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.