Citrus flavonoids against Fusarium verticillioides in post-harvest maize: Minimization of fumonisins and alteration of fungal ultrastructure.

Aims: To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize, using flavonoids obtained from citrus residues: naringin (NAR), neohesperidin (NEO), quercetin (QUER), and its mixtures.

Methods And Results: Response surface methodology with Box-Behnken design was applied in maize at 0.98 and 0.

Evaluation of citrus flavonoids against Aspergillus parasiticus in maize: Aflatoxins reduction and ultrastructure alterations.

In this study, the effects of citrus flavonoids naringin (NAR), neohesperidin (NEO) and quercetin (QUER) on aflatoxins accumulation by a selected Aspergillus parasiticus strain in maize at 0.95 a were studied by response surface methodology using a Box-Behnken design. Multiple response optimization was applied to simultaneously minimize the contamination with aflatoxins (AFs) B1, G1, B2 and G2.

Aflatoxins distribution in fractions derived from tofu production.

Tofu or bean curd is obtained from soybean seeds being a widespread food product in Asia. The commodity used for its production can be contaminated with aflatoxins, which are secondary metabolites synthetised by species of and . Intake of contaminated food products causes toxic effects on consumers.

[Extrinsic and intrinsic factors associated with mycotoxigenic fungi populations of maize grains (Zea mays L.) stored in silobags in Argentina].

In order to determine the behavior of mycotoxin-producing fungal populations linked with silobags stored corn grains with a moisture content greater at the recommended as safe, 270 samples taken in three times (beginning, 90 days, final) over a five month period of storage were evaluated. The fungal biota was quantified and identified and the contamination with fumonisin and aflatoxin was determined. Extrinsic factors (environment), intrinsic factors (grains) and technological factors (location of the grains in the profile of silobag) were taken into account to evaluate the presence and quantity of total and mycotoxigenic fungal populations.

Mycotoxigenic potential of fungi isolated from freshly harvested Argentinean blueberries.

Alternaria alternata, A. tenuissima, Fusarium graminearum, F. semitectum, F.

Mycoflora and mycotoxin contamination of Roundup Ready soybean harvested in the Pampean Region, Argentina.

A total of 89 freshly harvested soybean seed samples (Roundup Ready [transgenic] soybean cultivars) from the 2010/2011 crop season were collected from five locations in the Northern Pampean Region II, Argentina. These samples were analyzed for internal mycoflora, toxin production of isolated fungi, and for a range of mycotoxins. Mycotoxin analysis of aflatoxins (AFs), zearalenone (ZEA), fumonisins (FBs) and ochratoxin A (OTA) was done by HPLC-FLD (high performance liquid chromatography with postcolumn fluorescence derivatization), alternariol and alternariol monomethyl ether with HPLC-UV (HPLC with UV detection), trichothecenes (deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin, fusarenon X, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol were analyzed by GC-ECD (gas chromatography with electron capture detector).

Concentrations and exposure estimates of deoxynivalenol in wheat products from Argentina.

The aim of this work was to determine deoxynivalenol (DON) contamination in wheat-based food products in Argentina and to estimate DON exposure. The numbers of samples were determined according to a developed sampling plan. A total of 156 samples of different wheat products were randomly collected from food markets in Luján, Argentina, and analyzed for DON by gas chromatography.

Fungal and fumonisins contamination in Argentine maize (Zea mays L.) silo bags.

Fumonisins in maize (Zea mays L.) grain silo bags in the conditions of three Argentine provinces were analyzed to determine how this kind of storage affects contamination and if differential storage durations or times of the year of silo bag closing and opening are factors that could modify it. Moisture content, water activity (a(w)), molds and yeasts present, and fumonisins were analyzed in 163 maize silo bags, at the moment of closing and later at opening.

Survey of Argentinean human plasma for ochratoxin A.

The presence of ochratoxin A (OTA) in human blood has been reported for many countries, especially in Europe. However, so far no report exists concerning such a presence in Argentina. The aim of this study was to assess OTA concentration in human plasma in two different areas of Buenos Aires province.

Trichothecenes and mycoflora in wheat harvested in nine locations in Buenos Aires province, Argentina.

A total of 120 freshly harvested wheat samples from the 2004 season in nine locations from Northern Buenos Aires Province, Argentina, were analysed for trichothecene natural occurrence and associated mycoflora, and for determining the influence of commonly used fungicide field treatment and the cultivar type on trichothecene contamination. The trichothecenes T-2 tetraol, T-2 triol, HT-2 and T-2 toxin (HT-2, T-2), diacetoxyscirpenol (DAS), nivalenol (NIV), deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) were analysed by gas chromatography and electron capture detection. Detection limits ranged from 4 to 20 microg/kg.

Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina.

A mycological survey was carried out at Entre Ríos province, Argentina, on sorghum grain, maize, rice, soybean seeds and on freshly harvested and stored wheat. The isolation frequencies and relative densities of species belonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and other fungi were calculated. Alternaria alternata was the major fungal species isolated from sorghum, rice, soybean seeds and on freshly harvested wheat, and a low incidence of Fusarium species was observed on the same substrates.

Natural occurrence of aflatoxins, deoxynivalenol, fumonisins and zearalenone in maize from Entre Ríos Province, Argentina.

In Entre Ríos, Argentina, corn is one of the most important cereal grains produced, being an important income for the regional economy. The aim of this work was to assess aflatoxins, zearalenone, deoxynivalenol (DON) and fumonisins (FB) in corn harvest in 2003 and 2004 in the most contaminated departments found in previous studies in selected sampling places. At the harvest time, when the trucks arrived to store plants, samples of corn were taken from seven different positions of the trucks and from five in the trailer.

Mycoflora and potential for mycotoxin production of freshly harvested black bean from the Argentinean main production area.

A mycological survey was carried out, for the first time, on black bean samples from the northwestern Argentinean province of Salta in the 1999 harvest season. Ten varieties of black beans were evaluated at three locations. Species of the genus Alternaria were the most prevalent component of the black bean mycoflora.

Distribution of deoxynivalenol in wheat, wheat flour, bran, and gluten, and variability associated with the test procedure.

Analytical data obtained on deoxynivalenol (DON) concentration in naturally contaminated wheat during processing in an industrial mill were statistically analyzed, and the distribution functions of DON concentration in lots of wheat, bran, wheat flour, and gluten were estimated. The analytical method had acceptable precision (HORRAT 0.25-0.

Fungi associated with food and feed commodities from Ecuador.

Freshly harvested soybean, rice and corn from farms and corn-based pelleted feeds were collected from ranches from the coastal and mountain regions in Ecuador during 1998, and assessed for fungal contamination. The most prevalent fungi on pelleted feed were Aspergillus flavus and Fusarium graminearum. The prevalent fungi recovered from soybean were F.

Mycoflora of freshly harvested flint corn from Northwestern Provinces in Argentina.

A mycological survey was carried out for the first time, on red flint corn samples from the northwestern Andinian region of Argentina in the 1999 and 2000 harvest seasons. Species of the genus Fusarium were the most prevalent component of the flint corn mycoflora present in all provinces. F.

Natural occurrence of mycotoxins and mycoflora of argentinien popcorn.

Argentina is the first popcorn exporting country worldwide. In 1997-1998 harvest season, 40,000 ha were sown with a production of 125,000 tons; 120,000 tons of this production were exported to more than 40 countries. The objectives of this study were to isolate and to identify the fungi present in this cereal and to assess the occurrence of mycotoxins in freshly harvested popcorn in Buenos Aires province, Argentina, in 1999.

Distribution of fumonisins in dry-milled corn fractions in Argentina.

Corn samples and different dry-milled fractions collected from an industrial mill in Argentina were analysed. Average contaminations were FB(1) 1540 microg kg(-1), FB(2) 716 microg kg(-1) and FB(3) 152 microg kg(-1) in whole corn; FB(1) 135 microg kg(-1), FB(2) 39.1 microg kg(-1) and FB(3) 10.

Trichothecenes and zearalenone production by fusarium species isolated from Argentinean black beans.

Isolates of Fusarium species obtained from freshly harvested bean grains for human consumption collected from different Argentinean regions, were investigated for their ability to biosynthesise trichothecenes and zearalenone either on rice grains or beans. Low incidence of toxigenic fungi was observed. These mycotoxigenic species produced several toxins when grown on rice but none or little amount when cultured on beans.

Effect of fermentation on naturally occurring deoxynivalenol (DON) in Argentinean bread processing technology.

The stability of naturally occurring DON was evaluated during the fermentation stage of the bread-making process on a pilot scale. Two different products, French bread and Vienna bread, were prepared with naturally contaminated wheat flour (150 mg kg(-1)) under controlled experimental conditions. Dough was fermented at 30, 40 and 50 degrees C according to standard procedures employed in Argentinean low-technology bakeries.

Occurrence of trichothecenes in Argentinean beer: a preliminary exposure assessment.

The presence of trichothecenes (deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, nivalenol, neosolaniol and diacetoxyscirpenol) was studied in 50 samples of Argentinean beer (nine different brands). Gas chromatography with electron capture detector was used for identification and quantification of these mycotoxins. The only mycotoxin detected was deoxynivalenol (DON).

Natural co-occurrence of fumonisins, deoxynivalenol, zearalenone and aflatoxins in field trial corn in Argentina.

Corn samples collected from the main production area in Argentina in 1995 were surveyed for the natural occurrence of Fusarium mycotoxins and aflatoxins. Fumonisins B1, B2 and B3 and zearalenone were found in all samples. A positive relationship was found between fumonisins B1, B2 and B3, B1 and B3, and B2 and B3.

A survey of fumonisins, deoxynivalenol, zearalenone and aflatoxins contamination in corn-based food products in Argentina.

The presence of mycotoxins in corn-based foods available in Argentina was determined in order to make a preliminary exposure assessment. Thirty-eight samples [corn meal ('polenta') and corn flakes] of different local brands were analysed for zearalenone, deoxynivalenol and aflatoxins by TLC and fumonisins (FB1, FB2 and FB3) by HPLC. None of the 38 samples contained any detectable amount of aflatoxins (< 2 micrograms/kg), zearalenone (< 50 micrograms/kg) and deoxynivalenol (< 50 micrograms/kg).

Relationship between Fusarium graminearum and Alternaria alternata contamination and deoxynivalenol occurrence on Argentinian durum wheat.

A mycological survey was carried out on durum wheat (Triticum durum) samples from the main production area of Argentina. The isolation frequency and relative density of species of dematiaceous fungi, and genus Fusarium were calculated. Alternaria alternata and Fusarium graminearum were the predominant fungal species.