Factors Influencing the Maillard Reaction

Most food science smdents learn about the Maillard reaction in one of their food chemistry coiteses. They typically learn about this reaction in the context of either nutritional losses (e.g., the loss of essential amino acids or loss of digestibility) or color formation. It should be recognized that nutritional loss and color formation are generic in the sense that the heating of foods under nearly any conditions will result in the loss of nutritional quality and in color formation. However, the reactions 

One of the most important parameters influencing flavor formation via the Maillard reaction is processing temperature. This effect is obvious if one considers, for example, the sensory quality of roasted vs. stewed meats. Stewed meat lacks flavor notes characteristic of the roasted product. This is primarily because the stewed product has a water activity of approximately 1.0 and never exceeds a temperature of ca. lOO C. The roasted meat, however, dries on the surface so water activity is substantially less than 1.0. Also, since the surface dries, surface temperature may exceed lOO C. The lower water activity and higher surface tanperatures favor the production of flavor compounds giving the meat roasted notes from the same basic reactants rather than stewed notes. 

FIGURE 5.3 Influence of temperature on rate of formation of various aroma compounds. 

Roasting time (min) Roasting time (min) Roasting time (min) Roasting time (min) 

FIGURE 5.4 The influence of roasting time on the amount of some aroma compounds in coffee beans. (From Yamanishi, T., Flavor Research Recent Advances, R. Teranishi, R.A. Flath, H. Sugisawa, Eds., Marcel Dekker, New York, 1981, p. 231. With permission.) 

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