Non-target bioactive compound profiles of coffee roasts and preparations.

Coffee is an inherent part of our daily nutrition and seems to have protective effects against diseases, whereby it is often not fully understood, which ingredients are responsible for the observed effect. Hence, a non-targeted bioactivity profiling was developed to investigate 27 hand-filtered coffee brews of differently roasted coffee beans and 14 differently prepared and stored coffee brews. After separation, multi-imaging, and densitometry, six planar effect-directed assays were performed to reveal individual antioxidative, antibacterial, anti-cholinesterase, anti-diabetic, and estrogenic effects. Individual compounds were mainly responsible for the observed effects, e.g. 5-O-caffeoylquinic acid regarding antioxidative potential and α-glucosidase inhibition, while coffee brews made by a fully automated coffee machine showed the highest antioxidative potential. Unlike preparation and storage conditions, applied roasting conditions and origin of coffee samples played a less important role. Therefore, the way we daily consume our coffee has an impact on the magnitude of potential health effects.

Determination of dialkyl phosphates as breakdown products of organophosphorus insecticides in fruit juices by HPTLC with fluorescence detection.

Dialkyl phosphates (DAP) are common degradation products of organophosphorus pesticides that are used as urinary biomarkers for human exposure. An HPTLC method was developed for the quantitative determination of DAP in fruit juices, i.e., dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP), diethyl phosphate (DEP), and diethyl thiophosphate (DETP). Dibutyl phosphate (DBP) was used as an internal standard. The method was based on precipitation of fruit acids in the presence of barium chloride and acetonitrile and liquid-liquid extraction with acetonitrile-diethyl ether. Extracted DAP were derivatized with 1-(bromoacetyl)pyrene (BAP), and the BAP derivatives separated on HPTLC amino plates with dichloromethane as the mobile phase. Densitometry was performed by measurement of fluorescence at 366/>400 nm. The limit of quantification (LOQ) values were between 0.8 and 1.4 ng/zone. Fluorescence enhancement was achieved by dipping the plate into a paraffin oil solution, increasing the sensitivity and resulting in an LOQ of 0.5-0.6 ng/zone. Repeatabilities with relative standard deviations of < or = 3.5% (n = 5, at 15-20 ng/zone) and coefficients of correlation of 0.9999 were highly satisfactory for rapid trace analysis of DAP in the fruit juices by HPTLC. The mean recoveries from apple juice spiked at 0.5 mg/L were 74, 83, 70, and 57% for DMP, DEP, DMTP, and DETP, respectively. If an application volume of 5 microL of apple juice extract was applied, the LOQ in apple juice was 300 microg/L. However, this can be lowered by application of higher volumes (up to 50 microL) or a more concentrated derivatization batch.

Bioprofiling of Cosmetics with Focus on Streamlined Coumarin Analysis.

Facing the widespread use of cosmetic products in daily use and recognizing the very limited information obtained by target analysis, a method suited for comprehensive characterization of cosmetics was aimed at. The biological activity of ingredients of 20 cosmetics taken from 16 different product groups and their coumarin contents were investigated via chromatography linked to bioassays (direct bioautography) and mass spectrometry. It allows for screening a large number of cosmetic products within a short time to generate a more valid database on their coumarin content and their contribution to the overall exposure. Bioactivity profiling of cosmetics with regard to bioactive ingredients opens new avenues for a comprehensive characterization of important substances in products of daily use, helpful for the legally required safety and risk assessment of cosmetic products, especially for multiple product usage. As for coumarin, a ubiquitary fragrance compound of allergenic potential, which is under recurrent discussion due to its hepatoxic properties, it is necessary to be able to estimate the regular intake via cosmetics for a valid risk assessment. This newly developed bioprofiling method allowed a selective determination of coumarin down to 1.3 mg kg-1, even for very matrix-rich cosmetics despite minimalism in sample preparation. The declaration limits according to European Cosmetics Regulation were completely covered. Mean coumarin contents of 20 cosmetic products reached up to 2218 mg kg-1. The repeatabilities (%RSD, n = 3) were between 1.1 and 2.9%, and the mean recoveries (n = 5) were between 96 and 102% for the different cosmetic matrices.

Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather on the toxicological potential of different compounds of the pigment formulations. The results of the bioassay might be helpful to choose pigment compositions that provide both, a high printing quality but at the same time guarantee a high consumer safety, especially in regard to smaller pigment components, which tend to migrate through the packaging.

Photostability of cosmetic UV filters on mammalian skin under UV exposure.

Previous studies showed that the common UV filter substances benzophenone-3 (BP-3), butyl methoxydibenzoylmethane (BM-DBM), octocrylene (OCR), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (EHS) and ethylhexyl triazone (EHT) were able to react with amino side chains of different proteins in vitro. To transfer the results to mammalian skin conditions, sunscreen products were applied on both prepared fresh porcine skin and glass plates, followed by UV irradiation and the determination of depletion of the respective UV filters. Significantly lower recoveries of the UV filters extracted from skin samples than from glass plates indicated the additional reaction of the UV filters with skin constituents, when proteins will be the most important reactants. Among the products tested, BP-3 showed the greatest differences in recoveries between glass and skin samples of about 13% and 24% after 2 and 4 h of irradiation, respectively, followed by EHS > BM-DBM > OCR > EHMC > EHT. The obtained results raise the question, whether the common in vitro evaluations of sunscreens, using inert substrate materials like roughened quartz or polymethyl methacrylate (PMMA) plates are really suitable to fully replace in vivo methods, as they cannot include skin-typical reactions.