close

Вход

Забыли?

вход по аккаунту

код для вставкиСкачать
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.
1/--страниц
Пожаловаться на содержимое документа