Patulin Content Research Articles

Evaluation of the mycotoxin patulin on cytotoxicity and oxidative stress in human glioblastoma cells and investigation of protective effect of the antioxidant N-acetylcysteine (NAC)

Mycotoxins are secondary metabolites produced by various kinds of fungi that can induce disease in humans. The fungal species Penicillium expansum produces patulin (C7H6O4), a polyketide lactone mycotoxin found in fruits. Patulin is classified as noncarcinogen; however, recently, it has been associated with harmful effects on the central nervous system. Patulin's toxic action has been established in various brain models; however, its effect on human glioblastoma remains elusive. This study explores whether patulin induces cytotoxicity through oxidative stress in DBTRG-05MG human glioblastoma cells. This study also evaluates whether the antioxidant N-acetylcysteine (NAC) protects against patulin-induced cytotoxicity. In DBTRG-05MG cells, patulin concentration (10–60 μM) dependently induced cytotoxicity. Concerning oxidative stress, patulin (10 and 20 μM) increased the production of intracellular reactive oxygen species (ROS) but depleted reduced glutathione (GSH) contents and regulated the expressions of antioxidant-related proteins (Nrf2 and HO-1). Furthermore, patulin induced cytotoxicity via modulation of apoptosis-related protein expressions (Bax, cleaved caspase-9, and cleaved caspase-3). These cytotoxic responses were partially reversed via pretreatment with NAC (10 μM). In summary, these data help us understand the toxicology of patulin in human glioblastoma and evaluate whether NAC could clinically reduce patulin-affected brain damage.

Sensitive determination of Patulin by aptamer functionalized magnetic surface enhanced Raman spectroscopy (SERS) sensor

Food pollution caused by Patulin (PAT) seriously threatens the safety of human diets and has attracted extensive attention. Early and accurate detections of PAT are essential to prevent further toxin spreading and contamination. A surface enhanced Raman scattering (SERS) aptasensor was fabricated by combining a gold-silver core-shell structure containing signal molecule (ADANRs) and chitosan modified magnetic nanoparticles (CS-Fe3O4). The modified ADANRs with the complementary chain of the aptamer (SH-cDNA-ADANRs) which were served as the signal probes and the aptamer modified CS-Fe3O4 (NH2-apt-CS-Fe3O4) were served as the capture probes. In addition to the ability to recognize the target PAT, the capture probe also showed a strong enrichment ability under the action of external magnetic force. The intraparticle plasma coupling between the inner gold core and the outer silver shell can greatly improve the SERS activity of the signal molecules. SERS aptasensor was used to collect the spectra of actual apple samples spiked with different PAT content. The minimum detection limit of SERS aptasensor for detecting PAT in actual samples was 0.0384 ng/mL and the recovery rate range was from 96.3% to 108%. In conclusion, the sensitive and specific SERS aptasensor detection of PAT based on aptamer functionalized nanoparticles exhibited great potential for practical application in mycotoxin detection and analysis.

Insights into the Metabolic Response of Lactiplantibacillus plantarum CCFM1287 upon Patulin Exposure.

Patulin (PAT) is a common mycotoxin in the food industry, and is found in apple products in particular. Consumption of food or feed contaminated with PAT can cause acute or chronic toxicity in humans and animals. Lactiplantibacillus plantarum CCFM1287 is a probiotic strain that effectively degrades PAT in PBS and food systems. In this study, it was found that the concentration of PAT (50 mg/L) in MRS medium decreased by 85.09% during the first stages of CCFM1287 growth, and this change was consistent with the first-order degradation kinetic model. Meanwhile, the regulation of oxidative stress by L. plantarum CCFM1287 in response to PAT exposure and metabolic changes that occur during PAT degradation were investigated. The degree of intracellular damage was attenuated after 16 h of exposure compared to 8 h. Meanwhile, metabolomic data showed that 30 and 29 significantly different metabolites were screened intracellularly in the strain after 8 h and 16 h of PAT stress at 50 mg/L, respectively. The results of pathway enrichment analysis suggested that the purine metabolic pathway was significantly enriched at both 8 h and 16 h. However, as is consistent with the performance of the antioxidant system, the changes in Lactiplantibacillus diminished with increasing time of PAT exposure. Therefore, this study helps to further explain the mechanism of PAT degradation by L. plantarum CCFM1287.

Toxicity mechanism of patulin on 293T cells and correlation analysis of Caspase family.

Patulin (PAT), a kind of mycotoxin, is a widely disseminated mycotoxin found in agricultural products. Although the existing research results show that PAT can cause nerve, immune, and skin toxicities, resulting in heart, liver, and kidney damages. However, evidence on the underlying mechanisms of PAT is still lacking. Present study aims to investigate the renal toxicity and related mechanisms of PAT on 293T cells. Cell Counting Kit-8 method was used to reveal the dose-effect relationship and the time-effect relationship of PAT toxicity. Trypan blue staining and Hoechst 33342 staining were used to analyze PAT, which induced apoptosis on 293T cells. Superoxide-dismutase (SOD), GSH, and malondialdehyde (MDA) were used to measure the changes of oxidative stress status of 293T cells induced by PAT. The changes of reactive oxygen species (ROS) and ATP in mitochondria indicate the role of mitochondria when PAT induced cell damage and apoptosis. Through Cyt-C release assay analysis, caspase activity change, and correlation analysis, the potential mechanism of mitochondrial apoptosis pathway was proved. Results demonstrated that PAT significantly induced cell injury, and with the increase of time and concentration, the cell survival rate decreased significantly. Hoechst 33342 staining and Trypan blue staining showed that apoptosis rate was elevated by PAT. As PAT concentration increased, intracellular SOD, glutathion peroxidase activities were decreased and the MDA content was increased. The decrease of intracellular ATP level and accumulation of ROS content indicated an increased permeability of the mitochondrial membrane. Overexpression of Cyt-C activated the cascade reaction of caspase enzyme, leading to apoptosis. The results of enzyme activity assay and correlation analysis indicated that caspase 3 was the most critical caspase in the cascade system and that it was most correlated with caspase 8 and caspase 9.

Effects of fruit tissue pH value on the Penicillium expansum growth, patulin accumulation and distribution

AbstractpH is an important environmental factor for the virulence of fungi. To explore the effect of tissue pH on the diffusion behavior of Penicillium expansum and patulin, pear (pH 4.98), apple (pH 3.72) and kiwifruit (pH 3.31) were selected to inoculate P. expansum. When the diameter of the lesion was 1 cm or 2 cm, tissues within a certain distance (0, 1, 2, and 3 cm) from the lesion were sampled. Results showed that low pH could inhibit the growth of P. expansum and hinder patulin accumulation in the decayed parts. The quantity of P. expansum was 1.99 × 105 CFU/g and patulin content was 13.84 mg/kg in pear, which were 6.86 times and 92.89 times of that in kiwi‐fruit (lesion diameter 2 cm). In addition, the P. expansum colonies and patulin content decreased with the distance from the lesion, but there was no correlation between tissue pH and patulin distribution.Novelty impact statement Low fruit tissue pH (pH < 4.98 ± 0.08) would inhibit the growth of Penicillium expansum and hinder the accumulation of patulin in the decayed parts. The pH value of the fruit tissue affects the diffusion behavior of P. expansum and patulin in different decayed fruits.

Occurrence of Patulin and Polyphenol Profile of Croatian Traditional and Conventional Apple Cultivars during Storage.

Apples and apple-based products are among the most consumed fruits around the world. However, they are susceptible to infection with the fungi Penicilium expansum. In addition to the reduction of apple quality, secondary metabolism of this fungus produces a mycotoxin patulin that has a negative effect on human health. Currently, there is no available research in the literature on the resistance of Croatian traditional apple cultivars to contamination with P. expansum, and consequently, on the patulin content in apples and apple juice produced from those apples. Although the mechanism of apple resistance to fungal diseases has not yet been sufficiently investigated, some studies have shown that polyphenolic compounds have some impact on fungi growth. In order to contribute with new knowledge, this research deals with monitoring the growth of P. expansum on apples, patulin detection by LC/MS-MS, determination of polyphenol profile by validated HPLC method, and determining the effect of polyphenolic compounds on fungi growth and patulin production during apple storage. The results of this study have shown that Croatian traditional apple cultivars harvested from family farm Horvatić contain higher concentration of polyphenolic compounds and higher antioxidant activity. At the same time, they showed more resistance to infection by P. expansum than conventional ones. The higher content of dihydrochalcones and flavanols encouraged the biosynthesis of patulin in examined cultivars. However, the higher content of non-flavonoids such as 2-6 dimethoxybenzoic acid, 4-hydroxycinnamic acid and chlorogenic acid leads to decrease in content of patulin. In conclusion, it seems that content of polyphenols and patulin production are correlated.

Chromatographic Determination of the Mycotoxin Patulin in 219 Chinese Tea Samples and Implications for Human Health.

Patulin (PAT) is a mycotoxin, with several acute, chronic, and cellular level toxic effects, produced by various fungi. A limit for PAT in food of has been set by authorities to guarantee food safety. Research on PAT in tea has been very limited although tea is the second largest beverage in the world. In this paper, HPLC−DAD and GC−MS methods for analysis of PAT in different tea products, such as non-fermented (green tea), partially fermented (oolong tea, white tea, yellow tea), completely fermented (black tea), and post-fermented (dark tea and Pu-erh tea) teas were developed. The methods showed good selectivity with regard to tea pigments and 5-hydroxymethylfurfural (5-HMF) and a recovery of 90–102% for PAT at a 10–100 ppb spiking level. Limit of detection (LOD) and limit of quantification (LOQ) in tea were 1.5 ng/g and 5.0 ng/g for HPLC−UV, and 0.25 ng/g and 0.83 ng/g for GC−MS. HPLC was simpler and more robust, while GC−MS showed higher sensitivity and selectivity. GC−MS was used to validate the HPLC−UV method and prove its accuracy. The PAT content of 219 Chinese tea samples was investigated. Most tea samples contained less than 10 ng/g, ten more than 10 ng/g and two more than 50 ng/g. The results imply that tea products in China are safe with regard to their PAT content. Even an extreme daily consumption of 25 g of the tea with the highest PAT content (124 ng/g), translates to an intake of only 3 μg/person/day, which is still an order of magnitude below the maximum allowed daily intake of 30 µg for an adult.

Study on the mechanism of inhibiting patulin production by fengycin.

Penicillium expansum is the main cause of apple rot. Besides, it can also produce mycotoxin patulin (PAT). Therefore, the search for substances that can inhibit the activity and toxigenicity of P. expansum has become a hot research topic. This study investigates the inhibitory effects of fengycin on patulin production in P. expansum. P. expansum was cultured under different environments with different concentrations of fengycin. The patulin content produced per unit weight of P. expansum mycelium was detected and determined by high pressure liquid chromatography (HPLC). Synergy brands (SYBR) GreenI Real-time PCR was used to detect the expression levels of 6-methylsalicylic acid synthase (6-MSAS) and isoepoxydon dehydrogenase (IDH), which were the key genes of producing patulin of P. expansum mycelium, in the conditions treated by fengycin and untreated. After fengycin treatments, not only the patulin content in every unit weight of P. expansum mycelium but also the expression level of 6-MSAS decreased significantly. The expression level of 6-MSAS of treatment was 0.11 folds of control. However, the expression level of IDH treated by fengycin decreased slightly. Fengycin could inhibit the P. expansum from producing patulin by downregulating the expression of key synthetic genes 6-MSAS.

Fullerenol Quantum Dots-Based Highly Sensitive Fluorescence Aptasensor for Patulin in Apple Juice.

A highly selective and sensitive aptasensor for detecting patulin (PAT) was constructed based on the fluorescence quenching of fullerenol quantum dots (FOQDs) towards carboxytetramethylrhodamine (TAMRA) through PET mechanism. The π-π stacking interaction between PAT aptamer and FOQDs closed the distance between TAMRA and FOQDs and the fluorescence of TAMRA was quenched with maximum quenching efficiency reaching 85%. There was no non-specific fluorescence quenching caused by FOQDs. In the presence of PAT, the PAT aptamer was inclined to bind with PAT and its conformation was changed. Resulting in the weak π-π stacking interaction between PAT aptamer and FOQDs. Therefore, the fluorescence of TAMRA recovered and was linearly correlated to the concentration of PAT in the range of 0.02–1 ng/mL with a detection limit of 0.01 ng/mL. This PAT aptasensor also performed well in apple juice with linear dynamic range from 0.05–1 ng/mL. The homogeneous fluorescence aptasensor shows broad application prospect in the detection of various food pollutants.

Reduction the contamination of patulin during the brewing of apple cider and its characteristics

Patulin is one of the most significant food safety problems in fruit and derived products. The reduction of patulin contamination in food processing has always been the focus of research. In this study, nine yeast strains were applied for the brewing of apple cider and the fate of patulin was determined. In this process, the patulin contamination can be decreased by adsorption onto and degradation of yeast cells in the main fermentation (20.8–49.1%), as well as the adsorption removal during clarification (18.7–58%), inverted cans (21.3–31.4%) and aging (1.0–5.8%). Saccharomyces cerevisiae (1027) was selected to reveal the elimination mechanism of patulin in main fermentation. The decrease of patulin content was mainly due to degradation and the intracellular enzymes played a more important role than extracellular ones. In addition, the synthesis of enzymes was related to the induction of patulin. Furthermore, the degradation product of patulin in the main fermentation was identified as E-ascladiol, which is less toxic than patulin. Based on the representative strain of S. cerevisiae 1027, patulin contamination can be effectively eliminated during apple cider brewing. This study provides a new insight into eliminating patulin contamination in the brewing of apple cider.

Efficacy of Meyerozyma guilliermondii in controlling patulin production by Penicillium expansum in shuijing pears

Meyerozyma guilliermondii is an antagonistic yeast that efficiently controls the blue mold decay of pears and potentially degrades patulin in vitro conditions. However, the possible patulin controlling efficacy of M. guilliermondii in pears remains unclear. In this study, the patulin controlling effect of M. guilliermondii in pears was investigated. The results showed that M. guilliermondii could effectively control patulin content production by Penicillium expansum in shuijing pear wounds from 3 d to 11 d. However, M. guilliermondii has a poor patulin control effect on fragrant pear and dangshan pear wounds. The patulin degradation ability of M. guilliermondii in shuijing pear wounds increased with the higher concentration of the yeast cells, and 1 × 108 cells/mL showed the best patulin control effect. In shuijing pears, M. guilliermondii could effectively control patulin at 20 °C and 4 °C in wounds as well as the whole fruits. Our results provide a safe and efficient strategy to detoxify patulin using M. guilliermondii, thereby limitting the risks of patulin in shuijing pears.

A novel ratiometric fluorescent aptasensor accurately detects patulin contamination in fruits and fruits products

Patulin (PAT) contamination in fruit and fruit products is a significant public health concern. Here, we developed a ratiometric fluorescent aptasensor for PAT detection based on aptamer-recognition and Exonuclease III amplification. Two structure selective dyes, SYBR Green I (SGI) and N-methyl mesoporphyrin IX (NMM), were used as fluorescent probes. In the developed biosensing system, the binding of PAT to aptamer triggered the liberation of cDNA. Subsequently, amplification was mediated by Exonuclease III. S1 was released from the S1-S2 duplex by enzymatic hydrolyzation and incorporated into a stable G-quadruplex. As a result, the fluorescence of SGI decreased, whereas that of NMM increased. There was a strong linear correlation between the relative fluorescence intensity and PAT concentrations (20 to 500 ng·L−1 range) (R2 = 0.99). The biosensing system was highly sensitive, and could detect PAT concentration as low as 4.7 ng·L−1. The sensor was also highly specific, and could differentiate PAT from several other related mycotoxins. In summary, we developed a new bioassay for the accurate detection of PAT contamination in fruits and fruit products. This research provides a new approach for developing ratiometric bioassays based on structure-selective dyes and enzymatic conversion processes.

A highly selective and sensitive electrochemical sensor based on graphene oxide and molecularly imprinted polymer magnetic nanocomposite for patulin determination

Since a high concentration of patulin is caused cytotoxic, the detection of a novel approach for patulin determination plays an important guiding role in the research and development of new control technologies. For the first time, we have developed a novel sensor using a glassy carbon electrode modified by a composite consisting of ionic liquid-based molecularly imprinted polymer (MIP) and magnetic nanoparticles/graphene oxide (Fe3O4/GO) for the determination of patulin toxin using square wave voltammetry technique. The nanostructures were prepared and characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive X-ray spectroscopy (EDX) techniques. Several experimental parameters affecting the patulin determination, such as scan rate, the type, and pH of buffer solution, were studied and optimized. Under the optimized conditions, a linear range of 0.001 nM − 250.0 nM, a limit of quantification of 0.001 nM and a limit of detection of 3.33×10-4 nM was obtained. The RSDs for 1.0 nM and 250.0 nM patulin were calculate 1.65 % and 0.83%, respectively. The MIP/Fe3O4/GO/GCE was successfully applied to detect patulin toxin in apple juice real samples.

Cardiotoxicity of patulin was found in H9c2 cells

Patulin (PAT) is a kind of mycotoxins that is universally found at rotten fruits, especially apples and apple products. Previous studies have shown that PAT has hepatotoxicity and nephrotoxicity. However, cardiotoxicity of PAT is rarely reported. Present study aimed at investigate the cardiotoxicity and relevant mechanisms of PAT on H9c2 cells. Cytotoxicity of PAT were evaluated by MTT assay and LDH. Hoechst 33258 staining was used to examine the nuclear morphology and AV/PI double staining was employed for apoptosis on H9c2 cells. Expression level of Caspase-3, Caspase-9, Bax, Bcl-2 were quantified to verify the potential mechanism of mitochondrial apoptosis pathway. The tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin 6 (IL-6) were quantified to determine the inflammatory response by using ELISA assay. ROS, SOD, MDA, GSH levels were measured to determine the oxidative stress status. Results demonstrated that PAT significantly induced cell injury, as evidenced by the down-regulated of cell viability, and the increase of LDH release. Hoesst33258 staining and flow cytometry showed that apoptosis rate was elevated by PAT. PAT treatment up-regulated the expression of Caspase-3, Caspase-9, Bax level and down-regulated the expression of Bcl-2 level. TNF-α, IL-1β, IL-6 levels showed that PAT increased the pro-inflammatory response. As PAT concentration increased, intracellular MDA, ROS content were elevated, while GSH content and the activity of SOD were significantly decreased. Thus, it is concluded that PAT may induce apoptosis of H9c2 cells through oxidative stress.

TGF-β/Smad signaling pathway plays a crucial role in patulin-induced pro-fibrotic changes in rat kidney via modulation of slug and snail expression

Patulin (PAT) is a mycotoxin that contaminates a variety of food and foodstuffs. Earlier in vitro and in vivo findings have indicated that kidney is one of the target organs for PAT-induced toxicity. However, no study has evaluated the chronic effects of PAT exposure at environmentally relevant doses or elucidated the detailed mechanism(s) involved. Here, using in vitro and in vivo experimental approaches, we delineated the mechanism/s involved in pro-fibrotic changes in the kidney after low-dose chronic exposure to PAT. We found that non-toxic concentrations (50 nM and 100 nM) of PAT to normal rat kidney cells (NRK52E) caused a higher generation of reactive oxygen species (ROS) (mainly hydroxyl (•OH), peroxynitrite (ONOO−), and hypochlorite radical (ClO−). PAT exposure caused the activation of mitogen-activated protein kinases (MAPKs) and its downstream c-Jun/Fos signaling pathways. Moreover, our chromatin immunoprecipitation (ChIP) analysis suggested that c-Jun/Fos binds to the promoter region of Transforming growth factor beta (TGF-β1) and possibly induces its expression. Results showed that PAT-induced TGF-β1 further activates the TGF-β1/smad signaling pathways. Higher activation of slug and snail transcription factors further modulates the regulation of pro-fibrotic molecules. Similarly, in vivo results showed that PAT exposure to rats through gavage at 25 and 100 μg/kg b. wt had higher levels of kidney injury/toxicity markers namely vascular endothelial growth factor (VEGF), kidney Injury Molecule-1 (Kim-1), tissue inhibitor of metalloproteinase-1 (Timp-1), and clusterin (CLU). Additionally, histopathological analysis indicated significant alterations in renal tubules and glomeruli along with collagen deposition in PAT-treated rat kidneys. Overall, our data provide evidence of the involvement of ROS mediated MAPKs and TGF-β1/smad pathways in PAT-induced pro-fibrotic changes in the kidney via modulation of slug and snail expression.

Fungal growth, patulin accumulation and volatile profile in ‘Fuji Mishima’ apples under controlled atmosphere and dynamic controlled atmosphere

ABSTRACT The objective of this study was to evaluate fungal and patulin contamination, together with its correlation with the volatile compounds (VCs), in ‘Fuji Mishima’ apples (up to 25% decayed) under controlled atmosphere (CA) and dynamic controlled atmosphere with respiratory quotient (DCA-RQ) of 1.3 combined with different partial pressures of carbon dioxide (0.8, 1.2, 1.6 and 2.0 pCO2). Fruits were stored under the above conditions for 8 months at 0.5 °C plus 7 days shelf life at 20 °C. Toxigenic fungi and patulin accumulation were found in apples from all treatments. Penicillium expansum was the most prevalent species. For all storage conditions, patulin concentrations were above the maximum level allowed in Brazil (50 μg kg−1) with an exception of DCA-RQ1.3 + 0.8 kPa CO2. This condition, with lower pCO2, showed the lowest patulin accumulation, below the legal limit. The CA provided the highest patulin concentration (166 μg kg−1). It was observed that fungal growth could also contribute to changes in the volatile composition. Styrene and 3-methyl-1-butanol are considered P. expansum markers in some apple cultivars and were detected in the samples. However, it was not possible to identify volatile organic compounds (VOCs) that are biomarkers from P. expansum, because there were other fungi species present in all samples. In this study, styrene, n-decanoic acid, toluene, phenol and alpha-farnesene were the compounds that showed the most positive correlation with patulin accumulation. On the other hand, a negative correlation of patulin with acids has been shown, indicating that in treatments with a higher patulin concentration there were less acidic compounds.

Factors influencing the removal of patulin by cysteine

The removal of patulin in phosphoric acid buffer solution by cysteine was investigated. Cysteine could effectively decrease the patulin concentration at high acidic condition (pH 3.0–5.0) with the help of high temperature greater than 90 °C. Three removal mechanisms of patulin by cysteine under high acidic and high temperature conditions were deduced. Reaction temperature, pH of reactive media, molar ratio between cysteine and patulin, and reaction time were all the obvious factors influencing the removal efficiency of patulin, and the increase of any one factor could significantly improve the removal efficiency of patulin. The removal process of patulin could be simulated by the zero-order kinetic model, logarithmic model, and pseudo-first-order kinetic model, respectively, and the corresponding correlation coefficients (R2) were all greater than 0.90. Presently, this method can only be applied for the removal of patulin in contaminated water from washing fruits in juice processing industry due to the high treatment temperature more than 120 °C and the long detoxification time greater than 1 h.

Penicillium expansum Impact and Patulin Accumulation on Conventional and Traditional Apple Cultivars.

Penicillium expansum is a necrotrophic plant pathogen among the most ubiquitous fungi disseminated worldwide. It causes blue mould rot in apples during storage, transport and sale, threatening human health by secreting patulin, a toxic secondary metabolite that contaminates apples and apple-derived products. Nevertheless, there is still a lack of sufficient data regarding the resistance of different apple cultivars to P. expansum, especially ancient ones, which showed to possess certain resistance to plant diseases. In this work, we investigated the polyphenol profile of 12 traditional and 8 conventional apple cultivar and their resistance to P. expansum CBS 325.48. Eight polyphenolic compounds were detected; the most prominent were catechin, epicatechin and gallic acid. The highest content of catechin was detected in ‘Apistar’—91.26 mg/100 g of fresh weight (FW), epicatechin in ‘Bobovac’—67.00 mg/100 g of FW, and gallic acid in ‘Bobovac’ and ‘Kraljevčica’—8.35 and 7.40 mg/100 g of FW, respectively. The highest content of patulin was detected in ‘Kraljevčica’ followed by ‘Apistar’—1687 and 1435 µg/kg, respectively. In apple cultivars ‘Brčko’, ‘Adamčica’ and ‘Idared’, patulin was not detected. Furthermore, the patulin content was positively correlated with gallic acid (r = 0.4226; p = 0.002), catechin (r = 0.3717; p = 0.008) and epicatechin (r = 0.3305; p = 0.019). This fact indicates that higher contents of gallic acid, catechin and epicatechin negatively affected and boost patulin concentration in examined apple cultivars. This can be related to the prooxidant activity of polyphenolic compounds and sensitivity of P. expansum to the disturbance of oxidative status.

Contamination of Acorns of Pedunculate Oak (Quercus robur L.), as Feed Material, by Moulds and Mycotoxins

Abstract In the past, pigs were commonly fed with acorns, and this was of remarkable economic importance. Currently this habit is continued in some areas, especially for production of prime-quality Iberian ham. Mature acorns, after shedding and during storage in unsuitable conditions, can be quickly infected with spores of many moulds, which cause mummification, blackening, dehydration, and nutrient loss. This study aimed to evaluate the quality of acorns of pedunculate oak (Quercus robur L.). The samples were collected in 2017 in southern Wielkopolska (central part of Poland), as feed material. In mouldy acorns a very high number of fungi was found (2.6 × 106 cfu/g), and 97% of them represented pathogenic Penicillium spp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed in mouldy acorns high concentrations of mycophenolic acid (14580 μg/kg) and patulin (50 μg/kg). The dominant mould species, Penicillium expansum, showed a high cytotoxicity of swine kidney cells using assay based on the conversion of the tetrazolium salt, 3-(4,5, dimethylthiazol-2-yl)-2-5 diphenyltetrazolium (MTT). This raises the question if the pathogenic metabolites of moulds present in acorns can be dangerous for livestock, especially pigs, and people, as acorns are beginning to be seen as an interesting and functional part of their diet.

A novel insight into fluorescent sensor for patulin detection using thiol-terminated liposomes with encapsulated coumarin-6 as signal probe

Nanocomposites of thiol-terminated liposomes encapsulating with coumarin-6 (CM6@Lip-SH) were successfully prepared via a simple thin-film dispersion method to construct a novel fluorescent sensor for selectively detecting trace amounts of patulin. Thiol group (SH) was designed not only as a specific recognition element to capture patulin, but also as a convenient linker for the further separation of patulin-derivatized and un-derivatized CM6@Lip-SH by combination with magnetic NH2-Au@Fe3O4 nanoparticles. Liposomes primarily provided an effective platform with a large surface area for facilitated accommodation of large amounts of recognition element (SH group) and fluorophore (coumarin-6). In such an assay protocol, a reliable link was established between the changes in fluorescent intensity (ΔF) from the nanocomposites of CM6@Lip-SH/NH2-Au@Fe3O4 and the concentrations of patulin in the range of 0.05–20 ng mL−1, with the correlation coefficient of 0.996. This approach also effectively eliminated the background interference from other mycotoxins and metal ions. Under the optimal conditions, the designed sensor displayed excellent performance for patulin analysis, with an extremely low detection limit (0.033 ng mL−1), high recovery (96.2–107.6 %) and excellent selectivity. Furthermore, the feasibility of its applications has also been demonstrated in the analysis of real juice samples, providing a novel tactics for rational design of a fluorescence assay, for point-of-care diagnostics of patulin, with great potential to be extended to other hazardous compounds by substitution of the recognition elements.