Kelly Servaes

Analysis of phthalates in food products and packaging materials sold on the Belgian market

Phthalates are organic lipophilic compounds that are principally used as plasticiser to increase the flexibility of plastic polymers. Other applications are a.o. the use of phthalates in printing inks and lacquers. Human exposure to phthalates mainly occurs via food ingestion and can induce adverse health effects. In this study, the presence of eight phthalate compounds--dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-n-octyl phthalate (DnOP)--was investigated in 400 food products, divided over eleven groups, and packages sold on the Belgian market. For this purpose, suitable extraction techniques were developed and validated for four different matrices, namely high-fat foods, low-fat food products, aqueous-based beverages and packaging materials. The instrumental analysis was performed by means of gas chromatography-low resolution-mass spectrometry with electron impact ionisation (GC-EI-MS). A wide variety of phthalate concentrations was observed in the different groups. DEHP was found in the highest concentration in almost every group. Moreover, DEHP was the most abundant phthalate compound, followed by DiBP, DnBP and BBP. This survey is part of the PHTAL project, which is the first project that discusses phthalate contamination on the Belgian food market.

An improved mass spectrometric method for identification and quantification of phenolic compounds in apple fruits

Thirty-nine phenolic compounds were analysed using ultra high performance liquid chromatography (UHPLC) coupled with diode array and accurate mass spectrometry detection using electrospray ionisation (DAD/ESI-am-MS). Instrumental parameters such as scan speed, resolution, and mass accuracy were optimised to establish accurate mass measurements. The method was fully validated in terms of model deviation (r(2)>0.9990), range (typically 10-3500 ngg(-1)), intra/inter-day precision (<6% and <8%, respectively) and accuracy (typically 100 ± 10%). The mass accuracy of each selected phenolic compound was below 1.5 ppm. The results confirmed that the UHPLC-DAD/ESI-am-MS method developed here was convenient and reliable for the determination of phenolic compounds in apple extracts.

Thermal degradation of cloudy apple juice phenolic constituents

Although conventional thermal processing is still the most commonly used preservation technique in cloudy apple juice production, detailed knowledge on phenolic compound degradation during thermal treatment is still limited. To evaluate the extent of thermal degradation as a function of time and temperature, apple juice samples were isothermally treated during 7,200s over a temperature range of 80-145 °C. An untargeted metabolomics approach based on liquid chromatography-high resolution mass spectrometry was developed and applied with the aim to find out the most heat labile phenolic constituents in cloudy apple juice. By the use of a high resolution mass spectrometer, the high degree of in-source fragmentation, the quality of deconvolution and the employed custom-made database, it was possible to achieve a high degree of structural elucidation for the thermolabile phenolic constituents. Procyanidin subclass representatives were discovered as the most heat labile phenolic compounds of cloudy apple juice.

Determination of contamination pathways of phthalates in food products sold on the Belgian market

As numerous studies have indicated that food ingestion is the most important exposure pathway to several phthalates, this study aimed to determine possible contamination pathways of phthalates in food products sold on the Belgian market. To do this, concentrations of eight phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP)) were determined in 591 foods and 30 packaging materials. In general, the four most prominent phthalates in Belgian food products were DEHP, DiBP, DnBP and BBP. Special attention was given to the origin of these phthalates in bread, since high phthalate concentrations (especially DEHP) were determined in this frequently consumed food product. Phthalates seemed to occur in Belgian bread samples due to the use of contaminated ingredients (i.e. use of contaminated flour) as well as due to migration from phthalate containing contact materials used during production (e.g. coated baking trays). Also the results of the conducted concentration profiles of apple, bread, salami and two cheese types revealed the important role of processing - and not packaging - on phthalate contents in foods.

Speciation and fractionation of nickel in airborne particulate matter: comparison between selective leaching and XAS spectroscopy

Nickel speciation and fractionation using a multidisciplinary approach are discussed for different particulate matter samples collected in industrial and rural atmospheres. The technologies utilized in this research span from X-ray Absorption Near Edge Structure (XANES) and X-Ray Diffraction (XRD) to a wet chemistry sequential leaching assay (including determination by inductively coupled plasma atomic emission spectroscopy, ICP-AES). The Zatka sequential leaching method provides an inexpensive assay to differentiate among ‘soluble’, ‘sulfidic’, ‘metallic’, and ‘oxidic’ chemical forms of Ni. The XANES technique is especially well suited for Ni speciation between and to a lesser extent within the 4 defined Ni species groups of the Zatka sequential leaching procedure. Limitations for interpretation in the present study with respect to XANES are the availability of pure phase Ni species for uptake as reference spectra and the collinearity between the spectra of Ni compounds within a Ni species group (e.g. NiSO4·6H2O and Ni(NO3)2·6H2O). The Ni speciation and fractionation results on the particulate matter samples reflect in general a good agreement between the modified Zatka sequential leaching procedure and the XANES data. For the particulate matter collected in and close to a stainless steel factory, Ni included in a spinel structure (NiFe2O4) was identified as the principal Ni species. The particulate matter collected in rural atmosphere showed a 50/50 distribution between soluble and oxidic Ni species.

A comparative study between spiral-filter press and belt press implemented in a cloudy apple juice production process

In this study, advantages and disadvantages of the innovative, low-oxygen spiral-filter press system were studied in comparison with the belt press, commonly applied in small and medium size enterprises for the production of cloudy apple juice. On the basis of equivalent throughput, a higher juice yield could be achieved with spiral-filter press. Also a more turbid juice with a higher content of suspended solids could be produced. The avoidance of enzymatic browning during juice extraction led to an attractive yellowish juice with an elevated phenolic content. Moreover, it was found that juice produced with spiral-filter press demonstrates a higher retention of phenolic compounds during the downstream processing steps and storage. The results demonstrates the advantage of the use of a spiral-filter press in comparison with belt press in the production of a high quality cloudy apple juice rich in phenolic compounds, without the use of oxidation inhibiting additives.

Pilot-scale production of cloudy juice from low-quality pear fruit under low-oxygen conditions

In this study, a process for the production of premium quality yellowish, cloudy pear juice from low-quality fruit under low-oxygen conditions was developed. The production process consisted of (1) shredding, (2) pressing with spiral-filter technology including a vacuumised extraction cell, (3) holding in an inert gas buffer tank, (4) pasteurisation, (5) and refrigerated storage. First, the system parameters of a spiral-filter press were optimised with the aim of producing a yellowish, cloudy pear juice with the highest possible juice yield. A maximum juice yield of 78% could be obtained. Enzymatic browning during juice extraction could be suppressed as a result of the fast processing and the low air (oxygen) levels in the extraction chamber of the spiral-filter press. Furthermore, we observed that instantaneous pasteurisation at 107 °C for 6s, subsequent aluminium laminate packaging and cold storage had only a minimum effect on the phenolic composition.

Variability of the phenolic profiles in the fruits from old, recent and new apple cultivars cultivated in Belgium

The objective of this study was to explore the utility of the phenolic pattern (1) to differentiate or associate between cultivars with a different or same genetic background respectively and (2) to assess some important quality traits (color, disease resistance, and browning) in apple fruit. A unique set of cultivars/candivars occurring in Belgium were selected for this survey. It was possible to segregate the studied apple cultivars/candivars into three clusters: red-flesh apple candivars, classic/new cultivars and candivars and heritage apple cultivars. It was found that the heritage apple varieties selected for their disease resistance and cultivated under organic agricultural practice demonstrate a remarkable different phenolic profile. Furthermore, it was found that the phenolic makeup of the peel could suggest the genetic relationships among the apple cultivars. In conclusion, the knowledge of the phenolic profile could be a useful instrument in breeding programs to identify apples with better quality traits, processing characteristics and health-benefiting effects.

Supercritical CO2 Extraction of Nannochloropsis sp.: A Lipidomic Study on the Influence of Pretreatment on Yield and Composition

Algal lipids have gained wide interest in various applications ranging from biofuels to nutraceuticals. Given their complex nature composed of different lipid classes, a deep knowledge between extraction conditions and lipid characteristics is essential. In this paper, we investigated the influence of different pretreatments on lipid extraction with supercritical CO2 by a lipidomic approach. Pretreatment was found to double the total extraction yield, thereby reaching 23.1 wt.% comparable to the 26.9 wt.% obtained with chloroform/methanol. An increase in acylglycerides was concurrently observed, together with a nearly doubling of free fatty acids indicative of partial hydrolysis. Moreover, an alteration in the distribution of glyco- and phospholipids was noted, especially promoting digalactosyldiglycerides and phosphatidylcholine as compared to monogalactosyldiglycerides and phosphatidylglycerol. At optimized conditions, supercritical CO2 extraction provided a lipid extract richer in neutral lipids and poorer in phospholipids as compared to chloroform/methanol, though with a very similar fatty acid distribution within each lipid class.

Phthalates in food on the Belgian market: occurrence and possible contamination pathways

Phthalates are organic lipophilic compounds which are mainly used as plasticizer in plastic polymers. Human exposure occurs mainly via food intake and can cause a wide range of negative health effects. Phthalates are not only present in food because of environmental contamination, but also as a result of migration from contact materials. This study investigated phthalates in cow milk in order to determine the contamination pathways at farm level. The levels of eight phthalates were determined in raw milk samples collected during summer and winter at five farms located in ‘The Kempen’ (Belgium). Both manually obtained milk samples as milk samples milked by machine were collected. Analysis was performed by gas chromatography-mass spectrometry. The analysis of the milk samples milked by machine revealed a difference in average total phthalate level between the summer and the winter sampling period (572 versus 379 µg/kg fat). While the total phthalate levels of the different farms during winter were nearly of similar magnitude (291-587 µg/kg fat), a wide range could be observed during summer (95-1550 µg/kg fat). Comparing milk samples within a farm, lower total phthalate levels were found in the milk samples milked by hand than those by machine (100 versus 179 µg/kg fat). Di(2-ethylhexyl) phthalate which is the most commonly used plasticizer worldwide, was the most dominating one (79 % of the total concentration in milk from the central collecting tank). The results indicate that the contamination pathways for phthalates in cow milk vary across seasons. An explanation therefore is that the feed composition is different during summer than during winter. In summer, cows are grazing in the fields where an extra phthalate contamination can occur via soil ingestion. Comparing the milk samples milked by hand with those by machine reveals that the milking equipment is another important contamination pathway.The International Society for Environmental Epidemiology (ISEE) is an international organization with almost 1000 members from more than 60 countries. The annual international conference brings together many members and non-members and provides an excellent forum for the discussion of problems and benefits related to the environment and human health. Specific themes for the 23rd Annual Conference include: Sustainable transport and health: Impact of transport on health and approaches to reduce health impacts, Impact of climate change: from water scarcity to Saharan dust episodes, Early exposure - later life: in utero and early life exposures and effects in later life, New methods and technologies.Background and Aims: Phthalates are used in many industrial and consumer products. High-molecular-weight phthalates are primarily used as plasticizers to soften PVC products, while low-molecular-weight phthalates are widely used as solvents to hold colour and scent in products. Phthalates have been detected in food and also measured in humans. This study investigated phthalates in food products on the Belgian market in order to explore possible contamination pathways. Methods: 650 Representative samples of widely consumed foods were purchased in Belgian shops. The levels of eight phthalates were determined and product specific properties were stored in a database. This database was used to explore the contamination pathways by identifying relations between sample properties (e.g. fat content, pH and packaging) and measured phthalate concentrations. Results: The results of the measurement campaign show a wide variety of phthalate concentrations in the food samples. Concentrations are higher in high-fat food products like butter, oil and cheese compared to low-fat food products, like vegetables and juices. Higher phthalate concentrations were also detected in some cardboard packed food, probably due to migration from inks and glues. Aluminium inner package seems to be a good barrier for migration. A wide range of phthalate levels in bread was found and further research is necessary. Conclusions: A wide variety in phthalate concentration was found. The fat content of the food product, the composition of the food as well as the composition and properties of the packaging material have been identified as possible contamination causing conditions. In a next phase of this study, we will use these data to quantify the dietary intake of phthalates for the Belgian population.