Presence Of Patulin Research Articles

Chemometrics and electrochemistry joined hands to develop a novel and intelligent electronic device for simultaneous determination of malathion and diazinon in fruit juices: A progress in multidisciplinary studies

In this work, chemometrics and electrochemistry connected to each other to open a new way for assisting food industry specialists based on developing a novel electrochemical sensor for simultaneous determination of malathion (MT) and diazinon (DZ) in the presence of patulin (PT) and citrinin (CT) as uncalibrated interference in fruit juices. The sensor was fabricated based on modification of a glassy carbon electrode (GCE) by chitosan-ionic liquid (Ch-IL), electrodeposition of gold nanoparticles (Au NPs), drop-casting of multiwalled carbon nanotubes-IL (MWCNTs-IL), and electrochemical synthesis of dual templates molecularly imprinted polymers (DTMIPs) in which MT and DZ were used as templates. Effects of experimental variables on structure and response of the sensor were screened and optimized by Min Run screening and central composite design, respectively. After optimization, the third-order hydrodynamic differential pulse voltammetric (HDPV) data were generated based on changing modulation times and modulation amplitudes as instrumental parameters and modeled by N-PLS/RTL, U-PLS/RTL, U-PCA/RTL, APARAFAC, PARAFAC2 and MCR-ALS to select the best one to assist the sensor for ultra selective simultaneous determination of MT in the presence of PT and CT as uncalibrated interference in fruit samples. The results confirmed the MCR-ALS was the best assistance for DTMIPs/MWCNTs-IL/Au NPs/Ch-IL/GCE for simultaneous determination of MT and DZ in the presence of PT and CT as uncalibrated interference in both synthesis and real samples. Performance of the sensor assisted by MCR-ALS for ultra selective simultaneous determination of MT (0.1 pM to 12.5 pM, LOD=0.01 pM) and DZ (0.25 pM to 8.5 pM, LOD=0.15 pM) was really admirable which was comparable with HPLC with UV detection while it was faster, simpler and low-cost in comparison to HPLC-UV which motivated us to introduce it as a reliable method to assist food industry specialists for quality assurance purposes.

Core-satellite nanoassembly system with aptamer-conjugated Au@Ag nanoparticles for SERS detection of patulin in apples

Patulin (PAT), a major contaminant in apples, poses a huge threat to human health as well as the economic sector. There is an urgent need to develop a sensitive, selective, and fast-responsive method to detect PAT in apples. However, one of the main challenges is overcoming the interferences of complex food matrices. In this study, we developed a highly sensitive competitive SERS sensor based on plasmonic nanoparticles modified by aptamers. The study utilized the formation of nanocomposites through aptamer-modified Au@Ag nanoparticles (NPs) and gold nano-stars (AuNSs) to induce high-intensity Raman signals from the SERS tag. Subsequently, in the presence of PAT, the nanocomposites underwent decomposition, evident through the significant decrease in SERS intensity. According to the standard curve established in this study, the detection limit was 0.0281 ng/mL. The competitive sensor was applied to spiked apple fruit and juice samples, indicating a recovery rate ranging from 91.98% to 102.94%. The excellent analytical performances and high sensitivity observed suggest the potential of the plasmonic nanocomposite sensing strategy in detecting PAT in real matrices.

An antifouling biosensor with dual modality readouts for detection of patulin in complex fruit juice

Herein, an antifouling sensing platform with electrochemical and fluorometric dual-signal readouts is proposed for the reliable detection of patulin (PAT) in orange and apple juice. The incorporation of an antifouling peptide of D-amino acids endows sensing surface with a sustained antifouling capability in complex detection system, effectively preventing nonspecific adsorption at the sensing interface. Moreover, the integration of both electrochemical and fluorescent signal readouts addresses the limitations inherent in each signal channel. And both electrochemical and fluorescent signal readouts would make up for the drawbacks of each signal channel and merge with the benefits of each transduction channel, ensuring mutual complementation of the detection results. In the sensing process, antifouling peptides and PAT-binding aptamers tagged with methylene blue (Mb-Apta) are covalently attached to gold nanoparticles (AuNPs), forming antifouling monolayers and sensing probes, respectively. Subsequently, SiO2-polyamidoamine (SiO2-PAMAM) will integrate with aptamers through electrostatic attraction. In the presence of PAT in the detection system, the Mb-Apta selectively bind with PAT molecules, resulting in Mb near to electrode surface and release SiO2-PAMAM into sample systems. Consequently, noticeable electrochemical and robust aggregation-induced emission (AIE) dual-signals are generated. The combined utilization of both electrochemical and fluorescent signal readouts offers enhanced detection sensitivity and an extended linear range.

A novel ECL aptasensor for ultra-highly sensitive detection of patulin based on terbium organic gels as Co-reaction accelerator in a 3, 4, 9, 10-perylenetetracarboxylic acid/K2S2O8 system

Patulin (PAT), a fungal metabolite, which mainly exists in various moldy fruits, is greatly harmful to human. However, there are still many unsolved problems in the current detection of PAT. In the work, an ultra-highly sensitive and effective monitoring strategy for PAT was explored based on a novel electrochemiluminescence (ECL) aptasensor. Here, 3, 4, 9, 10-perylenetetracarboxylic acid (PTCA) was chosen as luminophore and terbium (Tb) metal organic gel (MOG) was prepared as a co-reaction accelerator. The MOG displayed a large surface area for immobilization of sufficient PTCA to catalyze co-reactant K2S2O8 to generate more sulfate radical anions (SO4• −), thus accelerating the electron-transfer (ET) rate to facilitate ECL efficiency. In the presence of PAT, the ECL signal was greatly quenched, which could be attributed to the specific binding effect between PAT aptamer and PAT. Based on this process, a wide range of PAT concentrations from 0.1 fg·mL−1 to 0.1 μg·mL−1 and a low detection limit of 0.02 fg·mL−1 (S/N = 3) were analyzed. The aptasensor showed excellent detection properties for trace patulin in terms of selectivity, sensitivity, stability, reproducibility and practicability. The designing ideas could serve as a model for the application of metal organic gels to design ultra-highly sensitive ECL platforms for food safety.

An ultrasensitive ratiometric aptasensor based on the dual-potential electrochemiluminescence of Ru(bpy)32+ in a novel ternary system for detection of Patulin in fruit products.

To sensitively monitor trace-level of toxic patulin (PAT), an ultrasensitive PAT ratiometric aptasensor based on the dual-potential electrochemiluminescence (ECL) of Ru(bpy)32+ was first proposed. Noteworthily, Ru(bpy)32+-doped trimetallic nanocube (Ru@Tri) innovatively integrated the luminophore and cathode coreaction accelerator (CCA), which could generate strong cathodic ECL in the existence of low concentration of K2S2O8. Simultaneously, anthocyanin-derived carbon quantum dots (anth-CQDs) prepared from purple potato skins was first served as a green anodic coreactant. And SiO2-coated anth-CQDs (anth-CQDs@SiO2) exhibited excellent performance for enhancing anodic ECL of Ru@Tri. Based on this, a novel ternary ECL system was established. In the presence of PAT, the ECL intensity ratio of anode to cathode (IECL-A/IECL-C) was significantly increased, and a low detection limit of 0.05pgmL-1 was obtained. Moreover, when proposed method and high performance liquid chromatography (HPLC) were simultaneously applied to series of fruit products, the obtained results were completely consistent, reflecting its practicability.

Ultrasensitive detection of patulin based on a Ag+-driven one-step dual signal amplification

Due to improper storage, the presence of patulin in fruits poses a threat to food safety. Herein, a one-step dual amplification strategy-based electrochemical aptasensor was proposed for patulin detection. Silver-palladium nanoparticles (AgPdNPs) with a hollow and branched structure were used as a supporting material for thionine to provide numerous attachment sites. AuNFs/g-C3N4 was employed as an electrode modification material, which has been demonstrated to facilitate electron transport and improve signal label loading capacity. Ag+ ions were released in the presence of patulin, activating the Ag+-DNAzyme on the electrode surface. The formed Ag+-DNAzymes further cyclically cleaved the substrate DNA, and the released sequences were used as a new trigger to mediate the secondary recirculation. This one-step dual amplification strategy enabled double target recycling without additional procedures. The signal cascade amplification through dual target recycling, was thus available for trace detection of patulin. Under the optimal conditions, the electrochemical aptasensor achieved a satisfactory linear range from 5.0 × 10-6 μg L-1 to 50 μg L-1 with a detection limit of 0.92 fg·mL-1 for the determination of patulin. In addition, the aptasensor exhibited favorable selectivity, reproducibility, repeatability and long-term stability, and thus can be employed for patulin detection in apple juice samples, providing excellent choice for the detection of trace patulin.

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.

A preliminary study on patulin contamination in spirit drinks

ABSTRACT A total of 120 spirit drinks and 40 apple juices were collected between 2018 and 2020 in three regions of Turkey and analysed by high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PDA) for the incidence of patulin. The analytical method was successfully validated for both matrices. In 26.7% of apple juice samples, patulin was quantified at levels between 5.8 and 66.4 µg L−1. Only one regulatory level exceedance was identified for apple juice. The mean dietary exposure of the adult population to patulin ranged from 0.083 to 0.091 ng kg−1 bw day−1. With the HPLC-PDA method, patulin was measured in quantifiable concentrations in 11 out of 25 cognac, 5 out of 40 liqueur, and 1 out of 10 whisky samples, up to a level of 42.6 µg/l, whereas all vodka samples were free from patulin. In only one liqueur sample, the presence of patulin could be confirmed with LC-MS/MS, at a level of 8.9 µg L−1.

An electrochemical aptasensor based on dual-enzymes-driven target recycling strategy for patulin detection in apple juice

The presence of patulin (PAT) in fruits poses a threat to human health. Herein, a dual-enzymes-driven target recycling (dual-EATR) strategy-based PAT electrochemical aptasensor was constructed. The branched structure of the labeling material silver-palladium nanoparticles (AgPdNPs) can effectively load thionine (Thi). Gold nanoparticles (AuNPs)/Fe metal-organic frameworks (FeMOF)-PEI-GO with effective catalytic activity can amplify the redox signal of Thi. The presence of PAT could trigger the dual target recycling assisted by Exonuclease Ⅲ and Mg2+-dependent DNAzyme. The dual-EATR strategy gradually accumulates detection signals and can realize ultra-sensitive detection of PAT. With the optimal conditions, the developed aptasensor showed satisfactory performance with the range from 5 × 10−7 ng mL−1 to 5 ng mL−1 and a low detection limit of 0.217 fg mL−1. Compared with the chromatographic method, the developed aptasensor has consistent detection results. In addition, the aptasensor exhibited favourable selectivity, reproducibility and long-term stability. In the analysis of real samples, the aptasensor had good accuracy (recovery%, 91.0–103) and high precision (RSD%, 2.69–4.98), and relative error of <13% compared with the spiked concentration. It is proved with 95% of confidence level that the spiked sample tested generated a signal response not significantly different from the true value (p > 0.6). The feasibility of the aptasensor in apple juice samples has been verified, providing an excellent choice for the detection of trace PAT.

A rapid and simple ratiometric fluorescent sensor for patulin detection based on a stabilized DNA duplex probe containing less amount of aptamer-involved base pairs

In this study, a sensor is described for determination of patulin by using ratiometric fluorescence measurement and strand displacement strategy. In the presence of patulin, the ratiometric fluorescence response decreases, owing to disassembly of DNA duplex structure and target-mediated release of TAMRA-labeled complementary DNA sequence2 (cDNA2). While, in the absence of target, the fluorescence resonance energy transfer (FRET) phenomenon happens between FAM and TAMRA under excitation at 490 nm, resulting in the enhancement of ratiometric signal. The use of ratiometric fluorescence signal with different signal indicators avoids the problem of environmental interference and improves the sensitivity of the aptasensor. Also, the DNA duplex structure contains minimum aptamer-involved base pair sequence, resulting in further improvement of the aptasensor sensitivity. This sensing platform provided a wide linear range from 15 ng/L to 35 μg/L and a detection limit of 6 ng/L for patulin. The aptasensor was used to determine patulin in spiked apple juice samples and showed satisfactory results.

Hierarchically porous Zr-MOFs labelled methylene blue as signal tags for electrochemical patulin aptasensor based on ZnO nano flower

In this work, the feasibility of a novel sensitive electrochemistry aptasensor for the detection of patulin (PAT) using hierarchically porous metal organic framework@methylene blue connection aptamer as signal tags was demonstrated. The substrate electrode of the aptasensor was prepared by electrodeposited gold nanoparticles (AuNPs) on chitosan-zinc oxide nano flower-modified electrode. Subsequently, the complementary single-stranded DNA was attached to the surface of the modified electrode by Au-S bond. Signal tags self-assemble on the surface of modified electrodes by aptamer-cDNA binding, while methylene blue as mediator for electrochemical detection. Thanks to the large specific surface area provided by zinc oxide nano flower, the electrode can load more signal tags and AuNPs to achieve signal amplification. In presence of PAT, Apt preferentially binds to PAT, causing dissociation of some Apt-cDNA and releasing some signal tags leading, resulting in decreased electrical signals. Under optimal conditions, the change in electrochemical signal was proportional to the logarithm of PAT concentration, from 5 × 10−8-5 × 10-1 μg mL−1, and the detection limit was estimated to be 1.46 × 10-8 μg mL-1. The aptasensor exhibited aceptable reproducibility, renewability, long-term stability and specificity. Moreover, aptasensor was reliable in determination of PAT in spiked apple juice samples.

A fluorometric aptasensor for patulin based on the use of magnetized graphene oxide and DNase I-assisted target recycling amplification.

A fluorometric patulin (PAT)assayis presented that is based on theuse of magnetic reducedgrapheneoxide (rGO) and DNase I. The fluorescence of the PAT aptamer labelled with6-carboxyfluorescein (FAM) is quenched by magnetized reduced graphene oxide (rGO-Fe3O4) due to fluorescence resonance energy transfer (FRET). However, in the presence of PAT, the labelled aptamer is stripped offfrom rGO-Fe3O4. The rGO-Fe3O4 is then magnetically separated so that the fluorescence of freelabelled PAT aptameris restored. DNase I cannot hydrolyze the aptamer on rGO-Fe3O4, but it can cleave the free aptamer-PAT complex. This will release FAM and PAT which can undergo a number of additional cycles to trigger the cleavage of abundant aptamer. Recycling of DNase I-assisted target therefore leads to a strong amplification of fluorescence and consequently to an assay with low limit of detection. The detection limit for PAT is as low as 0.28μgL-1 which is about 13 times lower than that without using DNase I. The method offers a new approach towards rapid, sensitive and selective detection based on anaptamer. Conceivably, it has a wide scope in that it may be applied to numerous other analytes if appropriate aptamers are available. Abstract Schematic of a fluorometric assay based on theuse of magnetic grapheneoxide and DNase I. It was applied to the determination of patulin. DNase I was introduced for recycling amplification. The detection limit is about 13 times lower than that without usingDNase I. Figure a contains poor quality of text in image. Otherwise, please provide replacement figure file.Thank you. I will provide the figure file.

Aptamer based voltammetric patulin assay based on the use of ZnO nanorods

The authors describe an aptamer based assay for the mycotoxin patulin (PAT). A gold electrode was modified with a composite made from ZnO nanorods (ZnO-NRs) and chitosan. The ZnO-NRs was prepared by reaction with ammonia and subsequent hydrothermal growth. Its properties were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Subsequently, thiol-modified aptamers were self-assembled on AuNPs that had been electrodeposited on the surface of the modified electrode. The presence of ZnO-NRs on the electrode increases the loading with AuNPs and aptamers. It also warrants a relatively stable microenvironment for the aptamers. In the presence of PAT, it will form a complex with the aptamer on the electrode surface. This hinders electron transfer from the electrode to the redox probe hexacyanoferrate and results in reduced current, which is typically measured at 0.176V (vs. Ag/AgCl). The concentration of PAT can be calculated from the differences in the peak current before and after incubation with PAT. The assay has a linear response in the 50ng·mL-1 to 0.5pg·mL-1 PAT concentration range and a 0.27pg·mL-1 lower detection limit. The sensor is specific, reproducible, repeatable, and long-term stable. It was successfully applied to the determination of PAT in spiked juice samples. Graphical abstract Schematic representation of aptamer based detection of patulin (PAT). It is based on the fact that ZnO nanorods on the surface of the electrode increase the loading of the gold nanoparticles and the aptamers, thereby improving the electrode performance.

Mimetic Ag nanoparticle/Zn-based MOF nanocomposite (AgNPs@ZnMOF) capped with molecularly imprinted polymer for the selective detection of patulin

Here, Ag nanoparticle/flake-like Zn-based MOF nanocomposite (AgNPs@ZnMOF) with great peroxidase-like activity was applied as an efficient support for molecularly imprinted polymer (MIP) and successfully used for selective determination of patulin. AgNPs@ZnMOF was simply synthesized by creating Ag nanoparticles (Ag NPs) inside the nano-pores of flake-like (Zn)MOF. The high surface area of MOF remarkably improved the catalytic activity of Ag NPs which was assessed by fluorometric, colorimetric and electrochemical techniques. Furthermore, it was observed that patulin could strangely reduce the catalytic activity of AgNPs@ZnMOF, probably due to its electron capturing features. This outcome was the motivation to design an assay for patulin detection. In order to make a selective interaction with patulin molecules, MIP layer was created on the surface of AgNPs@ZnMOF by co-polymerization reaction of 3-aminopropyl triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS) monomers wherein patulin was applied as template agent. Combination between the selective identifying feature of MIP and outstanding peroxidase-like activity of novel AgNPs@ZnMOF nanocomposite as well as the sensitive fluorescence detection system was led to the design of a reliable probe for patulin. The prepared MIP-capped AgNPs@ZnMOF catalyzed the H2O2-terephthalic acid reaction which produced a high florescent product. In the presence of patulin, the fluorescence intensity was decreased proportional to its concentration in the range of 0.1–10µmolL−1 with a detection limit of 0.06µmolL−1. The proposed method was able to selectively measure patulin in a complex media without significant interfering effects from analogue compounds.

Influence of production on the presence of patulin and ochratoxin A in fruit juices and wines of Argentina

In this study, the relative frequency and concentration of patulin (PAT) and ochratoxin A (OTA) in fruit juices and wines collected in Argentina between 2005 and 2013 were determined by high performance liquid chromatography. PAT was detected in 1997 of 5958 samples (ranging from 3.0 to 19,622 μg/L), and 510 samples presented PAT levels above 50 μg/L. The highest incidence of PAT was observed in 2005 (243 of 419 samples) while the lowest was quantified in 2009 (104 of 482 samples). OTA was detected in only 22 of 1401 samples at concentrations ranging from 0.15 to 3.6 μg/L, and the highest incidence was observed in 2007 (8 of 153 samples). The concentration of PAT and OTA in the beverages analyzed was found to be affected by the type of fruit product, fruit commodity and production year. A great amount of data on the incidence of these mycotoxins in these matrixes can be further used in the development and reinforcement of measures to reduce the burden of their presence in juices and wines. This is important since PAT levels above the limit set by regulations were high and fruit juices are quite consumed by children. Although OTA contamination was low, effective ways to safeguard consumer exposure to PAT and OTA and consequently to protect public health are essential and indispensable.

The Possible Mechanisms Involved in Degradation of Patulin by Pichia caribbica.

In this work, we examined the mechanisms involved in the degradation of patulin by Pichia caribbica. Our results indicate that cell-free filtrate of P. caribbica reduced patutlin content. The heat-killed cells could not degrade patulin. However, the live cells significantly reduced the concentration of the patulin. In furtherance to this, it was observed that patulin was not detected in the broken yeast cells and cell wall. The addition of cycloheximide to the P. caribbica cells decreased the capacity of degradation of patulin. Proteomics analyses revealed that patulin treatment resulted in an upregulated protein which was involved in metabolism and stress response processes. Our results suggested that the mechanism of degradation of patulin by P. caribbica was not absorption; the presence of patulin can induce P. caribbica to produce associated intracellular and extracellular enzymes, both of which have the ability to degrade patulin. The result provides a new possible method that used the enzymes produced by yeast to detoxify patulin in food and feed.

Molecularly imprinted polymer for extraction of patulin in apple juice samples

A new molecularly imprinted polymer (MIP) was prepared in a two-step process. First, SiO2-γ-MPTS was obtained by mixing γ-methacryloxypropyltrimethoxysilane (γ-MPTS) and tetraethoxysilane (TEOS). Second, SiO2-γ-MPTS was polymerized in the presence of patulin (PAT) as a template, maleic acid (MA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross linker, 2,2-azobis- (2- methylpropionitrile) (AIBN) as a precursor and acetonitrile as a porogen solvent. The prepared sorbent was successfully applied to selective solid phase extraction (SPE) of PAT in containing apple juices and the MIP@SPE method was validated. The optimum conditions for PAT extraction using the novel MIP@SPE were: 50 mg mass of adsorbent, sodium bicarbonate with (1%) acetic acid as washing solvent and 5 mL acetonitrile as eluting solvent. The developed MIP@SPE method had high selectivity and good affinity toward PAT and the recoveries of the target analyte were in the range of 82–98% with a precision of 3.03%–3.83% (RSD). In addition, a good linearity (r2 > 0.99) within the range 0.1–10 mg L−1 and a low LOD (8.6 μg L−1) and LOQ (28.6 μg L−1) were obtained. The test of reusability showed good results for at least 6 cycles.

Regulation of the antioxidant system in cells of the fission yeast Schizosaccharomyces pombe after combined treatment with patulin and citrinin

The effects of combined treatment with patulin (PAT) and citrinin (CTN) on Schizosaccharomyces pombe cells were investigated in acute toxicity tests. In comparison with the controls the exposure of fission yeast cells (107 cells ml−1) to PAT + CTN (250 μM each) for 1 h at a survival rate of 66.6% significantly elevated the concentration of total reactive oxygen species (ROS) via increased levels of peroxides without affecting the concentrations of superoxides or the hydroxyl radical. This treatment induced a 3.08-fold increase in the specific concentration of glutathione and elevated specific activities of catalase and glutathione S-transferase, while at the same time the activity of glutathione reductase decreased. The pattern of the ROS was the same as that induced by CTN (Máté et al., 2014), while the presence of PAT in the PAT + CTN combination treatment modified the activities of the antioxidant system (Papp et al., 2012) in comparison with the individual PAT or CTN treatment, suggesting toxin-specific regulation of glutathione and the enzymes of the antioxidant system and the possibility that the transcription factor (pap1 and atf1) -regulated processes might be influenced directly by ROS.

Patulin and its dietary intake by fruit juice consumption in Iran

A survey was conducted to determine levels and dietary intake of patulin (PAT) from fruit juices consumed in Iran. PAT content was determined using high performance liquid chromatography-diode array detection in 161 samples of fruit juices including apple, pineapple, pear, peach, pomegranate and white and red grape juices. Results revealed the presence of PAT in 16.1% of the samples examined, ranging from 5 to 190.7 µg/kg. Average and median PAT content in positive samples was 34.5 and 18.5 µg/kg, respectively. PAT concentration in 2.5% of the samples was higher than the maximum limit as set by European regulations for PAT in fruit products (50 µg/kg). Estimated daily intake of PAT by fruit juice was 16.4, 45.9 and 74.6 ng/kg bw/day for Iranian adults, children and babies, respectively. The results of this study showed that PAT does not seem to be a problem in fruit-based drinks commercialised in Iran, except for apple juice.

Investigation of the interaction between patulin and human serum albumin by a spectroscopic method, atomic force microscopy, and molecular modeling.

The interaction of patulin with human serum albumin (HSA) was studied in vitro under normal physiological conditions. The study was performed using fluorescence, ultraviolet-visible spectroscopy (UV-Vis), circular dichroism (CD), atomic force microscopy (AFM), and molecular modeling techniques. The quenching mechanism was investigated using the association constants, the number of binding sites, and basic thermodynamic parameters. A dynamic quenching mechanism occurred between HSA and patulin, and the binding constants (K) were 2.60 × 104, 4.59 × 104, and 7.01 × 104 M−1 at 288, 300, and 310 K, respectively. Based on fluorescence resonance energy transfer, the distance between the HSA and patulin was determined to be 2.847 nm. The ΔG 0, ΔH 0, and ΔS 0 values across various temperatures indicated that hydrophobic interaction was the predominant binding force. The UV-Vis and CD results confirmed that the secondary structure of HSA was altered in the presence of patulin. The AFM results revealed that the individual HSA molecule dimensions were larger after interaction with patulin. In addition, molecular modeling showed that the patulin-HSA complex was stabilized by hydrophobic and hydrogen bond forces. The study results suggested that a weak intermolecular interaction occurred between patulin and HSA. Overall, the results are potentially useful for elucidating the toxigenicity of patulin when it is combined with the biomolecular function effect, transmembrane transport, toxicological, testing and other experiments.