The roasting process Strecker and Maillard Reactions

Thaler and Gaigl (1963) compared the content of amino acids (after hydrolysis) in roasted coffee with their content in green coffee (Thaler and Gaigl, 1962). Serine, cystine and lysine are clearly reduced, 

Tressl et al. (1983) described the formation of aromatic substances in roasted coffee in relation to the levels of free amino acids and reducing sugars. They observed that over 99% of sucrose, glucose and fructose are degraded during roasting. 

According to Macdonald and Macrae (1986), proteins will be denatured upon roasting and further degraded to yield low-molecular-weight fragments. Some of the proteins will react with carbohydrates 

Studies of the behavior of Maillard reaction products analyzed by solid-phase microextraction (SPME) -GC/MS selective detection have been realized by Coleman (1996, 1997). A concerted procedure for the generation, concentration, fractionation, and sensory evaluation of Maillard reaction products has recently been published by Parliment (1999). 

Reviews have been published by Baltes (1980, 1982, 1990), Angrick and Rewicki (1980), Hurrell (1982), Danehy (1983), Ames (1987, 1988) and Reineccius (1995). The chemical pathways of the Maillard reaction have also been reviewed by Ledl (1990). 

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