Explain the Flavour Binding?

Some protein preparations, although acceptable from a functional and nutritional stand point, necessitate a deodorizing step to remove the bound off-flavors. Various substances, such as aldehydes, ketones, alcohols and oxidized fatty acids may cause beany or rancid odours and bitter or astringent taste. When bound to proteins or to other constituents, these substances are released and become perceptible after cooking and/or mastication.

Some are so strongly bound that even steam or solvent extraction do not remove them. Quite different from the problem of off-flavour removal, it may be useful to use proteins as carriers for desirable flavours. It is of interest to impart a meat flavour to texturized vegetable proteins. Ideally, all of the volatile constituents of desirable flavour must remain bound during storage, possibly also due to processing and then be released quickly and totally in the mouth without distortion. Problems mentioned above can be solved through investigation of the mechanism by which volatile compounds bound to proteins.