Molecular orbital theory and food colorants

For the melanoidins and caramels, given that these are complex polymeric molecules and their stracture has only been elneidated in a few cases (Amoldi et al., 1997), it is difficult to show possible resonanee stmctures. An examination of the proposed pathways for non-enzymatie browning give intermediates in which resonance straetures are important. This includes keto-enol trans- 

The effect of spectral changes, and evidence of the consequent increase in conjugation and resonance structures during the formation of melanoidins is shown in the data presented by MacDougall and Granor (1998). They showed that as the sugar-amino acid mixtures were heated the maximum absorption peak (Amax) increased from around 200 nm at the start (due to the amino acid), after 

Note All three forms of myoglobin have a high absorbance in the 420-440 nm region (Soret peaks). 

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