FORMATION OF CARCINOGENIC SUBSTANCES DURING HEATING OF FOODS

Heating of foods induces chemical reaction pathways that are not only leading to desired compounds (e.g. aroma and taste active) but also to degradation products that can pose a cancer risk. Especially the Maillard reaction is known for the formation of carcinogenic compounds in some instances. Recently, it was described that the uptake of oxidised lipids can also lead to cancer. However, the active principle is not yet identified and it has been suggested that the aldehydes, peroxides, or epoxides are the chemical structures that induce the changes of the DNA. From the Maillard reaction a number of different potentially toxic substances are formed which comprises the heterocyclic amines, acrylamide, and the furan derivatives. During the last few years a biochemical mechanism was described which activates the furan derivatives (e.g. furfuryl alcohol, HMF) which are then able to form DNA-adducts. Heterocyclic amines are formed from a reaction of amino acids with carbohydrates and creatinine. In contrast to this reaction acrylamide is formed from asparagine in the presence of sugars. The formation of HMF is not so much dependent on high temperatures as the heterocyclic amines or acrylamide. It is also formed during storage of carbohydrate rich foods. Other furan derivatives like furfuryl alcohol need higher temperatures as well.The concentration of these compounds covers a wide range from low ng/g in the case of heterocyclic amines to µg/g in the case of acrylamide and mg/g in the case of HMF and other furans. This means that even if the carcinogenic potential of the furans is low the high concentration and ubiquitous occurrence results in a chronic and high exposure which can also contribute significantly to the cancer risk of heated foods

FORMATION OF CARCINOGENIC SUBSTANCES DURING HEATING OF FOODS

Heating of foods induces chemical reaction pathways that are not only leading to desired compounds (e.g. aroma and taste active) but also to degradation products that can pose a cancer risk. Especially the Maillard reaction is known for the formation of carcinogenic compounds in some instances. Recently, it was described that the uptake of oxidised lipids can also lead to cancer. However, the active principle is not yet identified and it has been suggested that the aldehydes, peroxides, or epoxides are the chemical structures that induce the changes of the DNA. From the Maillard reaction a number of different potentially toxic substances are formed which comprises the heterocyclic amines, acrylamide, and the furan derivatives. During the last few years a biochemical mechanism was described which activates the furan derivatives (e.g. furfuryl alcohol, HMF) which are then able to form DNA-adducts. Heterocyclic amines are formed from a reaction of amino acids with carbohydrates and creatinine. In contrast to this reaction acrylamide is formed from asparagine in the presence of sugars. The formation of HMF is not so much dependent on high temperatures as the heterocyclic amines or acrylamide. It is also formed during storage of carbohydrate rich foods. Other furan derivatives like furfuryl alcohol need higher temperatures as well.The concentration of these compounds covers a wide range from low ng/g in the case of heterocyclic amines to µg/g in the case of acrylamide and mg/g in the case of HMF and other furans. This means that even if the carcinogenic potential of the furans is low the high concentration and ubiquitous occurrence results in a chronic and high exposure which can also contribute significantly to the cancer risk of heated food

"Hurlements en faveur de Guy"

Die vorliegende Arbeit beschäftigt sich mit der Person und dem Künstler Guy Debord und durchleuchtet den Zusammenhang zwischen seinem Leben und Werk im zeitgeschichtlichen Kontext des 20. Jahrhunderts. Durch die lettristische Bewegung inspiriert, gründete er in Paris Anfang der 1950er Jahre die Lettristische Internationale und folgend die Situationistische Internationale, die auf internationaler Ebene agierte und Künstler wie den Maler Asger Jorn oder den Architekten Constant zu ihren Mitgliedern zählte. Guy Debord selbst war nicht nur der theoretische Kopf der Gruppierungen, seine Rolle als (siutationistischer) Filmemacher und Revolutionär des Avantgarde-Kinos wird anhand mehrerer Filmbeispiele aufgezeigt. War das primäre Ziel das avantgardischte Konzept die Aufhebung der Trennung von Leben, Kunst und Politik, so gelang es Guy Debord – am Schnittpunkt zwischen Politik und Kunst - diesem Konzept zumindest in seinem Leben treu zu bleiben. In der paradoxen Rezeption seines künstlerischen Erbes wird die Bedeutung und Wirkung seines Schaffens ersichtlich. Die Arbeit gliedert sich in drei Haupteile: Im ersten wird seine Biografie in den zeitgeschichtlichen Kontext gestellt, im zweiten wird seine theoretische und filmische Arbeit erläutert, und im dritten Teil wird ein Abriss der Rezeptionsgeschichte dargelegt, mit dem Schwerpunkt der Inhaltsanalyse des Theaterstücks "Scanner", das Guy Debord als Inhalt hat und als beispielhaft für die aktuelle Rezeptionsweise in Frankreich gesehen werden kann

CHANGES OF NUTRITIONAL PROPERTIES OF THREE VARIANTS PEPPERS BY PROCESSING OF PICKLED RED PEPPERS

 Blanching was done at 85-90 °C for 5 min. To the pasteurized pepper, acetic acid was added at a concentration of 1.5 % in terms of finished product, which belongs to the low marinated products. Pasteurization is carried out at T 92 °Cfor 30 minutes. The chemical properties were determined by analyzing the following parameters: total dry matter, carbohydrates, proteins, oils, total acids, vitamin C, β-carotene and ash, both in fresh and in pasteurized peppers. Based on the obtained results the quality and nutritional composition were determined. The variety horgosh shows the highest content of total dry matter (11.45 %), vitamin C (138.9 mg/100 g), βcarotene (22.7 mg/100 g), and the highest energy value (41.7 kcal). In the gourp of the pasteurized peppers, the variety of palanechko chudo has been characterized by the lowest average value of total dry matter (7.49 %) and lowest total energy value (24.6 kcal); the variety of kurtovska kapija had the lowest contents of vitamin C (52.1 mg/100 g) and β-carotene (6.09 mg/100 g)

Enzymatic polymerization on the surface of functionalized cellulose fibers

Enzymatic coating of functionalized cellulose fibers with catechol was performed in the presence of Trametes hirsuta laccase. Cellulose functionalization was done by covalent fixation of aromatic amines onto the cellulose surface using a dyeing procedure with C.I. Reactive Black 5 (RB5) followed by reduction with sodium hydrosulfite. Cellulase enzymes were used on coated and control samples to obtain the analytes linked with the soluble sugars in solution, to prove the reaction concepts described in this paper. Hydrolyzed coated-cellulose showed lower concentration of reducing sugars (1188 mg/L) than control samples (2011 mg/L). The structures of these compounds were checked by LC/MS analysis confirming the presence of functionalized glucose and cellobiose units coupled to poly(catechol) molecules (m/z 580 and m/z 633). Alkali extraction method showed to be very promising to coat cellulose fibers with phenols in the presence of enzymes, at mild conditions of temperature and pH

Enzymatic reduction and oxidation of fibre-bound azo-dyes

A new customer and environmental friendly method of hair bound dye decolouration was developed. Biotransformation of the azo-dyes Flame Orange and Ruby Red was studied using different oxidoreductases. The pathways of azo dye conversion by these enzymes were investigated and the intermediates and metabolites were identified and characterised using UV–vis spectroscopy, high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Laccase from Pycnoporus cinnabarinus, manganese peroxidase (MnP) from Nematoloma frowardii and the novel Agrocybe aegerita peroxidase (AaP) were found to use a similar mechanism to convert azo dyes. They N-demethylated the dyes and concomitantly polymerized them to some extent. On the other hand the mechanism for cleavage of the azo bond by azo-reductases of Bacillus cereus and B. subtilis was based on reduction of the azo bond at the expense of NAD(P)H

Phenolic metabolites of anthocyanins following a dietary intervention study in post-menopausal women

Scope Numerous studies feeding anthocyanin-rich foods report limited bioavailability of the parent anthocyanins. The present study explores the identity and concentration of the phenolic metabolites of anthocyanins in humans. Methods and results Anthocyanin metabolites were quantified in samples collected from a previously conducted 12-wk elderberry intervention study in healthy post-menopausal women. Individual 1-, 2- and 3-h post-bolus urine samples and pooled plasma samples following acute (single bolus) and chronic (12-wk supplementation) anthocyanin consumption (500 mg/day) were analysed using HPLC-ESI-MS/MS. Twenty-eight anthocyanin metabolites were identified in urine and 21 in plasma (including sulfates of vanillic, protocatechuic and benzoic acid). Phenolic metabolites reached peak concentrations of 1237 nM in plasma, while anthocyanin conjugates only reached concentrations of 34 nM. Similarly, in urine, phenolic metabolites were detected at concentrations of 33 185 ± 2549 nM/mM creatinine, while anthocyanin conjugates reached concentrations of 548 ± 219 nM/mM creatinine. There was no evidence that chronic exposure had any impact on either the profile or quantity of metabolites recovered relative to acute exposure. Conclusion An extensive range of phenolic metabolites of anthocyanin was identified following elderberry consumption in humans, including 11 novel metabolites, which were identified at much higher concentrations than their parent compounds