Maillard reaction chemical reactions

G. R. Waller and M. S. Feather in The Maillard Reaction in Foods and Nutrition, American Chemical Society, Washington, D.C. 1983 F. Hata and M. Oimomi, Rinsho KensaSS, 893 (1989). 

Maillard Reactions in Food Chemical, Physiological and Technological Aspects, in C. Eriksson (Ed.), Progress in Food and Nutrition Science 5, Pergamon Press, Oxford, 1981. 

The Maillard reaction is likely to take on additional significance with the introduction of many new protein and peptide pharmaceuticals. For example, Tarelli et al. have demonstrated that lysine vasopressin undergoes rapid glycation in the presence of reducing sugars in both aqueous and solid formulations and that the N-terminal adduct can form rapidly even at — 20°C [52], A textbook that deals with the consequences for the chemical and life sciences of the Maillard reaction has been published [53]. 

R. Ikan, Ed, The Maillard Reaction Consequences for the Chemical and Life Sciences, John Wiley Sons, New York, 1996. 

Ho C-T (1996) Thermal degradation of Maillard aromas. In Ikan R (ed) the Maillard reaction Consequences for the chemical and life sciences. Wiley, Chichester, UK, pp 27-53... 

In summary, there are at least four ways in which residual moisture in the amorphous state can impact on chemical reactivity. First, as a direct interaction with the drug, for example, in various hydrolytic reactions. Second, water can influence reactivity as a by-product of the reaction, by inhibiting the rate of the forward reaction, for example, in various condensation reactions, such as the Maillard reaction. Third, water acting locally as a solvent or medium facilitating a reaction, without direct participation. Finally, by virtue of its high free volume and low Tg, water can act as a plasticiser, reducing viscosity and enhancing diffusivity [28]. 

The Maillard reaction is inextricably linked to the desirable flavour and colour characteristics of cooked foods and this review provides an insight into some of the chemistry associated with flavour generation in the reaction and the different aromas which are involved. The chemical pathways associated with the initial and intermediate stages of the Maillard reaction are presented and routes by which the important classes of aroma compounds may be formed from Maillard intermediates are discussed. 

Mauron J (1981) In Eriksson C (ed) Maillard Reactions in Food. Pergamon, Oxford, p 3 Mottram DS (1994) In Parliment TH, Morello M), McGorrin R) (eds) Thermally Generated Flavors Maillard, Microwave, and Extrusion Processes. ACS Symposium Series 543. American Chemical Society Washington, p 104 Nursten HE (1980) Food Chem. 6 263... 

Cysteine can be obtained by hydrolysis from cysteine-rich proteins in hair or feathers or from petrochemical sources. Cysteine is an important raw material in Maillard reactions for the preparation of process flavours, but it can also serve as a source of ammonia and hydrogen sulfide for the preparation of flavour chemicals, such as the terpene sulfur compounds mentioned in Sect. 13.2.4 and furfuryl mercaptan mentioned in Sect. 13.4.2.4. 

Methionine can be obtained from enzymatic protein hydrolysates or from petrochemical sources. To a lesser extent than cysteine, it is a raw material in Maillard reactions for the preparation of process flavours and it can also be utilised as a precursor for the chemical preparation of the sulfide methional, which is an important flavour constituent for potato, malt, seafood and many other flavours. Methional can be reduced to methionol, which can be esterified with organic acids to, for instance, methionyl acetate and methionyl butyrate, which are useful compounds for pineapple and other fruit flavours (Scheme 13.16). 

Instantized milk powder normally exhibits low bulk density but higher water dispersibility than conventionally spray-dried powder. However, the extra heat exposure from the agglomeration and redrying treatments causes additional Maillard reaction, whey protein denaturation, and related chemical and physicochemical reactions that tend to lower product quality. 

Chemically, fructose is very active and it readily takes part in maillard reactions, which may cause browning in some products. It is available in crystalline anhydrous form and also in high-concentration syrups. 

If food is heated over 300°F (154°C), it turns brown. This is why food that is boiled never browns. When food is boiled, its temperature never gets above 212°F (100°C), the boiling point of water. Food fried in oil gets brown, though, because oil boils at a temperature that is higher than 300°F. This browning is called the Maillard reaction and is caused by a chemical reaction that takes place between the amino acids and the sugars present in food when food is heated above this temperature. The Maillard reaction is named after the French chemist Louis Camille Maillard, who discovered it in 1912. 

The first symposium was held in Uddevalla, Sweden in 1979 and was published as Maillard Reactions in Food Chemical, Physiological, and Technological Aspects, Eriksson, C. E. Ed., (Progress in Food and Nutrition Science, Vol. 5, Pergamon Press, Oxford, 1981). The next meeting will be held in 1985, organized by Professor Masao Fujimaki of Tokyo, Japan. 

A historical review withl07 references. Life and work of Louis-Cami1le Maillard (Feb. 4, 1878 -May 12, 1936) are described. The first use of the index term Maillard reaction in Chemical Abstracts was in 1950. German scientists with early interest in this reaction were Lintner (1912) and Ruckdeschel (1914). Several aspects of this reaction are reviewed with emphasis on the work of Japanese scientists. 

Examination of the subject indexes of Chemical Abstracts (CA) restricted to the terms browning and Maillard reaction gave the results shown in Table I. 

Meat aroma is not the result of one chemical constituent but the sum of the sensory effects of many of these volatiles. Over 90% of the volume of volatile constituents from freshly roasted beef is from lipid, but approximately 40 percent of the volatiles from the aqueous fraction are thought to be heterocyclic compounds, many resulting from Maillard reaction products or their interactions with other ingredients. 

Literature information about the sensory properties for nearly 450 Maillard reaction products has been compiled in a survey. It includes qualitative aroma and flavor descriptions as well as sensory threshold values in different media for the compounds, classified according to their chemical structure. 

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