA production. In this study, fungal strains (Rhizopus oryzae, Lichtheimia ramosa, Aspergillus westerdijkiae, Aspergillus niger, Aspergillus tamarii, Aspergillus sp., and Aspergillus fumigatus) isolated from coffee beans were identified for their abilities to inhibit the growth of Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus carbonarius, and Aspergillus niger, and OTA production. All fungi strains tested were able to inhibit growth of the four Aspergillus species and OTA production, where A. niger showed the best results in both tests. L. ramosa showed the lowest growth-reducing potential, while the other fungal strains had a growth-reducing potential higher than 70% against all Aspergillus species tested. Regarding OTA production, L. ramosa and Aspergillus sp. completely inhibited the mycotoxin production by A. ochraceus and non-toxigenic strain A. niger completely inhibited OTA production by A. niger. Our findings indicate that the strains tested can be used as an alternative means to control growth of OTA-producing fungi and production of the mycotoxin in coffee beans.

Overview of Fungi and Mycotoxin Contamination in Capsicum Pepper and in Its Derivatives

Capsicum products are widely commercialised and consumed worldwide. These substrates present unusual nutritional characteristics for microbial growth. Despite this, the presence of spoilage fungi and the co-occurrence of mycotoxins in the pepper production chain have been commonly detected. The main aim of this work was to review the critical control points, with a focus on mycotoxin contamination, during the production, storage and distribution of Capsicum products from a safety perspective; outlining the important role of ecophysiological factors in stimulating or inhibiting mycotoxin biosynthesis in these food commodities. Moreover, the human health risks caused by the ingestion of peppers contaminated with mycotoxins were also reviewed. Overall, Capsicum and its derivative-products are highly susceptible to contamination by mycotoxins. Pepper crop production and further transportation, processing and storage are crucial for production of safe food.

Occurrence of Toxigenic Fungi and Mycotoxins during Smoked Paprika Production

'La Vera' smoked paprika is a traditional Spanish product regulated under a protected designation of origin. Mycotoxins are possible contaminants in paprika, yet there is little information about mycotoxin production during the processing of smoked paprika. In this study, samples of dried peppers collected from six traditional dryers from four producers were evaluated for physicochemical parameters, mycotoxins, and mycotoxin-producing fungi. The moisture content and water activity of the peppers ranged from 11.0 to 16.3% and 0.513 to 0.611, respectively, with significant differences among the dryers (P ≤ 0.05). Culture methods revealed fungal counts of 2.6 to 5.7 log CFU/g, with significant differences among the dryers (P ≤ 0.05), and real-time PCR revealed aflatoxin-producing fungi (2.00 to 3.42 log CFU/g) in all dryers. However, mycotoxins were not detected in dried pepper samples. Sixty-seven mold species isolated from dried peppers were identified by sequencing of the ITS1-5.8S rRNA-ITS2 region and characterized by mycotoxigenic ability. Four isolates of Penicillium expansum, four isolates of Penicillium thomii, and one isolate of Aspergillus parasiticus were producers of patulin, penicillic acid, and aflatoxins, respectively. Toxigenic fungi were inoculated onto smoked dried peppers and stored at 84, 91, 94, and 97% relative humidity (RH) at 20°C for 30 days. Patulin was not detected under any of these conditions. Penicillic acid was detected in dried samples stored at 91 to 97% RH, although the optimum condition was isolate dependent. Aflatoxins G₂, B₁, and B₂ were detected at 91 to 97% RH, with the highest concentrations at 94% RH. According to our results, hazard analysis critical control point systems should be used to control the drying and storage conditions of dried peppers until the milling step to avoid rehydration, which encourages fungal growth and mycotoxin production.

Mycobiota of spices and aromatic herbs

A total of 67 samples of spices and herbs were tested for mould contamination. From 50.7% of samples, moulds were not isolated. The most dominant genera were Aspergillus and Penicillium. Potential producers of mycotoxins Aspergillus spp. and Penicillium spp. were tested for the ability to produce some mycotoxins. Isolates of potentially toxinogenic species were found to produce various mycotoxins, namely alfatoxin B1 (Aspergillus flavus), cyclopiazonic acid (Aspergillus flavus), sterigmatocystin (Emericella nidulans), roquefortine C (Penicillium allii, P. chrysogenum, P. crustosum, P. expansum), penitrem A (P. crustosum) and patulin (P. expansum). Some of the tested isolates produce two mycotoxins: A. flavus (aflatoxin B1 and cyclopiazonic acid), P. crustosum (roquefortine C and patulin) and P. expansum (roquefortine C and patulin). None of the tested isolates of Aspergillus section Nigri screened, appeared to produce ochratoxin A. Totally 11 samples were analysed for the presence of aflatoxins and ochratoxin A. Aflatoxin B1 was found in 5 (45.5%) out of 11 samples analysed with levels ranging from 0.14 to 2.9 µg.kg-1. In one sample we detected aflatoxin G1.  Ochratoxin A was found in 3 samples (27.3%), with levels ranging from 2.2 to 5.19 µg.kg-1. No sample was contaminated by aflatoxins or ochratoxin A above the maximum admitted threshold established by the European legislation.

In vitro glucuronidation of ochratoxin a by rat liver microsomes

Ochratoxin A (OTA), one of the most toxic mycotoxins, can contaminate a wide range of food and feedstuff. To date, the data on its conjugates via glucuronidation request clarification and consolidation. In the present study, the combined approaches of ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), UHPLC-Orbitrap-high resolution mass spectrometry (HRMS) and liquid chromatography-multiple stage mass spectrometry (LC-MS(n)) were utilized to investigate the metabolic profile of OTA in rat liver microsomes. Three conjugated products of OTA corresponding to amino-, phenol- and acyl-glucuronides were identified, and the related structures were confirmed by hydrolysis with β-glucuronidase. Moreover, OTA methyl ester, OTα and OTα-glucuronide were also found in the reaction solution. Based on these results, an in vitro metabolic pathway of OTA has been proposed for the first time.

Advanced hyphenated chromatographic-mass spectrometry in mycotoxin determination: current status and prospects

Mass spectrometric techniques are essential for advanced research in food safety and environmental monitoring. These fields are important for securing the health of humans and animals, and for ensuring environmental security. Mycotoxins, toxic secondary metabolites of filamentous fungi, are major contaminants of agricultural products, food and feed, biological samples, and the environment as a whole. Mycotoxins can cause cancers, nephritic and hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders. Mycotoxin-contaminated food and feed can provoke trade conflicts, resulting in massive economic losses. Risk assessment of mycotoxin contamination for humans and animals generally depends on clear identification and reliable quantitation in diversified matrices. Pioneering work on mycotoxin quantitation using mass spectrometry (MS) was performed in the early 1970s. Now, unambiguous confirmation and quantitation of mycotoxins can be readily achieved with a variety hyphenated techniques that combine chromatographic separation with MS, including liquid chromatography (LC) or gas chromatography (GC). With the advent of atmospheric pressure ionization, LC-MS has become a routine technique. Recently, the co-occurrence of multiple mycotoxins in the same sample has drawn an increasing amount of attention. Thus, modern analyses must be able to detect and quantitate multiple mycotoxins in a single run. Improvements in tandem MS techniques have been made to achieve this purpose. This review describes the advanced research that has been done regarding mycotoxin determination using hyphenated chromatographic-MS techniques, but is not a full-circle survey of all the literature published on this topic. The present work provides an overview of the various hyphenated chromatographic-MS-based strategies that have been applied to mycotoxin analysis, with a focus on recent developments. The use of chromatographic-MS to measure levels of mycotoxins, including aflatoxins, ochratoxins, patulin, trichothecenes, zearalenone, and fumonisins, is discussed in detail. Both free and masked mycotoxins are included in this review due to different methods of sample preparation. Techniques are described in terms of sample preparation, internal standards, LC/ultra performance LC (UPLC) optimization, and applications and survey. Several future hyphenated MS techniques are discussed as well, including multidimensional chromatography-MS, capillary electrophoresis-MS, and surface plasmon resonance array-MS.

Development and validation of a QuEChERS based liquid chromatography tandem mass spectrometry method for the determination of multiple mycotoxins in spices

A reliable and rapid method for the determination of multiple mycotoxins was developed using a QuEChERS (quick, easy, cheap, effective, rugged and safe) based extraction procedure in highly pigmented and complex spice matrices, namely red chilli (Capsicum annum ssp.), black and white pepper (Piper nigrum ssp.). High-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was used for the quantification and confirmation of 17 chemically diversified mycotoxins. Different extraction procedures were studied and optimized in order to obtain better recoveries. Mycotoxins were extracted from the hydrated spices using acidified acetonitrile (1% formic acid), followed by partitioning with NaCl and anhydrous MgSO4; excluding the use of dispersive-solid phase extraction. Significant matrix effect was compensated using the matrix matched calibration curves. Electrospray ionization at positive mode was applied to simultaneously detect all the mycotoxins in a single run time of 20min. Multiple reaction monitoring mode, choosing at least two abundant fragment ions per analyte was applied. Coefficients of determination obtained were in the range of 0.9844-0.9997. Recoveries (ranging from 75% to 117%) were in accordance with the performance criteria required by the European Commission. Intra-day reproducibility ranged from 4% to 22% for most of the mycotoxins. The limit of quantification ranged from 2.3 to 146μgkg(-1). The validated method was finally applied to screen mycotoxins in ten of each spice matrix. Aflatoxins, ochratoxin, fumonisins, sterigmatocystin and citrinin were among the detected analytes. Positive findings were further confirmed using relative ion intensities. The potentiality of the method to be used for confirmatory purposes according to Commission Decision 2002/657/EC was assessed.

The effects of different ecophysiological factors on ochratoxin A production

Mycotoxin biosynthesis is affected by peculiar agro-ecosystem dependent conditions. Accordingly, the correlation between mycotoxin contamination and environmental condition change scenarios should be carefully considered. This is because fungal colonization and mycotoxin contamination could critically impair the availability of food products, especially in poor countries. At any time, the agricultural products might become susceptible to fungal contamination and mycotoxin production in uncontrolled storage. From 2000 to 2010, many studies were carried out in the case of the effects of different parameters on ochratoxin A (OTA) production by fungi in order to avoid providing the appropriate conditions for producing OTA. Water activity (a(w)), temperature, type of species and the substrates were introduced as the most important in these articles. This paper reviews the major published articles regarding the different ecophysiological factors influencing on OTA production.

Effect of processing on ochratoxin A content in dried beans

Dried pink beans naturally contaminated with ochratoxin A (OTA) and dried carioca beans artificially contaminated with OTA by inoculation with Aspergillus ochraceus (ATCC 22947) were tested for ochratoxin A levels as follows: dried beans were washed with water for 2, 60 or 120 min, soaked in water for 60, 120 min or 10 h, and cooked for 60 or 120 min. At each step, test water and beans were separated. Test water, raw beans and cooked beans were analyzed for OTA. The amount of OTA partitioned into water and in residual beans was determined by methanol-sodium bicarbonate extraction, buffer dilution, immunoaffinity column cleanup, liquid chromatographic separation and fluorescence detection. The results demonstrated that the distribution of OTA in processing water and beans depends on the method of preparation. All treatments (washing, soaking and cooking) when applied individually reduced the amounts of OTA retained in bean flour and whole beans. Higher amounts of OTA remained in whole beans than in bean flour after removing the processing water. The combination of the three treatments eliminated about 50% of the toxin from whole beans. This study provides evidence that discarding the washing, soaking and cooking water leads to a significant reduction in OTA contamination in dried beans.

In vitro effect of some fungicides on growth and aflatoxins production by Aspergillus flavus isolated from Capsicum powder

The aim of this study was to determine the effect of some pre-harvest fungicides on growth and aflatoxin (AF) production of three Aspergillus flavus strains found in Capsicum powder. Each isolate, previously isolated from paprika, chilli and smoked paprika, was inoculated on yeast extract sucrose agar and on a 3% paprika extract agar medium supplemented with different fungicides and incubated at 20 and 30°C during 7 days. Growth measurements were obtained on days 3, 5 and 7, and the AF production was determined on day 7. The significance of the effects of the factors (strain, medium, temperature, time and fungicides) and their interaction over colony diameter and AF production was determined. Temperature constrained the effectiveness of fungicides in reducing growth, the fungicides being most effective at 20°C. The efficacy of the fungicides over AF production depended on the medium used and temperature. The most effective fungicides in inhibiting growth and AF production, regardless of the strain tested or applied conditions, were tebuconazole 25% and mancozeb 80% applied at a concentration of 0.75 and 3.5 g l(-1), respectively. Care should thus be taken in the choice of a suitable fungicide because their effectiveness may depend on intra-specific variation and temperature. Moreover, it is necessary to take into account that the most efficient fungicide in reducing growth is not always the best choice for pre-harvest treatments because it may promote AF production. Thus, the best fungicide is the one that can simultaneous prevent growth and AF production.

Occurrence of ochratoxin A in Korean red paprika and factors to be considered in prevention strategy

A large amount-260,000 tons-of red paprika is consumed annually in Korea, where the people prefer hot and pungent to sweet foods. Concern has recently grown among consumers over contamination of paprika powder by mycotoxins; contamination can occur at any stage from pre-harvest to drying, storage, grinding, and eventually transport to the retail market. This study had dual aims: to investigate the current level of contamination of hot peppers by ochratoxin A and to identify the critical control points in the food chain. We measured the ochratoxin A (OTA) content of 200 samples from various sources including supermarkets, an online shopping mall, small stakeholder mills, Hazard Analysis and Critical Control Points (HACCP)-implemented factories, and an import company. Mycotoxin was determined using immunoaffinity column cleanup/HPLC quantification as well as strong anion exchange cleanup/stable isotope dilution assay. Monitoring revealed that approximately 30% of red paprika samples were OTA-positive, indicating a need to establish a maximum level for regulation. We selected two model factories that had adopted HACCP in different ways, and compared data in order to develop guidelines for alleviation of mitigation of the mycotoxin contamination.

Ultraviolet-C and induced stilbenes control ochratoxigenic Aspergillus in grapes

This study investigated the efficacy of ultraviolet-C (254 nm) and induced stilbenes to inhibit Aspergillus carbonarius and Aspergillus tubingensis and control ochratoxin A production in grapes. In addition, the stilbene synthesis as a response to UV-C treatment and to infection of ochratoxigenic Aspergillus was compared. The initial microbial inactivation by a previously optimized UV-C illumination protocol for increasing trans-resveratrol content in grapes (50 W/m (2), 40 cm, 60 s) was similar on undamaged and damaged grapes, achieving 1.2 and 1.3 log conidia/100 g reductions, respectively. After 5 days of storage at 22 degrees C, UV-C treatment and the stilbenes induced by UV-C inhibited ochratoxigenic Aspergillus growth in undamaged grapes. UV-C elicited the biosynthesis of trans-resveratrol, while microbial infection and tissue damage triggered the biosynthesis of trans-piceid. trans-Resveratrol was not synthesized as a consequence of ochratoxigenic Aspergillus contamination. However, when trans-resveratrol was synthesized by UV-C, it contributed to inhibiting the development of ochratoxin A producing aspergilli. Furthermore, UV-C treatment also contributed to decrease ochratoxin A production by ochratoxigenic aspergilli. Therefore, UV-C is a promising emerging technology either for reducing the potential ochratoxigenic risk in grapes, which is of particular interest to the wine industry, and also for increasing trans-resveratrol content of grapes, which would provide an added value to the wine.

Modelling of growth of aflatoxigenic A. flavus isolates from red chilli powder as a function of water availability

The aim of the present work was to apply mathematical models for the prediction of growth of aflatoxigenic moulds in powdered Capsicum fruits as a function of its water availability. As prevention of fungal growth effectively conduces to prevention of mycotoxin accumulation, the development of models for prediction of growth of mycotoxigenic fungi becomes a key step in risk management. Two aflatoxigenic A. flavus from chilli powder were grown on 3% chilli powder extract agar at different water activity levels and their growth was evaluated over time in terms of colony sizes and ergosterol accumulation. Both variables were modelled over time, and the resulting parameters (growth rates and lag phases) were modelled as a function of water availability using the Rosso cardinal model. Linear logistic regression was also applied to predict the probability of growth over storage time. Both isolates showed a similar pattern of behaviour, with decreasing growth rates and increasing lag phases with decreasing water activity level. While estimation of optimum a(w) for growth was consistently around 0.97-0.99, the minimum estimated a(w) varied from 0.82 to 0.88 depending on the isolate and on the parameters used for predictions. Comparing growth rates obtained for colony size and ergosterol accumulation, a linear relationship between them could be observed. The rate of root square ergosterol/colony diameter/unit of time was 0.25-0.27. Probabilities of growth before 10 days over 90% were estimated at a(w) 0.91, while the safe period could be extended to more than 20 days (22-29 days) if water activity was decreased to an a(w)=0.87. Finally, the probability of growth is always under 50% when water availability is under a(w) 0.85, and almost null for A. flavus UdLTA 3.147. It was concluded that for safe production, storage and transport, chillies and chilli powder must be kept under 31% mc (db) (probability of growth <50%). However, growth is unlikely to occur if chilli is kept at approx. 34% for less than 10 days, or at approx. 33% for less than 20 days. Careful hazard analysis and critical control point (HACCP) techniques during raw material production and the subsequent stages of drying, transportation, elaboration and storage are indispensable.

An exploratory investigation of several mycotoxins and their natural occurrence in flavour ingredients and spices, using a multi-mycotoxin LC-MS/MS method

An exploratory investigation was carried out of several flavour ingredients and spices for the occurrence of mycotoxins. For this purpose, a modern liquid chromatography-mass spectrometry technique was used, utilising a quadrupole mass spectrometer of the latest generation. The method includes the determination of the following mycotoxins: aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, ochratoxin A, deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin, zearalenone and fumonisin B1. The method has been successfully validated in-house and was used to determine the occurrence of mycotoxins in approximately 60 samples of flavour ingredients and spices (samples of lime oil, orange oil, melon extract, grapefruit oil, paprika extract, tangerine oil, olive oil, chilli pepper oil, peppermint oil, galangal root powder, gentian root powder, chilli pepper, black pepper, white pepper, garlic powder, paprika powder, coriander seed, dill herb and onion). Ochratoxin A was found in paprika powder and paprika extract; low levels of aflatoxins were found in paprika powder and pepper. Fumonisin B1 was found in garlic powder and onion powder. The presence of fumonisin B1 in onion and garlic powder has not been described before. For the moment, we can conclude that the found contamination levels are no reason for concern.

Capsicum and Mycotoxin Contamination: State of the Art in a Global Context

Owing to their usual conditions of production in countries with warm and humid climates and to poor storage conditions, products derived from Capsicum sp. are susceptible to fungal contamination and development, which can lead to the accumulation of mycotoxins in these foods. Thus, products as chilli or paprika can be contaminated with fungal toxins, such as aflatoxins, ochratoxins and other mycotoxins, which pose a serious risk to public health. This study reviews the main aspects regarding mycotoxin contamination of Capsicum, in the context of the importance of this product in a global market and approaches the effect of processing on final contamination of foods, as well as reviews the analytical methodology commonly employed in fungal and mycotoxin analysis in these types of products.