摘要:

Surveillance of chemical contaminants in food plays an important role in helping to ensure a safe food supply in those countries that undertake it. This paper reviews the methods used in the UK as a means of highlighting the essential elements required by any food chemical surveillance programme. The following topics have been covered: quantifying food consumption, setting priorities in food surveillance, developing a common approach to the surveillance of different chemicals in the food supply (including the use of Total and Duplicate Diet Studies), estimating human intakes of chemicals from the diet, developing suitably sensitive and reliable methods of analysis, obtaining representative samples, and assessing and managing risk.

ISSN:0265-203X    

DOI:10.1080/02652039109374009

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

To assess the significance of migration of polymeric plasticizers into foods, chemical characterization and quantification of individual oligomeric species is required. This paper reports the identification of seven individual oligomers isolated from a poly(butylene adipate) plasticizer. Based on mass spectrometry, NMR and chemical degradation, the oligomers were identified as a series of diol‐terminated units ranging from a trimer up to an 11‐monomer unit, along with a cyclic tetramer, all in the molecular weight range of 300–1100. A study of the migration of polymeric plasticizer from PVC film into olive oil indicated preferential migration of low molecular weight species. These oligomers which comprised 24% of the parent plasticizer contributed more than 90% of the plasticizer migration with the smallest oligomers migrating 90‐fold more readily than the bulk of the plasticizer. From a knowledge of total polymeric plasticizer migration from PVC films under actual conditions of food‐use, the abundance of individual oligomers in the foods has been estimated.

ISSN:0265-203X    

DOI:10.1080/02652039109374010

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The second check sample survey for the determination ofN‐nitrosamines in beer and malt has been initiated. Each laboratory received four samples: two beer, from the same batch, spiked respectively with 0.5μg/lN‐nitrosodimethylamine (NDMA) and 4μg/l NDMA plus30μg/lN‐nitrosoproline (NPRO) and two naturally contaminated malts. Sixteen laboratories sent their results and two apologized in view of analytical problems. Results from this have been statistically evaluated. Comparison to those from the previous study demonstrated a distinct improvement in the results from the analysis of NDMA in beer and malt. Little has been achieved for the other two common contaminants of beer and malt,N‐nitrosopyrrolidine (NPYR) and NPRO. For this latter compound in beer, however, some hope came from the data produced by the method of Senet al.(1983), but the number of results is insufficient to allow firm conclusions to be drawn.

ISSN:0265-203X    

DOI:10.1080/02652039109374011

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Twenty‐five smoked and unsmoked fried bacon samples have been analysed by a group selective procedure to measure the concentration of apparent totalN‐nitroso compounds (ATNC). The levels of a range of individualN‐nitroso compounds, including simple volatileN‐nitrosamines,N‐nitrosothiazolidines,N‐nitrosoamino acids andN‐nitrosothiazolidine carboxylic acids have also been examined. Concentrations of ATNC varied from 430 to 6800μg(N‐NO)/kg with a mean of 2700μg(N‐NO)/kg. Protein‐boundN‐nitrosoproline was the most abundant compound detected in unsmoked bacon, mean 260μg/kg, and on average accounted for 4% of the ATNC concentration. For smoked bacon, boundN‐nitrosoproline was detected in levels of up to 890μg/kg and contributed 5% to the ATNC total. The most abundant compound present in smoked bacon wasN‐nitrosothiazolidine‐4‐carboxylic acid, mean 660μg/kg, and this accounted for 6% of the ATNC.N‐Nitrosothiazolidine, mean 340μg/kg, and 2‐(hydroxymethyl)‐3‐nitrosothiazolidine‐4‐carboxylic acid, mean 180μg/kg, were the next most prominent compounds detected in smoked bacon. The combined sum of all the individualN‐nitroso compounds measured accounted for, on average, 16% of the total ATNC. The identities of theN‐nitroso compounds comprising the majority of the ATNC in bacon remain unknown.

ISSN:0265-203X    

DOI:10.1080/02652039109374012

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Fusariummycotoxins, principally trichothecenes, occurred commonly in grain from crops in the North Island of New Zealand, but were much less common and also at the much lower levels in grains from South Island regions. The principal contaminants were trichothecenes of the nivalenol (NIV) and deoxynivalenol (DON) types. Trichothecenes derived from scirpentriol and T‐2 tetraol were not common. Moniliformin occurred very rarely, while zearalenone contamination was not uncommon, but the levels were generally low. Maize kernels were commonly contaminated by moderate levels of both NIV‐ and DON‐type trichothecenes, with levels up to 3.6 mg/kg and 11.95 mg/kg respectively recorded. The occurrence of NIV‐type trichothecenes as a general contaminant in the range of 0.3–0.8 mg/kg, and frequently as the main contaminant, is unusual.

ISSN:0265-203X    

DOI:10.1080/02652039109374013

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

HPTLC was used to check for residues of chlorpropham, propham (sprout inhibitors) and thiabendazole (fungicide) applied to potatoes. The method used gave good precision and analytical sensitivity. The sample preparation method developed by the authors was simple and gave good recovery and selectivity as far as other components of the matrix were concerned. Comparison with liquid chromatography confirmed the validity of the results.

ISSN:0265-203X    

DOI:10.1080/02652039109374014

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The effect of microwave‐ and oven‐baking on residues of the postharvest fungicide thiabendazole (E 233) in potatoes was investigated by comparing amounts present in raw, microwave‐ and oven‐baked tubers. The levels of residues in the whole potato tubers were based on the determination of thiabendazole in peelings and flesh of potato tubers by reversed‐phase HPLC analysis with fluorescence and UV detection after extraction with dichloromethane in the presence of anhydrous sodium sulphate. Amounts of thiabendazole determined after microwave‐ and oven‐baking showed that thiabendazole was predominantly retained in the peelings (96.3–98.8%) and not lost during the two types of processing treatments atca.100°C. Thus residues did not migrate into the flesh of the tubers.

ISSN:0265-203X    

DOI:10.1080/02652039109374015

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An off‐odour, described by the growers as similar to profenofos, occurred in melons in which this pesticide had been used in crop treatment. However, profenofos, 0‐(4‐bromo‐2‐chlorophenyl)O‐ethylS‐propyl phosphorothioate, could not be detected in the melons using GC/MS although a component with a shorter retention time was found. Concentration of melon volatiles by steam distillation yielded a product identical to that obtained by hydrolysis of profenofos, identified as 4‐bromo‐2‐chlorophenol. A solution of this compound in water had similar organoleptic properties to that of the contaminated fruits. It was concluded that 4‐bromo‐2‐chlorophenol was responsible for the taint detected in melons.

ISSN:0265-203X    

DOI:10.1080/02652039109374016

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Formaldehyde is used in ruminant feeding for different purposes including the protection of dietary proteins from ruminai degradation. The formaldehyde content of milk of goats fed various levels of formaldehyde‐treated soybean oil‐meal has been determined by using a sensitive HPLC method. Results showed a significant linear correlation between ingested formaldehyde and formaldehyde concentration in milk. About 0.02% of ingested formaldehyde was excreted in milk, as free formaldehyde.

ISSN:0265-203X    

DOI:10.1080/02652039109374017

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Mackerel fillets associated with an outbreak of scombrotoxicosis have been analysed for their contents of cadaverine, histamine, putrescine, spermidine, spermine and tyramine, and fed to informed, healthy volunteers of both sexes under medical supervision. Of the 86 fillets examined, 30 rapidly induced nausea/vomiting and/or diarrhoea when 50 g were consumed. The remaining fillets failed to provoke such symptoms, even though 17 of them were tested by volunteers proven to be susceptible to scombro‐intoxication. Statistical analysis failed to detect any differences in amines content between fillets shown to be scombrotoxic and those failing to induce nausea/vomiting and/or diarrhoea, and failed also to establish any significant relationships between the amines doses and volunteer responses, even after manipulations to simulate additive or synergistic interactions. Accordingly it is concluded that the content of such amines in mackerel have little or no role in the aetiology of scombrotoxicosis.

ISSN:0265-203X    

DOI:10.1080/02652039109374018

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor