Application of new technologies in decontamination of mycotoxins in cereal grains: Challenges, and perspectives.

Emerging decontamination technologies have been attracted considerable attention to address the consumers' demand for high quality and safe food products. As one of the important foods in the human diet, cereals are usually stored for long periods, resulting in an increased risk of contamination by different hazards. Mycotoxins comprise one of the significant contaminants of cereals that lead to enormous economic losses to the industry and threats to human health. While prevention is the primary approach towards reducing human exposure to mycotoxins, decontamination methods have also been developed as complementary measures. However, some conventional methods (chemical treatments) do not fulfill industries' expectations due to limitations like safety, efficiency, and the destruction of food quality attributes. In this regard, novel techniques have been proposed to food to comply with the industry's demand and overcome conventional methods' limitations. Novel techniques have different efficiencies for removing or reducing mycotoxins depending on processing conditions, type of mycotoxin, and the food matrix. Therefore, this review provides an overview of novel mycotoxin decontamination technologies such as cold plasma, irradiation, and pulse light, which can be efficient for reducing mycotoxins with minimum adverse effects on the quality and nutritional properties of produce.

Is Gamma Radiation Suitable to Preserve Phenolic Compounds and to Decontaminate Mycotoxins in Aromatic Plants? A Case-Study with Aloysia citrodora Paláu.

This study aimed to determine the effect of gamma radiation on the preservation of phenolic compounds and on decontamination of dry herbs in terms of ochratoxin A (OTA) and aflatoxin B1 (AFB1), using Aloysia citrodora Paláu as a case study. For this purpose, artificially contaminated dry leaves were submitted to gamma radiation at different doses (1, 5, and 10 kGy; at dose rate of 1.7 kGy/h). Phenolic compounds were analysed by HPLC-DAD-ESI/MS and mycotoxin levels were determined by HPLC-fluorescence. Eleven phenolic compounds were identified in the samples and despite the apparent degradation of some compounds (namely verbasoside), 1 and 10 kGy doses point to a preservation of the majority of the compounds. The mean mycotoxin reduction varied between 5.3% and 9.6% for OTA and from 4.9% to 5.2% for AFB1. It was not observed a significant effect of the irradiation treatments on mycotoxin levels, and a slight degradation of the phenolic compounds in the irradiated samples was observed.

[REDUCTION OF THE CONTENT OF AFLATOXIN-FORMING FUNGI IN CONTAMINATED GRAINS BY METHODS OF HYDROTHERMAL TREATMENT].

Microscopic fungi affecting grain and products of its processing, under certain conditions, are capable of producing over 100 mycotoxins, some of which are carcinogenic. Mycotoxins are falled to the most dangerous contaminants of food and compound animal feedstuff, they possess toxicity, mutagenic and carcinogenic properties. The most toxic and dangerous carcinogens are aflatoxins which affect on virtually all cells of the body of the human and agricultural animals, provoking the occurrence of diseases--aflatoxicoses. Aflatoxins give rise to encephalopathy and fatty degeneration of internal organs. The World Health Organization mentions aflatoxins as a cause of the origin of cancer. Currently in Russia there is a real danger of the negative impact of mycotoxins on farm animals in feeding grain affected by aflatoxins. The gain in the number of aflatoxicoses is a serious hygienic problem. This is related with the wide spread of producers of aflatoxins in nature and also with the intensive trade of grain and products of its processing between countries, a lack of control over their content. Detoxification of the affected products is an actual task, because its use causes irreparable harm to human health andfarm animals. Currently there are known several ways of inactivation of aflatoxins in the grain, based on the use of hydrothermal treatment. IR heat treatment, ultraviolet irradiation and extrusion were established to be the most rational approaches, providing the reduction offungi in the grain of aflatoxin-forming fungi by 80 ... 100%, aflatoxin B1--by the 76... 100% and a decrease in the degree of toxicity by 2.3 times. There are presented experimental data of various ways of disinfecting grain and appropriateness of their application in practice.

Structure-activity relationships imply different mechanisms of action for ochratoxin A-mediated cytotoxicity and genotoxicity.

Ochratoxin A (OTA) is a fungal toxin that is classified as a possible human carcinogen based on sufficient evidence for carcinogenicity in animal studies. The toxin is known to promote oxidative DNA damage through production of reactive oxygen species (ROS). The toxin also generates covalent DNA adducts, and it has been difficult to separate the biological effects caused by DNA adduction from that of ROS generation. In the current study, we have derived structure-activity relationships (SAR) for the role of the C5 substituent of OTA (C5-X = Cl) by first comparing the ability of OTA, OTBr (C5-X = Br), OTB (C5-X = H), and OTHQ (C5-X = OH) to photochemically react with GSH and 2'-deoxyguanosine (dG). OTA, OTBr, and OTHQ react covalently with GSH and dG following photoirradiation, while the nonchlorinated OTB does not react photochemically with GSH and dG. These findings correlate with their ability to generate covalent DNA adducts (direct genotoxicity) in human bronchial epithelial cells (WI26) and human kidney (HK2) cells, as evidenced by the (32)P-postlabeling technique. OTB lacks direct genotoxicity, while OTA, OTBr, and OTHQ act as direct genotoxins. In contrast, their cytotoxicity in opossum kidney epithelial cells (OK) and WI26 cells did not show a correlation with photoreactivity. In OK and WI26 cells, OTA, OTBr, and OTB are cytotoxic, while the hydroquinone OTHQ failed to exhibit cytotoxicity. Overall, our data show that the C5-Cl atom of OTA is critical for direct genotoxicity but plays a lesser role in OTA-mediated cytotoxicity. These SARs suggest different mechanisms of action (MOA) for OTA genotoxicity and cytotoxicity and are consistent with recent findings showing OTA mutagenicity to stem from direct genotoxicity, while cytotoxicity is derived from oxidative DNA damage.

Evaluación de la flora fungica del ambiente del archivo general del Estado Sucre Venezuela / Evaluation of the fungic flora of the atmosphere of the general archives of the Sucre State Venezuela

Los agentes fúngicos son capaces de descomponer materia orgánica como madera, papel, pintura, suelo, polvo, alimentos. Pueden ocasionar deterioro de material bibliográfico , texto, mobiliario, pinturas, igualmente causan enfermedades de tipo alérgico. El Archivo General del Estado Sucre es un centro de consulta e investigación donde se encuentran documentos y otros textos que se han ido dañando a través del tiempo; las condiciones de almacenamiento de un área con deficiencias estructurales y ambientales, favorecen el desarrollo de hongos, causando el deterioro dl material bibliográfico. Se realizaó una investigación para evaluar la flora fúngica tanto del mobiliario como documentos y textos existentes, que se servirá de base para un futuro plan de conservación y restauración. Utilizando el método de sedimentación en placa conteniendo Agar Sabouraud Dextrosa, se expusieron 60 placas durante 15 minutos en diferentes secciones del área de estudio, incubándose 10 días a temperatura ambiente. Se aislaron 86 colonias que se caracterizaron macro y microcóspicamente. Los géneros aislados fueron: Aspergillus (38,46%), Fusarium (21,70%), Curcularia (16,76%), Cladosporium (12,76%), Penicillium (10,32%), los cuales han sido descritos como contaminantes habituales de libros o textos, mobiliarios, pinturas, además capaces de causar reacciones alérgicas de tipo respiratorios resultando un riesgo para el material bibliográfico, usuarios y personal de la institución.

The fungies agents are able to disturb organics material as wood, paper, paint, ground, drust, foods they can produce deterioration of bibliographycal material, texts, house-hold goods, paintings, and equally they cause disease of alergic type. The general archives of Sucre state is a consulting center and investigation where it is found historic documents and another texts which have been damaging throuth the time, the conditions of storing in an area with estructural deficiencis and environment improve the development of fungies causing the depreciation of bibliographycal material. An investigation was done to evaluate the fingis flora as the house-hold godos, as the existen documents and texts, that it would serve the base to desing the future plan of conservation and restauration. Using the method of sedimentation in plaque containing Agar Sabouraud Dextrosa, 60 plaques were exposed during 15 minutes in different sections of study area, incubating 10 days at atmosphere temperatura. 86 colonies were isolated that were characterized macro and microcospyly. The aislated fungic species were: Aspegillus (35,46%), Fusarium (21,70%), Curvalaria (16,76%), Cladosporium (12,76%), Penicillium (10,32%), which have been described as usual contaminating of book o texts, house-hold godos, paintings, in addiction to this they are able to cuse alergic rections of respiratory type, resulting a risk to the bibliographycal material, usuaries and personal of the institution.

Influence of gamma radiation on productivity parameters of chicken fed mycotoxin-contaminated corn.

The aim of this study was to evaluate productivity parameters and carcass yield of broiler chickens fed irradiated corn contaminated with mycotoxins. For this purpose, 180 one-day-old male chicks were divided into nine treatments and fed for 42 days. The results indicated that irradiation of corn with 5 kGy improved the productivity parameters studied. Therefore, gamma radiation may become an alternative for the control of the deleterious effects of mycotoxins on broiler chickens, which cause marked economic losses for rural producers.

Reduction of feed-contaminating mycotoxins by ultraviolet irradiation: an in vitro study.

Ultraviolet (UV) germicidal irradiation has been applied to the sterilization of agricultural products including stored grain for foodstuffs or animal feed. Although UV treatment is known to be effective for killing pathogenic moulds that contaminate the surface of grain, it remains unclear how and to what extent such irradiation is able to eliminate mycotoxins, the fungal metabolites that have adverse effects on human and animal health. We evaluated in vitro the effects of mild (intensity = 0.1 mW cm(-2) at 254 nm UV-C) and strong (24 mW cm(-2)) UV irradiation on two feed-contaminating mycotoxins, zearalenone (ZEN) and deoxynivalenol (DON). When exposed to mild irradiation, the levels of ZEN and DON (both 30 mg kg(-1) initially) were reduced as irradiation time increased, and became undetectable at 60 min. Strong UV irradiation also reduced the mycotoxin levels in the same time-dependent manner, but more rapidly. It was therefore confirmed in vitro that UV irradiation is effective at reducing the levels of ZEN and DON. The present study provides preliminary data for establishing a practical method of using UV irradiation to reduce mycotoxin contamination in grain intended for use in feed.

An investigation into techniques for cleaning mold-contaminated home contents.

This study examined the efficacy of the following treatments to reduce selected fungal spore and mycotoxin levels on materials commonly found in home contents: (1) gamma irradiation at a 10-13 kiloGray exposure, (2) a detergent/bleach wash, and (3) a steam cleaning technique. A minimum of six replicates were performed per treatment. Paper, cloth, wood, and carpet were inoculated with either fungal spores (Stachybotrys chartarum, Aspergillus niger, Penicillium chrysogenum, or Chaetomium globosum) at 240,000 spores/2.54 cm2 of material or with the mycotoxins roridin A, T-2, and verrucarin A at 10 microg per 2.54 cm2 of material. Treatments were evaluated with an agar plating technique for fungal spores and a yeast toxicity culture assay for mycotoxins. Results showed that gamma irradiation inactivated fungal spores, but the treatment was not successful in inactivating mycotoxins. The washing technique completely inactivated or removed spores on all materials except for C. globosum, which was reduced on all items except paper (p < 0.05). Washing inactivated all mycotoxins on paper and cloth but not on carpet or untreated wood (p < 0.001). The steam cleaning treatment did not completely eliminate any fungal spores; however, it reduced P. chrysogenum numbers on all materials, C. globosum was reduced on wood and carpet, and S. chartarum was reduced on wood (p < 0.05). Steam cleaning was unsuccessful in inactivating any of the tested mycotoxins. These results show that the bleach/detergent washing technique was more effective overall in reducing spore and mycotoxin levels than gamma irradiation or steam cleaning. However, the other examined techniques were successful in varying degrees.

Differential response of maize catalases and superoxide dismutases to the photoactivated fungal toxin cercosporin.

Many fungi of the genus Cercospora produce a light-induced, photoactivated polyketide toxin called cercosporin. In the presence of light an excited form (triplet state) of the toxin molecule is produced which, depending on the reducing potential of the environment, reacts with molecular oxygen to produce singlet oxygen and/or superoxide radicals. In this paper a system is presented for analysis of antioxidant defense gene response using purified cercosporin under conditions demonstrated to favor superoxide formation. Under the assay conditions employed, changes in total catalase activity, as well as individual isozyme protein levels generally mirrored the changes observed in corresponding steady-state RNA levels in response to applied cercosporin. In contrast, while transcript accumulation for most maize superoxide dismutases increased dramatically, both total superoxide dismutase activity and individual isozyme protein levels remained constant in all toxin treatments. In one case, the analyses indicated that there are two distinct transcripts that hybridize with a gene-specific probe for Sod3. These two transcripts responded differentially to applied toxin (levels of the larger transcript increased while the smaller decreased), whereas corresponding steady-state levels for the SOD-3 isozyme proteins remained constant. This suggests that protein turnover might play a role in the response of these SODs to activated oxygen species.

[Voluntary poisoning by Cortinarius orellanus: usefulness of an original early treatment after determination of orellanine in the biological fluids and tissues]. / Intoxication volontaire par Cortinarius orellanus: intérêt d'un traitement précoce original après dosage de l'orellanine dans les milieux biologiques et tissulaires.

Cortinarius poisoning is generally caused by orellanine, a hydroxy bipyridine N, N-dioxide. This intoxication is characterized by acute nephritis which can lead to death without treatment. We reported a highly sensitive and simple fluorimetric technique to analyse orellanine by thin-layer chromatography on the basis of its characteristic photodecomposition into orelline. Using this procedure, we detected and assayed orellanine for the first time in plasma and renal biopsies of a woman who had deliberately ingested two fruit-bodies of Cortinarius orellanus. An early original treatment was carried out based on hemodialysis, combination plasmapheresis-hemoperfusion, and amino acids and diltiazem administration. These results indicate that it is now possible to make a precise diagnosis of orellanine poisoning.