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The exposure to selected chemical contaminants from fish has been calculated for the Danish population, both for adults (15–75 years of age) and children (4–14 years of age). The Danish mean consumption of fish is 21 g person−1 day−1 for adults and 12 g person−1 day−1 for children. Fish consumption is the main food group contributor for exposure to mercury and dioxins and dioxin-like polychlorinated biphenyls (PCDD/F and DL-PCB) for the Danish population. Comparison of the mean exposure with the TDI or TWI values shows for these substances as well as for perfluorooctane sulphuric acid (PFOS) that the exposure is below the TDI/TWI values. However, even without taking other food groups into account, PCDD/Fs and DL-PCB exposure is close to the actual TWI-value. Calculation of the Margin of Exposure (MOE) for the sum of hexabromocyclododecanes (HBCDD) and polycyclic aromatic hydrocarbons (PAHs) revealed fish consumption to be of low concern for the consumer health regarding these contaminants.

Vanilla is one of the most popular spices in the world and is therefore often added to food products to enhance the taste with its desirable flavour. Vanilla flavour is highly susceptible to economically motivated food fraud since the main component ‘vanillin’ can easily be produced by much cheaper synthetic processes. The determination of the vanillin source is not always an easy task, especially when very low concentrations are incorporated in complex food matrices. Here, we present an easy sample preparation procedure that includes a solid‐phase extraction clean‐up to determine the isotopic carbon ratio of vanillin in food products by headspace solid‐phase microextraction and gas chromatography coupled to isotope ratio mass spectrometry. Isotopic fractionation during the sample preparation procedure was carefully evaluated. The method was applied to 23 commercial food samples including vanilla sugar, dairy and soy products. The study illustrates the potential and limitations of the authentication of vanilla flavour by the isotopic carbon ratio of vanillin. Further, the complexity of the authenticity assessment of vanilla flavours in composite food is demonstrated.

Vegetable crisps are usually perceived to be a healthier alternative to potato crisps, though thermal treatment can generate harmfull contaminants such as monochloropropanediol and glycidol fatty acid esters (MCPDEs and GEs) or acrylamide in these products. This study is among the first to investigate MCPDE, GEs, and acrylamide in commercial potato, sweet potato, parsnip, beetroot, and carrot crisps. These contaminants were found in all crisp samples on the market. The novel alternative vegetable crisps (n = 16) showed substasntial higher concentrations than in traditional potato crisps (n = 29), e.g. beetroot crisps had 7 times higher amount of 3-MCPDEs (mean 212 µg/kg), while acrylamide was 8 times higher in carrot crisps (mean 2893 µg/kg) and ∼3-4 times higher in beetroot, parsnip and sweet potato crisps. All vegetable crisp had mean values of acrylamide higher than European Commission established benchmark level for potato crisps at 750 µg/kg. Consequently, risk assessment demonstrated concerning Margin of Exposure (MoE) values for acrylamide exposure via crisp consumption in all age groups from 4-75. On the other hand, no apparent health risk was observed for dietary intake of 3-MCPDEs or GEs in crisps.

Alkylfurans have been found concurrently to furan in thermally processed food and might add to the overall exposure, thereby increase the health concern. The analytical methods developed for these compounds are based on gas chromatography separation coupled to mass spectrometry. Two of those alkylfurans, 2,5-dimethylfuran and 2-ethylfuran, are isomers, for which accurate quantification require either complete chromatographic separation or tandem mass spectrometry (MS/MS) selectivity. A new chromatographic method is reported using the Supelco Equity-1 column, demonstrating complete baseline separation of these two isomers, with a shorter runtime when using single mass spectrometry. Full validation was performed successfully for furan, 2- and 3-methylfuran, 2-ethylfuran, 2,5-dimethylfuran and 2-pentylfuran on different food matrices with recovery rates in the range of 80-110 %, repeatability below 14%, intermediate reproducibility below 22% as well as expanded uncertainty under 50%.

Standard infant formula and specialised infant formula for medical purposes in Denmark (n = 42) were assessed for the levels of 2-MCPDEs, 3-MCPDEs, and GEs. Similar concentrations of GEs were observed in both standard and specialised powder infant formula at around 11.5 µg/kg. For 2-MCPDEs and 3-MCPDEs, significantly higher concentrations were observed in specialised products (18.0 and 49.8 µg/kg, respectively) in comparison with the standard ones (11.8 and 31.0 µg/kg, respectively). The concentration profiles also revealed discrepancies in MCPDEs and GEs concentrations not only between different manufacturers but also in terms of infant formula variety. For instance, the hypoallergenic powder formula showed twice as much MCPDEs as the normal formula variety. Exposure estimation using average contaminant concentrations in each variety suggested no potential risk of 3-MCPDEs and GEs intake for Danish infants via infant formula consumption. However, special attention is required for a few specific products where risks might occur in terms of 3-MCPDEs and/or GEs consumption.

Whilst beers have been produced using various levels of unmalted grains as adjuncts along with malt, brewing with 100 % unmalted grains in combination with added mashing enzymes remains mostly unknown. The aim of this study was to investigate the brewing potential of 100 % unmalted barley, wheat, oat and rye in comparison with 100 % malt. To address this, identical brewing methods were adopted at 10-L scale for each grain type by applying a commercial mashing enzyme blend (Ondea® Pro), and selected quality attributes were assessed for respective worts and beers. Different compositions of fermentable wort carbohydrates were observed in the worts (all at ca. 12°P), and in particular oat wort had lower concentration of maltose compared to the others, resulting in the lowest concentration of alcohol in final beer. Moreover, wort made from unmalted grains also showed lower free amino nitrogen and higher viscosity than malt wort. Furthermore, the use of 100 % unmalted grains resulted in a decrease in the levels of colour and brightness, as well as higher alcohols and esters in the final beers. Consequently, the study provides valuable information for exploring beer brewing with 100 % unmalted barley, oat, rye or wheat using exogenously added enzymes. It also helps to understand the process ability by revealing specific needs when manufacturing different type of beers from unmalted grains, potentially paving the way to process optimisation and development of future products.

Nile perch (L. niloticus ) and Nile tilapia (O. niloticus) are the major commercial fish species in Lake Victoria region of Tanzania. This study was conducted to assess the levels of persistent organochlorine compounds, namely PCBs and OCPs in these two fish species and the probable human health risks associated with the consumption of these two fish species from Lake Victoria. Fish samples were collected between May and August 2016 and the necessary anthropometric measurements such as length and weight were taken. The extraction was done using a modified QuEChERS method and the identification and quantification of the chemicals were done using GC/ECDs. The results of this study revealed that fish species sampled were undersize, which was an indication of overfishing and abuse of bylaws. Among the 19 OCPs which were considered, only four (β- HCH, HCB, Aldrin and Dieldrin) were detected at measurable quantities. β- HCH ranged from

Vanilla flavour is highly vulnerable to economically motivated adulteration as the main component vanillin can be derived by much cheaper production methods than by the extraction from vanilla pods. The δ13C ranges for synthetic vanillin from petroleum and C3 plants are depleted in comparison to the reported δ13C range for vanillin from vanilla orchids. However, with the invention of new biosynthetic pathways, vanillin overlapping with the characteristic δ13C range reported for vanillin from vanilla pods can be produced. Here, we present bulk and site-specific analysis by GC-IRMS of stable carbon and hydrogen isotope ratios of vanillin derived from glucose. This is the first time a δ13C value for biovanillin that is higher compared to vanillin from vanilla pods is reported. The possibility to simulate the δ13C range of vanillin from vanilla pods by combining vanillin derived from inexpensive sources constitutes an increased risk for fraud being perpetrated while remaining unnoticed.

This study assessed the health risks of organochlorine pesticides in fish products from Lake Victoria. Nine organochlorine pesticides (α- Hexachlorocyclohexane (HCH), β- HCH, γ- HCH (Lindane), Hexachlorobenze (HCB), Dieldrin, p, pežŒ- DDE, α- endosulfan, Oxychlordane and α- chlordane) were identified at variable levels in fish products. Of the nine organochlorine pesticides which were identified, p, pežŒ- DDE (3.73µg/kg) was the highest in deep fried Nile tilapia while the lowest amount was α- HCH (0.14 µg/kg) in smoked Nile tilapia. In the smoked products, several of the organochlorine pesticides were detected at high concentrations. This is attributed to the fact that organochlorine pesticides are fat soluble and therefore found in the lipid phase of the fish during smoking. There were high levels and prevalence of p, pežŒ- DDE, α- endosulfan, HCB, Dieldrin and Lindane in deep fried Nile tilapia compared to other fish products probably due to environmental contamination. However, the levels of organochlorine pesticides in this study are below the maximum residual limits (MRLs) set by FAO/WHO for fish products indicating that the fish products were safe for human consumption and do not present health risks in terms of organochlorine pesticides residues. Key words: Cancer risk, hazard index, Kayabo, organochlorine pesticides, trims.

Analytical methods for authenticity testing of organically grown vegetables are urgently needed. Here we present a novel method for organic authentication based on stable isotope ratio analysis of oxygen in plant-derived sulphate. We combined this method with stable isotope ratio analysis of bulk plant tissue and plant-derived nitrate to discriminate organic and conventional potato, carrot, and cabbage from rigidly controlled long-term field trials and from a case study using retail potatoes. It was shown that oxygen isotope ratios of sulphate from organic vegetables were significantly lower compared to their conventional counterparts and the values were directly linked to the fertilisation strategy. The classification power of sulphate isotope analysis was superior compared to known bulk tissue isotope markers and nitrate isotope values. In conclusion, oxygen isotope analysis of plant-derived sulphate represents a promising new method for authentication of organic vegetables.

A GC/MS-MS method for determination of monochloropropanediol (MCPDEs) and glycidol (GEs) was developed, validated, and applied to analyze 60 infant formula and baby food products commercially available on the Danish market. The contaminants were quantifiable in almost all sample categories with the exception of fruit or vegetable based purees. The highest concentrations of 3-MCPDEs and 2-MCPDEs were found in a baby biscuit product at 102.6 μg/kg and 52.8 μg/kg, respectively. Meanwhile, a baby puff item contained GEs as high as 149 μg/kg. MCPDEs and GEs concentrations are well correlated with each other in all sample types except puffs and biscuits. Occurrence data suggested that GEs formation might have taken place during production of baby puffs by unknown mechanisms. Preliminary exposure and risk assessment showed no apparent risk of Danish infants to these chemicals in formula and baby foods. However, special attention should be paid when feeding babies with puffs or similar items due to their relatively high level of GEs.

Heating foods immersed in oil during frying provides many attractive sensorial attributes including taste, flavor and color. However, some toxic compounds formed during frying of potatoes such as furan and acrylamide may constitute an increased cancer risk for consumers. The objective of this work was to mitigate the furan and acrylamide formation in potato chips without increasing their oil uptake by optimizing the blanching treatment before final frying. Potato slices were blanched in order to simultaneously leach out ascorbic acid and reducing sugars, the most important precursors of furan and acrylamide generation in thermally treated starchy foods. A central composite design was implemented to optimize the temperature-time blanching conditions under which furan, acrylamide and oil content in potato chips were minimized. The optimum blanching conditions were 64 °C and 17 min in which significant reductions of furan, acrylamide and oil content (91%, 54% and 19% respectively) were reached.

Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g(-1). In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed "American"-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g(-1)) and low moisture starchy products like crisps and "soda"-type crackers showed the highest furan concentrations (259 and 91 ng g(-1), respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g(-1)), jarred fruit baby foods (8.5 ng g(-1)) and orange juice (7.0 ng g(-1)). School children (aged 9-13 years) represented the highest intake of furan (about 500 ng kg(-1)(bw) day(-1)), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk.

Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p < 0.05). The strongest effect was observed for baked products. Additionally, the furan content in fried products increased with the increase of the oil uptake levels. As for Maillard reactions, in general, the furan level in all samples linearly correlated with their degree of non-enzymatic browning, represented by L* and a* color parameters (e.g., wheat flour baked samples showed a R(2) of 0.88 and 0.87 for L* and a*, respectively), when the sample moisture content decreased during heating.

Levels of organochlorine substances, including a number of organochlorine pesticides and PCB, are monitored in food, including meat, fish and dairy products. The substances are slowly degradable and therefore persist for long periods in the environment, where they accumulate in the fatty tissues of animals and humans. They are included, because of the potential health-hazardous effect of these compounds on humans. The highest average contents are found in cod liver and fatty fish. The Danish population’s average daily intake has been estimated at between 0.03 and 0.3 μg/day for organochlorine pesticides and 0.9 μg/day for the indicator PCB-sum. People with a relatively high intake of these substances (the 95th percentile) are estimated to consume approximately twice as much. In general, the highest contributions to the intake of the organochlorine environmental contaminants are from fish, meat and dairy products. However, children have a relatively higher intake from milk and milk products and a lower intake from fish compared to adults.

A fast and simple method for authenticating raspberry flavors from food products was developed. The two enantiomers of the compound (E)‐α‐ionone from raspberry flavor were separated on a chiral gas chromatographic column. Based on the ratio of these two enantiomers, the naturalness of a raspberry flavor can be evaluated due to the fact that a natural flavor will consist almost exclusively of the R enantiomer, while a chemical synthesis of the same compound will result in a racemic mixture. Twenty‐seven food products containing raspberry flavors where investigated using SPME‐chiral‐GC‐MS. We found raspberry jam, dried raspberries, and sodas declared to contain natural aroma all contained almost only R‐(E)‐α‐ionone supporting the content of natural raspberry aroma. Six out of eight sweets tested did not indicate a content of natural aroma on the labeling which was in agreement with the almost equal distribution of the R and S isomer. Two products were labeled to contain natural raspberry flavors but were found to contain almost equal amounts of both enantiomers indicating a presence of synthetic raspberry flavors only. Additionally, two products that were labeled to contain both raspberry juice and flavor showed equal amounts of both enantiomers, indicating the presence of synthetic flavor.

The levels of toxaphene congeners, in addition to PCB congeners and organochlorine pesticides, were determined in various fish samples from different Danish waters. While PCB-153 and p,p'-DDE show different levels depending on the fishing area, with highest levels in fish from the Western Baltic Sea, toxaphene was detected in all the samples investigated at a more constant level. The distribution of the three toxaphene congeners Parlar #26, #50 and #62 depends on the fishing area, with the Western Baltic Sea being different from the other waters by having almost equal levels of toxaphene congeners #26 and #50.

An analytical method for polychlorinated biphenyls (PCBs) and chlorinated pesticides in mussels, fish liver, bird liver, and seal blubber is described. Different calibration functions were tested to establish the optimal fit to the nonlinear response of all included compounds. Detection limits and within-batch variations were determined from standard deviations of duplicate analyses of real samples. Within-batch, between-batch, and total relative standard deviations were calculated from regular use of control material. Percentage recovery was estimated by spiking samples with 3 selected PCB congeners and by spiking selected samples with all compounds included in the procedure. Quality assurance is described, covering analysis of about 450 samples divided into 38 batches. Because between-batch variation was twice the within-batch variation, the use of in-house control material and control charts is considered to be mandatory for this type of analyses. Use of certified reference material and regular participation in intercomparison exercises have demonstrated the high quality of the method and the adequacy of the quality assurance applied.

The literature concerning persistent organic pollutants (POPs) in the environment of Greenland and the Faroe Islands covering the period up to 1995 has been revisited. It is difficult to compare data from earlier studies with those from more recent investigations. Thus as the former quantified the content of CBs by comparison to a technical mixture of CBs (e.g. Aroclor 1254), the latter analyses typically are quantified on a single congener level. Single CB congeners have in some cases been determined, but the results were subsequently expressed as total PCB related to an Aroclor standard. For studies based on single CB congener determinations, the highest levels are reported for porpoise blubber from Greenland (700-4500 micrograms/kg wet weight), the conclusion, however being based on two determinations only. In Greenlandic seal blubber and peregrine falcon plasma equal levels of CBs (130-750 micrograms/kg ww) and of DDTs (150-860 micrograms/kg ww) were found. Levels of CBs and DDTs in fish liver were found to be around 40-75 micrograms/kg ww. In sediment samples the CBs were almost all below the detection limit (< 0.02-0.1 microgram/kg dry weight), and thereby being the matrix with the lowest CBs concentration levels. Earlier data based on Aroclor standards showed DDT levels in Greenlandic whale blubber in the range of 2700-4100 micrograms/kg ww and PCB levels of 3700 micrograms/kg-5400 micrograms/kg ww. DDT levels for seal blubber were at the same level (2700-4500 micrograms/kg ww) whereas the PCB level was lower (900-3900 micrograms/kg ww). The PCB level corresponds to the level found in human adipose tissue determined with a similar quantification technique. The lowest levels reported for mammals correspond to walrus blubber, the sum of PCBs and DDTs being in the ranges of 180-360 micrograms/kg ww and 50-90 micrograms/kg ww, respectively. The content of PCBs in scallops was found to be 3 micrograms/kg ww near the Thule Air base.

Quantitative analysis by headspace solid-phase microextraction (HS-SPME) of twenty chloro- and nitrobenzenes and -anilines spiked into soil samples was possible when the calibration was performed with the same matrix. The SPME response increased with addition of water to the air dried soil samples, and by optimisation of extraction conditions such as temperature, extraction time and sample agitation. Distribution constants between the fibre coating materials and water were determined. They showed that polyacrylate, rather than polydimethylsiloxane, should be used in the analysis of polar compounds. Matrix effects, mainly depending on the organic carbon content of the soil, were so large that quantitative analyses of real soil samples would not be reliable with model matrix calibration. This problem would be overcome if a nearly exhaustive extraction could be achieved. Recovery studies showed that this was possible only in the case of extraction of the lightest non-polar analytes from a soil with a very low content of organic carbon. Instead quantification could be performed with calibration by standard addition. By this approach the non-linear calibration curves at concentrations near the detection limits would cause inaccurate results at trace level, whereas it could be applied successfully within the linear ranges. Hence, the potential of HS-SPME in soil analysis is primarily as a rapid screening technique.

A semi-automatic method for the determination of polycyclic aromatic hydrocarbons (PAHs) in edible oils using a combined gel permeation chromatography/solid-phase extraction (GPC/SPE) clean-up is presented. The method takes advantage of automatic injections using a Gilson ASPEC XL sample handling system equipped with a GPC column (S-X3) and pre-packed silica SPE columns for the subsequent clean-up and finally gas chromatography-mass spectrometry (GC-MS) determination. The method was validated for the determination of PAHs in vegetable oils and it can meet the criteria for the official control of benzo[a]pyrene levels in foods laid down by the Commission of the European Communities. A survey of 69 vegetable oils sampled from the Danish market included olive oil as well as other vegetable oils such as rapeseed oil, sunflower oil, grape seed oil and sesame oil. Levels of benzo[a]pyrene in all the oils were low (

The non-linear response of PCBs and OCPs is a well-known problem when performing analysis on GC/ECD. Thus, three different non-linear calibration functions were tested experimentally using 12 calibration solutions (1–200 ng ml −1 ), six of them used for calibration and six of them for testing the reliability of the function. The piecewise calibration was chosen as the most robust for all compounds in question, while the power function fitted best for all except two compounds; the second-order function showed problems at the very low concentration levels.

Furan, a potential carcinogen, can be formed in foods processed at high temperatures such as coffee, baby foods, bread and snacks. Although there is still no clarity about the risks associated with the current intake levels of dietary furan, to limit the furan occurrence in foods may be considered as a challenge in the prevention of human diseases as cancer. Considering that heat processed starchy products are characterized by their high worldwide consumption, we decided to dig into the mechanisms that would define their final content of furan. The present study explored the effect of heating conditions (frying and baking) and ascorbic acid concentration over furan occurrence in a starchy model system. Two different formulations of wheat flour dough (WF: wheat flour and WF-AA: wheat flour and ascorbic acid) were prepared with a 40 % of moisture (wb). Then, dough were cut in circle chips (40 mm of diameter ; 2.3 mm of thickness) which were fried and baked at 170°C and 200°C for 5, 7 and 9 minutes. Furan contents of heat processed products were quantified by GC-MS. WF fried products contained higher furan levels than baked ones for all different processing times (e.g. 97 % higher furan in 5 minutes fried chips). For the case of WF-AA chips baking produced more furan compared to the frying (e.g. 58 % higher furan in 7 minutes baked chips). For all process conditions ascorbic acid addition produced an increase in furan levels (̴17%-58% in frying and ̴74-98 % in baking). As for Maillard reactions in general, for all samples, an increase in furan level was observed when the moisture content decreased. Additionally, in fried products furan level was directly proportional to their oil uptake. We conclude that for the present model conditions, ascorbic acid improves the furan generation, having a stronger effect in baked products. We also propose that while lipid oxidation has been considered as one of main furan generation routes, for this particular case, it should not have a greater influence over furan formation; since frying experiments were realized with commercial sunflower oil with added antioxidant. Finally, considering that furan is an unpolar compound, for fried product the oil uptake may be responsible for the higher furan retention.

For authentification of vanilla flavours, vanilla pods of the type Vanilla planifolia and Vanilla tahitensis from different geographical habitats were extracted and analyzed together with vanilla flavours made by fermentations and chemical synthesis. Isotopic delta values were determined using Gas Chromatography Isotope Ratio Mass Spectrometry (GC-IRMS). The main contributor to the characteristic vanilla flavour is 4-hydroxy-3-methoxybenzaldehyde, also called vanillin. Delta13C values of vanillin originating from the vanilla plant differ from delta13C values from vanillin made synthetically or by fermentation. Furthermore the results showed that there was a significant difference in the isotopic composition of vanillin for the two types of vanilla plants analyzed, where Vanilla tahitensis contained more 13C than Vanilla planifolia. Delta2H values of precipitation at different geographic locations of vanilla plantations are reflected in the water the vanilla plant take up and incorporate in the biosynthesis of aroma components. Therefore analysis of delta2H can provide information about the geographic origin. Results show a tendency towards depletion of 2H in areas with high precipitation.

Furan is formed in canned, jarred or browned food items. As furan is carcinogenic in animal experiments, attention has been drawn to the presence in commercial and home-cooked foods. The formation of furan in home cooked foods were studied as well as the stability of furan during cooking, saving and reheating of meals. In addition the occurrence of furan in some commercially dried and browned food products were determined. Several recipes of European homemade food were prepared but in most cases fortunately furan was not found. I few exceptions were e.g. apple pie (133 ng/g furan in the rasp) and tea buns with raisins (83 ng/g furan in the raisins). The influence on heating and reheating of ready to eat foods like different soups, baked beans and vegetable meals known to contain furan, showed that heating roughly reduced the furan level to half the initial level and reheating reduced the level a bit further, hence furan is relatively stable in food products.Of the food items surveyed relatively many sundried fruit and vegetable products like raisins, tomatoes, and dried bananas contained furan, for example a sample of raisins contained 83 ng/g and banana crisps 11ng/g furan. Furthermore one sample of breakfast cereals contained 387 ng/g furan while the others were below 87 ng/g (n=11). The Maillard browning reactions of carbohydrate rich foods are responsible for furan formation in heat treated foods as breakfast cereals, toasted bread, cookies and crisps/snacks. When preparing potato crisps (diameter 40 mm x width 2 mm) by deep frying in oil at 150°, 170° and 190°C to the same water content (crispiness) of ~ 2% simulating industrial conditions, the furan content increased from 12-15 ng/g up to 31-52 ng/g. A similar study on French fries (0.8 x 0.8 x 5 cm) showed furan contents of 11-21 ng/g.

Contaminants like acrylamide, furan or PAHs (polyaromatic hydrocarbons) as e.g. Benz(a)pyrene may be formed during food processing. All of the substances are genotoxic carcinogens, and for that reason mitigation strategies to reduce the levels are needed. Examples of the formation of the processing contaminants and factors that influence the occurrence are given as well as suggestions for mitigation.