Maillard reaction AGEs

Several markers for the Maillard reaction have been described in the literature. For example, the product initially formed between glucose and lysine is partly transformed into furosine (Heyns et ah, 1968) on acid hydrolysis. Conversely, the fluorescent amino acid pentosidine (Sell and Monnier, 1989) is an advanced glycation endproduct (AGE) and may form covalent bonds between proteins (cross-linking). Furthermore, the Maillard reaction leads to an increase in characteristic fluorescence (excitation 370 nm, emission 440 nm) (Monnier et ah, 1984 Pongor et ah, 1984). 

Monnier VM and Sell DR (1994) The advanced Maillard reaction in aging and age-related diseases probed with pentosidine. Spec Publ - R Soc Chem 151, 235-243. 

Monnier, V. U. Stevens, V. J. Cerami, A. Maillard reactions involving protein and carbohydrates rn vivo relevance to diabetes mellitus and aging. Prog. Food Nutr. Sci. 1981, 5, 315-27. 

Numerous y- and 8-lactones were identified in Tokaji aszu grapes (Miklosy and Kerenyi, 2004 Miklosy et al., 2004). The odor notes of the y-lactones were described as resin- and caramel-like, roasted, or honey, while the 8-lactones exhibited characteristic notes of coconut, chocolate, and peach. The same lactones had been identified earlier from botrytized wines but not from normal wines (Schreier et al., 1976). Lactones are mostly found in oxidatively aged wines but seem to develop in fruit due to the oxidizing effect of B. cinerea, water loss, or Maillard reactions (Miklosy et al., 2004). 

The relationship between the Maillard reaction and Alzheimer s disease has recently been considered by Gasic-Milenkovic el al.324 AGE concentrations in the serum and urine of healthy individuals increase after the ingestion of an AGE-rich protein meal, in a manner directly proportional to the amount consumed. Only one-third of the AGEs appearing in the serum had been detected in the urine after 48 h, the fate of... 

A series of heterocyclic /V-amidino compounds has been synthesised by Niigata et al., comprising triazoles,592 pyrazoles,593-595 and indazoles.596 All had inhibitory effects on the Maillard reaction, the IC50 values for the triazoles ranging from 6.6 to 30.0 jUM, with low toxicity. The compounds were considered to have potential applications in the treatment of diabetic complications and aging-related diseases, as well as in skin medication, cosmetics, food products, and beverages. 

J. W. Baynes and V. M. Monnier (eds), The Maillard Reaction in Aging, Diabetes, and Nutrition, Alan Liss, New York, 1989. 

T. Araki, Y. Chijiiwa, R. Nagai, N. Araki, and S. Horiuchi, Application of the amino acid analysis for the detection of AGE-proteins of the Maillard reaction, in G, 2002, 391-393. 

E. B. Frye, T. P. Degenhardt, S. R. Thorpe, and J. W. Baynes, Role of the Maillard reaction in aging tissue proteins Advanced glycation end product-dependent increase in imi-dazolium cross-links in human lens, J. Biol. Chem., 1998, 273, 18714—18719. 

K. Nakamura, T. Hasegawa, Y. Fukunaga, and K. Ienaga, Crosslines A and B as candidates for the fluorophores in age- and diabetes-related cross-linked proteins, and their diacetates produced by Maillard reaction of -/V-acety 1-L-lysi nc with D-glucose,. /. Chem. Soc., Chem. Commun., 1992, 992-994. 

D.G. Dyer, J.A. Dunn, S.R. Thorpe, K.E. Bailie, TJ. Lyons, D.R. McCance, and J.W. Baynes, Accumulation of Maillard reaction products in skin collagen in diabetes and aging, J. Clin. Invest., 1993, 91, 2463-2469. 

Study and characterization of the Maillard reaction products could allow one to control the formation of advanced Maillard products (AMP), responsible in part for noxious effects in diabetes and in age-related cardiovascular diseases (Al-Abed et al, 1999). This knowledge could lead to a better control of these reactions in order to modify food proteins and their functions. Maillard reactions are one of the simplest ways to modify food proteins because they take place when a protein and a sugar are just heated together (Chuyen, 1998). 

Heating also produces a series of other substances as a result of Maillard reactions. These include cyclotene, maltol and its derivatives (hydroxymaltol, dihydro-maltol), 2,3-dihydro-5-hydroxy-2-methyl4(/7) pyranone (DHM) and its 5-hydroxy derivative (DDMP) and furaneol. The sensory impact of these components can play an important role in developing the toasted , burnt , or caramel aromas of some barrel-aged wines (Cutzach et al. 1997,1999). 

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