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L Castle

Publications and source records attributed to L Castle.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products.

Migration of mineral hydrocarbons into dairy products and sunflower oil (fatty food simulant) has been studied using a gas chromatographic procedure. The food contact materials examined were polystyrene and ABS pots and tubs, and waxed paperboard. Levels of mineral oil in the polystyrene and ABS articles ranged from 0.3 to 5.5% w/w (13 to 366 mg/dm2) and as a coating on the paperboard ranged from 1.0 to 7.7% (55 to 565 mg/dm2). Exposure conditions were 7 days at 4 degrees C for the dairy products and 10 days at 40 degrees C for the oil. However, individual serving milk and creams (UHT) were retail samples which were stored at ambient temperature before analysis. Migration into the milk products was less than 3 mg/kg. Transfer to sunflower oil simulant and into individual serving milk products was much higher at levels up to 150 mg/kg (2 mg/dm2) and 90 mg/kg (4 mg/dm2) for the oil and milk respectively.

Acrylic Resins↗
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Migration of mineral hydrocarbons into foods. 3. Cheese coatings and temporary casings for skinless sausages.

Levels of mineral hydrocarbons which have migrated from wax coatings into cheese have been determined for 20 retail samples using a gas chromatographic procedure. Contamination was limited to the outermost 2 mm of cheese in direct contact with the wax where levels of hydrocarbons were found to range from 10 to 150 mg/kg. On a whole cheese weight basis these amounted to < 1 to 27 mg/kg (< 0.2 to 3 mg/dm2 contact area). Components attributed to hydrocarbons in cheese samples remote from the waxed surface (background levels) were typically 3-5 mg/kg. Background levels were subtracted from the results for surface samples to obtain migration values. There was evidence that the surface contamination of cheese with mineral hydrocarbons occurred by a combination of diffusion into the cheese and adhesion of wax components onto its surface. Mineral hydrocarbons are used in the manufacture of the temporary casings used to mould skinless sausages. Of 33 retail products examined, including skinless sausages, hot-dog sausages and frankfurters, 25 (75%) contained levels of mineral hydrocarbons from 10 to 105 mg/kg. These hydrocarbons were shown to be present principally at the surface of the food and so could be attributed to migration. Nine other minced meat products were examined for comparison, including minced beef, pâté, sausage meat and sausages with skins. Levels of mineral oil in these products were insignificant by comparison, typically below the limit of detection of ca 4 mg/kg, indicating insignificant adventitious contamination from routes other than migration.

Animals↗
PubMedDate not supplied

Migration from plasticized films into foods. 6. Hydrolysis of polymeric plasticizers under simulated gastric and intestinal conditions.

The polymeric plasticizers poly(butylene adipate) and poly(propylene adipate), and a low molecular weight oligomer fraction from each, were exposed in vitro to simulated gastric and intestinal hydrolysis in order to study their likely fate after ingestion of foods contaminated by migration from plastics packaging. Analysis for loss of the parent compounds indicated that partial hydrolysis occurred under simulated gastric conditions, with the low molecular weight oligomers being the most susceptible. Analysis for one of the starting materials, adipic acid, revealed however that the hydrolysis did not result in a significant conversion to free monomer under either simulated gastric or intestinal conditions. This is explained on the basis of partial hydrolysis of the plasticizers to smaller oligomer units but with the more resistant ester linkages resisting complete breakdown to monomer.

Adipates↗
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Migration of styrene monomer from thermoset polyester cookware into foods during high temperature applications.

Migration of styrene from thermoset polyester cookware into foods has been studied during normal cooking applications and for the fatty food simulant olive oil under high temperature test conditions. The analysis of foods was by automated headspace gas chromatography/mass spectrometry (GC/MS) in the selected ion mode. Cyclohexane was added to the slurried foods to improve headspace partition and deuterated-styrene was the internal standard. To achieve adequate sensitivity with olive oil, styrene was extracted and concentrated by a steam distillation method and then determined by GC/MS. Styrene in foods cooked in thermoset polyester articles was in the range < 5 to 5 micrograms/kg and 5 to 30 micrograms/kg where the polyester contained 9 and 380 mg/kg residual monomer respectively. Testing for 2 h at 175 degrees C into olive oil resulted in significantly higher migration of styrene than seen for other foods, although there was a marked decrease in migration on repeat-use. Testing of the complete articles as sealed systems filled with olive oil led to higher migration than testing by total immersion of plaques. Of the test methods used with olive oil, testing as filled articles with no lidding gave migration results closest to (but generally higher than) those seen for real foods.

Cooking and Eating Utensils↗
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Combined compositional analysis and threshold of regulation as a possible control measure for microwave susceptors.

A testing scheme is described whereby the susceptor is heated in an enclosed system and potential volatile migrants detected by GC-FID or GC-MS. This compositional information is then combined with knowledge on the relationship between volatility and transfer to foods to predict migration levels. The scheme can be simplified to a threshold of regulation approach by addition of internal standards at suitable concentrations. This approach could be of value in screening new susceptor compositions for potential migrants, followed, as required, by more exhaustive testing using foods or food simulants. In support of this approach, 15 model substances with a boiling range of 77-440 degrees C were incorporated into susceptors via the vapour phase or by formulation into the adhesive. Migration to microwaved foods was measured to provide the required information on the approximate relationship between the boiling point of a potential migrant and its migration level. The impregnated susceptors were also used to measure migration of the model substances to the test simulants Tenax and a semi-solid simulant of olive oil and water absorbed on an inert support. Migration to both simulants was much higher than to foods, indicating that for volatiles analysis at least, both simulants are suitable for screening purposes and err on the side of safety.

Cooking and Eating Utensils↗
PubMedDate not supplied

Migration of mineral hydrocarbons into foods. 4. Waxed paper for packaging dry goods including bread, confectionery and for domestic use including microwave cooking.

Retail samples of dry goods (bread, biscuits and breakfast cereals) packaged in waxed paper were examined for the presence of mineral hydrocarbon wax. Bread loaves contained up to 50 mg/kg of the wax (associated with the outer surfaces) and crackers up to 185 mg/kg. Mineral oil was found in bread samples, at up to 550 mg/kg and was dispersed throughout indicating its use in food processing machinery as the likely source. Retail confectionery products wrapped in waxed paper (containing 12-44% w/w) gave rise to levels of 12-1300 mg/kg mineral hydrocarbon in the individually wrapped sweets. Migration into boiled sweets was lowest at 10-130 mg/kg, whilst soft chews and toffee products contained 110-1300 mg/kg. The distribution of wax hydrocarbons (principally n-alkanes) in the confectionery coincided exactly with that for the paper wrapping, with a range of C23 to C33 (95% material) centred around C26. This indicated that the transfer to the food occurred largely by adhesion rather than by diffusion since the latter would be expected to favour preferential migration of the low molecular weight components. In simulated home-use experiments with waxed bags sold in the United States for domestic use, migration into sandwiches and cake amounted to 40 mg/kg (1% transfer of wax). Use of these waxed bags in the microwave oven (as recommended) gave rise to contamination of foods from 210 to 1650 mg/kg (up to 60% transfer of wax).

Bread↗
PubMedDate not supplied

Practical aspects of testing food contact materials for migration.

Progress in three areas has provided analytical methods and understanding to assist in migration testing for compliance with European Community Directives on food contact materials. A simple migration test has been developed to indicate whether or not a food makes fatty contact with plastics. This test is then used to guide the initial choice of appropriate food simulants. The Karl Fischer technique for water determination has been used to eliminate the need to humidity condition plastics in overall migration testing. This results in more rapid and more reliable migration testing. Finally, the stability of 'positive-list' monomers and other starting substances has been examined in food simulants. This identifies those substances which, for reasons of reactivity, may not be expected to survive a migration test and for which, therefore, migration testing as such is inappropriate.

European Union↗
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Current research on food contact materials undertaken by the UK Ministry of Agriculture, Fisheries and Food.

Recent research funded by the UK Ministry of Agriculture, Fisheries and Food (MAFF) in the area of migration from food contact materials is reviewed and set within a framework of surveillance; evaluation of new technology; support of current regulations; and anticipation of future controls. Recent surveillance projects monitoring foods for migration of monomeric plasticizers (in particular di-(2-ethylhexyl)adipate), polymeric additives and mineral hydrocarbons are highlighted. Development of high temperature testing conditions for food contact materials has been carried out in support of regulations and proposals are made for the control of susceptors by analysis of release of volatiles. Migration of benzophenone from the printing ink of a paper board sleeve during microwave heating of a pre-cooked meal is described as a recent example of a migration situation that would not easily have been anticipated. Finally, the approach being adopted for investigating paper and board food contact materials for inorganic constituents, for volatile organic and for solvent-extractable organic components is outlined as an example of work being carried out in anticipation of future regulatory controls.

Chromatography, High Pressure Liquid↗
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Migration of mineral hydrocarbons into foods. 5. Miscellaneous applications of mineral hydrocarbons in food contact materials.

Polystyrene and acrylonitrile/butadiene/styrenes (ABS) containers for individual serving portions (80 samples of milk, cream, butter, margarine and spreads) used in the catering industry were found to contain 1-4% mineral oil. Levels of mineral oil migrating into the foods were generally low (< 5-15 mg/kg) except in one instance where levels of 45-85 mg/kg were detected in a low fat spread, and this was attributed to mineral hydrocarbon transfer from an adhesive used in the lidding. Analysis of wine bottle corks (105 samples from 11 different countries) indicated that 50% had been treated with mineral wax or mineral oil, although in all cases mineral hydrocarbon contamination of the wine was < 0.2 mg/l. Waxed paper discs sold for home-use for covering the surface of jams and preserves were found to be coated with 100 mg/dm2 of mineral hydrocarbons. However, in experiments with a variety of jams and preserves levels of migration were not significant, ranging from 0.15 to 1.2 mg/kg.

Acrylic Resins↗
PubMedDate not supplied

Levels of di-(2-ethylhexyl)phthalate and total phthalate esters in milk, cream, butter and cheese.

Di-(2-ethylhexyl)phthalate (DEHP) and total phthalate ester plasticizer levels were determined in milk, cream, butter and cheese samples from a variety of sources from three European countries (UK, Norway and Spain). Samples of milk (from Norway) obtained at various stages during collection, transportation and packaging operations showed no apparent trends in phthalate contamination with total phthalate levels (expressed as DEHP equivalents) in the raw milk of between 0.12 and 0.28 mg/kg. On processing the DEHP was concentrated in the cream at levels up to 1.93 mg/kg, whereas low fat milk contained from < 0.01 to 0.07 mg/kg. Retail dairy products (from Spain) were contaminated with < 0.01-0.55 mg/kg DEHP with a maximum total phthalate level of 3.0 mg/kg in cream samples. UK pooled milk samples from doorstep delivery (obtained from different regions of the country) contained low levels of DEHP (< 0.01-0.09 mg/kg) and total phthalate (0.06-0.32 mg/kg). Retail UK samples of cheese, butter and other fatty products varied considerably in their levels of contamination, the highest being cheese samples containing 17 mg/kg of DEHP and 114 mg/kg total phthalate. However, the majority of samples contained 0.6-3.0 mg/kg DEHP and 4-20 mg/kg total phthalate. UK cream samples contained levels of 0.2-2.7 mg/kg DEHP and 1.8-19.0 mg/kg total phthalate. The level found in these products was too high to have resulted solely from milk by concentration in the fat phase and must therefore have arisen in other ways.

Animals↗
PubMedDate not supplied

Migration of mineral hydrocarbons into foods. 6. Press lubricants used in food and beverage cans.

Unused food and beverage cans were supplied by manufacturers together with two typical samples of press lubricants used to facilitate stamping of can ends. The lubricants were based on mineral hydrocarbon fractions. The cans were of aluminium two-piece construction (two sizes) and tin-plate steel three-piece construction (two sizes) and of four representative types. Gas chromatographic analysis was used to distinguish the two press lubricants from one another by their n-alkane profiles. Analysis of solvent extracts of the cans indicated that one of the two press lubricants had been used in the manufacture of the three-piece cans and the other lubricant for the two-piece cans. Residual levels of hydrocarbons were between 0.05 and 1.1 mg per can. Based on the capacity of the cans and assuming all the mineral hydrocarbon transferred to the contents, maximum levels in foods and beverages could be between 0.1 and 4.4 mg/kg. A limited number of retail products were also analysed. For the 35 samples covering 18 retail brands of canned foods and beverages, press lubricants were considered to be present in 50% of the products at levels ranging from 0.05 to 1.0 mg per can, equivalent to 0.1 to 3.6 mg/kg of food. Additionally mineral oil of unknown origin was detected in 10 of the retail products at levels of 0.1 to 4.7 mg/kg. Analysis of a sparkling apple juice packed in a glass bottle showed mineral oil at 0.3 mg/kg compared with 0.7 mg/kg for the same canned product, indicating that although mineral oils may be used in can manufacture they may also be derived from other parts of the food processing chain.

Beverages↗
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Element residues in food contact plastics and their migration into food simulants, measured by inductively-coupled plasma-mass spectrometry.

Polymers intended for food contact use have been analysed for inorganic residues which can be attributed to a range of substances employed as polymerization aids (e.g. catalysts), or to additives incorporated into the polymer to fulfil a specific task (e.g. lubricants). The migration of these residues into food simulants was studied. Residues were determined by using the multi-element capability of Inductively-Coupled Plasma-Mass Spectrometry (ICP-MS). Semi-quantitative analysis was carried out on acid digests of polymer materials, obtained by microwave heating in sealed Teflon containers. Limits of detection in the polymer were generally less than 1 mg/kg. Migration experiments were carried out with three food simulants and under two sets of conditions. Analysis for element residues was performed directly or, in the case of olive oil, on an emulsion of the simulant. Migration of certain elements into aqueous simulants was observed: Zr from polystyrene (650 micrograms/kg), Sb from polyethylene terephthalate (4 micrograms/kg) and Mg from acrylonitrile/butadiene/styrene copolymer (50 micrograms/kg). In all cases, where limits of detection permit, the levels which migrated from polymer to stimulant were less than proposed limits on migration.

Drug Residues↗
PubMedDate not supplied

Detection of residues of the epoxy adhesive component bisphenol A diglycidyl ether (BADGE) in microwave susceptors and its migration into food.

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 Begley et 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.

Adhesives↗
PubMedDate not supplied

Validation studies of a quick test for predicting the sorption and washing properties of refillable plastic bottles.

Quick tests are proposed in the literature as alternatives to the large scale contamination and washing studies performed to date to assess the acceptability of plastic beverage bottles for refilling. These tests use small plastic specimens ('strips') in place of bottles and use mixtures of surrogate contaminants to model the myriad of chemicals that could in principle contaminate returned bottles because of consumer mis-use. The work reported here has measured the sorption and wash performance using the quick test protocol with PET (polyethyleneterephthalate) strips and laboratory washing and compared the results with tests using actual bottles and a commercial washing process. The comparison indicates that the quick test satisfactorily simulated contamination and commercial washing of intact bottles. The results also show that repeated washing of PET bottles does not cause higher sorption of contaminants.

Absorption↗
PubMedDate not supplied

Investigations into the potential degradation of polycarbonate baby bottles during sterilization with consequent release of bisphenol A.

Twenty-four brands of plastic baby feeding bottles were purchased and all were found to be made of polycarbonate. Taking a batch of one representative sample, the polymer was tested for stability and possible release of bisphenol A following domestic practice of sterilization. Sterilization was by alkaline hypochlorite, steam, or washing in an automatic dishwasher at 65 degrees C with detergent. A total of 20 cycles of sterilization and subsequent food use were performed for each of the three procedures. Bisphenol A migration was in all cases not detectable in infant feed using a very sensitive method of liquid chromatography with fluorescence detection with a 0.03 mg/kg detection limit.

Benzhydryl Compounds↗
PubMedDate not supplied

Thermal stability of polyethylene terephthalate food contact materials: formation of volatiles from retain samples and implications for recycling.

PET packaging materials have been tested for volatile content after exposure to high temperatures. Samples included laminates, bottles, and roasting bags, and were heated at 120 degrees C, 150 degrees C and 230 degrees C for 50 min, according to sample type. Volatiles released from the material were trapped on Tenax, identified by GC-MS and assessed against a 10 micrograms/kg migration threshold limit. Few volatiles were found for samples composed only of PET. Volatiles from laminates varied according to the sample structure, but the main substances identified were not related to PET, but probably came from printing inks and adhesives. It is concluded that the migration potential of PET in high temperature applications is very low and that the formation of volatiles during use is unlikely to cause any special problems in polymer recovery in recycling schemes, provided that other packaging residues are removed effectively.

Drug Residues↗
PubMedDate not supplied

Gas chromatographic-mass spectrometric determination of epoxidized soybean oil contamination of foods by migration from plastic packaging.

A method for the quantitative determination of epoxidized soybean oil (ESBO) in foods is described. The procedure involves addition of a diepoxidized fatty acid ester internal standard, followed by lipid extraction from the food and transmethylation under basic conditions. Without further cleanup, the methylated fatty acid epoxides are derivatized to form 1,3-dioxolanes, which are then determined by capillary gas chromatography-mass spectrometry with selected ion monitoring. A detection limit of 2.0 mg/kg of epoxidized soybean oil in foods and a relative standard deviation of 7% have been achieved routinely. The method has been applied successfully to the analysis of cheeses, sandwiches, cakes, and microwave-cooked meals which have been contaminated with ESBO by migration from PVC film.

Epoxy Compounds↗