Lisbeth Krüger Jensen
Technical University of Denmark
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Featured researches published by Lisbeth Krüger Jensen.
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment | 2008
Gitte Alsing Pedersen; Lisbeth Krüger Jensen; Anja Fankhauser; Sandra Biedermann; Jens Højslev Petersen; Bente Fabech
Nineteen samples of food in glass jars with twist closures were collected by the national food inspectors at Danish food producers and a few importers, focusing on fatty food, such as vegetables in oil, herring in dressing or pickle, soft spreadable cheese, cream, dressings, peanut butter, sauces and infant food. The composition of the plasticizers in the gaskets was analysed by gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Epoxidized soybean oil (ESBO) and phthalates were determined in the homogenized food samples. ESBO was the principal plasticizer in five of the gaskets; in 14 it was phthalates. ESBO was found in seven of the food samples at concentrations from 6 to 100 mg kg(-1). The highest levels (91-100 mg kg(-1)) were in oily foods such as garlic, chilli or olives in oil. Phthalates, i.e. di-iso-decylphthalate (DIDP) and di-iso-nonylphthalates (DINP), were found in seven samples at 6-173 mg kg(-1). The highest concentrations (99-173 mg kg(-1)) were in products of garlic and tomatoes in oil and in fatty food products such as sauce béarnaise and peanut butter. For five of the samples the overall migration from unused lids to the official fatty food simulant olive oil was determined and compared with the legal limit of 60 mg kg(-1). The results ranged from 76 to 519 mg kg(-1) and as a consequence the products were withdrawn from the market.
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment | 2010
Jens Højslev Petersen; Lisbeth Krüger Jensen
The migration of phthalates into foodstuffs from food-contact materials (FCM) is a well-known source of food contamination. In 2005, the European Food Safety Authority finalized its risk assessment for several of the classical phthalate plasticizers. In their risk management procedure the European Commission transformed the tolerable daily intakes established by the Authority into legislative limits for phthalates in both plastic and food simulants, while taking exposure from other sources into consideration. These limits have been into force since 1 July 2008. A detailed interpretation of the regulation of these substances was agreed upon in the European network of FCM reference laboratories. This paper reports results from a Danish control campaign of samples collected by official food inspectors and analysed by a newly validated analytical method run under accreditation. Samples were from FCM producers, FCM importers and importers of packed foodstuffs from third-party countries. Products containing phthalates above the current limits were found in several categories of FCM: conveyor belts (six of six), lids from packed foodstuffs in glasses (eight of 28), tubes for liquid foodstuffs (four of five) and gloves (five of 14). More than 20% of the samples analysed contained dibutylphthalate (DBP) or di-(2-ethylhexyl)phthalate (DEHP) above the compositional limits of 0.05% and 0.1%, respectively. Analysis of residual phthalates in metal lid gaskets instead of analysis of phthalates in the food when controlling foodstuffs packed outside the European Union proved to be an efficient and simple control method. All findings of phthalates were associated with the use of plasticized polyvinylchloride (PVC).
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment | 2016
Linda Bengtström; Anna Kjerstine Rosenmai; Xenia Trier; Lisbeth Krüger Jensen; Kit Granby; Anne Marie Vinggaard; Malcolm Driffield; Jens Højslev Petersen
ABSTRACT Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including extraction, high-performance liquid chromatography (HPLC) fractionation, tentative identification of relevant substances and in vitro testing of selected tentatively identified substances. As a case study, we used two fractions from a recycled pizza box sample which exhibited aryl hydrocarbon receptor (AhR) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven were commercially available and subsequently tested in vitro and quantified. Of these seven, the identities of three pigments found in printing inks were confirmed by UHPLC tandem mass spectrometry (QqQ MS/MS). Two pigments had entries in the database, meaning that a material relevant accurate mass database can provide a fast tentative identification. Pure standards of the seven tentatively identified substances were tested in vitro but could not explain a significant proportion of the AhR-response in the extract. Targeted analyses of dioxins and PCBs, both well-known AhR agonists, was performed. However, the dioxins could explain approximately 3% of the activity observed in the pizza box extract indicating that some very AhR active substance(s) still remain to be identified in recycled low quality P&B.
Archive | 2015
Ågot Li; Signe Sem; Julie Tesdal Håland; Jens Højslev Petersen; Lisbeth Krüger Jensen
Denmark, Finland, Faroe Islands, Iceland, Norway and Sweden have in 2013–2015 conducted a Nordic project on food contact materials. Food contact materials are used in all stages of food production ...
Archive | 2015
Lisbeth Krüger Jensen; Ågot Li; Julie Tesdal Håland; Signe Sem; Jens Højslev Petersen
Archive | 2014
Mette Holm; Charlotte Legind; Jens Højslev Petersen; Lisbeth Krüger Jensen
International Journal of Food Contamination | 2016
Jens Højslev Petersen; Lisbeth Krüger Jensen
Archive | 2017
Tommy Licht Cederberg; Lisbeth Krüger Jensen
Archive | 2016
Xenia Trier; Tommy Licht Cederberg; Lisbeth Krüger Jensen
Archive | 2015
Lisbeth Krüger Jensen; Ågot Li; Julie Tesdal Håland; Signe Sem; Jens Højslev Petersen