Proteomics of wine additives: mining for the invisible via combinatorial peptide ligand libraries.
Combinatorial peptide ligand libraries (CPLLs) have been adopted for harvesting and identifying traces of casein (used as a fining agent) present in white wines. Although minute amounts (200 microL) of CPLL beads are added to the entire content of a wine bottle (750 mL), they are able to sequester with high efficiency (up to 80%) residual traces of casein, permitting a signal "amplification" of at least 5000-fold. It is here demonstrated that as little as 1 microg/L of casein can be efficiently detected in white wines, a major improvement over previous investigations in which the lower detection limit had been estimated at 100 microg/L. The fact that such very low levels of fining agents can still be detected in treated white wines should be taken into consideration by winemakers in labelling their products and by EC rulers in issuing proper regulations.
Cereda
Angelo
A
Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy.
Kravchuk
Alexander V
AV
D'Amato
Alfonsina
A
Bachi
Angela
A
Righetti
Pier Giorgio
PG
D000818:Animals; D002364:Caseins / Q000032:analysis*; D002417:Cattle; D005503:Food Additives / Q000032:analysis*; D057230:Limit of Detection; D019151:Peptide Library; D040901:Proteomics / Q000379:methods*; D014920:Wine / Q000032:analysis*
D002364:Caseins; D005503:Food Additives; D019151:Peptide Library