Mycotoxins In Food Commodities Research Articles

Determination of mycotoxins in human foods

This tutorial review deals with the analytical methods available for the determination of mycotoxins in food commodities. As the secondary metabolites of a range of fungal species, mycotoxins possess diverse chemical structures, presenting analytical chemists with a unique set of challenges in the microg kg(-1) (ppb) range. A number of analytical methods have been applied to mycotoxin analysis. These include widely applicable HPLC methods with UV or fluorimetric detection, which are extensively used both in research and for legal enforcement of food safety legislation and for regulations in international agricultural trade. Other chromatographic methods, such as TLC and GC, are also employed for the determination of mycotoxins, whereas recent advances in analytical instrumentation have highlighted the potential of LC-MS methods, especially for multi-toxin determination and for confirmation purposes. Conventional chromatographic methods are generally time consuming and capital intensive, and hence a range of methods, mostly based on immunological principles, have been developed and commercialised for rapid analysis. These methods include, among others, enzyme-linked immunosorbent analysis (ELISA), direct fluorimetry, fluorescence polarization, and various biosensors and strip methods.

Mycotoxins in the food chain: human health implications.

Mycotoxins are secondary fungal metabolites that can be produced in crops and other food commodities both pre- and post-harvest. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health globally. Reduced growth and development, immunosuppression and cancer are chronic effects that have a higher incidence following continual exposure to low level mycotoxin ingestion as is experienced in many developing countries. It has been estimated that 25% of the world's crops are affected by mould or fungal growth and as stable, natural contaminants of the food chain, mycotoxin reduction requires a multifaceted approach, including farmers, government agencies, food processors and scientists. This can have a significant impact on the cost of food production. International regulatory standards for mycotoxins in food commodities determines the extent of global trade in contaminated commodities.

Mycotoxin producing fungi and mycotoxins in foods in Hungary in the period 1994-2002

Our knowledge on the presence of mycotoxin producing fungi and mycotoxins in food commodities in the last decade in Hungary has been summarized in this review. Among the mycotoxin producing fungi, detailed data are available for Fusarium species in cereals, and mycotoxigenic Aspergillus species in different food commodities including coffee, raisins and spices. Ochratoxin concentrations above the tolerable limit have mostly been detected in imported products such as peanuts and coffee. Ochratoxin levels close to the tolerable limit have been observed in Hungarian red peppers. Besides, ochratoxin A has also been detected in Hungarian wine, beer and raisins. Aflatoxins are usually detected in considerable quantities only in imported agricultural products in Hungary, while patulin concentrations were usually below the allowable limit in Hungarian apple juice concentrates. In the future, continuous sampling and analysis of foods and feeds are required to ensure consumer safety in Hungary.

Multiplex Polymerase Chain Reaction Assay for the Differential Detection of Trichothecene- and Fumonisin-Producing Species of Fusarium in Cornmeal

The genus Fusarium comprises a diverse group of fungi including several species that produce mycotoxins in food commodities. In this study, a multiplex polymerase chain reaction (PCR) assay was developed for the group-specific detection of fumonisin-producing and trichothecene-producing species of Fusarium. Primers for genus-level recognition of Fusarium spp. were designed from the internal transcribed spacer regions (ITS1 and ITS2) of rDNA. Primers for group-specific detection were designed from the TRI6 gene involved in trichothecene biosynthesis and the FUM5 gene involved in fumonisin biosynthesis. Primer specificity was determined by testing for cross-reactivity against purified genomic DNA from 43 fungal species representing 14 genera, including 9 Aspergillus spp., 9 Fusarium spp., and 10 Penicillium spp. With purified genomic DNA as a template, genus-specific recognition was observed at 10 pg per reaction; group-specific recognition occurred at 100 pg of template per reaction for the trichothecene producer Fusarium graminearum and at 1 ng of template per reaction for the fumonisin producer Fusarium verticillioides. For the application of the PCR assay, a protocol was developed to isolate fungal DNA from cornmeal. The detection of F. graminearum and its differentiation from F. verticillioides were accomplished prior to visible fungal growth at <105 CFU/g of cornmeal. This level of detection is comparable to those of other methods such as enzyme-linked immunosorbent assay, and the assay described here can be used in the food industry's effort to monitor quality and safety.

IDENTIFICATION OF HAZARDOUSFUSARIUMSECONDARY METABOLITES OCCURRING IN FOOD RAW MATERIALS

Hazardous secondary metabolites produced byFusariummolds were identified in the first step of a risk assessment procedure, the hazard identification. These mycotoxins are excreted, often simultaneously, by the fungus into plant tissue. A literature survey revealed the occurrence of 61Fusariumspecies in agricultural produce (cereals, vegetables, fruits) of which 35 species were reported to produce a total of 137 secondary metabolites in laboratory experiments. This literature review shows that 41 (30%) of these secondary metabolites have been tested and found toxic in various assays and should be considered hazardous if present in food. Six of these were reported to be related to human intoxications. Four metabolites belonged to the trichothecenes (T‐2 toxin, nivalenol, deoxynivalenol and acetyldeoxynivalenol), the others were zearalenone and fumonisin B1. Twelve metabolites, including the previously mentioned six, were reported to have been tested in feeding trials using vertebrates. These twelve secondary metabolites should be regarded as most important and need to be evaluated in each risk assessment procedure for mycotoxins in food commodities.