Do GC/MS methods available for furan and alkylfurans in food provide comparable results? - An interlaboratory study and safety assessment of 2-pentylfuran in food.

A call for data on the occurrence of alkylfurans in food and feed from EFSA triggered the development of new methods to cover next to furan also 2- and 3-methylfuran, 2,5-dimethyl- and 2-ethylfuran as well as 2-pentylfuran. A significant variability was noticed when comparing analysis of 2-pentylfuran and furans in the same matrix performed by different laboratories. To assess the variability an interlaboratory study including eight laboratories was organised. The highest variabilities were observed when analysing cereals, with measurements of 2-pentylfuran indicating concentrations from 8 mg/kg up to more than 1000 mg/kg in the same sample. This study illustrates that the analysis of 2-pentylfuran requires special attention, and that additional method development would be necessary to ensure reliable and reproducible determination of 2-pentylfuran at contamination level. Moreover, a recent evaluation of the EFSA Panel on Food Additives and Flavourings indicates that concerns for genotoxicity, reason why it was grouped with the shorter alkylfurans, are now ruled out. We question the need and justification to include 2-pentylfuran in the analytical method as requested by EFSA, from both the analytical and the safety perspective.

Unexpected Potential of Iso-oligosaccharides in the Generation of Important Food Odorants.

The generation of selected Maillard-derived odorants from iso-oligosaccharides (IOSs), namely, from isomaltose, isomaltotriose, isomaltulose, and melibiose, was studied and compared with that from other oligosaccharides (maltose, lactose, and panose) and monosaccharides (glucose, galactose, and fructose). The study was carried out in binary mixtures of sugar and amino acids (glycine, proline, and cysteine) and upon wafer baking. The results indicate that IOSs induce browning and generation of the majority of the monitored odorants, in particular 4-hydroxy-2,5-dimethyl-3(2 H)-furanone, 2,3-butanedione, 2-acetyl-1-pyrroline, 2-propionyl-1-pyrroline, 2-acetylthiazole, and 2-acetyl-2-thiazoline, far more than the other oligosaccharides and to a higher or similar degree to that of the monosaccharides. Plausible mechanisms, consistent with the yields obtained from individual sugars, were proposed for the formation of the studied compounds. This newly obtained data brought for the first time evidence about the extraordinary potential of IOSs in the formation of several potent food odorants.

Study to elucidate formation pathways of selected roast-smelling odorants upon extrusion cooking.

The formation pathways of the N-containing roast-smelling compounds 2-acetyl-1-pyrroline, 2-acetyl-1(or 3),4,5,6-tetrahydropyridine, and their structural analogues 2-propionyl-1-pyrroline and 2-propionyl-1(or 3),4,5,6-tetrahydropyridine were studied upon extrusion cooking using the CAMOLA approach. The samples were produced under moderate extrusion conditions (135 °C, 20% moisture, 400 rpm) employing a rice-based model recipe enriched with flavor precursors ([U-(13)C6]-D-glucose, D-glucose, glycine, L-proline, and L-ornithine). The obtained data indicate that the formation of these compounds upon extrusion follows pathways similar to those reported for nonsheared model systems containing D-glucose and L-proline. 2-Acetyl-1-pyrroline is formed (i) by acylation of 1-pyrroline via C2 sugar fragments (major pathway) and (ii) via ring-opening of 1-pyrroline incorporating C3 sugar fragments (minor pathway), whereas 2-propionyl-1-pyrroline incorporates exclusively C3 sugar fragments. 2-Acetyl-1(or 3),4,5,6-tetrahydropyridine and the corresponding propionyl analogue incorporate C3 and C4 sugar fragments, respectively. In addition, it has been shown that the formation of 2-acetyl-1-pyrroline in low-moisture systems depends on the pH value of the reaction mixture.