The Maillard Reaction Literature Meeting Lucie Zimmer January the 30th 2007 Caramel (sugars) Cream (amino compounds) Browning • Brown or black pigments • Characteristic odour and taste • Alteration of Nutritive properties • Browning of banana / reding of pasta Maillard Reaction • From the name of the french chemist, Louis-Camille Maillard • Main steps published in 1912 but still studied. • Lead to the formation of many organoleptic compounds • Antioxydative and carcinogenic properties of Maillard products Very versatile reaction (schizophrenic?) Maillard Reaction : main steps Bristow, M.; Isaacs, N. S. J. Chem. Soc., Perkin Trans. 2, 1999, 2213-2218 Maillard Reaction : main steps • Three main steps – Maillard condensation and Amadori rearrangement – Formation of caracteristic compounds – Melanoidin formation Machiels, D.; Istasse, L. Ann. Med. Chem. 2002, 146, 347-352. I. Condensation de Maillard Aldose, cetose… Every reductive sugars Amino acids, peptides, proteines N-substitued glycosylamines Stable if from proteines or peptides If from aminoacids : Amadori rearrangement Reaction easier with small sugar and amine function far from carboxylic acid moeity. (special case of lysine: rate 5-15 times higher) I. Amadori and Heyns rearrangements Amadori rearrangement : Heyns rearrangement : (A bit slower) Application: transformation of aldose in ketose and ketose in aldose II. CHARACTERISTIC COMPOUND FORMATION II. Characteristic compounds: formation 1. Scission: Formation of small molecules : retroaldol cleavage. Those molecule can react by aldolic condensation to give polymeres. Ledl, F.; Scleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-705. II. Characteristic compounds: formation 1. Scission: recombination of the small molecules Ledl, F.; Scleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-705. II. Characteristic compounds: formation 2. 1,2 or 2,3 enolisation followed by dehydratation: 2.1 Low or neutral pH : enolisation 1,2 favored Machiels, D.; Istasse, L. Ann. Med. Chem. 2002, 146, 347-352. II. Characteristic compounds: formation 2.2 Higher pH : 2,3 enolisation Exemple: furaneol synthesis (strawberry, ananas, caramel) Lizzani-Cuvelier L. et al. L’Act. Chim. 2002, 04, 4-14. II. Characteristic compounds: formation At « high » pH apparition of nitrogenous heteroaromatic rings. Reductones so obtained can condensate with amino ketones to give after dehydratation different kind of pyrroles: dehydratation condensation … II. Characteristic compounds: formation 3. Strecker degradation : Reductones and dehydroreductones can undergo Strecker degradation by reacting with amino acid II. Characteristic compounds: formation Aminoketones can condensate and give heteroaromatics or react with another amino acid to give colored compound. Bristow, M.; Isaacs, N. S. J. Chem. Soc., Perkin Trans. 2, 1999, 2213-2218 Lizzani-Cuvelier L. et al. L’Act. Chim. 2002, 04, 4-14. Particular amino acids: Protein-bound tryptophane hardly reactive Occur also in free state : No Amadori rearrangement observed if N-glycosyl derivative In the case of over-cooked products: formation of carcinogenic product Ledl, F.; Schleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-706. Particular amino acids: Occurs in large amount in cereals, particularly in malt. Lead to tastefull molecules Ledl, F.; Schleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-706. Particular amino acids: Do not occur free in food stuff Release hydrogene sulfide Low odor threshold (roasted coffee beans…) Retarding effect on the reaction Ledl, F.; Schleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-706. Particular amino acids: No reaction with guanido group Trapping of carbonylated compounds Cross linking to form colored compounds. Ledl, F.; Schleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-706. Arg-pyrimidine Step which gives the taste and the color to the beer = roasting of the malt. Main parameters : time, temperature and humidity rate during the roasting Glomb et al. J. Agric. Food Chem., 2001, 49, 366-372 Arg-pyrimidine Barley, water mixture EBC: European Brewery Convention Filled circles = darker beers For the same wort the darker beers have got a higher content of Arg-pyrimidine Color not only depending of Arg-pyrimidine III. POLYMERISATION: MELANOIDIN FORMATION III. Polymerisation: Melanoidin formation Polymerisation: Melanoidin formation Give to the meat hardness and color… No structure found to date… Mix of polymers of different molecular weights Made by polymerisation of different heterocycles thanks to retroaldolisation products… Formation delayed by addition of water enhanced by transition metal (Fe2+, Cu2+) Maillard Reaction : in vivo… Evidence of the first products of Maillard reaction found in vivo Diabete: N-term of hemoglobin can be glycosilated = Marker of diabetic people (2-3 months) Other proteins can give shorter markers (2-3 weeks) or longer (hair’s or nails proteins) Severe complications = high degree fructolysation increased damage to eyes and kidney Aging: Maillard products accumulate in the organisme Link between aging damages and Maillard reaction… (collagen) Ledl, F.; Schleicher, E. Angew. Chem. Int. Ed. 1990, 29, 565-706. Control of Maillard reaction to preserve food and body 1. Kinetics: Glucose + amino acids at 2°C : two months to have light yellow coloration 2. Additives: Addition of sulfites : use strickly control specially because of their bad effects on asthmatic people Structure identified after sulfite addition : 3. In vivo: Administration of aminoguanidine : Relatively well tolered by mammals Lowered concentration of cross-linking of collagen and deposition of cholesterol transporting lipoproteins on the arterial walls. APPLICATION : HETEROCYCLE SYNTHESIS Pop corn like odorant… De Kimpe, N. G., Rochetti, M. T. J. Agric. Food Chem., 1998, 46, 2278-2281 Analogue synthesis THT1 glucose transporter of parasite causing African sleeping sickness also accepts D-fructose. Azéma, L.; Bringaud, F.; Blonski, C.; Périé, J. Bioorg. Med. Chem. 2000, 8, 717-722. Applications Fernandez-Bolaños, J. G. et al. Tetrahedron Ass.. 2000, 14, 1009-1018. Yeagley, D. A.; Benesi, A. J., Miljkovic, M. Carbohydr. Res. 1996, 289, 189-191. Horvat, S. et al. J. Chem. Soc., Perkin Trans.1 1998, 909-913. Application piperidinone Guzi, T. J.; Macdonald, T.L. Tetrahedron Lett. 1996, 17, 2939-2942 Application piperidinone synthesis Guzi, T. J.; Macdonald, T.L. Tetrahedron Lett. 1996, 17, 2939-2942 Application piperidinone synthesis Guzi, T. J.; Macdonald T. L. Tetrahedron Lett. 1996, 17, 2939-2942 Conclusion Maillard reaction lead to a huge amount of different compounds: Molecular Gastronomy Nicholas Kurti Hervé This Ferran Adria, Heston Blummenthal, Pierre Gagnaire, Emile Jung, Bernard Leprince, Michel Roth, Pierre Hermé… Molecular Gastronomy First target : eggs and mayonnaise Scientifical optimisation of the emulsion quality 1 litre of mayonnaise from 1 yolk ! Verification of advice When eggs are overcooked: apparition of gray-green layer around the yolk. Iron from yolk and sulfure from white lead to FeS2 which give bad taste and color. Molecular Gastronomy KBH4 Molecular Gastronomy « Pour the peas in cold water to fix the chlorophyll… » During the cooking, Mg2+ of chlorophyll are replaced by 2 H+ Solution : baking soda in the cooking water…. This, H. Nature Materials, 2005, 4, 5-7 Molecular Gastronomy « Red berries should not be cooked in tin or copper pan... » Raspberries crushed in water Raspberries crushed with Sn2+ Complexation with polyphenols This, H. Nature Materials, 2005, 4, 5-7. Molecular Gastronomy Cheap Tips…. Whisky few drops of vaniline : ethanol + lignin of wood barrels give 4-hydroxy-3-methoxybenzaldehyde No Mushrooms ? Use an appropriate amount of 1-octen-2-ol or benzyl trans-2-methylbutenoate Molecular Gastronomy Märkl, G. Angew. Chem. Int. Ed. 2003, 42, 5386-5388.