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This study evaluates the content and formation of free and bound monochloropropanediol (MCPD) and bound glycidol (GE) in fine bakery wares from the German market. The analytical screening revealed, that free 3-MCPD can be quantified in products with low water and fat content, which are produced using high baking temperatures. Concentrations resulted to be 10.0 µg/kg (wafers), 14.1 µg/kg (crispbread) and 22.8 µg/kg (rusk) and are thus judged to be of minor significance when it comes to a potential introduction of a combined maximum level for free and bound species. As exception, considerable amounts of free 3-MCPD (maximum level of 265.4 µg/kg) were only quantified in cinnamon stars containing glycerine as additive. As expected, MCPDE were only quantified in products produced with refined vegetable oil (short bread, puff pastry, caramel biscuits, speculoos, cake, wafers, wholemeal biscuits and rusk). GE levels have already been significantly reduced compared to former studies, one cake showed a maximum content of 127.8 µg/kg. A model baking trial using 13C-3-MCPDE spiked butter as fat component in shortbread confirmed that free 3-MCPD and 2-MCPD, 3-MCPDE, 2-MCPDE or GE are not endogenously formed in marketable browned biscuits. A thermal or lipase-catalysed release of free 3-MCPD from its fatty acid esters can be excluded.

The δ13CVPDB and δ18OVSMOW values of caffeine isolated from commercial caffeine-containing foods were determined by isotope ratio mass spectrometry (IRMS) using elemental analysis (EA) in the 'combustion' (C) and 'pyrolysis' (P) modes (EA-C/P-IRMS), respectively. In total, 69 samples (32 guarana products, 20 teas, 12 coffee products, and 5 mate teas) were analyzed together with three references of synthetic caffeine. Validation was done by excluding isotope discrimination in the course of sample preparation and determining linear dynamic ranges for EA-P-IRMS measurements. In total, five samples (one caffeine-containing soft drink and four guarana products) under study contained synthetic caffeine.