Search results for "contamination"

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…

Survey of mycotoxins in dates and dried fruits from Tunisian and Spanish markets

2015

Abstract In an effort to enforce the knowledge on mycotoxin occurrence and co-occurrence in dates and dried fruits, 228 samples purchased from Tunisian and Spanish markets were subjected to multi-mycotoxin liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis of 16 mycotoxins. At least one mycotoxin was detected in 160 samples (70%). The frequency of contaminated samples was 83%, 80%, 64%, 59% and 26% for dates, dried vine fruits, figs, apricots and plums, respectively but none of the analyzed samples contained detectable levels of fumonisins (FB1, FB2, FB3) or T-2 toxin (T2). The incidence and levels of mycotoxins varied in samples. The most prevalent mycotoxin was enniat…

Regeneration of total RNA purification silica-based columns

2010

Silica-based columns are largely used in RNA purification, allowing fast extractions and good yields of high quality nucleic acid, but their major limitation is the high cost. The reuse of such columns, although desirable, is not recommended because of residual amounts of material from the previous sample trapped in the column matrix, which might be released during further purification. Thus, recycling does need previous complete removal of any detectable RNA trace, but to date no protocol which allows decontamination and reuse is available.We report a very rapid decontamination procedure, based on treatment with warm alkaline solution containing Triton X-100, which ensures no RNA carry-ove…

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/…

Incidence of microorganisms from fresh orange juice processed by squeezing machines

2012

Abstract This study was carried out to evaluate the microbiological quality of orange juice obtained from squeezing machines in foodservice establishments. The samples included fresh squeezed orange juice and juice which is maintained in metal jugs until consumption. According to the European Commission Regulation (No. 2073/2005 and No. 1441/2007) and Spanish microbiological criteria (No. 3484/2000), 12% and 43% of the total examined lots exceed the adopted limits of mesophilic aerobic counts and Enterobacteriaceae, respectively. Possibly, this contamination is caused by incorrect handling of oranges and juices and also by inadequate cleaning and sanitization of squeezing machine and metal …

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

1981

Sprectroradiometric characteristics of inland water bodies infestated by Oscillatoria rubescens algae

2010

In December 2006 blooms of Oscillatoria rubescens were found in the reservoir Prizzi in Sicily. Oscillatoria is a genus of filamentous alga comprising approximately 6 species, between these the O. rubescens is sadly famous since this organism produces microcystins which are powerful hepatotoxins. Firstly found in Europe in 1825 on Geneva lake, recently (2006) those algae has been find out in Pozzillo, Nicoletti e Ancipa reservoirs (Enna Province), as well as in Prizzi (Palermo Province) and Garcia reservoirs (Trapani Province). Toxins produced by those bacteria (usually called microcystine LR-1 and LR-2) are highly toxic since they can activate oncogenes cells causing cancer pathologies on …