Per- and poly-fluoroalkyl substances in commercial organic eggs via fishmeal in feed.

Chicken eggs can be a significant source of human PFAS exposure. A survey of PFAS in commercial eggs from larger farms across Denmark showed the absence or low contents of PFAS in free-range and barn eggs. However, organic eggs from eight farms collected in September 2022 had a similar profile of nine PFASs with a predominance of odd over even carbon length PFCAs. Farm 11-13 e.g. had egg yolk ng/g concentrations of PFOA 0.07 ± 0.02; PFNA 0.37 ± 0.04; PFDA 0.13 ± 0.00; PFUnDA 0.22 ± 0.04; PFDoDA 0.06 ± 0.02; PFTrDA 0.15 ± 0.04; PFTeDA 0.02 ± 0.02; PFHxS 0.10 ± 0.04; PFOS 2.62 ± 0.11. Normalised to PFOS, the relative sum of other PFAS showed no difference between the eight organic egg samples, but significant differences between mean individual PFASs (p = 1.4E-25), reflecting a similar profile. The PFAS found in two fishmeal samples with the same origin as the fishmeal used for the organic feed production, could account for the contents in the eggs via estimated transfer from the feed. Furthermore, the estimated transfer from concentration in feed to concentration in egg increased with the carbon length of the PFCA. Exposure (95th percentile) of ∑4PFAS (PFOA, PFNA, PFHxS, PFOS) solely from consumption of 311 g âˆ¼ 5-6 organic eggs/week was for children 4-9 years 10.4 ng/kg bw, i.e. a significant exceedance of the tolerable weekly intake of 4.4 ng/kg bw established by the European Food Safety Authority. Based on the PFAS exposures from organic egg consumption, the organic egg producers decided voluntarily to cease adding fishmeal to the feed. Since the feed-to-egg half-lives are ≤1 week for PFOA, PFOS, and PFHxS, the removal of fishmeal as a feed ingredient should eliminate PFAS after 1-2 months. This was demonstrated in analyses of ten organic egg samples collected by the authorities without PFAS in eight and with 0.1 and 0.4 ng/g ∑4PFAS in two samples.

Suggestion for a subdivision of processed meat products on the Danish market based on their content of carcinogenic compounds.

Carcinogenic effects in humans are ascribed to processed meat by organisations such as International Agency for Research on Cancer, World Cancer Research Fund and American Institute for Cancer Research. However, the term 'processed meat' covers a heterogenic group of products whose content of potential hazards differ considerably. To improve estimates of associations between processed meat intake and cancer risk we investigated ways to divide processed meat into subgroups that more precisely reflects its carcinogenic characteristics. We collected ingredient lists and declarations of salt content for >1000 processed meat products on the Danish market and combined the information with knowledge related to processing parameters. Some compounds that could affect the products' carcinogenic characteristics, alone or in combination, were evaluated and compared for 12 types of processed meat products, and we suggest subgrouping of processed meat with similar level of carcinogenic potential, which could improve the understanding of the cancer risk associated with processed meat intake in scientific human studies.

Kainic acid in the seaweed Palmaria palmata (dulse).

Twenty samples of the seaweed Palmaria palmata (dulse) purchased mainly from commercial Internet shops on the European market were analysed by a liquid chromatograph coupled with a tandem mass spectrometer method for the content of kainic acid, a naturally occurring neurotoxic compound in P. palmata. Kainic acid levels in the samples ranged widely from trace levels to approximately 560 µg g-1 dry weight.

Pre-diagnostic acrylamide exposure and survival after breast cancer among postmenopausal Danish women.

Acrylamide is a probable human carcinogen, with industrial contact, tobacco smoking and foods processed at high temperatures as the main routes of exposure. In animal studies oral intake of acrylamide has been related to cancer development, with indications that the increased cancer occurrence especially regards endocrine related tumors. In human epidemiological studies, dietary exposure to acrylamide has also been suggested related to higher risk of endocrine related tumors, like estrogen sensitive breast cancer. The aim of the present study was to evaluate if pre-diagnostic acrylamide exposure, measured by acrylamide and glycidamide hemoglobin adducts (AA-Hb and GA-Hb), were associated to mortality in breast cancer cases. Among 24,697 postmenopausal women included into a Danish cohort between 1993 and 1997, 420 developed breast cancer before 2001 and 110 died before 2009. AA-Hb and GA-Hb concentrations measured in blood samples were related to mortality by Cox proportional hazard models. Estimates are given per 25 pmol/g globin higher levels. Among non-smokers, higher concentrations of GA-Hb were associated to a higher hazard rate of breast cancer specific mortality (HR (95% CI): 1.63 (1.06-2.51)), the hazard rate among women diagnosed with estrogen receptor positive tumors was (HR (95% CI): 2.23 (1.38-3.61)). For AA-Hb the tendency was similar, but only statistically significant among those with estrogen receptor positive tumors (HR (95% CI): 1.31 (1.02-1.69)). In conclusion, the present study indicates that pre-diagnostic exposure to acrylamide may be related to mortality among breast cancer patients and that this may especially concern the most endocrine related type of breast cancer.

Use of external metabolizing systems when testing for endocrine disruption in the T-screen assay.

Although, it is well-established that information on the metabolism of a substance is important in the evaluation of its toxic potential, there is limited experience with incorporating metabolic aspects into in vitro tests for endocrine disrupters. The aim of the current study was a) to study different in vitro systems for biotransformation of ten known endocrine disrupting chemicals (EDs): five azole fungicides, three parabens and 2 phthalates, b) to determine possible changes in the ability of the EDs to bind and activate the thyroid receptor (TR) in the in vitro T-screen assay after biotransformation and c) to investigate the endogenous metabolic capacity of the GH3 cells, the cell line used in the T-screen assay, which is a proliferation assay used for the in vitro detection of agonistic and antagonistic properties of compounds at the level of the TR. The two in vitro metabolizing systems tested the human liver S9 mix and the PCB-induced rat microsomes gave an almost complete metabolic transformation of the tested parabens and phthalates. No marked difference the effects in the T-screen assay was observed between the parent compounds and the effects of the tested metabolic extracts. The GH3 cells themselves significantly metabolized the two tested phthalates dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall the results and qualitative data from the current study show that an in vitro metabolizing system using liver S9 or microsomes could be a convenient method for the incorporation of metabolic and toxicokinetic aspects into in vitro testing for endocrine disrupting effects.

Biomarkers of human exposure to acrylamide and relation to polymorphisms in metabolizing genes.

Acrylamide (AA) is formed in heat treated carbohydrate rich foods in the so-called Maillard reaction. AA is readily absorbed in the body and converted to glycidamide (GA) by epoxidation by the CYP2E1 (cytochrome P450 2E) enzyme. Both AA and GA may be detoxified through direct conjunction to glutathione by glutathione-S-transferases and GA by hydrolysis to glyceramide. Recently, we reported that biomarkers of AA exposure reflect intake of major food sources of AA; there were large interindividual variations in the blood ratio of GA-Hb/AA-Hb (GA- and AA-hemoglobin adducts). In this study we investigated whether the ratio of GA-Hb/AA-Hb in subjects could be related to polymorphic differences in genes coding for metabolizing enzymes CYP2E1, EPHX1 (microsomal epoxide hydrolase), GSTM1, GSTT1, and GSTP1, all being expected to be involved in the activation and detoxification of AA-associated adducts. We found significant associations between GSTM1 and GSTT1 genotypes and the ratio of GA-Hb/AA-Hb (p = 0.039 and p = 0.006, respectively). The ratio of GA-Hb/AA-Hb in individuals with the combined GSTM1- and GSTT1-null variants was significantly (p = 0.029) higher than those with the wild-type genotypes. Although the number of subjects was small, there were also significant associations with other combinations; CYP2E1 (Val179Val) plus GSTM1-null (p = 0.022); CYP2E1 (Val/Val), GSTM1-null plus GSTT1-null (p = 0.047); and CYP2E1 (Val/Val), GSTT1 null, EPHX1 (Tyr113Tyr) plus EPHX1 (His139Arg) (p = 0.018). Individuals with these combined genotypes had significantly higher blood ratio of GA-Hb/AA-Hb than other combinations. The observed associations correspond with what would be expected from the relative roles of these enzymes in activation and detoxification of AA, except for individuals with the EPHX1 (His139Arg) variant. The internal dose of genotoxic metabolite and also the concentration of AA in blood seem to be affected by these polymorphic genes. The genotypes and their combination may constitute useful biomarkers for the assessment of individual susceptibility to AA intake, and could add to the precision of epidemiological studies of dietary cancer.

Acrylamide exposure and incidence of breast cancer among postmenopausal women in the Danish Diet, Cancer and Health Study.

Acrylamide, a probable human carcinogen, is formed in several foods during high-temperature processing. So far, epidemiological studies have not shown any association between human cancer risk and dietary exposure to acrylamide. The purpose of this study was to conduct a nested case control study within a prospective cohort study on the association between breast cancer and exposure to acrylamide using biomarkers. N-terminal hemoglobin adduct levels of acrylamide and its genotoxic metabolite, glycidamide in red blood cells were analyzed (by LC/MS/MS) as biomarkers of exposure on 374 breast cancer cases and 374 controls from a cohort of postmenopausal women. The adduct levels of acrylamide and glycidamide were similar in cases and controls, with smokers having much higher levels (approximately 3 times) than nonsmokers. No association was seen between acrylamide-hemoglobin levels and breast cancer risk neither unadjusted nor adjusted for the potential confounders HRT duration, parity, BMI, alcohol intake and education. After adjustment for smoking behavior, however, a positive association was seen between acrylamide-hemoglobin levels and estrogen receptor positive breast cancer with an estimated incidence rate ratio (95% CI) of 2.7 (1.1-6.6) per 10-fold increase in acrylamide-hemoglobin level. A weak association between glycidamide hemoglobin levels and incidence of estrogen receptor positive breast cancer was also found, this association, however, entirely disappeared when acrylamide and glycidamide hemoglobin levels were mutually adjusted.

Generation of flavour compounds in fermented sausages-the influence of curing ingredients, Staphylococcus starter culture and ripening time.

The volatile profiles of fermented sausages made with either Staphylococcus xylosus or Staphylococcus carnosus starter cultures were studied with regard to the influence of salt concentration, ripening time and three different combinations of curing ingredients-nitrate, nitrite or nitrite/ascorbate. Emphasis was laid on volatile compounds originating from degradation of branched-chain amino acids. Volatile compounds were collected using dynamic headspace sampling and were identified by gas chromatography/mass spectrometry (GC/MS). Development in water activity, water loss and pH was monitored throughout maturation. Curing salts had a pronounced effect on the level of volatile compounds. In particular, curing with nitrate instead of nitrite resulted in a striking difference. Generally, nitrate increased the level of volatile compounds compared to nitrite, whereas ascorbate had only a small influence. The concentration level of NaCl had a considerable effect on the amount of volatile compounds but the effect was highly related to the ripening stage. Most compounds, but not all, increased in concentration as ripening proceeded. Major differences in the development of volatile compounds were observed depending on whether S. xylosus or S. carnosus were used as starter culture. In particular the effects of nitrate was much more predominant in the sausages made with S. carnosus than S.xylosus.

Effect of ascorbate, nitrate and nitrite on the amount of flavour compounds produced from leucine by Staphylococcus xylosus and Staphylococcus carnosus.

Resting cells of Staphylococcus xylosus and S. carnosus were incubated with ascorbate, nitrate and nitrite in defined reaction medium and their degradation of (3)H-labelled leucine into methyl-branched catabolites were studied using HPLC/radiometric detection. The experiments were carried out with and without addition of α-ketoglutarate. The main catabolic product of leucine degradation was 3-methylbutanoic acid but also small amounts of α-hydroxy isocaproic acid were produced. Nitrite addition lowered the concentration of 3-methylbutanoic acid for both Staphylococcus species and this effect was strongly amplified by ascorbate for S. xylosus but not for S. carnosus. For both species ascorbate alone had little if any effect. Also nitrate lowered the concentration of 3-methylbutanoic acid for S. xylosus. The concentration of α-hydroxy isocaproic acid was, however, increased by addition of nitrite and nitrate for S. xylosus. Addition of α-ketoglutarate generally increased the concentration of 3-methylbutanoic acid for both S. xylosus and S. carnosus.