Polycyclic aromatic hydrocarbons in the bakery chain.

The level of polycyclic aromatic hydrocarbons occurrence and the possibility of their formation in the bakery chain, its raw materials and final products, were examined. Experimental bread baking, with different baking temperatures, was performed in the Warsaw bakery, using cyclothermic deck ovens. PAHs determination was performed by high-pressure liquid chromatography with fluorescent and diode array detectors (HPLC-FLD/DAD) and confirmed by gas chromatography coupled with mass spectrometry (GC/MS). Total content of 19 PAHs in the grain, flour and bran varied from 1.07 to 3.65 µg/kg and, in bread, from 1.59 to 13.6 µg/kg depending on the part of bread and baking temperature. Based on the dough's contamination level and the influence of the baking temperature on the bread's PAHs content, it was confirmed that PAHs are formed during baking. Considering the results of the average dietary exposure to PAHs and the MOE (Margin of Exposure) analysis, it could be concluded that analysed bread and cereal products constitute little concern for consumer health.

Seasonal and geographical variations in levels of polychlorinated biphenyls (PCB) and polybrominated diphenyl ethers (PBDE) in Polish butter fat used as an indicator of environmental contamination.

The aim of this study was to evaluate the seasonal variation/geographical distribution of environmental concentration of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) across Poland using butter fat as an indicator of the contaminants. The average concentration of six indicator PCBs determined in the studied samples was 1500 pg g(-1) fat. The average concentration of 12 dioxin-like PCBs expressed as lower-bound dioxin-equivalent toxicity was 0.684 pg TEQ g(-1) fat. The average total concentration of 14 investigated PBDE congeners was 105 pg g(-1) fat. Statistically significant concentration differences between summer and winter samples were found. The results of this study indicate also a significant geographical diversification of butter contamination reflecting regional differences in environmental contamination. The seasonal variation of PBDE profiles evidences transformation of PBDE within the environment.

Non-dioxin-like and dioxin-like polychlorinated biphenyls in butter sampled from the Polish retail market.

The aim was to investigate levels of polychlorinated biphenyls (PCBs) in butter available on the Polish retail market. A gas chromatography-based method was developed for the purpose of this study. An ion-trap mass spectrometer was used as a detection system with high-resolution chromatography. Recoveries of individual PCBs from spiked samples varied from 58% to 105% with a recovery relative standard deviation in the range 3-16%. Levels of eight non-dioxin-like and twelve dioxin-like congeners were determined. Toxic equivalent factors (TEQs) were calculated using World Health Organization (WHO) TEQs. The average concentration of the sum of six PCBs (28, 52, 101, 138, 153, and 180) was found to be 1561±728 pg g(-1) (fat) and the upper-bound concentrations of dioxin-like congeners were (1 standard deviation uncertainty) 0.441±0.384 pg PCB-TEQ g(-1) (fat).

[Unsaturated fatty acids omega-3. I. Structure, sources, determination, metabolism in the organism]. / Nienasycone kwasy tluszczowe z rodziny omega-3. Cz. I. Struktura, zródla, oznaczanie, przemiany w organizmie.

Fats covered approximately 22% of energy requirements in diets of ancient human being, and simultaneously the value of ratio of polyunsaturated fatty acids (PUFA) to saturated (SFA) was estimated as 1.4 and the proportion of PUFA omega 6 to PUFA omega 3 was 1:1. During the last twenty thousands years the composition of human diets was changing dramatically due to economical, culture and social changes. However, there are indicators that the ratio of PUFA omega 6 to PUFA omega 3 in human diet was unchanging until beginning of XIX century. Dramatic technological breakthrough in food technology during last 100 years caused radical changes in the structure and quality of food consumption. It is estimated that at present fats cover about 40% of energy requirements in diets of people in developed countries, and the value of ratio of dietary PUFA omega 6 to PUFA omega 3 is 25:1 and even 50:1. Epidemiological nutritional studies indicate that in populations which consume inadequate amount of PUFA omega 3 most often occur the disorders on atherosclerotic and immunological background as compared to populations which consume diets with appropriate covering the requirements of dietary PUFA omega 3. Therefore, it could be supposed that increased occurrence so-called civilization disorders is the result of increased consumption of highly manufactured food with changed composition (and also to increased fats consumption and decreased consumption of PUFA omega 3). This hypothesis is confirmed by the observations that the supplementation of diets with PUFA omega 3 gives the desirable results in the treatment of many disorders. The main objective of this two parts paper is to characterize the polyunsaturated fatty acids, their metabolic path ways as well as the possibilities of the use of the diet supplementation with PUFA omega 3 in the treatment and prophylaxis of some metabolic disorders. The structure, sources, determination and pathways in organism are discussed in part I, and the role of eicosanoids originating from respective PUFA omega 3 and advantages of the supplementation the diet with PUFA are discussed in part II.

Identification of the major serum albumin adduct formed by 4-aminobiphenyl in vivo in rats.

Serum albumin was isolated from rats at 27 h after administration of the carcinogen [2,2'-3H]-4-aminobiphenyl. Pronase digestion of the purified albumin yielded a mixture of radiolabeled materials which was resolved into 5 major components by reverse-phase liquid chromatography. From detailed UV, 1H-NMR, and mass spectral analyses, four of these were determined to be 4-aminobiphenyl, 4'-hydroxy-4-acetylaminobiphenyl, and two other metabolites, all of which are presumed to be non-covalently associated with the serum albumin. The fifth component, however, resulted from covalent bond formation and was identified as a tetrapeptide containing 3-tryptophanyl-4-acetylaminobiphenyl, the amino acid sequence of which was H2N-ala-trp-ala-val. Since rat serum albumin contains only a single tryptophan residue in a hydrophobic drug binding site, its high selectivity for carcinogen binding suggests a unique role for this protein in the detoxification and/or transport of ultimate carcinogenic metabolites.