title: Study to elucidate formation pathways of selected roast-smelling odorants upon extrusion cooking.
abstract: 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.
authors.affiliation: Nestlé Product Technology Center Orbe , 1350 Orbe, Switzerland.
authors.forename: Tomas
authors.initials: T
authors.lastname: Davidek
authors.forename: Daniel
authors.initials: D
authors.lastname: Festring
authors.forename: Thierry
authors.initials: T
authors.lastname: Dufossé
authors.forename: Ondrej
authors.initials: O
authors.lastname: Novotny
authors.forename: Imre
authors.initials: I
authors.lastname: Blank
mesh_terms: D003296:Cooking; D005421:Flavoring Agents / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D015416:Maillard Reaction; D009812:Odorants / Q000032:analysis; D012275:Oryza / Q000737:chemistry*; D011392:Proline / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry
chemical_list: D005421:Flavoring Agents; D011758:Pyrroles; D011392:Proline; C426303:2-acetyl-1-pyrroline; D005947:Glucose