Search results for "Food Contamination"

Immunoanalytical methods for ochratoxin A monitoring in wine and must based on innovative immunoreagents.

2020

Immunochemical methods are highly deployed in analytical laboratories worldwide for monitoring the incidence of mycotoxins in the food chain. Nevertheless, most conventional immunoassays for ochratoxin A (OTA), including commercial kits, show limitations to robustly determine this mycotoxin in grape-derived products below regulated levels (2 ng/mL). Herein, two rapid tests for sensitive OTA determination in wine and must were developed capitalizing on a collection of bioconjugates from innovative synthetic haptens and monoclonal antibodies with subnanomolar affinity. The ELISA (LOD = 8 pg/mL) showed excellent performance in recovery studies, and it was applied to survey commercial wines and…

Mycobiota and toxigenic Penicillium species on two Spanish dry-cured ham manufacturing plants

2013

The present study reports the natural mycobiota occurring in dry-cured hams, and in particular on the incidence of mycotoxin-producing fungi. A total of 338 fungal colonies were isolated from three stages of production, these being the post-salting, ripening and aging stages in two manufacturing plants. The results show that fungi were more frequently isolated from the aging stage and that the predominant filamentous fungal genus isolated was Penicillium. Seventy-four of the 338 fungal strains were selected for identification at the species level by using morphological criteria and internal transcribed spacers sequencing. Of the 74 fungal strains, 59 were Penicillium strains. Sixteen Penici…

Analytical, thermodynamical and kinetic characteristics of photoluminescence immunosensor for the determination of Ochratoxin A

2017

Ochratoxin A (OTA) is one of the most widespread and dangerous food contaminants. Therefore, rapid, label-free and precise detection of low OTA concentrations requires novel sensing elements with advanced bio-analytical properties. In the present paper we report photoluminescence (PL) based immunosensor for the detection of OTA. During the development of immunosensor photoluminescent ZnO nanorods (ZnO-NRs) were deposited on glass substrate. Then the ZnO-NRs were silanized and covalently modified by Protein-A (Glass/ZnO-NRs/Protein-A). The latest structure was modified by antibodies against OTA (Anti-OTA) in order to form OTA-selective layer (Glass/ZnO-NRs/Protein-A/Anti-OTA). In order to im…

Real-time PCR based procedures for detection and quantification of Aspergillus carbonarius in wine grapes

2008

9 pages, 4 tables, 1 figure.

Levels of ochratoxin A in wheat and maize bread from the central zone of Portugal.

2007

Ochratoxigenic fungi are natural contaminants of cereal and the produced toxins are harmful to humans and animals. Ochratoxin A (OTA) is among the most important mycotoxins, and the International Agency for Research on Cancer (IARC) classifies it as possibly carcinogenic to humans (group 2B). A total of 61 samples of bread from the central zone of Portugal were analysed for OTA by liquid chromatography (LC) with fluorescence detection (FD). For confirmation two procedures were applied, methyl ester derivatization with boron trifluoride-methanol and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS). As far as we know, this is the first report where on-line…

A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.

2008

Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …

Potential Health Risk Associated with Mycotoxins in Oat Grains Consumed in Spain

2021

Spain is a relevant producer of oats (Avena sativa), but to date there has been no study on the occurrence/co-occurrence of mycotoxins in oats marketed in Spain. The present study is addressed to overcome this lack of knowledge. One hundred oat kernel samples were acquired across different Spanish geographic regions during the years 2015–2019 and analyzed for mycotoxin content using an ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC–ESI–MS/MS) method and matrix-matched calibration. The focus was on the regulated mycotoxins although other relevant mycotoxins were considered. The percentage of incidence (levels ≥ limit of detection), mean an…

PCR-fingerprinting and RAPD approaches for tracing the source of yeast contamination in a carbonated orange juice production chain.

2005

Aims: To investigate the sort and the origin of the contamination of a packed fruit juice. Methods and Results: Fifty-eight yeast isolates were collected in a survey of two different visits to a carbonated orange juice factory. In each visit, samples were collected, six times, from seven points in the production chain. For each visit, no significant differences were observed among the yeast average values obtained in the control points considered. The random amplified polymorphic DNA (RAPD) with primer P24 and the PCR-fingerprinting with the microsatellites primers (GTG)5 and (GAC)5 were used, in order to discriminate the isolates, rendering 29 composite profiles; the most frequent one (24/…

High-performance liquid chromatography of the mycotoxin sterigmatocystin and its application to the analysis of mouldy rice for sterigmatocystin.

1981

Non-target and suspected-target screening for potentially hazardous chemicals in food contact materials: investigation of paper straws

2020

A non-target screening strategy was developed for the safety evaluation of potentially hazardous chemicals in paper food contact materials (FCMs). A tentative list of suspect analytes was generated using publicly available FCM substance inventories, the presence of contaminants in paper straws was confirmed by high-resolution Orbitrap mass spectrometry. Data-independent and data-dependent MS and MS/MS results for candidate compounds were processed using a workflow including peak detection by deconvolution, blank subtraction, retention time alignment, formula assignment and fragmentation spectra search against spectral libraries followed by