Research Publications (Food Safety)

Escherichia coli O157:H7 is an important food-borne pathogen and has ability to contaminate food, such as water, meat products, and milk. Moreover, E. coli O157:H7 is the main toxin-producing serotype which can produce Shiga toxin type 1 and type 2 and cause intestinal disease. The strong pathogenicity and lethality of Escherichia coli O157:H7 pose a serious threat to human. This study aims to develop a rapid and visual detection assay of E.

In this study, a cobalt-based mesoporous carbon material (Co@C) was prepared by self-assembly method and impregnation method, and carboxyl functionalization was carried out to obtain COOH-Co@C. Then, the penicillinase (Pen X) was immobilized on the carrier material by covalent binding. The methylene blue was electropolymerized onto the glassy carbon electrode, and then the immobilized enzyme material was modified onto the modified electrode to prepare a biosensor.

In this study, a simple and reliable sample preparation method based on an efficient version of homogeneous liquid-liquid extraction combined with dispersive liquid-liquid microextraction solidification of floating organic drop has been introduced to analyze some pesticide residues in fruit and fruit juice samples with gas chromatography-flame ionization detection.

A biochip chemiluminescent immunoassay was validated for multi-mycotoxins screening in maize. Screened mycotoxins were aflatoxins B1 (AFB1) and G1 (AFG1) ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2), fumonisins (sum of FB1 and FB2) and deoxynivalenol (DON). The method included a single extraction step with acetonitrile:methanol:water (50:40:10, v/v/v).

Many pesticides are used for pest control during oat production and storage, making necessary to employ multiclass methods for pesticide residue determination. In this work, an efficient QuEChERS method was established for multiresidue determination of 60 pesticides in oats by liquid chromatography with tandem mass spectrometry (LC-MS/MS).

Water activity (aw) is an important property of foods, with correlations to safety, quality, and shelf-life. The presence of high concentrations of non-water volatiles has been problematic for analytical aw instruments, thereby limiting potential applications of aw measurements for quality assessments of fermented beverages and foods.

Throughout the US Food and Drug Administration’s routine monitoring of various juice samples for elemental contaminants, a limited number of samples exhibited unexpected behavior related to the arsenic content.

Moldy peanuts may contain aflatoxin, a highly carcinogenic substance that threatens the health of humans and livestock. This study aimed to identify moldy peanuts using hyperspectral measurements and continuous wavelet transform (CWT). Peanuts were allowed to develop mold in a simulation of natural process of fungal infection; detailed hyperspectral images of healthy and moldy peanuts were captured.

A matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) method were established to detect Campylobacter jejuni and Listeria monocytogenes from a chicken farm and samples from commercial live chickens. Suspected isolates were pretreated and crystallized by matrix solutions consisting of ethanol, acetonitrile, and water with different proportions.

Flumequine (FLU) is widely used as an antibiotic in the treatment and control of animal diseases, which may result in the presence of residues harmful to humans in food products of animal origin. A novel and fast biomimetic enzyme-linked immunosorbent assay (BELISA) was developed for the determination of FLU based on a molecularly imprinted polymer (MIP) as a selective affinity agent.

Salmonella causes illness in millions of people each year with severe cases resulting in death. Traditional detection methods are well established but are associated with disadvantages such as time or reoccurring sample cost. Hyperspectral microscope imaging (HMI) has shown potential as an early and rapid detection method, identifying bacteria based on spectral signatures unique to the microorganism. Bacteria undergo physiological changes when introduced to environmental stresses.

An automated optical biosensor-based immunoassay exploiting surface plasmon resonance detection for the quantitation of aflatoxin M1 (AFM1) in milk and milk powders is described. A monoclonal antibody and an immobilized protein–AFM1 conjugate are utilized in a simple inhibition format following aqueous extraction and immunoaffinity clean-up of the sample, thereby avoiding the need for signal amplification techniques.

The continuous release of anthropogenic pollutants into marine environment increases the needs for the development of analytical procedures for their accurate determination in many sample types. Sound strategies for seafood safety monitoring call for measurement systems capable of producing comparable analytical results with demonstrated quality. Method validation, traceability, and uncertainty of analytical results are the three milestones to assess data quality.

In this study, a simple and rapid dispersive liquid-liquid microextraction method was established, and the residuals of four isomers of hexachlorocyclohexane and six kinds of pyrethroid pesticides in milk were simultaneously determined by gas chromatography electron capture detector (GC-ECD). The milk sample was first extracted with acetonitrile and cleaned with primary secondary amine (PSA).

In this study, a rapid and sensitive real-time loop-mediated isothermal amplification (Rti-LAMP) assay was developed for quantitative and evaluation of viable but non-culturable (VBNC) Salmonella. Four micrograms per milliliter of ethidium bromide monoazide (EMA) could significantly inhibit DNA amplification derived from dead cells in Rti-LAMP assays.

Detection and classification of potato defects are of great significance to ensure food safety and improve product quality. This study investigated the potential of a novel multispectral imaging system based on single shot method for detection and classification of potato defects. A total of 417 potato samples were used in the experiment. The 25 spectral images with spatial resolution of 409 × 216 pixels over the spectral region between 676 and 952 nm were acquired for each potato.

Functional foods provide nutritional and health benefits, yet they could be contaminated with residues like pesticides and polychlorobiphenyls. These residues affect the safety, quality, and consequently the commercial value of functional foods. Therefore, the validity and efficiency of residue determination methods constitute a major analytical concern. Reduction of matrix effect (ME) has always been the golden key for guaranteed sensitivity, selectivity, and high throughput analysis.

A simple and sensitive method based on dummy molecular imprinting and matrix solid-phase dispersion (DMI–MSPD) was developed for the simultaneous detection of estrogens including estrone, 17β-estradiol, aestriol, ethinylestradiol, dienestrol, diethylstilbestrol, and hexestrol in aquatic products. The method was followed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS).

In this study, the new approach of dispersive micro-solid phase extraction using a magnetic sheet was developed. A circle magnetic sheet (diameter, 25 mm; thickness, 0.4 mm) was perforated and used as a support for fixing and re-collecting three-dimensional magnetic graphene nanoparticles as an adsorbent. The method was coupled with high-performance liquid chromatography-fluorescence detector (HPLC-FLD) and utilized for extraction of aflatoxins (B1, B2, G1, and G2).

A novel multiresidue analytical method based on disposable pipette extraction (DPX) to determine the trace level of 28 pesticides in wine samples using liquid chromatography–tandem mass spectrometry (LC–MS/MS) has been developed. The DPX method is used for both extraction and purification. After the optimization, targets were eluted with 1% HCl in acetonitrile and the eluent was placed into LC analysis.

Campylobacter jejuni (C. jejuni), a foodborne pathogen, is a major contributor to human bacterial gastroenteritis worldwide and detrimental to public health. In this paper, we developed a dual-mode aptasensor for Campylobacter jejuni (C. jejuni) determination. Based on surface-enhanced Raman scattering (SERS) and chiral optical response, the concentrations of C.