摘要:

One hundred and thirty samples comprising bread (64), hamburger buns (33), pittas (16), cakes (9) and Christmas puddings (8) from various retail outlets in the UK, have been analysed for the preservative propionic acid. Only one sample of bread, two samples of hamburger buns and three samples of pitta contained propionic acid in excess of 1000 mg/ kg (range 1110–2625 mg/kg). The three samples of pitta exceeded 2000 mg/kg of propionic acid, which is the maximum amount permitted for these products under a recently adopted European Union directive.

ISSN:0265-203X    

DOI:10.1080/02652039609374391

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Samples of sound home‐grown wheat (one hard and one soft milling) were obtained, cleaned, and y‐irradiation used to reduce numbers of viable naturally‐occurring fungi. Each sample was inoculated with a toxigenic strain ofPenicillium verrucosumand monitored for ochratoxin A formation. When ochratoxin A had reached a level of 60μg/kg, the samples were milled into ten fractions which were analysed for ochratoxin A by an HPLC method with immunoaffinity column clean‐up. Each straight‐run white flour was baked into bread which was analysed in the same way. Relationships between ochratoxin A levels in naturally‐contaminated wheat and the products of milling and baking were established. The recovery of ochratoxin A in wholemeal compared with the cleaned wheat was essentially complete and no significnt loss occurred on baking white or wholemeal flour into bread. Recoveries in the straight‐run white flours, however, were only approximately one‐third for the hard wheat and two‐thirds for the soft wheat of the ochratoxin A in the uncleaned wheat. The reason for this was that a much higher proportion of the ochratoxin A was found in the bran and offal fractions from hard wheat than from soft. Conversely, a much higher proportion of the ochratoxin A was found in the reduction flour from soft wheat than from hard. Scouring was examined as a possible method of decontamination of wheat prior to milling. This process removes a proportion of the pericarp (bran coat) prior to milling. The results of the study confirmed that scouring reduced the ochratoxin A level in white and wholemeal flour three‐fold for both the hard and soft wheat.

ISSN:0265-203X    

DOI:10.1080/02652039609374392

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The uptake and distribution of radioactive material‐derived residues were determined in tissues of growing pigs consuming14C‐labelled fumonisin B1(FB1) in the diet. Animals were fed 3.0mg (30μCi)14C‐FB1/kg feed from days 1–12, followed by 2.0 mg (2.0μCi)14C‐FB1/kg feed during days 13–24, followed by a 9‐day withdrawal period where pigs received clean feed only. Of the tissues analysed, residues were found to accumulate only in liver and kidney. Radioactivity was detected at the first sampling time (day 3), and continued to increase until theI4C‐toxin was removed from the diet. Peak tissue levels (dpm/g tissue ± SD,N = 2)in liver and kidney were 347 ± 28 and 146 ± 14, respectively, on day 24, which were equivalent to about 160 and 65 ng FB1and/or metabolites per g tissue, respectively. Once pigs were placed on clean feed, tissue levels declined rapidly; down to approximately 35% of peak levels after 3 days, and only marginally above detection limits ( ∼ 25 dpm/g) after 9 days. Delayed recovery of the radioactive material consumed indicated a persistence within the body of FB1‐derived residues, which could be eliminated only upon removal of the contaminated diet.

ISSN:0265-203X    

DOI:10.1080/02652039609374393

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Eighteen corn samples collected from Thailand were analysed for fumonisins and aflatoxins by high performance liquid chromatography. Fumonisins B1and B2were detected in 16 (89%) and 12 (67%) samples at levels ranging from 63 to 18800ng/g (mean, 1790ng/g) and from 50 to 1400 ng/g (mean, 251 ng/g), respectively.Fusarium moniliformeandF. proliferatumisolated from Thai corn showed the production of fumonisins in corn grit cultures. Aflatoxins B1and B2were found in 15 and 10 samples at mean levels of 72 and 15 ng/g, respectively. It was noted that as many as 72.2% (13/18) of samples were coincidentally contaminated with fumonisins and aflatoxins. Based on these results, the interaction of fumonisin‐producers and aflatoxin‐producers on kernel infection and contamination of these mycotoxins in corn is discussed. This is the first report on the natural co‐occurrence of fumonisins and aflatoxins in Thailand.

ISSN:0265-203X    

DOI:10.1080/02652039609374394

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

One hundred and fifty‐two samples of pasteurized milk, powdered milk, cheese and yoghurt, marketed in Campinas, Brazil in 1989–1990, were analysed for aflatoxin M1by the AOAC TLC method (visual quantitation) 980.21. Fifty‐two pasteurized milk samples were also analysed in 1992 by the AOAC HPLC method 986.16. Aflatoxin M1was not detected in the 1989–1990 samples. Four milk samples of the 1992 batch were contaminated at 73–370 ng/1. Except for the sample with 370 ng/1, which would have been also found positive by the TLC method, the detection of aflatoxin M1in 1992 reflects the higher sensitivity of the HPLC method, not a greater occurrence of the toxin. Contamination of milk and milk products with aflatoxin M1does not appear to be a serious public health problem in the city of Campinas at the moment.

ISSN:0265-203X    

DOI:10.1080/02652039609374395

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Since animal intoxication related to corn‐based feed is frequently observed in the State of Paraná, Brazil, natural contamination by fumonisins in 48 corn samples (39 from the State of Paraná, and 9 from the Brazilian tropical states, Mato Grosso do Sul and Goias) harvested in 1990–1991 was investigated, along with fungal flora. The total mould count ranged from 6.3 X 102to 5·5 X 107cfu/g, andFusarium moniliformeandAspergillusspecies belonging to sectionFlaviwere detected in 41 and 33 samples, respectively. Regarding the samples from the State of Paraná,F. moniliformewas present in 33 samples at a count of 1.0 × 102to l.6X107cfu/g andAspergillusspp. in sectionFlaviin 27 samples at 1.0 X 102to 10 X 106cfu/g. HPLC analysis of fumonisins in the corn showed that fumonisins B1(FB1and B2(FB2) were positive for 97.4% and 94.8% of samples respectively. All the corn from North Paraná was positive for fumonisins, with average FB1levels of 4·79μg/g and average FB2levels of 3.95μg/g: the Central‐West region had average levels of 3.30 and 2.52μg/g, and the Central‐East had average levels of 3.25 and 2.34μg/g, respectively. Except for one negative sample all the corn samples from the Central Region were positive for fumonisins, averaging FB1levels being 5.45μg/g and FB2levels being 5.09μg/g. Out of eight samples from the tropical state of Mato Grosso do Sul,F. moniliformewas detected in seven andAspergillusspp. in sectionFlaviin five samples with average FB1levels of 10.59μg/g and average for FB2levels of 10.31 μg/g.The samples from Goias were also contaminated with these two fungi, with the FB1contamination being 5.83 and the FB2contamination 3.62μg/g.

ISSN:0265-203X    

DOI:10.1080/02652039609374396

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A survey of swine destined for slaughter in Manitoba was conducted to examine the incidence of ochratoxin A (OA) in swine herds from different regions of Manitoba throughout the year 1989–90. Thirty‐six percent of the serum samples which were collected from 1600 pigs contained detectable levels of OA. The identity of this toxin was confirmed using liquid chromatography‐mass spectrometry and enzymatic hydrolysis. There was a significant effect of the region from which the herds originated, as well as the season in which the samples were collected on both the incidence(p <0.001) and concentration of OA (p < 0.001). In July, 65% of the samples contained detectable levels of OA, compared with 38, 21 and 17%, in April, October and January respectively. Furthermore, 24% of the samples collected in July contained greater than 15 ng/ml of OA, while only 2, 9, and 1% of the samples collected in April, October and January respectively, contained greater than 15 ng/ml of OA. Based on the six samples collected from each herd, it appears that the presence and concentration of OA within a herd may be estimated from a limited number of animals per herd.

ISSN:0265-203X    

DOI:10.1080/02652039609374397

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A high level of14C was found to bind irreversibly with the liver proteins of rainbow trout (Oncorhyncus mykiss) exposed to 135 mg/kg bodyweight of14C‐labelled furazolidone (14C‐FZ) in fish feed daily for 10 days. After the cessation of14C‐FZ treatment, hepatic protein‐bound14C in trout stayed high for at least 30 days. The chemical identity of protein‐bound14C remained to be elucidated. However, a part of the protein‐bound14C in the liver and muscle could be released as 3‐amino‐2‐oxazolidinone by acid hydrolysis. The formation of protein‐boundI4C in the liver was investigated further with trout dosed intravenously with different14C‐FZ doses at 10°C or with 5 mg/kg FZ at different water temperatures.14C binding to the liver proteins was found to increase with increasing FZ dose or water temperature. Results of these studies indicate that protein‐bound14C in the muscle and liver of trout is related to the formation of reactive intermediates from FZ. However, additional studies on the identities of the protein‐bound FZ residues are required before they can serve as useful biomarkers to monitor FZ exposure in farm fish.

ISSN:0265-203X    

DOI:10.1080/02652039609374398

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The production of stable homogeneous reference materials containing the antimicrobial agent sulphadimidine in pig tissue is described. These were commissioned by the Community Bureau of Reference (BCR), established by the Commission of the European Communities, to promote improvements in analytical accuracy and to ensure uniformity of results determined by member states. Sulphadimidine‐containing tissue powders (400 vials each of muscle, liver and kidney) were prepared by orally dosing pigs with drug, producing lyophilized tissue powders and blending these with negative tissues from unmedicated animals to achieve target concentrations. Details of the production process, the stabilizing procedure developed and the analytical assessments of homogeneity and stability are given.

ISSN:0265-203X    

DOI:10.1080/02652039609374399

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Potatoes, commercially treated with thiabendazole, tecnazene and chlorpropham, were processed into potato crisps and jacket potato crisps at a crisp factory using standard manufacturing conditions. A multi‐residue method based on gas chromatography with mass spectrometric detection was developed and used to determine pesticide residue levels in the potatoes and potato crisps. Results showed that the residues of all three pesticides were significantly reduced to less than 2% and less than 10% of the maximum theoretical residue carry‐through level for potato crisps and jacket potato crisps respectively.

ISSN:0265-203X    

DOI:10.1080/02652039609374400

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor