The Experts below are selected from a list of 2835 Experts worldwide ranked by ideXlab platform

Randy W Worobo - One of the best experts on this subject based on the ideXlab platform.

  • Patulin reduction in apple juice from concentrate by uv radiation and comparison of kinetic degradation models between apple juice and apple cider
    Journal of Food Protection, 2012
    Co-Authors: Kitipong Assatarakul, John J Churey, David C Manns, Randy W Worobo
    Abstract:

    Patulin, a mycotoxin produced by several genera of fungi, includingByssochlamys, Aspergillus,andPenicillium,has been an important concern in apple cider and apple juice due to its toxicity and health consequences. In this study, the effects of UV on the Patulin level, physical and chemical properties, and sensory attributes in apple juice from concentrate were investigated. Kinetic modeling of Patulin reduction by UV radiation in apple juice from concentrate was calculated and compared with the degradation rate observed previously in apple cider. From an initial Patulin contamination of approximately 1,000 ppb (mg/liter), the UV exposure, ranging from 14.2 mJ/cm 2 (one pass) to 99.4 mJ/cm 2 (seven passes), was successful in reducing Patulin levels by 72.57%i2.76%to 5.14%i0.70%, respectively. Patulin reduction by UV radiation followed first-order kinetic modeling in a fashion similar to first-order microbial inactivation. An exponential correlation between UV exposure and the percentage of Patulin remaining was observed, giving anr 2 value of 0.9950. Apple juice was repeatedly exposed to 14.2 mJ/cm 2 for each treatment, and Patulin levels were significantly decreased when compared with the level obtained with the previous UV exposure treatment. While there were no significant differences in the percentages of titratable acidity and ascorbic acid (P.0.05), there were minor yet random sampling differences in pH and degrees Brix (1uBrix is 1 g of sucrose in 100 g of solution; theuBrix represents the soluble solids content of the solution as percentage by weight [%, wt/wt]) (P#0.05). A significant difference (P# 0.05) in sensory perception for the finished apple juice was detected between the control and the full seven-pass UV radiation treatment using an experienced consumer panel and a triangle test. Patulin reduction by UV radiation from both the current study and a previous study involving apple cider was compared, which showed that both matrices strongly fit a first-order kinetic degradation model. However, the kinetic constant for degradation in apple juice was approximately 5.5 times greater than that observed in an apple cider matrix.

  • reducing Patulin contamination in apple juice by using inactive yeast
    Journal of Food Protection, 2011
    Co-Authors: Tianli Yue, Qinfang Dong, Caixia Guo, Randy W Worobo
    Abstract:

    The mycotoxin, Patulin (4-hydroxy-4H-furo[3,2c]pyran-2[6H]-one), is a secondary metabolite produced mainly in rotten parts of fruits and vegetables, most notably apples and apple products, by a wide range of fungal species in the genera Penicillium, Aspergillus, and Byssochlamys. Due to its mutagenic and teratogenic nature and possible health risks to consumers, many countries have regulations to reduce levels of Patulin in apple products. In the present study, reduction of Patulin contamination in apple juice by using 10 different inactivated yeast strains was assessed. Our results indicated that nearly twofold differences in biomass existed among the 10 yeast strains. Eight of the 10 inactivated yeast strains could provide >50% Patulin reduction in apple juice within 24 h, with the highest reduction rate being >72%. Furthermore, juice quality parameters, i.e., degrees Brix, total sugar, titratable acidity, color value, and clarity, of the treated apple juice were very similar to those of the untreated Patulin-free juice. Potential applications of using inactivated yeast strain for Patulin control are also discussed.

  • reduction of Patulin in apple cider by uv radiation
    Journal of Food Protection, 2010
    Co-Authors: Qingfang Dong, John J Churey, David C Manns, Guoping Feng, Randy W Worobo
    Abstract:

    The presence of the mycotoxin Patulin in processed apple juice and cider presents a continual challenge to the food industry as both consumer health and product quality issues. Although several methods for control and/or elimination of Patulin have been proposed, no unifying method has been commercially successful for reducing Patulin burdens while maintaining product quality. In the present study, exposure to germicidal UV radiation was evaluated as a possible commercially viable alternative for the reduction and possible elimination of the Patulin mycotoxin in fresh apple cider. UV exposure of 14.2 to 99.4 mJ/cm 2 resulted in a significant and nearly linear decrease in Patulin levels while producing no quantifiable changes in the chemical composition (i.e., pH, Brix, and total acids) or organoleptic properties of the cider. For the range of UV doses tested, Patulin levels decreased by 9.4 to 43.4%; the greatest reduction was achieved after less than 15 s of UV exposure. The method of UV radiation (the CiderSure 3500 system) is an easily implemented, high-throughput, and cost-effective method that offers simultaneous UV pasteurization of cider and juice products and reduction and/or elimination of Patulin without unwanted alterations in the final product.

  • influence of storage temperature and apple variety on Patulin production by penicillium expansum
    Journal of Food Protection, 2009
    Co-Authors: Beatriz De Cassia Martins Salomao, John J Churey, Glaucia Maria Falcao De Aragao, Olga I Padillazakour, Randy W Worobo
    Abstract:

    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°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°C yielded significantly higher Patulin concentrations than did those incubated at 11°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 ...

  • Comprehensive Review of Patulin Control Methods in Foods
    Comprehensive reviews in food science and food safety, 2005
    Co-Authors: Matthew M. Moake, Olga I. Padilla-zakour, Randy W Worobo
    Abstract:

    The mycotoxin, Patulin (4-hydroxy-4H-furo [3, 2c] pyran-2[6H]-one), is produced by a number of fungi common to fruit- and vegetable-based products, most notably apples. Despite Patulin's original discovery as an antibiotic, it has come under heavy scrutiny for its potential negative health effects. Studies investigating these health effects have proved inconclusive, but there is little doubt as to the potential danger inherent in the contamination of food products by Patulin. The danger posed by Patulin necessitates its control and removal from foods products, creating a demand for handling and processing techniques capable of doing so, preferably at low cost to industry. With this being the case, much research has been devoted to understanding the basic chemical and biological nature of Patulin, as well as its interaction within foods and food production. While past resarch has elucidated a great deal, Patulin contamination continues to be a challenge for athe food industry. Here, we review in depth the past research on Patulin with an emphasis upon its influence within the food industry, including its regulation, health effects, biosynthesis, detection, quantification, distribution within foods, and control, during the various stages of apple juice production. Finally, key areas where future Patulin research should focus to best control the Patulin contamination problem within the food industry are addressed.

Dov Prusky - One of the best experts on this subject based on the ideXlab platform.

  • apple intrinsic factors modulating the global regulator laea the Patulin gene cluster and Patulin accumulation during fruit colonization by penicillium expansum
    Frontiers in Plant Science, 2018
    Co-Authors: Dilip Kumar, Joanna Tannous, Nancy P Keller, Dov Prusky, Edward Sionov
    Abstract:

    The mycotoxin Patulin is produced in colonized tissue by Penicillium expansum during storage of apples and is significantly affected by environmental factors that contribute to its accumulation. Few reports have, however, examined the effect of natural intrinsic factors associated with the fruit on the production of Patulin. Here we find that with advancing maturity, Golden Delicious apples show increased concentrations of total soluble solids (TSS) from 14 to 17% associated with the increased expression of the global transcription factor involved in regulation of secondary metabolite biosynthesis in filamentous fungi, laeA expression and Patulin accumulation. However, the apple cultivar Granny Smith, with similar TSS values but differing in pH levels and malic acid concentrations, showed reduced expression levels of laeA and the Patulin biosynthesis gene cluster (pat genes) and Patulin accumulation, suggesting a complexity of host factors contribution to Patulin accumulation during P. expansum colonization. To start elucidating these apple intrinsic factors, we examined their in vitro impact on laeA and pat gene expression concomitant with Patulin synthesis. Increasing sucrose concentrations from 15 to 175 mM repressed laeA and pat gene expression and Patulin production. However, this affect was modified and often reversed and sometimes accentuated by changes in pH, or the addition of malic acid or the major apple phenolic compounds, chlorogenic acid and epicatechin. While the increase in malic acid from 0 to1% increased laeA and pat gene expression, the decrease in pH from 3.5 to 2.5 reduced their expression. Also the increased laeA and pat genes expressions at increasing epicatechin concentrations from 0 to 1mM, was reversed by increasing sucrose concentrations, all together suggesting the complexity of the interactions in vivo. .

  • laea regulation of secondary metabolism modulates virulence in penicillium expansum and is mediated by sucrose
    Molecular Plant Pathology, 2017
    Co-Authors: Dilip Kumar, Joanna Tannous, Nancy P Keller, Shiping Tian, Yong Chen, Shiri Barad, Xingyu Luo, Amit Dubey, Nofar Glam Matana, Dov Prusky
    Abstract:

    Summary Penicillium expansum, the causal agent of blue mould rot, is a critical health concern because of the production of the mycotoxin Patulin in colonized apple fruit tissue. Although Patulin is produced by many Penicillium species, the factor(s) activating its biosynthesis are not clear. Sucrose, a key sugar component of apple fruit, was found to modulate Patulin accumulation in a dose-responsive pattern. An increase in sucrose culture amendment from 15 to 175 mm decreased both Patulin accumulation and expression of the global regulator laeA by 175- and five-fold, respectively, whilst increasing expression of the carbon catabolite repressor creA. LaeA was found to regulate several secondary metabolite genes, including the Patulin gene cluster and concomitant Patulin synthesis in vitro. Virulence studies of ΔlaeA mutants of two geographically distant P. expansum isolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit, ranging from no reduction for Ch-Pe-T01 strains to 15%–25% reduction for both strains in mature fruit, with the ΔlaeA strains of Is-Pe-21 always showing a greater loss in virulence. The results suggest the importance of abiotic factors in LaeA regulation of Patulin and other secondary metabolites that contribute to pathogenicity.

  • ammonia activates pacc and Patulin accumulation in an acidic environment during apple colonization by penicillium expansum
    Molecular Plant Pathology, 2016
    Co-Authors: Shiri Barad, Amir Sherman, Eduardo A Espeso, Dov Prusky
    Abstract:

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin Patulin in colonized tissue. The factor(s) inducing Patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although Patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to Patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and Patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the Patulin biosynthesis cluster. Ammonia induced Patulin accumulation concurrently with the transcript activation of pacC and Patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as Patulin.

  • accumulation of the mycotoxin Patulin in the presence of gluconic acid contributes to pathogenicity of penicillium expansum
    Molecular Plant-microbe Interactions, 2014
    Co-Authors: Shiri Barad, Sigal Brown Horowitz, Ilana Kobiler, Amir Sherman, Dov Prusky
    Abstract:

    Penicillium expansum, the causal agent of blue mold rot, causes severe postharvest fruit maceration through secretion of D-gluconic acid (GLA) and secondary metabolites such as the mycotoxin Patulin in colonized tissue. GLA involvement in pathogenicity has been suggested but the mechanism of Patulin accumulation and its contribution to P. expansum pathogenicity remain unclear. The roles of GLA and Patulin accumulation in P. expansum pathogenicity were studied using i) glucose oxidase GOX2-RNAi mutants exhibiting decreased GOX2 expression, GLA accumulation, and reduced pathogenicity; ii) IDH-RNAi mutants exhibiting downregulation of IDH (the last gene in Patulin biosynthesis), reduced Patulin accumulation, and no effect on GLA level; and iii) PACC-RNAi mutants exhibiting downregulation of both GOX2 and IDH that reduced GLA and Patulin production. Present results indicate that conditions enhancing the decrease in GLA accumulation by GOX2-RNAi and PACC-RNAi mutants, and not low pH, affected Patulin accumulat...

Joanna Tannous - One of the best experts on this subject based on the ideXlab platform.

  • apple intrinsic factors modulating the global regulator laea the Patulin gene cluster and Patulin accumulation during fruit colonization by penicillium expansum
    Frontiers in Plant Science, 2018
    Co-Authors: Dilip Kumar, Joanna Tannous, Nancy P Keller, Dov Prusky, Edward Sionov
    Abstract:

    The mycotoxin Patulin is produced in colonized tissue by Penicillium expansum during storage of apples and is significantly affected by environmental factors that contribute to its accumulation. Few reports have, however, examined the effect of natural intrinsic factors associated with the fruit on the production of Patulin. Here we find that with advancing maturity, Golden Delicious apples show increased concentrations of total soluble solids (TSS) from 14 to 17% associated with the increased expression of the global transcription factor involved in regulation of secondary metabolite biosynthesis in filamentous fungi, laeA expression and Patulin accumulation. However, the apple cultivar Granny Smith, with similar TSS values but differing in pH levels and malic acid concentrations, showed reduced expression levels of laeA and the Patulin biosynthesis gene cluster (pat genes) and Patulin accumulation, suggesting a complexity of host factors contribution to Patulin accumulation during P. expansum colonization. To start elucidating these apple intrinsic factors, we examined their in vitro impact on laeA and pat gene expression concomitant with Patulin synthesis. Increasing sucrose concentrations from 15 to 175 mM repressed laeA and pat gene expression and Patulin production. However, this affect was modified and often reversed and sometimes accentuated by changes in pH, or the addition of malic acid or the major apple phenolic compounds, chlorogenic acid and epicatechin. While the increase in malic acid from 0 to1% increased laeA and pat gene expression, the decrease in pH from 3.5 to 2.5 reduced their expression. Also the increased laeA and pat genes expressions at increasing epicatechin concentrations from 0 to 1mM, was reversed by increasing sucrose concentrations, all together suggesting the complexity of the interactions in vivo. .

  • laea regulation of secondary metabolism modulates virulence in penicillium expansum and is mediated by sucrose
    Molecular Plant Pathology, 2017
    Co-Authors: Dilip Kumar, Joanna Tannous, Nancy P Keller, Shiping Tian, Yong Chen, Shiri Barad, Xingyu Luo, Amit Dubey, Nofar Glam Matana, Dov Prusky
    Abstract:

    Summary Penicillium expansum, the causal agent of blue mould rot, is a critical health concern because of the production of the mycotoxin Patulin in colonized apple fruit tissue. Although Patulin is produced by many Penicillium species, the factor(s) activating its biosynthesis are not clear. Sucrose, a key sugar component of apple fruit, was found to modulate Patulin accumulation in a dose-responsive pattern. An increase in sucrose culture amendment from 15 to 175 mm decreased both Patulin accumulation and expression of the global regulator laeA by 175- and five-fold, respectively, whilst increasing expression of the carbon catabolite repressor creA. LaeA was found to regulate several secondary metabolite genes, including the Patulin gene cluster and concomitant Patulin synthesis in vitro. Virulence studies of ΔlaeA mutants of two geographically distant P. expansum isolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit, ranging from no reduction for Ch-Pe-T01 strains to 15%–25% reduction for both strains in mature fruit, with the ΔlaeA strains of Is-Pe-21 always showing a greater loss in virulence. The results suggest the importance of abiotic factors in LaeA regulation of Patulin and other secondary metabolites that contribute to pathogenicity.

  • Secondary metabolism in Penicillium expansum: Emphasis on recent advances in Patulin research
    Critical Reviews in Food Science and Nutrition, 2017
    Co-Authors: Joanna Tannous, André El Khoury, Ali Atoui, Roger Lteif, Isabelle Oswald, Nancy P Keller, Olivier Puel
    Abstract:

    The plant pathogenic fungus Penicillium expansum is a major concern of the global food industry due to its wide occurrence and ability to produce various mycotoxins, of which the most significant is Patulin. Relatively less highlighted in the literature, in comparison with the other food-borne mycotoxins, Patulin is one of the main factors in economic losses of vegetables and fruits. Otherwise, Patulin is a health hazard which results in both short-term and long-term risks. This review includes knowledge on the biosynthetic mechanisms used for secondary metabolite production in P. expansum, with special emphasis on Patulin biosynthesis. The abiotic factors triggering the production of Patulin and the strategies developed to reduce or prevent the contamination by this mycotoxin are comprehensively discussed. The database presented in this review would be useful for the prioritization and development of future research.

  • Patulin transformation products and last intermediates in its biosynthetic pathway, E- and Z-ascladiol, are not toxic to human cells
    Archives of Toxicology, 2017
    Co-Authors: Joanna Tannous, Yannick Lippi, André El Khoury, Selma P. Snini, Rhoda El Khoury, Cécile Canlet, Philippe Pinton, Imourana Alassane-kpembi, Thierry Gauthier, Ali Atoui
    Abstract:

    Patulin is the main mycotoxin contaminating apples. During the brewing of alcoholic beverages, this mycotoxin is degraded to ascladiol, which is also the last precursor of Patulin. The present study aims (1) to characterize the last step of the Patulin biosynthetic pathway and (2) to describe the toxicity of ascladiol. A patE deletion mutant was generated in Penicillium expansum. In contrast to the wild strain, this mutant does not produce Patulin but accumulates high levels of E-ascladiol with few traces of Z-ascladiol. This confirms that patE encodes the Patulin synthase involved in the conversion of E-ascladiol to Patulin. After purification, cytotoxicities of Patulin and E- and Z-ascladiol were investigated on human cell lines from liver, kidney, intestine, and immune system. Patulin was cytotoxic for these four cell lines in a dose-dependent manner. By contrast, both E- and Z-ascladiol were devoid of cytotoxicity. Microarray analyses on human intestinal cells treated with Patulin and E-ascladiol showed that the latter, unlike Patulin, did not alter the whole human transcription. These results demonstrate that E- and Z-ascladiol are not toxic and therefore Patulin detoxification strategies leading to the accumulation of ascladiol are good approaches to limit the Patulin risk.

  • Patulin is a cultivar dependent aggressiveness factor favouring the colonization of apples by penicillium expansum
    Molecular Plant Pathology, 2016
    Co-Authors: Joanna Tannous, Selma P. Snini, Pauline Heuillard, Sylviane Bailly, Yannick Lippi
    Abstract:

    The blue mould decay of apples is caused by Penicillium expansum and is associated with contamination by Patulin, a worldwide regulated mycotoxin. Recently, a cluster of 15 genes (patA-patO) involved in Patulin biosynthesis was identified in P. expansum. blast analysis revealed that patL encodes a Cys6 zinc finger regulatory factor. The deletion of patL caused a drastic decrease in the expression of all pat genes, leading to an absence of Patulin production. Pathogenicity studies performed on 13 apple varieties indicated that the PeΔpatL strain could still infect apples, but the intensity of symptoms was weaker compared with the wild-type strain. A lower growth rate was observed in the PeΔpatL strain when this strain was grown on nine of the 13 apple varieties tested. In the complemented PeΔpatL:patL strain, the ability to grow normally in apple and the production of Patulin were restored. Our results clearly demonstrate that Patulin is not indispensable in the initiation of the disease, but acts as a cultivar-dependent aggressiveness factor for P. expansum. This conclusion was strengthened by the fact that the addition of Patulin to apple infected by the PeΔpatL mutant restored the normal fungal colonization in apple.

Ting Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Patulin in apples and apple based food products the burdens and the mitigation strategies
    Toxins, 2018
    Co-Authors: Lei Zhong, Jason Carere, Ting Zhou
    Abstract:

    Apples and apple-based products are among the most popular foods around the world for their delightful flavors and health benefits. However, the commonly found mold, Penicillium expansum invades wounded apples, causing the blue mold decay and ensuing the production of Patulin, a mycotoxin that negatively affects human health. Patulin contamination in apple products has been a worldwide problem without a satisfactory solution yet. A comprehensive understanding of the factors and challenges associated with Patulin accumulation in apples is essential for finding such a solution. This review will discuss the effects of the pathogenicity of Penicillium species, quality traits of apple cultivars, and environmental conditions on the severity of apple blue mold and Patulin contamination. Moreover, beyond the complicated interactions of the three aforementioned factors, Patulin control is also challenged by the lack of reliable detection methods in food matrices, as well as unclear degradation mechanisms and limited knowledge about the toxicities of the metabolites resulting from the degradations. As apple-based products are mainly produced with stored apples, pre- and post-harvest strategies are equally important for Patulin mitigation. Before storage, disease-resistance breeding, orchard-management, and elicitor(s) application help control the Patulin level by improving the storage qualities of apples and lowering fruit rot severity. From storage to processing, Patulin mitigation strategies could benefit from the optimization of apple storage conditions, the elimination of rotten apples, and the safe and effective detoxification or biodegradation of Patulin.

  • mitigation of Patulin in fresh and processed foods and beverages
    Toxins, 2017
    Co-Authors: Ting Zhou, David J Ioi, Rong Tsao, Massimo F Marcone
    Abstract:

    Patulin is a mycotoxin of food safety concern. It is produced by numerous species of fungi growing on fruits and vegetables. Exposure to the toxin is connected to issues neurological, immunological, and gastrointestinal in nature. Regulatory agencies worldwide have established maximum allowable levels of 50 µg/kg in foods. Despite regulations, surveys continue to find Patulin in commercial food and beverage products, in some cases, to exceed the maximum limits. Patulin content in food can be mitigated throughout the food processing chain. Proper handling, storage, and transportation of food can limit fungal growth and Patulin production. Common processing techniques including pasteurisation, filtration, and fermentation all have an effect on Patulin content in food but individually are not sufficient safety measures. Novel methods to remove or detoxify Patulin have been reviewed. Non-thermal processing techniques such as high hydrostatic pressure, UV radiation, enzymatic degradation, binding to microorganisms, and chemical degradation all have potential but have not been optimised. Until further refinement of these methods, the hurdle approach to processing should be used where food safety is concerned. Future development should focus on determining the nature and safety of chemicals produced from the breakdown of Patulin in treatment techniques.

  • kinetics of Patulin degradation in model solution apple cider and apple juice by ultraviolet radiation
    Food Science and Technology International, 2013
    Co-Authors: Tatiana Koutchma, Yan Zhu, Keith Warriner, Suqin Shao, Ting Zhou
    Abstract:

    Patulin is a mycotoxin produced by a wide range of molds involved in fruit spoilage, most commonly by Penicillium expansum and is a health concern for both consumers and manufacturers. The current study evaluated feasibility of monochromatic ultraviolet (UV) radiation at 253.7nm as a possible commercial appli- cation for the reduction of Patulin in fresh apple cider and juice. The R-52G MINERALIGHT UV bench top lamp was used for Patulin destruction. It was shown that 56.5%, 87.5%, 94.8% and 98.6% reduction of Patulin can be achieved, respectively, in the model solution, apple cider, apple juice without ascorbic acid addition and apple juice with ascorbic acid addition in 2-mm thickness sample initially spiked by 1mgL � 1 of Patulin after UV exposure for 40min at UV irradiance of 3.00mWcm � 2 . A mathematic model to compare the deg- radation rate and effective UV dose was developed. The effective UV doses that were directly absorbed by Patulin for photochemical reaction were 430, 674, 724 and 763mJcm � 3 , respectively. The fluence-based decimal reduction time was estimated to 309.3, 31.3, 28.9 and 5.1mWcm � 2 � min, respectively, in four media mentioned above. The degradation of Patulin followed the first-order reaction model. The time-based and fluence-based reaction rate constants were determined to predict Patulin degradation. The time-based reac- tion rate constant of samples treated in dynamic regime with constant stirring (model solution: 2.95E-4s � 1 , juice: 4.31E-4s � 1 ) were significantly higher than samples treated in static regime (model solution: 2.79E- 4s � 1 , juice: 3.49E-4s � 1 , p <0.05) when applied UV irradiance and sample thickness were consistent. The reaction rate constant of Patulin degradation in apple juice was significantly higher than model solution (p <0.05). Although further investigations are still needed, the results of this study demonstrated that UV radiation may be an effective method for treating Patulin-containing apple cider and juice.

  • Factors Affecting Patulin Production by Penicillium expansum
    Journal of Food Protection, 2002
    Co-Authors: J. L. Mccallum, R. Tsao, Ting Zhou
    Abstract:

    Patulin, a mycotoxin produced by Penicillium spp. during fruit spoilage, is a major concern with regard to human health because exposure can result in severe acute and chronic toxicity, including carcinogenic, mutagenic, and teratogenic effects. In this study, we investigated the effects of Penicillium expansum isolate, apple cultivar, storage temperature and time, and pH on the production of Patulin. Patulin was analyzed by a previously developed micellar electrokinetic capillary electrophoresis method. P. expansum isolates originating from across Ontario produced widely differing levels of Patulin, ranging from 0 to >6 mg/g by dry mycelial weight. The highest Patulin levels were those for isolates displaying aggressive growth (characterized by rapidly increasing acidity) accompanied by profuse mycelial development. Distinct patterns in fungal growth rates and Patulin production were evident among isolates grown in McIntosh, Empire, and Mutsu ciders. Extensive fungal growth and higher Patulin levels (538...

Shiping Tian - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a short chain dehydrogenase reductase and its function in Patulin biodegradation in apple juice
    Food Chemistry, 2021
    Co-Authors: Mengyang Xing, Yong Chen, Shiping Tian
    Abstract:

    Abstract Biodegradation based on microbial enzymes is considered to be one of the promising ways for controlling Patulin contamination. However, few Patulin degrading enzymes have been isolated and characterized until now. Here, a short-chain dehydrogenase/reductase (SDR) gene, CgSDR, was cloned from a yeast strain Candida guilliermondii, and expressed in Escherichia coli. The expression of CgSDR conferred a strong Patulin tolerance and degradation ability to E. coli, and purified CgSDR could transform Patulin into E-ascladiol in vitro with NADPH as a coenzyme. Moreover, addition of CgSDR at 150 μg/mL could reduce 80% of Patulin in apple juice and the biodegradation process did not affect the quality of the apple juice. A molecular docking analysis and site-directed mutagenesis indicated that CgSDR might interact with Patulin via VAL188 as an active binding sites. The findings provide new insights for developing enzymic formulations for mycotoxin detoxification in fruit derived products.

  • ribonucleoside diphosphate reductase plays an important role in Patulin degradation by enterobacter cloacae subsp dissolvens
    Journal of Agricultural and Food Chemistry, 2020
    Co-Authors: Mengyang Xing, Yong Chen, Boqiang Li, Shiping Tian
    Abstract:

    : Patulin contamination is a worldwide concern due to its significant impact on human health. Several yeast strains have been screened for Patulin biodegradation; however, little information is available on bacterial strains and their mechanism of degradation. In the present study, we isolated a bacterial strain TT-09 and identified it as Enterobacter cloacae subsp. dissolvens based on the BioLog system and 16S rDNA phylogenetic analysis. The strain was demonstrated to be able to transform Patulin into E-ascladiol. Isobaric tags for relative and absolute quantitation and reverse transcription quantitative polymerase chain reaction analyses provided evidence that ribonucleoside diphosphate reductase (NrdA), an important enzyme involved in DNA biosynthesis, plays a crucial role in Patulin degradation. Deletion of nrdA resulted in a total loss in the ability to degrade Patulin in TT-09. These results indicate a new function for NrdA in mycotoxin biodegradation. The present study provides evidence for understanding a new mechanism of Patulin degradation and information that can be used to develop new approaches for managing Patulin contamination.

  • dissection of Patulin biosynthesis spatial control and regulation mechanism in penicillium expansum
    Environmental Microbiology, 2019
    Co-Authors: Yong Chen, Yuanyuan Zong, Xiao Wang, Manyuan Long, Yanjiao Shang, Zhanquan Zhang, Shiping Tian
    Abstract:

    The Patulin biosynthesis is one of model pathways in an understanding of secondary metabolite biology and network novelties in fungi. However, molecular regulation mechanism of Patulin biosynthesis and contribution of each gene related to the different catalytic enzymes in the biochemical steps of the pathway remain largely unknown in fungi. In this study, the genetic components of Patulin biosynthetic pathway were systematically dissected in Penicillium expansum, which is an important fungal pathogen and Patulin producer in harvested fruits and vegetables. Our results revealed that all the 15 genes in the cluster are involved in Patulin biosynthesis. Proteins encoded by those genes are compartmentalized in various subcellular locations, including cytosol, nucleus, vacuole, endoplasmic reticulum, plasma membrane and cell wall. The subcellular localizations of some proteins, such as PatE and PatH, are required for the Patulin production. Further, the functions of eight enzymes in the 10-step Patulin biosynthetic pathway were verified in P. expansum. Moreover, velvet family proteins, VeA, VelB and VelC, were proved to be involved in the regulation of Patulin biosynthesis, but not VosA. These findings provide a thorough understanding of the biosynthesis pathway, spatial control and regulation mechanism of Patulin in fungi.

  • laea regulation of secondary metabolism modulates virulence in penicillium expansum and is mediated by sucrose
    Molecular Plant Pathology, 2017
    Co-Authors: Dilip Kumar, Joanna Tannous, Nancy P Keller, Shiping Tian, Yong Chen, Shiri Barad, Xingyu Luo, Amit Dubey, Nofar Glam Matana, Dov Prusky
    Abstract:

    Summary Penicillium expansum, the causal agent of blue mould rot, is a critical health concern because of the production of the mycotoxin Patulin in colonized apple fruit tissue. Although Patulin is produced by many Penicillium species, the factor(s) activating its biosynthesis are not clear. Sucrose, a key sugar component of apple fruit, was found to modulate Patulin accumulation in a dose-responsive pattern. An increase in sucrose culture amendment from 15 to 175 mm decreased both Patulin accumulation and expression of the global regulator laeA by 175- and five-fold, respectively, whilst increasing expression of the carbon catabolite repressor creA. LaeA was found to regulate several secondary metabolite genes, including the Patulin gene cluster and concomitant Patulin synthesis in vitro. Virulence studies of ΔlaeA mutants of two geographically distant P. expansum isolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit, ranging from no reduction for Ch-Pe-T01 strains to 15%–25% reduction for both strains in mature fruit, with the ΔlaeA strains of Is-Pe-21 always showing a greater loss in virulence. The results suggest the importance of abiotic factors in LaeA regulation of Patulin and other secondary metabolites that contribute to pathogenicity.

  • biodegradation mechanisms of Patulin in candida guilliermondii an itraq based proteomic analysis
    Toxins, 2017
    Co-Authors: Yong Chen, Huaimin Peng, Xiao Wang, Manyuan Long, Shiping Tian
    Abstract:

    Patulin, a potent mycotoxin, contaminates fruits and derived products worldwide, and is a serious health concern. Several yeast strains have shown the ability to effectively degrade Patulin. However, the mechanisms of its biodegradation still remain unclear at this time. In the present study, biodegradation and involved mechanisms of Patulin by an antagonistic yeast Candida guilliermondii were investigated. The results indicated that C. guilliermondii was capable of not only multiplying to a high population in medium containing Patulin, but also effectively reducing Patulin content in culture medium. Degradation of Patulin by C. guilliermondii was dependent on the yeast cell viability, and mainly occurred inside cells. E-ascladiol was the main degradation product of Patulin. An iTRAQ-based proteomic analysis revealed that the responses of C. guilliermondii to Patulin were complex. A total of 30 differential proteins involved in 10 biological processes were identified, and more than two-thirds of the differential proteins were down-accumulated. Notably, a short-chain dehydrogenase (gi|190348612) was markedly induced by Patulin at both the protein and mRNA levels. Our findings will provide a foundation to help enable the commercial development of an enzyme formulation for the detoxification of Patulin in fruit-derived products.