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

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

Enzymatic reduction of azo and indigoid compounds

A customer- and environment-friendly method for the decolorization azo dyes was developed. Azoreductases could be used both to bleach hair dyed with azo dyes and to reduce dyes in vat dyeing of textiles. A new reduced nicotinamide adenine dinucleotide-dependent azoreductase of Bacillus cereus, which showed high potential for reduction of these dyes, was purified using a combination of ammonium sulfate precipitation and chromatography and had a molecular mass of 21.5 kDa. The optimum pH of the azoreductase depended on the substrate and was within the range of pH 6 to 7, while the maximum temperature was reached at 40°C. Oxygen was shown to be an alternative electron acceptor to azo compounds and must therefore be excluded during enzymatic dye reduction. Biotransformation of the azo dyes Flame Orange and Ruby Red was studied in more detail using UV-visible spectroscopy, high-performance liquid chromatography, and mass spectrometry (MS). Reduction of the azo bonds leads to cleavage of the dyes resulting in the cleavage product 2-amino-1,3 dimethylimidazolium and N∼1∼,N∼1∼-dimethyl-1,4-benzenediamine for Ruby Red, while only the first was detected for Flame Orange because of MS instability of the expected 1,4-benzenediamine. The azoreductase was also found to reduce vat dyes like Indigo Carmine (C.I. Acid Blue 74). Hydrogen peroxide (H2O2) as an oxidizing agent was used to reoxidize the dye into the initial form. The reduction and oxidation mechanism of Indigo Carmine was studied using UV-visible spectroscopy

Description of data-sources used in SafetyCube. Deliverable 3.1 of the H2020 project SafetyCube

Safety CaUsation, Benefits and Efficiency (SafetyCube) is a European Commission supported Horizon 2020 project with the objective of developing an innovative road safety Decision Support System (DSS) that will enable policy-makers and stakeholders to select and implement the most appropriate strategies, measures and cost-effective approaches to reduce casualties of all road user types and all severities. This deliverable describes the available data in the form of an inventory of databases that can be used for analyses within the project. Two general types of data are available: one describing the involvement of different components for the road safety (vehicles, infrastructure, and the road user) and one describing the injury outcomes of a crash. These two database categories are available to the partners of SafetyCube and gathered in two excel tables. One table contains traffic databases (accident and naturalistic driving studies) and the second table contains injury databases. The tables contain information on 58 and 35 variables, respectively. The key information describing the databases that was needed for the inventory were items such as: Type of data collected (crashes, injuries, etc.) Documentation of the variables Sampling criteria for the data collected SafetyCube partners with access to the data Extent of data access (raw data vs. summary tables) The tables contain 36 traffic accident databases, five naturalistic driving studies or field-tests and 22 injury databases where of four were coded in both sheets