Development of ELISA methods to detect the presence of milk and egg proteins in wine after fining

摘要

The clarification or fining of wine removes undesirable substances such as proteins and phenolic and tannin compounds that would cloud the wine and cause bitterness and astringency. Caseinates and ovalbumin have very useful fining properties, but their residues could represent a risk for allergic subjects.rnThe methods developed are based on ELISA technique and have been applied expressly to wine matrix; they show sensitivity suitable to detect caseinates and ovalbumin in concentrations highly below 1 ppm.rnThe principle of the caseinate assay (here described in detail) is roughly as follows: the Casein Assay is a sandwich ELISA; the microplate is precoated with a specific anti-Casein antibody where wine samples are loaded; after the incubation period, the addition of an anti-casein antibody conjugated with Horse Radish Peroxidase (HRP) allows the sandwich reaction.rnAntibodies used in the assays are characterized for their immunoreactivity and for the reproducibility of antigen recognition. Any measure by ELISA test is confirmed for specificity using SDS-PAGE and/or immunoblotting.