Migration of polyolefin oligomeric saturated hydrocarbons (POSH) into food.

POSH are polyolefin oligomeric saturated hydrocarbons, such as oligomers from polyethylene or polypropylene. POSH that have migrated into foods are easily mistaken for mineral oil-saturated hydrocarbons (MOSH). In fact, both POSH and MOSH largely consist of highly isomerised branched and possibly cyclic hydrocarbons, both forming humps of unresolved components in gas chromatography. Chromatograms are reported to show typical elution patterns of POSH and help analysts distinguishing POSH from MOSH as far as possible. Since the structures of the POSH are not fundamentally different from those of the MOSH, it would be prudent to apply the evaluation of the MOSH. However, the migration is frequently beyond that for which safety has been demonstrated. This is shown for a few examples, particularly for powdered formula for babies.

Acrylamide monitoring in Switzerland, 2007-2009: results and conclusions.

Parallel to the European Union acrylamide monitoring for the years 2007-2009, Switzerland performed its own monitoring, covering the whole range of products that significantly contain acrylamide (almost 300 samples per year), but focusing on those products that may result in high exposure. As reducing sugars are critical for potato products, these were included. No significant change, particularly improvement, was noticed, especially regarding those products for which substantial potential for improvement is known. 'Western-style' French fries continued to contain some four times more reducing sugars than 'traditional' fries, with correspondingly higher acrylamide in the finished product. The supply of raw potatoes low in reducing sugars by retail shops needs improvement, but there seemed to be insufficient willingness on a voluntary basis. A foreign producer was successful in penetrating the Swiss market with special potato chips containing up to 7000 microg kg(-1) acrylamide and only harsh measures could stop this. Three of about 61 products in the group of bakery ware showed a marked improvement. But there was also a store brand cracker that competed with a leading brand which contained 15 times more acrylamide (845 microg kg(-1)). Cereals contained 1080 microg kg(-1) acrylamide and even a warning did not prompt the producer to sell substantially better products one year later. It seems that only measures by the authorities will achieve improvements. The following seem promising: a limit for reducing sugars in prefabricates for French fries; the improved supply of raw potatoes low in sugars for roasting and frying; a legal limit for acrylamide content in potato chips; a general provision that products must not contain substantially more acrylamide than achievable by good manufacturing practice; and fryers with a temperature profile from an initial high to a lower final value.

Acrylamide in fried and roasted potato products: a review on progress in mitigation.

The workshop of the European Commission and the Confederation of the Food and Drink Industries of the European Union (CIAA) held in March 2006 in Brussels, Belgium, discussed the key knowledge and achievements in the mitigation of acrylamide. This paper presents the progress made by the potato sector and identifies areas for future research. Because of the important contribution of potato products to acrylamide intake, it is an area that has received much attention. The discovery of the method of formation and the role of reducing sugars meant that long-standing knowledge in respect of sugar and fry colour could be used to identify methods of mitigation. Improvement in parameters such as (1) potato variety, (2) potato storage temperature, (3) process control (thermal input, pre-processing), (4) final preparation, and (5) colour have all contributed to a significant overall reduction in the average acrylamide content in French fries and potato crisps (termed 'chips' in the USA). There is evidence that the limit of reduction that these measures can offer for crisps has now been approached, but clearly more can be done for French fries and roasted potato products. The use of asparaginase offers potentially significant reduction in certain prefabricated potato products. More research is required into new potato varieties and the agronomical factors that influence the levels of asparagine and sugars in potatoes.

Options for legal measures to reduce acrylamide contents in the most relevant foods.

Options of taking measures for reducing acrylamide exposure are discussed from the viewpoint of health authorities. To achieve a significant effect on total exposure (without changing eating habits), a substantial reduction must be accomplished for the foods contributing most to total intake. Priority should be given to consumers with high exposure, which means that the average intake profile is not relevant, but high consumption of products with high acrylamide contents is relevant. Rather than introducing legal limits on acrylamide in the end-products, more basic factors determining acrylamide formation should be brought under control. Five measures are proposed. (1) For the preparation of fried and roasted products, potatoes low in reducing sugars should be made available to households and commercial outlets. (2) The content of reducing sugars in prefabricates for French fries should be limited. (3) Newly installed fryers should control the temperature profile from an initially high to a lower final value. (4) The use of ammonium carbonate in bakery products should be restricted. (5) There should be provisions to intervene if an acrylamide content clearly exceeds the level determined by good manufacturing practice and the products involved substantially contribute to total exposure in cases of high consumption.

Relative hopane content confirming the mineral origin of hydrocarbons contaminating foods and human milk.

Hopanes, triterpenoid hydrocarbons formed under geological conditions, were analysed to confirm the mineral origin of the unresolved complex mixtures of hydrocarbons observed in the gas chromatography with flame ionization detection chromatograms of human milk and certain foodstuffs. The 'relative hopane content' (RHC) is introduced, i.e. it is the area ratio of the sum of the hopanes and the paraffins in the same segment of the chromatogram. The RHC in various mineral oil products (motor oils, hydraulic oils, lubricating oils, Vaseline) was 3.4%, with a relative standard deviation of 19%. The RHC determined in samples of vegetable oils, mussels and clams as well as of human milk containing an unresolved complex mixture of hydrocarbons was in the same range, confirming that these samples were contaminated by mineral oil material.

Occurrence of C15-C45 mineral paraffins in olives and olive oils.

Different classes of olive oils and other olive samples (olives, olive paste and olive pomace) collected during their production were analysed for mineral paraffins in the range of C(15)-C(45). None of the 22 extra virgin olive oils contained mineral paraffins above the detection limit of 1 mg kg(-1). Also, lampante virgin olive oil from the olive mill showed no detectable amounts, but olive oil from the market contained 6-30 mg kg(-1). This contamination cannot be attributed to the refining step, which, on the contrary, partially removes the more volatile hydrocarbons, but could result from transport. Olive-pomace oils obtained by second centrifugation contained 16-145 mg kg(-1) mineral paraffins, presumably because of contamination during storage of the pomace. All olive-pomace oils from solvent extraction contained more than 100 mg kg(-1) mineral paraffins, also mainly from storage. Deposition of particulate matter from the air, vehicle exhaust emissions and direct contamination from the bulldozers used to move the pomace were identified as potential sources.

Determination of furan fatty acids in extra virgin olive oil.

The presence of 4 different furan fatty acids (F-acids) was detected in 18 samples of transmethylated monovarietal extra virgin olive oil: methyl 10,13-epoxy-11,12-dimethyloctadeca-10,12-dienoate [diMeF(9,5)], methyl 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoate [diMeF(11,5)] and both olefinic derivatives of diMeF(11,5) with one unsaturation on the side chains conjugated with the furan ring. Transmethylated oils were analyzed by normal phase high-performance liquid chromatography coupled on-line with capillary gas chromatography. After the gas chromatographic separation step, a more selective detection of F-acids was achieved by using a photoionization detector mounted in series with a flame ionization detector. The concentration of F-acids ranged between 50 ppb (detection limit of the method) and 2.1 ppm in the oil. The olefinic derivatives of diMeF(11,5) acids detected were not artifacts created during the sample preparation or during the chromatographic analysis.

On-line high-performance liquid chromatography-solvent evaporation-high-performance liquid chromatography-capillary gas chromatography-flame ionisation detection for the analysis of mineral oil polyaromatic hydrocarbons in fatty foods.

An automated on-line method is described that involves a first LC separation on a large column, evaporation of a 6-ml fraction in an on-line solvent evaporator, a second LC separation using a different mobile phase, fractionating the components of interest and transfer to GC through the in-line vaporizer/overflow interface. The method is designed for the injection of a large amount of food extract (e.g. up to 200 mg of fat) and is applied to the analysis of mineral oil material in a linseed oil.

On the origin of benzene, toluene, ethylbenzene, and the xylenes in virgin olive oil--further results.

Investigations into the sources of contamination of virgin olive oil by gasoline components were concluded. Olives on the tree contained volatile aromatic hydrocarbons at concentrations exceeding those corresponding to the equilibrium with the environment. Present knowledge indicates that up to 10 micrograms/kg of benzene and 250 micrograms/kg for the sum of benzene, toluene, and the C2-benzenes must be considered as possible background concentrations. Aside from the oil mills, the rooms for intermediate storage of the olives were found to be an important source of contamination by gasoline vapours, since they often contain vehicles and other gasoline-driven engines. Parking of a small, hot grass mower into a similar room released an amount of gasoline that was sufficient to contaminate the oil in olives above the proposed limit by a factor of 100. Recommendations are derived for the producers to avoid contamination of olive oil with gasoline components.

On the origin of benzene, toluene, ethylbenzene and xylene in extra virgin olive oil.

Concentrations of benzene, toluene, C2-benzenes and styrene were determined in olives and the oils produced thereof, as well as at various intermediate steps during production. Concentrations were compared to those found in samples of air taken from the olive grove and the olive mills. In an exposition experiment in the laboratory, olives absorbed aromatic compounds, approaching saturation corresponding to the partition coefficient between air and oil. However, concentrations in olives delivered to the mills were 4-10 times higher than expected from the analysis of the air in the olive grove. In the olive mills, concentrations were increased further by a factor of up to 2 because of uptake from air which contained high concentrations of aromatics. Styrene concentrations strongly increased during storage of crushed olives at ambient temperature, which confirms the hypothesis that styrene is a product of metabolism.

Ten-year follow-up in pediatric patients with allergic bronchial asthma: evaluation of specific immunotherapy.

Specific immunotherapy as a treatment for bronchial asthma has been a controversial field. A collaborative study was designed in an attempt to further define the possible contribution of specific immunotherapy in a pediatric population. One hundred and sixty-six patients were treated with immunotherapy and 248 received no immunotherapy. The results were compared during 10 years of follow-up in both groups. There was a significant decrease in the number of acute crisis in the treated group (p < 0.05). However, no differences were seen in the number of hospital admissions or in the quality of life between the treated and untreated groups. The treated group required significantly fewer drugs (p < 0.05). Thus, it is probable that the untreated group shows the same clinical indexes as the treated group due to their increased use of medication. Specific immunotherapy represents an effective treatment that changes the natural course of allergic bronchial asthma in pediatric patients.

Determination of organophosphorus insecticides in edible oils and fats by splitless injection of the oil into a gas chromatograph (injector-internal headspace analysis).

Direct injection of oil or fat into a moderately heated injector enables performance of a kind of headspace technique in the injector: oil or fat is diluted 1:1 with acetone and injected into a vaporizing chamber at 200 degrees C. Components, for example organophosphorus insecticides, evaporate from the oil film on the insert wall and are transferred into the column in the splitless mode; the oil slowly flows along the wall to the bottom of the insert and is retained there in a kind of a bag. Using a flame photometric detector, detection limits are below 10 micrograms/kg.

On-line coupled liquid chromatography-gas chromatography (LC-GC) and LC-LC-GC for detecting irradiation of fat-containing foods.

On-line coupled liquid chromatography-gas chromatography-flame ionisation detection (LC-GC-FID) enables efficient and unambiguous determination of irradiation for some fat-containing foods (e.g. meat). Other products, however, contain interfering components or are contaminated, e.g., with mineral oil. Since more selective detection by mass spectrometry has limited success, the determination was improved by a more selective isolation of some key components among the fat degradation products, e.g. the dienes or trienes, by LC-LC-GC-FID. Applications are shown for soup mixes, some spices, fish, and shrimps.

Determination of food contamination by mineral oil from jute sacks using coupled LC-GC.

Jute fibers are treated with about 5-7% of a high boiling mineral oil fraction ("batching oil") to render them flexible for making fabrics. Foods transported in jute bags are contaminated by this batching oil. A method involving automated on-line LC-GC is described for determining these hydrocarbons in various foods. Complete transfer of the LC fraction to GC is presupposed for obtaining the required sensitivity. Results are given for nuts, coffee, cocoa products, and rice. Contamination ranged between about 5 and 500 ppm.

Uptake by foods of tetrachloroethylene, trichloroethylene, toluene, and benzene from air.

Transition rates from air into food as well as equilibrium concentrations in air and critical foods were determined for tetrachloroethylene, trichloroethylene, benzene and toluene. From these data, maximum concentrations of the four substances in air were estimated that keep contamination of critical foods at an acceptable level. A simple and rapid method allowed us to determine the risk of food contamination from the air, e.g. in shops and kitchens, by the analysis of the air. Estimations showed that concentrations in the air of shops should not exceed 1 mg/m3 if tetrachloroethylene concentrations in foods are limited to 100 micrograms/kg (slightly higher concentrations can be accepted for the other three compounds); in kitchens of restaurants and households, even 0.3 mg/m3 cause the target concentration to be exceeded rather frequently If the limit in foods is 50 micrograms/kg, recommended maximum concentrations in air are 0.5 and 0.15 mg/m3. The data also shows that the recommended limits for concentrations in air conflict with the accepted emission limits: If emission at the accepted limit occurs near shops or households, contamination of foods far exceed that considered as tolerable.