Hidden Exogenous Proteins in Wine: Problems, Methods of Detection and Related Legislation – a Review

Fining agents are commonly used in the winemaking process to clarify and stabilise wines. They have different origins (animal, vegetal or mineral) and are added to wines in order to remove specifically undesirable compounds that are discarded. Fining agents should not be present in the final product but their possible persistence, as well as other exogenous residual proteins such as the enzymes utilised in winemaking, cannot be excluded for sure. The principal concern about the presence of exogenous residual proteins is the health of allergic subjects. Nevertheless, the respect of religious creed or other practice of living of the consumer must be considered as well. In the present review we itemise the proteins used in winemaking and possible drawbacks of their permanence in the final products and the related risks, depict the status of the art of the studies performed about the detection of exogenous proteins, and describe the wine labelling laws adopted in different countries to avoid the drawbacks associated with these hidden substances.