Binding of  Pigments, synthetic dye

In  addition  to water, lipids and  volatile  flavours,  food proteins  can  bind  a number of other  substances  by  weak interactions  or  by covalent bonds,  depending  upon  their chemical  structure.

Eg. Pigments, synthetic dyes (which may be used for analytical determination of proteins) and substances with mutagenic, sensitizing biological activity.

Such binding may result both in increased toxicity or detoxification and in some cases; the nutritional values can be adversely affected.