DNA-damaging activity of patulin in Escherichia coli

Natural Thiols, but Not Thioethers, Attenuate Patulin-Induced Endoplasmic Reticulum Stress in HepG2 Cells

Patulin, a mycotoxin, is known to have cytotoxic effects, but few studies have focused on the involvement of the endoplasmic reticulum (ER) stress response in patulin toxicity and the natural compounds that attenuate it in HepG2 cells. This study tested the ability of patulin to induce ER stress, and that of four thiols and three thioethers to attenuate patulin-induced ER stress in HepG2 cells. Patulin dose-dependently inhibited cell proliferation (IC₅₀, 8.43 μM). Additionally, patulin was found to increase the expression levels of ER stress-related genes and/or protein markers, including BiP, CHOP, and spliced XBP1, in HepG2 cells compared to the vehicle control, indicating its potential in ER stress induction. Patulin-induced cytotoxicity in HepG2 cells was reduced by naturally occurring thiol compounds (glutathione, L-acetyl-L-cysteine, cysteine, and captopril), but not by thioether compounds (sulforaphane, sulforaphene, and S-allyl-L-cysteine). Patulin-thiol co-treatment decreased CHOP expression and BiP and CHOP levels in HepG2 cells but did not alter BiP expression. Spliced XBP1 expression was decreased by patulin-thiol co-treatment. Thus, patulin induced ER stress in HepG2 cells and thiols, but not in thioethers, attenuated patulin-induced ER stress.

Mycotoxin patulin in food matrices: occurrence and its biological degradation strategies

Patulin is a mycotoxin produced by a number of filamentous fungal species. It is a polyketide secondary metabolite which can gravely cause human health problems and food safety issues. This review deals with the occurrence of patulin in major food commodities from 2008 to date, including historical aspects, source, occurrence, regulatory limits and its toxicity. Most importantly, an overview of the recent research progress about the biodegradation strategies for contaminated food matrices is provided. The physical and chemical approaches have some drawbacks such as safety issues, possible losses in the nutritional quality, chemical hazards, limited efficacy, and high cost. The biological decontamination based on elimination or degradation of patulin using yeast, bacteria, and fungi has shown good results and it seems to be attractive since it works under mild and environment-friendly conditions. Further studies are needed to make clear the detoxification pathways by available potential biosorbents and to determine the practical applications of these methods at a commercial level to remove patulin from food products with special reference to their effects on sensory characteristics of foods.

In vitro and in silico docking studies of antibacterial compounds derived from endophytic Penicillium setosum

Occasionally, endophytic fungal species cognize as a hidden prospective source of plant secondary metabolites. In this study, a potent Penicillium setosum sp. nov. was explored for its detailed antibacterial action on Escherichia coli and Staphylococcus aureus through different in vitro and in silico assays. Fluorescence based viability assay determined increase in the number of dead cells in course of time with the continual exposure of extract during a 4 h period. Scanning electron micrographs reflect the distinguishable morphological changes in treated cells, namely shortening of size, bubbles, and blisters on the surface of E. coli, as well as open holes and deep craters on the surface of S. aureus, ultimately leading to rupture of cells. Significant intracellular changes in bacteria were remarkably noticed through different membrane permeabilization assays. The rate of Na⁺ and K⁺ leakage with respect to time, intracellular material and cytoplasmic β-galactosidase release were measured spectroscopically. The results indisputably prove that membrane disruption of S. aureus cells occurs within 2 h and in E.coli occurs in between 2 and 4 h of exposure. Crude extract of P. setosum was fractioned using semi-preparative HPLC and the separated antibacterial active fraction showed antibacterial efficacy with the minimum inhibitory concentration of 8 μg/mL against both organisms. Active fraction contains four well-known plant metabolite belongs to the polyphenolic group (Leucodelphinidin, dihydroquercetin, kaempferol, and quercetin) and one polyketide (patulin) familiar as fungal metabolite, identified through high resolution LC-MS. Interaction mechanisms of identified compounds with nine important antimicrobial drug targets showed highest binding affinity by leucodelphinidin followed by dihydroquercetin > kaempferol > quercetin. This is the first instance of using leucodelphinidin and dihydroquercetin for detailed interaction study with multiple targets, and it was found that they showed more effective interaction than quercetin, which was earlier utilized for antibacterial studies.

Low dose exposure of patulin and protective effect of epicatechin on blood cells in vitro

In the present study, we aimed to assess antioxidant status in erythrocytes in vitro after patulin (PAT) and epicatechin exposure by measuring antioxidant enzymes (superoxide-dismutase - SOD, glutathione peroxidase - GPx and catalase - CAT) and parameters associated with oxidative stress (malondialdehyde - MDA and ROS). We also investigated the effect of PAT on viability and count of lymphocytes and lymphocyte subpopulations in rabbit blood in vitro. Whole blood of rabbits was used for analysis of antioxidant changes in rabbit erythrocytes after epicatechin and PAT treatment (separately or in combination, at concentrations of 0.2; 2; 20; 200 µg mL^-1 of epicatechin and 0.5; 5; 10 µg mL^-1 of PAT). Whole blood of rabbits was also used for analysis of count and viability of lymphocytes after PAT treatment at concentrations of 10; 25 and 50 µg mL^-1. Results from our experiment confirmed the ability of epicatechin to protect cells against oxidative stress and lipoperoxidation. Our findings indicate that mycotoxin PAT in low concentrations did not affect the activity of antioxidant enzymes in erythrocytes of rabbits significantly. Only slight non-significant changes in lymphocytes count after treatment with low doses of PAT in rabbit blood were observed.

A high-throughput, whole cell assay to identify compounds active against carbapenem-resistant Klebsiella pneumoniae

Enteric Gram-negative rods (GNR), which are frequent causes of community-acquired and nosocomial infections, are increasingly resistant to the antibiotics in our current armamentarium. One solution to this medical dilemma is the development of novel classes of antimicrobial compounds. Here we report the development of a robust, whole cell-based, high-throughput metabolic assay that detects compounds with activity against carbapenem-resistant Klebsiella pneumoniae. We have used this assay to screen approximately 8,000 fungal extracts and 50,000 synthetic compounds with the goal of identifying extracts and compounds active against a highly resistant strain of Klebsiella pneumoniae. The primary screen identified 43 active fungal extracts and 144 active synthetic compounds. Patulin, a known fungal metabolite and inhibitor of bacterial quorum sensing and alanine racemase, was identified as the active component in the most potent fungal extracts. We did not study patulin further due to previously published evidence of toxicity. Three synthetic compounds termed O06, C17, and N08 were chosen for further study. Compound O06 did not have significant antibacterial activity but rather interfered with sugar metabolism, while compound C17 had only moderate activity against GNRs. Compound N08 was active against several resistant GNRs and showed minimal toxicity to mammalian cells. Preliminary studies suggested that it interferes with protein expression. However, its direct application may be limited by susceptibility to efflux and a tendency to form aggregates in aqueous media. Rapid screening of 58,000 test samples with identification of several compounds that act on CR-K. pneumoniae demonstrates the utility of this screen for the discovery of drugs active against this highly resistant GNR.

Toxicological effects of patulin mycotoxin on the mammalian system: an overview

The mycotoxin PAT (4-hydroxy-4H-furo[3,2c]pyran-2[6H]-one) is a secondary metabolic product of molds such as Penicillium, Aspergillus, and Byssochlamys species. PAT is a common contaminant of fruit and vegetable based products, most notably apples. Despite PAT's original discovery as an antibiotic, it has come under heavy scrutiny for its potential to impart negative health effects. Studies investigating these health effects have proved its toxic potential. PAT occurrence in the food commodities poses a serious threat and necessitates novel and cost-effective mitigation methods to remove it from food products. It also creates a demand to improve handling and food processing techniques. With this being the case, several studies have been devoted to understanding the key biological and chemical attributes of PAT. While past research has elucidated a great deal, PAT contamination continues to be a challenge for the food industry. Here, we review its influence within the mammalian system, including its regulation, incidences of experimental evidence of PAT toxicity, its interaction with intracellular components, and the effects of PAT induced systemic toxicity on vital organs. Finally, key areas where future PAT research should focus to best control the PAT contamination problem within the food industry have been addressed.

Apigenin attenuates patulin-induced apoptosis in HEK293 cells by modulating ROS-mediated mitochondrial dysfunction and caspase signal pathway

Mycotoxins like patulin (PAT) are among the most significant food contaminant with regard to public health. This study aimed to evaluate the protective effect of apigenin (API), one of the most bioactive flavonoids in plant-derived food, on PAT-induced apoptosis in HEK293 cells. Cells were treated under basic conditions, 8 μM PAT without or with API (2.5, 5 and 10 μM) concomitantly for 10 h. API exerted renoprotective effect by inhibiting intracellular reactive oxygen species (ROS) accumulation, modulating oxidative phosphorylation especially elevating the expression of ATP synthase, re-establishing mitochondrial membrane potential (MMP) and maintaining higher intracellular ATP level, accompanied by p53, Bax downregulation and Bcl-2 upregulation. Thereby, cytochrome c release from mitochondria to cytoplasm was reduced, causing inhibition of initiator caspases-9 and executioner caspases (3, 6 and 7) expression and enzyme activities. Results revealed dietary apigenin attenuates patulin-induced apoptosis in HEK293 cells by modulating ROS-mediated mitochondrial dysfunction and caspase signal pathway.

Screening of a Combinatorial Library of Organic Polymers for the Solid-Phase Extraction of Patulin from Apple Juice

Patulin is a water-soluble mycotoxin produced by several species of fungi. Governmental bodies have placed it under scrutiny for its potential negative health effects, and maximum residue limits are fixed in specific food matrices to protect consumers’ health. Confirmatory analysis of patulin in complex food matrices can be a difficult task, and sample clean-up treatments are frequently necessary before instrumental analyses. With the aim of simplifying the clean-up step, we prepared a 256-member combinatorial polymeric library based on 16 functional monomers, four cross-linkers and four different porogenic solvents. The library was screened for the binding towards patulin in different media (acetonitrile and citrate buffer at pH 3.2), with the goal of identifying polymer formulations with good binding properties towards the target compound. As a proof of concept, a methacrylic acid-co-pentaerithrytole tetraacrylate polymer prepared in chloroform was successfully used as a solid-phase extraction material for the clean-up and extraction of patulin from apple juice. Clean chromatographic patterns and acceptable recoveries were obtained for juice spiked with patulin at concentration levels of 25 (64 ± 12%), 50 (83 ± 5.6%) and 100 μg L⁻¹ (76 ± 4.5%). The within-day and between-day reproducibility evaluated at a concentration level of 25 μg L⁻¹ were 5.6 and 7.6%, respectively.

Effects of different mycotoxins on humans, cell genome and their involvement in cancer (Review)

The chemical nature of most of the mycotoxins makes them highly liposoluble compounds that can be absorbed from the site of exposure such as from the gastrointestinal and respiratory tract to the blood stream where it can be dissimilated throughout the body and reach different organs such as the liver and kidneys. Mycotoxins have a strong tendency and ability to penetrate the human and animal cells and reach the cellular genome where it causes a major mutagenic change in the nucleotide sequence which leads to strong and permanent defects in the genome. This defect will eventually be transcribed, translated and lead to the development of cancer. In this review, the chemical and physical nature of mycotoxins, the action of mycotoxins on the cellular genome and its effect on humans, mycotoxins and their carcinogenicity and mycotoxins research gaps are discussed, and new research areas are suggested. The research review posed various questions. What are the different mycotoxins that can cause cancer, what is the role of mycotoxins in causing cancer and what types of cancers can be caused by mycotoxins? These questions have been selected due to the significant increase in the mycotoxin contamination and the cancer incidence rate in the contemporary world. By revealing and understanding the role of mycotoxins in developing cancer, measures to reduce the risks and incidents of cancer could be taken.

Quality of meat of rabbits after application of epicatechin and patulin

The aim of the present study was to determinate the effect of epicatechin and patulin on selected parameters of meat quality of rabbits. Adult female rabbits (n=25), maternal albinotic line (crossbreed Newzealand white, Buskat rabbit, French silver) and paternal acromalictic line (crossbreed Nitra's rabbit, Californian rabbit, Big light silver) were used in experiment. Animals were divided into five groups: control group (C) and experimental groups E1, E2, E3, and E4. Animals from experimental groups E1, E2, E3, E4 received patulin through intramuscular injection (10 µg.kg-1) twice a week and animals from groups E2, E3, E4 received epicatechin three times a week through intramuscular injection. After 30 days animals were slaughtered. For analysing of meat quality the samples of Musculus longissimus dorsi (50 g) were used. Application of  epicatechin and patulin to rabbits had slight or no effect on the pH levels in stomach, small intestine, large intestine and urinary bladder contents, however differences among the groups were insignificant (p ˃0.05). Application of epicatechin and patulin to rabbits had slight or no effect on total water, protein, fat   and differences among the groups were insignificant (p >0.05). The values of amino acids concentrations were not influenced after application of epicatechin and patulin. The fatty acid profiles in animals after application of different doses of epicatechin and 10 µg.kg-1 patulin were similar (p >0.05). Concentration of cholesterol increased in experimental groups in comparison with the control group, but differences were insignificant (p >0.05). pH levels of meat of rabbits in experimental group E3 was lower when compared with the control group, but differences was not significant (p >0.05).  Electric conductivity parameter was increased in each experimental group (in E3 the highest) against the control but without significant differences (p >0.05). Colour L parameter was slightly decreased in experimental groups with comparison to the control group (in E3 the lowest). Generally we can conclude that intramuscular application of epicatechin or patulin did not affect parameters of meat quality as well as pH values of internal organs content. Further investigations are needed to prove the final answer concerning the health promoting effects of epicatechin and patulin.

Patulin induces apoptosis through ROS-mediated endoplasmic reticulum stress pathway

Patulin (PAT) is a toxic metabolite produced by several filamentous fungi of the genera of Penicillium, Aspergillus, and Byssochlamys. PAT is the most common mycotoxin found in apples and apple-based products including juice, compotes, cider, and baby food. Exposure to this mycotoxin has been reported to induce intestinal and kidney injuries. This study investigated the mechanism of PAT-induced toxicity in human colon carcinoma (HCT116) and embryonic kidney cells (HEK293). We demonstrated that PAT activated endoplasmic reticulum (ER) and unfolded protein response as evidenced by up-regulation of GRP78 and GADD34, splicing of XBP1 mRNA, and expression of the proapoptotic factor CHOP. This ER stress response was accompanied by the induction of the mitochondrial apoptotic pathway. Apoptosis occurred with ROS production, drop in mitochondrial membrane potential and caspase activation. Further, we showed that deficiency of the proapoptotic protein Bax or Bak protected cells against PAT-induced apoptosis. The treatment of cells with the ROS scavenger N-acetyl cysteine inhibits the ER stress response and prevents mitochondrial apoptosis. Collectively, our data provide new mechanistic insights in the signaling pathways of the cell death induced by PAT and demonstrate that PAT induces cytotoxicity through a ROS-dependent mechanism involving ER stress and activation of mitochondrial apoptotic pathway in human intestinal and kidney cells.

Evaluation of genotoxicity, cytotoxicity and cytostasis in human lymphocytes exposed to patulin by using the cytokinesis-block micronucleus cytome (CBMN cyt) assay

Patulin (PAT) is a fungal secondary metabolite commonly present in apples and apple products. In the present study, PAT was evaluated for its genotoxic, cytotoxic and cytostatic effects to human peripheral blood lymphocytes by using the cytokinesis-block micronucleus cytome (CBMN Cyt) assay. Lymphocyte cultures were treated with PAT at the following concentrations, 0.1, 0.3, 0.5, 1.0, 2.5, 5.0, and 7.5 μM, as well as 0.5 μM mitomycin c (MMC) as a positive control and dimethyl sulfoxide (DMSO) as a vehicle control. PAT was found to induce nucleoplasmic bridges (NPBs) at 5.0 and 7.5 μM concentrations (P < 0.05), apoptotic cells at 0.1, 1.0, 5.0 μM (P < 0.05), 7.5 μM concentrations (P < 0.01) and necrotic cells at 0.3 and 2.5 μM (P < 0.05), 5.0 and 7.5 μM (P < 0.01) concentrations in human lymphocytes. The 2.5, 5.0, and 7.5 μM PAT concentrations also led to a clear decrease in the nuclear division index (NDI) (P < 0.05). PAT caused a significant dose-dependent increase in the number cells of NPBs, in the frequency of apoptotic and necrotic cells, and a significant dose-dependent decrease in the NDI values in lymphocytes. These results indicate that PAT at high concentrations is genotoxic, cytotoxic and cytostatic in cultured human lymphocytes.

Regulation of patulin-induced oxidative stress processes in the fission yeast Schizosaccharomyces pombe

Patulin (PAT), is one of the most widely disseminated mycotoxins found in agricultural products. In this study the PAT-induced accumulation of reactive oxygen species (ROS) and the regulation of the specific activities of antioxidant enzymes were investigated in the single cell eukaryotic organism Schizosaccharomyces pombe. In comparison with the untreated cells, 500 μM PAT treatment caused a 43% decrease in the concentration of the main intracellular antioxidant, glutathione (GSH); this depletion of GSH initiated a 2.44- and a 2.6-fold accumulation of superoxide anion and hydrogen peroxide, respectively, but did not increase the concentration of hydroxyl radicals; the reduction of ROS-induced adaptation processes via the activation of Pap1 transcription factor resulted in significantly increased specific activities of Cu/Zn superoxide dismutase, catalase and glutathione S-transferase to protect the cells against the ROS-induced unbalanced redox state. However, no change was measured in the activities of glutathione reductase, glutathione peroxidase and glucose-6-phosphate dehydrogenase. It seems reasonable to assume that the temporary PAT-induced ROS accumulation plays a crucial role in adaptation processes. The adverse effects of PAT may be exerted mainly through the destruction of cellular membranes and protein/enzyme functions.

Influence of storage temperature and apple variety on patulin production by Penicillium expansum

This study examined the potential for patulin production in six different varieties of apples (Red Delicious, Golden Supreme, Gala, Fuji, Empire, and McIntosh) inoculated with Penicillium expansum spores and stored at two different temperatures (11 and 20.5 degrees C). Samples for patulin analysis were randomly taken from apples stored at different times, ranging from 21 to 93 days. While patulin was produced at both storage temperatures, apples incubated at 20.5 degrees C yielded significantly higher patulin concentrations than did those incubated at 11 degrees C. All apple varieties showed mold spoilage at both temperatures, except Red Delicious and Empire. A total of 44% of the samples analyzed showed patulin concentrations above the U.S. Food and Drug Administration regulatory limit (50 ppb). The highest patulin productions occurred in Golden Supreme (54,221 ppb) and McIntosh (52,131 and 48,457 ppb) varieties. Our results showed that careful culling of apples is essential for high juice quality, since high patulin levels in some apples varieties could result in a level greater than 50 ppb of this mycotoxin in the finished juice or cider, even when only one contaminated apple occurs in 1,000 apples.

Involvement of cytoplasmic membrane damage in the copper (II)-dependent cytotoxicity of a novel naturally occurring tripyrrole

In the presence of a nonlethal concentration of Cu(II), washed Escherichia coli ATCC8739 cells were killed by a novel tripyrrole 1, isolated as a red pigment from the Serratia sp. Cell killing was accompanied by a depletion in the potassium pools of the cells due to the damage to the cytoplasmic membrane, without any detectable DNA damage as revealed by the transformed plasmid DNA and phage induction assay. This revealed that the bactericidal activity of compound 1 in the presence of Cu(II) results from membrane damage. Induction of endogenous catalase in the E. coli cells increased their resistance against the combination of compound 1 and Cu(II). Although compound 1 alone generated large amount of reactive oxygen species (ROS), it did not show any cell killing against E. coli in the absence of Cu(II). The Cu(II)-dependent bactericidal activity of compound 1 was suppressed by ethylenediaminetetraacetate, bathocuproine, catalase and superoxide disumutase (SOD), but not by dimethyl sulfoxide. These findings suggest that recycling redox reactions between Cu(II) and Cu(I), involving compound 1 and hydrogen peroxide on the cell surface, must be important in the mechanism of the killing. Compound 1 alone showed selective bactericidal activity against the gram positive bacterium, Bacillus cereus ATCC 6630, possibly due to its differential cellular transport.

Mutagenicity of the mycotoxin patulin in cultured Chinese hamster V79 cells, and its modulation by intracellular glutathione

Because the ability of the mycotoxin patulin (PAT) to cause gene mutations in mammalian cells is still ambiguous, we have studied the mutagenicity of PAT at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene locus in cultured Chinese hamster V79 cells with normal, depleted, and elevated glutathione (GSH) levels. PAT was more toxic to GSH-depleted cells than to normal cells and caused an increase of the intracellular GSH level in normal and GSH-depleted cells. It also caused synchronization of the cell cycle due to a temporary accumulation of cells in the G2/M phase; this G2/M arrest was more persistent in GSH-depleted than in normal cells. PAT gave rise to a clear and concentration-dependent induction of HPRT mutations at non-cytotoxic concentrations in V79 cells with normal GSH level; the lowest PAT concentration causing a significant number of mutant cells was 0.3 micromolar, and the mutagenic potency of PAT equaled that of the established mutagen 4-nitroquinoline-N-oxide. The mutagenicity of PAT was again more pronounced, by a factor of about three, in GSH-depleted V79 cells. Elevated GSH levels abolished all observed effects of PAT. These data support the notion that PAT is a mutagenic mycotoxin, in particular in cells with low GSH concentration. The ability of PAT to cause gene mutations in mammalian cells might have a bearing on its carcinogenicity.

Rapid degradation of the mycotoxin patulin in man quantified by stable isotope dilution assays

The absorption and degradation of the mycotoxin patulin in man was quantified by using a recently developed stable isotope dilution assay. Application of this currently most sensitive method revealed a patulin content less than 200 ng l(-1) in the blood serum of five consumers of apple juice. Likewise, no patulin was found in the serum of a volunteer, whose blood was drawn shortly after consumption of a juice containing a maximum tolerable amount of patulin. In further in vitro experiments, the degradation of patulin by reacting it with whole blood was investigated. After addition of 100 microg patulin to 9 ml blood, only 6.1% of the mycotoxin was detected after 2 min. It was concluded, therefore, that even high naturally occurring concentrations of patulin in foods are quickly degraded before reaching other tissues than the gastrointestinal tract.

Genotoxicity of fungi evaluated by SOS microplate assay

By an introduction of sodium dodecylsulfate for cell lysis and immunomicroplate for mass assay, the modified SOS microplate assay method was established and applied for the evaluation of genotoxicity of mycotoxins and fungal cultures. Among 20 mycotoxins, the carcinogenic dihydrobisfuranoids such as aflatoxin B1, sterigmatocystin, and versicolorin A were positive in the presence of the activation system. While, the carcinogenic anthraquinones and lactones such as luteoskyrin, rugulosin, ochratoxin A, patulin, and citrinin were negative. The survey on genotoxic fungi revealed that, among 15 fungal isolates Aspergillus versicolor, Emericella acristata, and others were positive. Additional survey on 265 fungal isolates have revealed that various Aspergillus genera such as A. flavus, A. parasiticus, A. ustus, A. nidulans, and others were positive for SOS induction, along with several isolates of Fusarium moniliforme. The chemical analysis revealed that the dihydrobisfuranoids such as aflatoxin B1, and sterigmatocystin were the major genotoxic metabolites of several Aspergillus species. The SOS microplate assay system is a simple and rapid procedure for the mass screening of genotoxic fungi, particularly of the dihydrobisfuranoids-producing strains.

Elimination of the toxic effects of patulin on Bacillus subtilis and B.megaterium by irradiation

The bacteriological toxicity of patulin irradiated in aqueous solutions was investigated using two strains of bacteria, Bacillus subtilis and B.megaterium. The results of the plate cultivation test showed that the growth inhibition of both strains decreased in relation to absorbed dose. A dose of 1.8 kGy was sufficient to eliminate the bacteriological toxicity of patulin at an initial concentration of 125 micrograms/ml. There was good correlation between the concentration of patulin in the irradiated solution as measured spectrophotometrically and that calculated from the diameter of the inhibition zone.

Structure-activity relationships among mycotoxins

Relationships between structural features and biological effects of mycotoxins are reviewed. Structure-activity relationships are characterized at the molecular, subcellular, cellular, or supracellular level. Major chemical and physicochemical factors responsible for bioactivity of mycotoxins are stressed. A variety of chemical families of mycotoxins are then discussed from the point of view of structure-activity relationships. The structurally related families comprise small lactones, macrocyclic lactones, isocoumarin derivatives, aflatoxins and related compounds trichothecenes, anthraquinones, indole-derived tremorgens and selected amino acid-derived mycotoxins such as sporidesmins and cyclosporines. Biological effects of mycotoxins include acute and chronic toxicity, antimicrobial activity, mutagenicity and genotoxicity, carcinogenicity and biochemical modes of action.

Effect of irradiation on the patulin content and chemical composition of apple juice concentrate

The influence of ionizing radiation on the patulin content of apple juice concentrate was investigated. The results indicated that patulin, at an initial concentration of about 2 mg/kg, disappeared after irradiation of the concentrate with doses as low as 2.5 kGy. For lower doses, the extent of patulin degradation was proportional to the absorbed dose. Irradiation of the concentrate with doses sufficient for patulin disappearance did not change the titratable acidity, the content of reducing sugars and carbonyl compounds or the amino acid composition. The content of ascorbic acid slightly decreased and the colour of the concentrate brightened. The intensity of the patulin absorption spectra after irradiation of mycotoxin in aqueous solutions decreased.