摘要:

A liquid chromatographic method for determining residues of ionophores in bovine, porcine, and avian tissues is described. Tissues were extracted with iso‐octane‐ethyl acetate and the extracts purified on silica solid‐phase extraction columns. Monensin, narasin and salinomycin were detected by UV absorbance following post‐column derivatization with vanillin, and lasalocid was detected underivatized using fluorescence. In muscle, kidney and fat, all drugs were determined from a single sample extract. In liver, a separate extraction was done to determine lasalocid. The detection limit for lasalocid, narasin and salinomycin was 5 ppb; for monensin it was 2ppb. Average recoveries were: lasalocid—71.0%; monensin—94.3%; salinomycin—97.2%; narasin—94.1 %.

ISSN:0265-203X    

DOI:10.1080/02652039509374365

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The heat stability of sulphamethazine was investigated. The drug was shown to be stable in boiling water at 100°C. In cooking oil at 260°C, losses were observed, indicating a half‐life of about 5 min. At 180°C in cooking oil, sulphamethazine was unstable with a half‐life of about 2h. The effect of a range of cooking processes (boiling, roasting, grilling, frying, pressure cooking and microwaving) on sulphamethazine residues in incurred animal tissue was studied. Once allowance for weight loss during cooking had been made no net unaccountable change in concentration of sulphamethazine was observed in any of the cooking processes investigated. During frozen storage, sulphamethazine residues were found to be stable over a period of 3 months. It was found during this investigation that the method used for analysis which involved acid extraction converted theN4‐metabolites to parent sulphamethazine, and hence only sulphamethazine was measured. Sulphamethazine was found to be evenly distributed in the raw incurred tissue used for analysis. Migration from the tissue into the surrounding liquid or meat juices was observed during the cooking process. The findings of this investigation show that surveillance data obtained from measurements on raw tissue are applicable for use in consumer exposure and dietary intake calculations, but only if an acidic extraction method which converts theN4‐metabolites to parent sulphamethazine is used for the surveillance. This may not however conform to current Maximum Residue Limit legislation which refers to total parent sulphonamides. Different methods of analysis for sulphonamides are likely to give rise to inter‐laboratory variation.

ISSN:0265-203X    

DOI:10.1080/02652039509374366

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The biological activities of diethylstilbestrol (DES) and 17‐β‐oestradiol (17βE) were initially tested, based on the uterus enlargement induced by different doses given with food to immature female mice. In a second series of experiments, the drugs were given in higher dosesper osto rats (relay animals) and after 24 h, the livers of the relay rats were removed. Parts of the livers were freeze‐dried and were added (10% w/w) to the food of immature female mice, while the remainder underwent chemical analysis to determine the DES and 17βE content. When given directly to mice with their food, DES showed about six times more biological activity than 17βE. When given through the livers of relay rats, the biological activity of the livers from DES‐ and 17βE‐treated relay rats was of the same magnitude. The content of 17ßEin the livers of relay rats was 10–20 times higher than the DES. Such concentrations corresponded directly to the biological activity of livers. These data show that the bioavailability and the relative potency of xenobiotic drugs and natural hormones may be profoundly altered after passing through metabolic pathways, and may give useful indications for the evaluation of biological activity of resfdues and contaminants and their metabolites in the food.

ISSN:0265-203X    

DOI:10.1080/02652039509374367

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Dehydrated fruits and vegetables, which may well be used in baby foods, must be of excellent bacteriological quality with an absence of contamination. In order to define the effects of the industrial dehydration process, according to the ‘Hatmacker’ drying method, on an organophosphorus pesticide, we have studied phosalone in Golden Delicious apples as an example. The technological process undertaken leads to a reduction in phosalone levels on the apples of more than 80%, whatever the initial dose between 0 and 4.29μg/g.Washing brings about a reduction of 30–50%, probably by the dissolution of the phosalone in the water. The cooking and especially the filtration of the puréed apple mechanically eliminates, without notable deterioration, 40–70% of the phosalone. However, drying, which takes place at the end of the process, does not lead to significant variations in phosalone levels. Consequently, the reduction in phosalone residue levels in dehydrated apple products manufactured by this process provides the consumer with a greater degree of security with respect to this contaminant. In addition, we have presented several possibilities to add to the quality of dehydrated products.

ISSN:0265-203X    

DOI:10.1080/02652039509374368

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Hydrolysis studies using simulated gastrointestinal fluids have been performed on oleamide, an important fatty acid amide slip additive used in plastics food packaging. Experiments have been conducted using the simulated gastrointestinal fluids, specified by the Scientific Committee for Food for hydrolysis studies, and with slightly modified preparations believed to be more representative of thein vivosituation. The degree of hydrolysis in simulated gastric fluids was found to be negligible after incubation for 4 h at 37°C. Addition of ‘bile salts’ to simulated intestinal fluid was found to significantly increase the degree of hydrolysis to about 95% loss of oleamide after incubation for 4 h at 37°C. Stoichiometric formation of oleic acid, an innocuous substance, was also demonstrated. It has therefore been concluded that ingestion of the very low levels of oleamide expected to migrate into most foods from food packaging is unlikely to pose a threat to the health of the consumer.

ISSN:0265-203X    

DOI:10.1080/02652039509374369

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Susceptors are an example of one of the many new products being introduced into food packaging. They are used to achieve local areas of high temperature; this has the effect of browning the food during microwave cooking. Previous work by Begleyet al.had suggested that one particular cold cure adhesive component, bisphenol A diglycidyl ether (BADGE), might be present in some susceptor products but gave little indication as to the retail use of these products. As a result an investigation of UK retail samples was carried out in January 1992. Most of the susceptors tested contained no detectable BADGE ( < 0.1 mg/kg), however, two brands of pizza were found to be packaged with susceptors containing BADGE at between 700 and 800 mg/kg (1.8–2.0 mg/dm2). Migration of BADGE into the pizzas in question was 0.1–0.7 mg/kg when they were cooked in their packaging according to on‐pack instructions. Further tests undertaken in June 1992 confirmed earlier findings when from a total of 54 samples purchased covering seven manufacturers, nine samples of susceptors used in one brand contained BADGE at concentrations between 1900 and 3200 mg/kg. The manufacturer of this brand has stopped supplying further products to the retail market using this particular type of susceptor. A third set of tests was undertaken in November 1992 to ensure that these products were no longer on sale in the UK. Of 44 susceptors analysed, only one contained BADGE above 0.1 mg/kg; this appeared to be old stock pre‐dating the manufacturers’ action.

ISSN:0265-203X    

DOI:10.1080/02652039509374370

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Lead and cadmium contents were determined in nationally representative samples of low‐fat milk, cheese and eggs consumed in Finland. Nationally representative samples of milk and cheese were collected from dairies. Egg samples were collected from the major distributors. Samples of imported cheese and egg products collected in surveillance studies were analysed, together with domestic samples. Lead and cadmium were determined by GFAAS after wet digestion in cone. HNO3. In lead determinations of milk and cheese platinum was employed as the matrix modifier and NH4H2PO4was employed for the lead determinations of eggs and in all cadmium determinations. Mean lead content was 1.7μg/kg in milk, 17μg/kgin Finnish cheese, 17–60μg/kg in imported cheese, 1μg/kg in eggs and 6–72μg/kg in imported dry egg products. Although Finnish consumption of milk, cheese and eggs is high the dietary intake of lead and cadmium from these sources is very low compared with the tolerance limits.

ISSN:0265-203X    

DOI:10.1080/02652039509374371

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A survey of intense sweetener intakes was carried out in the winter of 1990 and summer of 1991 in Brazil. Data on the potential intake of the intense sweeteners aspartame, cyclamate and saccharin were generated, based on a representative sample of 673 individuals who completed a questionnaire designed to collect information on demographic details and habitual usage of sweetener‐containing food and drinks. The respondents were randomly chosen among intense sweetener consumers living in the cities of Campinas, São Paulo and Curitiba, Paraná. Potential daily intakes by individuals were calculated for each sweetener by combining each person's consumption of sweetener‐containing food and beverages with information generated by the determination of the concentrations of the sweeteners used in these products. The data showed that 72% of the studied population consumed saccharin, 67% cyclamate and 40% aspartame. The main reasons alleged for the use of intense sweeteners were weight‐control diet (36%), diabetes (35%) and weight loss (23%). Table‐top sweeteners were the major source of sweeteners, followed by soft drinks. The median daily intake of aspartame, cyclamate and saccharin represented approximately 2.9, 15.5, and 16.4% of the corresponding ADI, respectively. Diabetics in general had a much higher intake within the studied population.

ISSN:0265-203X    

DOI:10.1080/02652039509374372

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An International Interface Standard for Food Databases is under development to help overcome the technical and semantic barriers to the use of food‐related databases. The Interface Standard is a system for efficient storage of all relevant descriptive information about foods. The schema for the Standard consists of ten components—food/food product identification, food names, LANGUAL factors, other food descriptors, other descriptive coding systems, ingredients/recipes, standards, substances, organizations, and data sources. The Interface allows for retrievals of data associated with specific foods from databases by using queries based on any of a wide variety of descriptive terms. The schema of the Interface has been completed; the remaining work is to build the computer software to provide access to, and use of, the schema.

ISSN:0265-203X    

DOI:10.1080/02652039509374373

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652039509374364

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor