Mycotoxins are secondary metabolites of fungi, and pose a threat to human and animal health. The importance of mycotoxins in food safety was recognized worldwide through a discovery of aflatoxin, which was found to be a potent carcinogen in the process of investigation of the turkey X disease that occurred in the UK in 1960.
Ergotism is known as a human mycotoxicosis which has occurred since ancient times. The toxin, ergot alkaloids, killed more than 40,000 people in the Middle Ages in Europe. Some other well known human diseases that have happened by natural contamination of foods with mycotoxins are: ATA (alimentary toxic aleukemia) in Siberia, acute aflatoxicosis in India and Kenya, food poisoning caused by Fusarium toxins in Japan, Balkan nephropathy and hepatic cancer in some regions of Asia, Africa and China. Famous outbreaks of animal diseases include reproductive disorders in swine in Canada and U.S.A., equine leucoencephalomalacia in South Africa and U.S.A. and porcine nephropathy in Denmark.
In recent years, the need for mycotoxin research has increased with the increase of public demands for food safety. It should be emphasized that the control of mycotoxin contamination in Asia is a key for assurance of food safety in Japan, whose foods depend largely on Asian agricultural products.

抄録全体を表示

Aflatoxins were found as causal agents of the so-called turkey-X disease that occurred in the UK in 1960. The toxins are produced by certain strains of Aspergillus flavus, A. parasiticus and A. nomius. Among various mycotoxins contaminating foodstuffs, aflatoxin B₁ is the most important in terms of its frequent occurrence and strong toxicity. IARC determined that there is sufficient evidence in humans for the carcinogenicity of aflatoxin B₁. Aflatoxins have been associated with several cases of human lethal acute intoxications in some regions of Asia and Africa.
Fusarium head blight or scab is a significant fungal disease of wheat, barley and maize, and historically associated with human intoxications. Nivalenol and deoxynivalenol were found in Japan as trichothecene mycotoxins of Fusarium species, principally of F. graminearum, and their worldwide occurrence in cereals are now well recognized. T-2 toxin is another trichothecene metabolite of F. sporotrichioides, and is speculated to be involved in the alimentary toxic aleukia, an historical episode of human lethal intoxication in Russia. F. graminearum also can produce zearalenone, an estrogenic mycotoxin, which causes field cases of a specific estrogenic syndrome in swine and of infertility in cattle. Fumonisins are produced mainly by F. moniliforme (=F. verticillioides) and F. proliferatum, and cause animal diseases including leucoencephalomalacia in horses, pulmonary edema in swine, hepato- and nephrotoxicity in multiple species, and kidney and liver cancer in rodents.
Ochratoxin A is produced by A. ochraceus, A. carbonarius, and Penicillium verrucosum. It has been shown to be nephrotoxic in all mammalian species tested. Its main target is the renal proximal tubule, where it exerts cytotoxic and carcinogenic effects. Cereals, wine, grape juice and coffee are estimated as major sources of human exposure for ochratoxin A.
A patulin-producing strain of P. urticae was isolated from the feed responsible for the lethal poisoning in dairy cattle in Japan in 1952. P. expansum, known as apple blue mold, is a causative fungus for the contamination of patulin in apple juice.
Before the 1950’s, the rice exported from several countries of Southeast Asia and other regions was often contaminated with Penicillium species, and is called yellowed rice. A neurotoxic mycotoxin, citreoviridin, was isolated as a possible causal agent of beriberi from P. toxicarium (= P. citreonigrum). P. islandicum, another fungal contaminant of the yellowed rice was found to produce two mycotoxins, luteoskyrin and cyclochlorotine, that are both simultaneously carcinogenic and hepatotoxic.

抄録全体を表示

Toxic secondary metabolites of fungi are called mycotoxins. Although thousands of mycotoxins exist, only a few occurrences of unavoidable natural contaminants in foods are a serious problem.
When these compounds are present in foods in sufficiently high levels, they can have adverse health effects that range from acute to chronic. This is also a significant problem. Of the acute symptoms, liver or kidney deterioration is caused by aflatoxins and ochratoxin A. Gastro-enteric dysfunction is caused by fusarium toxins. Of the chronic symptoms, aflatoxin B₁, fumonisin, and ochratoxin A are suspected human carcinogens. Trichthecens, aflatoxins and ochratoxin A are recognized as immunosuppresant compounds. Ochratoxin A is a potential renal toxin.
In this article, the five mycotoxins: aflatoxins, ochratoxin A, fumonisins, trichthecenes and zearalenone, are presented as typical contaminants in food worldwide and are introduced with focus on their toxicity and their mechanisms.

抄録全体を表示

There are various fungi in foods or food environments, including examples with harmful action in humans which can present as health hazards. Fungal second metabolites, like mycotoxins produced from food borne fungi are serious problems from the viewpoint of food safety. Some species or strains in Aspergillus, Penicillium and Fusarium are sources of strong mycotoxins such as aflatoxins, ochratoxins, patulin, deoxynivalenol, and fumonisins. It is therefore very important that mycotoxigenic fungi are monitores, with efforts to understand biological and ecological interpretations for fungal control in foods and food environments. In this paper a mycological and ecological review of mycotoxigenic fungi existing in foods or food environments is provided.

抄録全体を表示

Mycotoxins currently considered the most significant are aflatoxins (AF), ochratoxin A (OTA), patulin, fumonisins (FM), zearalenone (ZEN) and some trichothecenes including deoxynivalenol (DON) and T-2/HT-2 toxins. Recent information on the worldwide occurrence of these mycotoxins in food, published by international organizations (JECFA, IARC), EC and Japan, are overviewed.
The risk assessment of mycotoxins (FM, OTA, DON, T-2/HT-2 and AFM₁) was carried out at the 56^th JECFA meeting in 2001, and provisional tolerable daily intake (PTDI) values were proposed for the four toxins. In addition, the evaluation of AFM₁ by JECFA indicated that, with worst case assumptions, the projected risks for liver cancer attributable to use of the proposed levels of AFM₁ of 0.05μg/kg milk and 0.5μg/kg milk are very small, and that there is no significant health benefit if a 0.5μg/kg limit were to be reduced to 0.05μg/kg.
Exposure assessment is another main ingredient of the risk assessment. The extensive activities of EC-SCOOP projects resulted in several reports on exposure assessment of OTA and several Fusarium mycotoxins, trichothecenes, FM and ZEN. While the dietary intakes of Fusarium toxins are often less than the TDI’s for the entire population and adults, they are close or even exceed in some cases the TDI’s for risk groups like infants and children.
The recent situation of worldwide mycotoxin regulations as of December 2003 is updated in the FAO Food and Nutrition Paper 64. On a worldwide basis, at least 99 countries had mycotoxin regulations, including guidelines, for food and/or feed in 2003, an increase of approximately 30% compared to 1995. The total population in these countries represents approximately 87% of the world’s inhabitants. Several regulations have been harmonized between countries belonging to economic communities (EU, MERCOSUR).

抄録全体を表示

Regulation of mycotoxins has been established for aflatoxin, zearalenone and deoxynivalenol in feed in Japan. We have conducted analysis of mycotoxins in feed in accordance with the official method of feed analysis in Japan. Regarding contamination rates for aflatoxin in corn and formula feed, appreciable differences were observed from year to year, posaitive samples being mainly imports from Southeast Asia. In addition, we have surveyed contamination of feed ingredients by other mycotoxins such as ochratoxin, deoxynivalenol, nivalenol, zearalenone and fumonisin.

抄録全体を表示

Mycotoxin regulations have been established in many countries to prevent the risks to human and animal health. The regulation of aflatoxin B₁, which is a carcinogenic mycotoxin, in food was enforced in Article 4 (Article 6 at present) of the Food Sanitation Law in 1971 in Japan. At the same time, the notified official method has been given to judge the value of the regulatory limit of it, and revised to a liquid chromatographic (LC) procedure for determination of it in 2002.
The provisional maximum tolerable daily intake of patulin and deoxynivalenol have been established at 0.4 and 1.0μg/kg bw/day, respectively, by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1995 and 2001. In line with this, the Ministry of Health, Labor and Welfare of Japan set the regulatory limits for them at a level of 0.050 ppm for patulin in apple juice and 1.1 ppm for deoxynivalenol in wheat in 2003 and 2002 along with the official analytical method for them.
Each official analytical method has been validated in inter-laboratory studies, and evaluated based on parameters of recovery, precision and HorRat value.
The regulatory limit for ochratoxin A, which is a nephrotic mycotoxin, is being discussed actively in JECFA and Japan, though it isn't decided. We examined the LC analytical method of ochratoxin A using a multifunctional column for cleanup.
In this paper is described the contents and the validity evaluation for the chemical analytical method for aflatoxin B₁, patulin, deoxynivalenol and ochratoxin A.

抄録全体を表示

Liquid chromatography/mass spectrometry (LC/MS) has become a most useful technique for detection of trace levels of mycotoxins in foodstuffs because of its high selectivity and sensitivity. This overview covers mycotoxin-residue determination in food samples by LC/MS including quadrupole mass spectrometry (Q-MS), triple quadrupole mass spectrometry(QqQ-MS) and time-of-flight mass spectrometry(TOF-MS). We here present applications of LC/MS with reference to sensitivity, selectivity and separation for the quantitative analysis of mycotoxins in crops and food products, including examples like aflatoxins, major trichothecene mycotoxins, zealarenone, ochratoxin A and patulin.

抄録全体を表示

To minimize interference from co-extracted compounds from food and feed samples in which mycotoxins occur, the conventional methods for chemical analysis of mycotoxins consume large amounts of time and solvents, need several cleanup steps, and sometimes require practical experience. From the viewpoint of earth environment protection and operator safety, toxic and carcinogenic solvents such as chloroform and benzene used for mycotoxin analysis should be avoided. Under these circumstances, specific antibodies have been developed against several mycotoxins such as aflatoxins, ochratoxin A, zearalenone, T-2 toxin, deoxynivalenol and fumonisins since the ending of seventies. Using these antibodies, simple and rapid methods of immunochemical analysis for mycotoxins such as enzyme-linked immunosorbent assay (ELISA) and immunoaffinity column (IAC) chromatography have been developed. The major advantages of these immunochemical methods are their high specificity, simplicity, rapidity and minimal use of toxic solvents. This review focuses on recent immunochemical methods for mycotoxins, in particular ELISA, enzyme linked immunofiltration assays (immunoconcentration assay), lateral flow assays (immunochromatography assay), and IAC.

抄録全体を表示

Since mycotoxins have been accepted as unavoidable compounds, numerous strategies for control of mycotoxins have been attempted. As traditional strategies, Good Agricultural Practice (GAP), the implementation of Hazard Analysis and Critical Control Point (HACCP) plans and physical and chemical means are effective methods to prevent and reduce mycotoxin contamination. As novel avenues, the availability of genetic modification and the application of innate biochemical functions in plants and animal have shed new light on the prevention of contamination of mycotoxins in food.
Establishment of standards for mycotoxins in feed and food is necessary for detention of imported food and feed contaminated with mycotoxin. In Japan, we have established standards for patulin, provisional standards for deoxynivalenol and regulations for aflatoxin B₁. In the near future, the regulations for total aflatoxins will be discussed.

抄録全体を表示

Hydroxypropyl methylcellulose (HPMC) which is a kind of cellulose ether, has only been used for food capsules and tablets with Health Claims under the limitations of Standard for Use since it was approved as a food additive in June 2003 in Japan. And now the Food Safety Commission and other Authorities are investigating and discussing abolishing this limitation in order to use HPMC for general foods. HPMC was evaluated as a low toxicity material by the Food Safety Commission because it has no absorption ability in the digestive tract, no carcinogenicity and no significant toxicity in terms of teratogenicity, generation reproductive toxicity and other studies. It is expected to be used for various food product applications because of its safety and unique characteristics as a material of vegetable origin.

抄録全体を表示