Mycotoxins in cereal grain Part VII. A simple method to assay mycotoxin potential of cereal grain and cereal products

A simple test to assay mycotoxin potential of cereal grain and products was elaborated. In cereal grain samples during 1977 and 1981 formation of ochratoxin A, citrinin and zearalenone was observed respectively in 40%, 7 % and 31 % of cereals samples. Aflatoxin and sterigmatocystin were not formed in any sample of cereal grain. Citrinin and penicillic acid were found as mycotoxins accompanying ochratoxin A.     

Mycotoxins in cereal grain. Part VII. A simple method to assay mycotoxin potential of cereal grain and cereal products

A simple test to assay mycotoxin potential of cereal grain and products was elaborated. In cereal grain samples during 1977 and 1981 formation of ochratoxin A, citrinin and zearalenone was observed respectively in 40%, 7% and 31% of cereals samples. Aflatoxin and sterigmatocystin were not formed in any sample of cereal grain. Citrinin and penicillic acid were found as mycotoxins accompanying ochratoxin A.     

Mycotoxin contamination of cereal grain commodities in relation to climate in North West Europe

This study aimed to investigate mycotoxin contamination of cereal grain commodities for feed and food production in North Western Europe during the last two decades, including trends over time and co-occurrence between toxins, and to assess possible effects of climate on the presence of mycotoxins. For these aims, analytical results related to mycotoxin contamination of cereal grain commodities, collected in the course of national monitoring programmes in Finland, Sweden, Norway and the Netherlands during a 20-year period, were gathered. Historical observational weather data, including daily relative humidity, rainfall and temperature, were obtained from each of these four countries. In total 6382 records, referring to individual sample results for mycotoxin concentrations (one or more toxins) in cereal grains were available. Most records referred to wheat, barley, maize and oats. The most frequently analysed mycotoxins were deoxynivalenol, 3-acetyl-deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin and zearalenone. Deoxynivalenol had the highest overall incidence of 46%, and was mainly found in wheat, maize and oats. Mycotoxins that showed co-occurrence were: deoxynivalenol and 3-acetyl-deoxynivalenol in oats; deoxynivalenol and zearalenone in maize and wheat; and T-2 toxin and HT-2 toxin in oats. The presence of both deoxynivalenol and zearalenone in wheat increased with higher temperatures, relative humidity and rainfall during cultivation, but the presence of nivalenol was negatively associated with most of these climatic factors. The same holds for both nivalenol and deoxynivalenol in oats. This implies that climatic conditions that are conducive for one toxin may have a decreasing effect on the other. The presence of HT-2 toxin in oats showed a slight decreasing trends over time, but significant trends for other toxins showed an increasing presence during the last two decades. It is therefore useful to continue monitoring of mycotoxins. Obtained results can be used for development of predictive models for presence of mycotoxins in cereal grains.     

Mycotoxins in cereal grain Part 12. Contamination with ochratoxin A and penicillic acid as indicator of improper storage of cereal grain

Formation of ochratoxin A and penicillic acid in wheat kernels at 6 moisture levels: 15, 18, 21, 24, 27 and 30% at 15 °C has been examined during 4 months of storage. The minimum time for formation of significant amount (0.5–1 mg/kg) of ochratoxin A and penicillic acid (6–8 mg/kg) in stored grain has been found for the various water contents as follows: 18%–16 weeks, 21%–6 weeks, 24% and more — 2 weeks. At 15% of moisture content formation of ochratoxin A and penicillic acid was not observed until 4 months of storage.     

Gluten contamination of cereal foods in Canada

Persons suffering from celiac disease (CD) must avoid foods containing gluten or those contaminated with wheat, barley, or rye. This study was designed to estimate gluten contamination of cereal-based foods available in Canada, whether labelled gluten-free or not. About half of the 148 foods sampled were labelled as gluten-free. According to R5-enzyme-linked immunosorbent assay (ELISA), twenty-three cereal-based foods (or 15%) contained more than 20 mg of gluten per kg, including sixteen regular and seven gluten-free foods, the latter being the least contaminated. When used in combination with R5-ELISA, AOAC-ELISA (not detecting barley) was a simple and efficient tool to roughly estimate the nature of the gluten contamination, which was later confirmed by real-time polymerase chain reaction for barley, and wheat/barley/rice. Rice-, corn- or quinoa-based foods were the safest for celiac patients. In addition to misleading food labelling for both gluten-rich and gluten-free foods, critical issues for persons with CD included foods made with oats or buckwheat (contaminated with wheat and barley gluten) in addition to those, such as breakfast cereals, specifically enriched with barley malt ingredients.     

Mycotoxins in cereal grain. Part 12. Contamination with ochratoxin A and penicillic acid as indicator of improper storage of cereal grain

Formation of ochratoxin A and penicillic acid in wheat kernels at 6 moisture levels: 15, 18, 21, 24, 27 and 30% at 15 degrees C has been examined during 4 months of storage. The minimum time for formation of significant amount (0.5-1 mg/kg) of ochratoxin A and penicillic acid (6-8 mg/kg) in stored grain has been found for the various water contents as follows: 18%-16 weeks, 21%-6 weeks, 24% and more - 2 weeks. At 15% of moisture content formation of ochratoxin A and penicillic acid was not observed until 4 months of storage.     

Mycotoxins in cereal grain Part VOL Microbiological evaluation of cereal grain quality,connected with mycotoxins occurrence

Four classes of microbiological quality of cereal grain are proposed. For classification the frequency of kernels contamination with Penicillia, Aspergilli and Phycomycetes is considered as essential. Lots contaminated with mycotoxins (ochratoxins) were usually of IIIrd and IVth class of quality.     

Vitamins B in grain and cereal–grain food,soy-products and seeds

The present study provides information about the concentrations of vitamins B (thiamine, riboflavin, pyridoxine and niacin) in cereal and soy-products, grain and seeds. The concentrations of vitamins were determined by microbiological analytical methods. The results demonstrated that there are great differences in vitamin B composition within varieties of the analysed products. Whole grain products and seeds, are better sources of the vitamin B group than technologically processed products, and therefore more nutritionally efficacious.     

Detection of fungal infection and Ochratoxin A contamination in stored wheat using near-infrared hyperspectral imaging

A study was done to detect Aspergillus glaucus, and Penicillium spp., infection and Ochratoxin A contamination in stored wheat using a Near-Infrared (NIR) Hyperspectral Imaging system. Fungal-infected samples were imaged every two weeks, and the three dimensional hypercubes obtained from image data were transformed into two dimensional data. Principal component analysis was applied to the two dimensional data and based on the highest factor loadings, 1280, 1300, and 1350 nm were identified as significant wavelengths. Six statistical features and ten histogram features corresponding to the significant wavelengths were extracted and subjected to linear, quadratic and Mahalanobis discriminant classifiers. All the three classifiers differentiated healthy kernels from fungal-infected kernels with a classification accuracy of more than 90%. The quadratic discriminant classifier provided classification accuracy higher than the linear and Mahalanobis classifiers for pair-wise, two-way and six-way classification models. The Ochratoxin A contaminated samples had a unique significant wavelength at 1480 nm in addition to the two significant wavelengths corresponding to fungal infection. The peak at 1480 nm was identified only in the Ochratoxin A contaminated samples. The Ochratoxin A contaminated samples can be detected with 100% classification accuracy using NIR hyperspectral imaging system. The NIR hyperspectral system can differentiate between different fungal infection stages and different levels of Ochratoxin A contamination in stored wheat.     

The relation between yield and protein in cereal grain

An analysis of published data on genetic relations between dry grain yields (y, t ha^?1) and protein content [p, protein as a fraction (g g^?1) of dry grain] of cereals is presented. In all, 106 usable regressions of y on p across geneotypes were assembled. The long-recognised negative relation between yield and protein concentration was fully substantiated. There is a strong positive relation between grain yield and protein yield. The linear regression coefficient of yield on protein concentration is related to yield, with slope about ?15. This relation holds approximately over all cereals. The data can be used to estimate a characteristic parameter described by C = dy/d(yp) = ～ 15–25 at the mean of each experiment. The relationship is surprisingly consistent but no simple physiological interpretation is available. In discussion, the high C, the impact of strong negative regressions of y on p for breeding strategies, the fact that protein yield increases with gross grain yield but at falling p and certain socio-economic consequences are emphasized. An acute need for orderly reporting of experimental data is also emphasised; the existing literature is chaotic as to units, moisture contents and conversion factors.     

粮食收获质量调查和品质测报工作有关问题探讨

分析了当前粮食收获质量调查和品质测报工作中存在的问题,并提出了一些建议。     

国产粮食机械发展初步探索

我国粮食机械制造业在经济改革开放大潮推动下,取得了长足进展,国际市场上物美价廉的中国产品受到了普遍赞誉.在新的形势下,粮机企业应根据自身情况,制定企业发展计划.一步一步地向研发延伸,把产品往价值链的高端推进,把企业做大做强.     

Mycotoxins in cereal grain. Part 5. Changes of cereal grain biological value after ammoniation and mycotoxins (ochratoxins) inactivation

Ammoniation was proved to be a suitable detoxification procedure to remove toxicity of Aspergillus ochraceus mycotoxins (mainly ochratoxin A) from contaminated cereal grain (corn, wheat and barley). It was found that ammoniation should be performed to achieve decomposition of ochratoxin A to nondetectable level. Ammoniated grain can be used as feedstuff component without essential change of nutritive value during ammoniation.     

Microbial contamination of harvested colostrum on Czech dairy farms

The objective of this study was to perform a quantitative and qualitative evaluation of microbial contamination of harvested colostrum on 39 Czech dairy farms. The study identified the proportion of colostrum samples that met the recommended goals for total plate count (TPC), total coliform count (TCC), and gram-negative noncoliform count (NCC), and evaluated the effect of the farm, breed, parity, season of the year, time of calving, and colostrum volume on these 3 microbiological parameters. Colostrum samples from cows (n = 1,241; 57.6% from Czech Fleckvieh, and 42.4% from Holstein breed) were collected on dairy farms between autumn of 2015 and spring of 2017. The samples were collected after the first milking directly from milking buckets. In 155 out of 1,241 colostrum samples (26 farms, 6 samples each, except 1 farm), the species of microorganisms obtained by culture were determined, and the findings were classified into 4 groups according to the probable source of contamination as follows: (1) normal inhabitants of bovine skin and mucosa, (2) fecal contaminants, (3) environmental contaminants, and (4) potential gram-positive mammary pathogens. Our results showed heavy microbial contamination of collected colostrum samples (TPC median = 408,000 cfu/mL; TCC median = 200 cfu/mL; NCC median = 80 cfu/mL). Only 28.4% of samples met the requirement for TPC (<100,000 cfu/mL), 88.2% for TCC (<10,000 cfu/mL), and 86.0% for NCC (<5,000 cfu/mL). Among the tested factors, we found that farm had a significant effect on all 3 microbiological parameters, volume of colostrum had an effect on TPC (the highest TPC in <3.0 L of colostrum), and season had an effect on TCC and NCC (higher TCC in summer than in autumn and winter; the highest NCC in summer and higher in autumn than in spring and winter). Our results showed that most microbes isolated from colostrum belonged to normal inhabitants of bovine skin and mucosa, fecal, or environmental contaminants (i.e., 82.6%, 81.9%, and 75.5% of colostrum samples, respectively). Potential gram-positive mammary pathogens were found in 13.5% of samples. Escherichia coli was isolated from 9.0% of colostrum samples, and Streptococcus uberis and Streptococcus parauberis were each isolated from 5.2% of samples. Our study showed high microbial contamination of colostrum collected on dairy farms. Therefore, better hygiene and sanitation around colostrum harvest should be addressed by farmers.     

Ochratoxin A contamination of coffee batches from Kenya in relation to cultivation methods and post-harvest processing treatments

This study set out to assess the relative importance of sound and unsound beans in a batch of coffee with regard to ochratoxin A (OTA) contamination. Initially, unsound beans were found to account for 95% of contamination in a batch of coffee, whatever the methods used for post–harvest processing. It was also found that beans displaying traces of attacks by Colletotrichum kahawae were the greatest contributors to OTA contamination. In a second stage, the study compared the contamination of sound beans with that of beans attacked by Colletotrichum kahawae. On average, beans attacked by Colletotrichum kahawae had a statistically higher OTA content than sound beans (18.0 µg kg^?1 as opposed to 1.2 µg kg^?1). In addition, the average OTA content in unsound beans varied depending on growing conditions.     

Ochratoxin A contamination of cereals in an area of high incidence of Balkan endemic nephropathy in Bulgaria

In an effort to provide further evidence for the hypothesis that a mycotoxin is involved in the aetiology of Balkan endemic nephropathy and that the latter is associated with the occurrence of urinary system tumours, a survey was made of ochratoxin A contamination of cereal samples from an area of Bulgaria where both endemic nephropathy and urinary system tumours are prevalent and from non-endemic areas. In all, 130 samples of beans, maize and wheat flour were analysed. Ochratoxin A levels were 16.7% (25-27 micrograms/kg) in bean samples from the endemic area and 7.1% (25-50 micrograms/kg) in those from the control areas: in maize samples, the levels were 27.3% (25-35 micrograms/kg) and 9.0% (10-25 micrograms/kg), respectively.     

Ochratoxin A in conventional and organic cereal derivatives: a survey of the Italian market, 2001-02.

Ochratoxin A is a mycotoxin produced mainly by Penicillium verrucosum and Aspergillus ochraceus. Although typically considered a cereal contaminant, it has also been detected in dried fruit, nuts, meat and derivatives. To estimate the quantity of ochratoxin A that might be ingested by Italian consumers from these foods, 211 cereal derivatives (flours and bakery products) were analysed by high-performance liquid chromatography. Products were from conventional and organic agriculture and from integrated pest management agriculture. All commercial flours and derivatives examined contained ochratoxin A at concentrations very much below the legal limit (3 microg kg(-1)): the highest value, 0.816 microg kg(-1), was detected in a sample of spelt whole flour from organic agriculture. In many samples, the ochratoxin content was below the limit of detection; only rarely did values exceed 0.5 microg kg(-1). In baby foods, four samples were above the particularly restrictive Italian legal limit of 0.5 microg kg(-1). Although some significant differences were found between samples from conventional and organic agriculture when some product categories were examined (namely, baby foods as semolina and rice creams), no important difference was found between the two types of agricultural practice when all types of cereal derivatives were considered together.     

Trichothecenes, ochratoxin A and zearalenone contamination and Fusarium infection in Finnish cereal samples in 1998

The occurrences and concentrations of trichothecenes, ochratoxin A and zearalenone in Finnish cereal samples are presented in this study. Furthermore, infections by moulds, especially Fusarium contamination of grains in the same samples, are reported. In total 68 cereal samples, including 43 rye, 4 wheat, 15 barley and 6 oats samples, were collected after a cool and very rainy growing season in 1998. A gas chromatograph combined with a mass spectrometric detector was used for determination of seven different trichothecenes. A high performance liquid chromatograph with a fluorescence detector was used for ochratoxin A and zearalenone determination. For the identification of moulds, the grain samples were incubated and the moulds were isolated and identified by microscopy. The analytical methods were validated for mycotoxin analysis and they were found to be adequately reliable and sensitive. Heavy rainfalls in the summer and autumn of 1998 caused abundant Fusarium mould infection in Finnish cereals, particularly in rye. Fusarium avenaceum was the most common Fusarium species found in cereals. However, the mycotoxin concentrations were very low and only deoxynivalenol, nivalenol and HT-2 toxin were detected. Deoxynivalenol was detected in 54 samples in the concentration range 5-111 µg/kg. Nivalenol and HT-2 toxin were detected in three and two samples, respectively, in the concentration range 10-20 µg/kg.     

Modeling water uptake in a cereal grain during soaking

A diffusion equation to describe the isothermal absorption of liquid water in a spherical solid that undergoes uniform swelling was derived. The resulting partial differential equation was solved using a finite difference method, taking into consideration water content dependence of the diffusion coefficient. The developed model was applied to simulate the water uptake of brown rice for the soaking temperatures of 25, 45, 55 and 65 °C. The estimated “differential” diffusion coefficients were a strongly increasing function of moisture content for all temperatures tested, approaching to the self-diffusion coefficients of water for brown rice moisture contents near to the saturation values. The “integral” diffusion coefficient corresponding to range of moisture content resulting from soaking conditions were calculated and correlated according to Arrhenius equation with an activation energy of 32.5 kJ/mol.     

Ochratoxin A in Wines

Mycotoxins are produced by fungi, commonly known as mold. Ochratoxins are a dangereous group of mycotoxins produced as secondary metabolites by several fungi of the Aspergillus or Penicillium families. Ochratoxin have been detected in foods and beverages, including grape juice and wine. Several analytical methods have been developed for detection of Ochratoxin A [OTA] in wine. In this article, the chemical structure, biosynthesis, formation, microorganisms, determination methods, regulations and the removal of OTA have been reviewed.