摘要:

Flaxseed is increasingly being used in some food products because of its high content of α‐linolenic acid and dietary fibre. However, flaxseed contains cyanogenic glycosides which release toxic hydrogen cyanide in the presence of water (autohydrolysis). A method for estimation of cyanide in flaxseed under these conditions is described. The determination is carried out by homogenizing the sample with water, letting it stand, filtering it through a membrane and then injecting the filtrate into an HPLC system consisting of an anion exchange column and an electrochemical (amperometric, oxidation) detector. The homogenate is analysed at various intervals until a maximum value of cyanide is observed. The cyanide content of ten cultivars of flaxseed, when analysed by this method, was found to range from 124 to 196μg/g. The release of cyanide showed a maximum at about 3h of hydrolysis. Virtually no cyanide was detected on boiling the homogenate or the flaxseed before determination.

ISSN:0265-203X    

DOI:10.1080/02652039509374341

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A rapid technique for the extraction and gas chromatographic determination of five organochlorine and five organophosphorus pesticide residues in milk is described. Milk (5.0 ml) is blended with 2.0 g of C18[octadecylsilyl‐derivatized silica] and 1.5 ml acetonitrile in a syringe barrel. After the aqueous phase is removed from the column by vacuum aspiration, the pesticide residues are eluted from the C18/milk matrix with acetonitrile which is then eluted through a Florisil solid phase extraction (SPE) column. The acetonitrile is evaporated under nitrogen and the residue is dissolved in petroleum ether. This extract is directly analysed for organophosphorus pesticides by gas chromatography with flame photometric detection. After further clean‐up of the extract on a mini‐Florisil column, the organochlorine pesticide residues are determined by gas chromatography with electron capture detection. Grade A homogenized and raw milk samples were fortified with five organochlorine and five organophosphorus pesticide residues. The average recoveries of fortified organochlorine pesticide residues (2.0–20 ppb) ranged from 76.0% to 97.8%. The average recoveries of fortified organophosphorus pesticide residues (10–50 ppb) ranged from 75.0% to 104.5%. The MSPD and the AOAC International multiresidue method for pesticides in milk produced comparable results for milk samples containing incurred organochlorine pesticide residues. The use of the MSPD method results in a 90% reduction in organic solvent consumption and a 95% reduction in the hazardous waste generated when compared with the AOAC method.

ISSN:0265-203X    

DOI:10.1080/02652039509374342

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The organochlorine contaminant (OCC) data generated by the Swedish National Food Administration (NFA) since 1973 has been utilized to calculate average Swedish dietary intakes. Direct food consumption statistics based on the yearly per capita Swedish consumption of five principal food groups has been used with OCC levels over 5‐year periods, up to 1992. The present study shows the decline in OCC dietary intakes between 1975 and 1990. It is suggested that this is principally because of a decline in OCC concentrations in foods of animal origin rather than because of changes in food consumption patterns. The estimated intakes for the DDT complex, HCH isomers, dieldrin and HCB are generally well below the ADIs established by FAO/WHO. For total PCBs, no such ADI/TDI has been set up, either by FAO/WHO or in a Nordic PCB risk assessment. However, when compared with a US FDA guideline, the average Swedish total PCB dietary intake in 1990 is approximately 10‐fold lower. Finally, this study shows the good relationship between OCC dietary intakes via foods of animal origin and the concentrations measured on a fat weight basis in Swedish human milk.

ISSN:0265-203X    

DOI:10.1080/02652039509374343

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The influence of processing on the degradation of DDE in meat products was investigated. First, the current level of contamination in six different types of Spanish meat products was determined. Analysis were carried out by capillary gas chromatography with electron capture detector. Of the three residues analysed (botho,p’andp,p’ isomers of DDT, DDD, and DDE), onlyp,p‘‐DDE was found above the detection limit of 4μg/kg fat. The frequency ofp,p’‐DDE detection for the various products investigated varied between 78 and 100% of the 129 samples analysed, although mean levels were very low, in the range within 6–16μg/kg. No sample contained DDE residues above the EC maximum residue limit of 1 mg/kg for DDT and metabolites on meat products. Mean concentrations of DDE in Spanish meat products have declined since 1980 by more than 10‐fold as compared with previously reported data.

ISSN:0265-203X    

DOI:10.1080/02652039509374344

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This study proposed a new strategy assessing the health risks of mineral water packaging and compared the chemical analytical techniques and somein vitrocytotoxicological assays for the study of PVC and PET materials at the main stages of the manufacturing process of bottles. These evaluations were carried out with food simulant (deionized‐endotoxin‐tested water) and with natural mineral water in real conditions of packaging and storage (from 0 to 24 months). The complementarity of these two approaches is discussed. Some analytical and cytotoxic abnormalities were detected in the food simulant after contact with the batches of powdered PVC compound, PET resin and their intermediate steps of transformation (PVC‐'paraison’, PET‐'preform'). But thèse results did not reflect the actual behaviour of the finished PVC and PET bottles, for which no major abnormality was detected in the natural mineral water.

ISSN:0265-203X    

DOI:10.1080/02652039509374345

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Two insect growth regulators, namely CME 134 and Dowco 439, have been tested for their effect on growth and on aflatoxin B1and lipid productivity inAspergillus flavus.No effect on growth and lipid production was detected. However, various concentrations of CME 134 and Dowco 439 showed significant inhibitory effects on aflatoxin B1production. The degree of inhibition was dependent on the concentration and time of application. Inhibition was observed when Dowco 439 was added at inoculation and again 3, 6, 9, 12 and 15 days after inoculation, as well as after the addition of either CME 134 or Dowco 439 to the individual cultures at inoculation and 3 days after inoculation. However, the addition of either CME 134 or Dowco 439 as late as 6 days after inoculation markedly decreased the inhibition of aflatoxin B1production.

ISSN:0265-203X    

DOI:10.1080/02652039509374346

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Because of concern about possible transmission of ochratoxin A (OA) from contaminated grain adjuncts, development of a sensitive method for its determination in beer was investigated. Solid phase extraction (SPE) on C‐18 and silica gel columns in series and on an immunoaffinity column (OchraTest™) were used to obtain extracts for quantitation by reverse phase liquid chromatography with fluorescence detection. The standard curve was linear in the range 2.5–50 pg OA injected and detection limits for both methods were of the order 0.05–0.1 ng/ml beer (signal to noise 3:1). Per cent recovery of OA from various beer samples spiked at a level of 1 ng/ml averaged 82–100% for three modifications of the SPE method and 97% for the immunoaffinity column method. Forty‐one samples of Canadian and imported beers were analysed. Trace levels of OA (≤ 0.2 ng/ml) were detected in 26 samples by SPE and/or immunoaffinity column methods; there was generally good agreement between the methods. Identity of OA was confirmed by methyl ester formation in five samples cleaned up by the immunoaffinity column procedure.

ISSN:0265-203X    

DOI:10.1080/02652039509374347

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Six selected samples of preharvest maize ear rot, from different localities in Sardinia, Italy, were examined for causalFusariumspecies and associated mycotoxins. All samples were almost exclusively found to be affected byFusarium moniliformewhich was isolated from all infected ear sample kernels (100%). In two samples, in addition toF. moniliforme, F. proliferatumwas also present but in a reduced percentage of kernels (up to 42%). All samples were found to be contaminated by fumonisin B1(up to 250 mg/kg). Four samples were also found to be contaminated by beauvericin (up to 10 mg/kg), with higher concentration in samples also infected byF. proliferatum.When cultured on autoclaved maize kernels for 4 weeks at 25°C, all 13 strains ofF. moniliformeexamined produced fumonisin B1(up to 3750 mg/kg), whereas only three strains also produced beauvericin, but in very low amounts (5 mg/kg). In the same assay, four isolates ofF. proliferatumalso produced high amounts of fumonisin B1(up to 2500 mg/kg) but this was associated with higher concentrations of beauvericin (up to 175 mg/kg). This is the first indication of the production of beauvericin byF. moniliformeas well as of its co‐occurrence with fumonisin B1in preharvestF. moniliformemaize ear rot.

ISSN:0265-203X    

DOI:10.1080/02652039509374348

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of mixing on the migration of Irganox 1010®antioxidant from polypropylene and high‐density polyethylene to water and corn oil was compared at 77,100, and 135°C. Irganox 1010 migration to water is enhanced almost five‐fold by mixing at 77°C, whereas at 135°C, mixing has only a nominal effect on migration. Irganox 1010 migration to corn oil is virtually unaffected by mixing at the temperatures studied. Migration data indicate a similar trend for Irganox 1076.

ISSN:0265-203X    

DOI:10.1080/02652039509374349

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652039509374340

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor