Research Publications (Food Safety)

Enterotoxigenic Escherichia coli (ETEC) K88 causes diarrhea in weaned piglets and represent a suitable model system for ETEC causing childhood diarrhea. This study aimed to evaluate the effects of oligosaccharides against ETEC K88 adhesion to porcine erythrocytes with two bioassays. Galactosylated chitosan-oligosaccharides (Gal-COS) were synthesized through transgalactosylation by β-galactosidase.

The matrix effects of ethyl acetate extracts from seven different citrus fruits on the determination of 80 pesticide residues using liquid chromatography coupled to high-resolution time-of-flight mass spectrometry (UHPLC-(ESI)-HR-TOF) at 4 GHz resolution mode were studied. Only 20% of the evaluated pesticides showed noticeable matrix effects (ME) due to coelution with natural products between tR = 3 and 11 min.

Ochratoxins A, B, and C (OTA, OTB, and OTC) can be found in cereals and feeds; the simultaneous detection of these ochratoxins holds a great need in food safety.

In this study, a paper spray ionization mass spectrometric (PS-MS) method was developed for the rapid in situ screening and simultaneous quantitative analysis of bisphenol A and its analogues, i.e., bisphenol S, bisphenol F, and bisphenol AF, in food packaging products. At the optimal PS-MS conditions, the calibration curves of bisphenols in the range of 1–100 μg/mL were linear. The correlation coefficients were higher than 0.998, and the LODs of the target compounds were 0.1–0.3 μg/mL.

A new near-infrared fluorescence off–on probe was developed and applied to fluorescence imaging of carboxylesterase in living HepG-2 cells and zebrafish pretreated with pesticides (carbamate, organophosphorus, and pyrethroid). The probe was readily prepared by connecting (4-acetoxybenzyl)oxy as a quenching and recognizing moiety to a stable hemicyanine skeleton that can be formed via the decomposition of IR-780.

Aflatoxin contamination has a major economic impact on crop production in the southern United States. Reduction of aflatoxin contamination in harvested crops has been achieved by applying nonaflatoxigenic biocontrol Aspergillus flavus strains that can out-compete wild aflatoxigenic A. flavus, reducing their numbers at the site of application. Currently, the standard method for applying biocontrol A.

An extraction method using acidified methanol based on the quick polar pesticide (QuPPe) method using suppressed ion chromatography coupled to mass spectrometry was developed and validated for the direct analysis of polar pesticides, without the need for derivatization or ion pairing, in cereals and grapes.

To characterize the dynamic mobilization of heavy metals (HM) in a crop–soil system affected by cattle manure (CM) application, soybean [Glycine max L. Merr. cv. Toyoharuka] crops were exposed in a chronological pot experiment to three CM application rates and sampled at two vegetative stages and two reproductive stages. A sequential extraction procedure for metal fractionation, soil pH, microbial activity, and plant HM uptake was determined.

Food safety problems such as damage to immune, nervous, and endocrine systems leading to cancer and malformations have received increasing attention. To achieve the maximum residue limits, the most discussed method of high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) is widely used with a advantage of high precision and resolution. Prothioconazole is a broad-spectrum thiocarbamate fungicide.

To develop a sensitive fluorescence polarization immunoassay (FPIA) for screening the zearalenone class of mycotoxins in maize, two new monoclonal antibodies with uniform affinity to the zearalenone class and four fluorescein-labeled tracers were prepared. After careful selection of appropriate tracer–antibody pairs in terms of sensitivity and specificity, a FPIA that could simultaneously detect the zearalenone class with similar sensitivity was developed.

Mycotoxins and antibacterial agents are the main chemical hazards that lead to several health problems. Nowadays, multiplex immunoassay is a primary goal throughout the world. Here, aflatoxin M1 and pirlimycin were selected as models, and a novel dual colorimetric encoded frit-based immunoassay was developed for simultaneously screening of aflatoxin M1 and pirlimycin residues in milk.

Soils contaminated with heavy metals have been reused for agricultural, building, and industrial uses following remediation. This study assesses plant growth and bioaccumulation of heavy metals following remediation of industrially contaminated soil. The soil was collected from a field site near a nonferrous smelter and was subjected to laboratory- and field-scale studies.

Cronobacter sakazakii is a foodborne pathogen that has been associated with severe infections, mainly in neonates. The binding of this bacterium to host cell surfaces represents the first step in the pathogenesis of disease. An ELISA-based assay has been developed using a polyclonal antiserum against C. sakazakii to determine its adhesion to Caco-2 cells. The antiserum used recognized many of the outer membrane proteins of C. sakazakii.

Ovomucin is a glycoprotein from egg white with potential to act as an anti-adhesive agent against infectious diseases. This study aimed to determine whether ovomucin or ovomucin hydrolysates could prevent adhesion of two porcine K88 enterotoxigenic Escherichia coli (ETEC) strains. Adhesion was assessed in vitro using a hemagglutination assay. Ovomucin hydrolysates, but not intact ovomucin, prevented adhesion of ETEC to porcine erythrocytes.