Determinação de resíduos alergênicos de coadjuvantes enológicos em vinhos

Abstract

During winemaking, technology aids are used as processing aids. These compounds have important oenological properties; however, if derived from allergenic foods, such as milk and eggs, the presence of their residues can represent risks to people who are predisposed to these foods. The use of clarificants such as albumin (protein obtained from egg white) and casein (protein obtained from milk), is performed with the function of coagulating and sedimenting impurities. Another practice used in oenology is the control of malolactic fermentation, through the use of lysozyme (extracted from egg white). Since wine is a complex matrix from an analytical point of view and possible residues of these processing aids may be present in very low concentrations in bottled wine, it is necessary to apply analytical methods that are sensitive to identify and quantify these allergenic compounds. Different analytical methods are proposed in the literature to quantify allergenic residues in wines, based on immunoassay and mass spectrometry techniques, however, many of them are under discussion, as is the case of immunoassays, with regard to analytical repeatability and accuracy. Mass spectrometry methods allows the determination of allergenic proteins in low concentrations in wines, however the preparation of the sample is a challenge due to all the necessary steps for the recovery of the analytes. Therefore, the general objective of this work, presented in the form of scientific articles, was to determine the presence of residues of potentially allergenic processing aids in wines through the development of a method for protein analysis by LCMS/MS, in a single run. Protein residues were not identified in the experimental wines treated with different amounts of albumin, potassium caseinate and lysozyme, as well as in the twelve commercial samples analyzed. These results demonstrate the absence of caseinate, albumin and lysozyme residues in the concentrations tested in wines, if good treatment practices recommended by the OIV and the respective manufacturers of oenological products are followed. A sample preparation procedure with reduced time and steps, less sample volume required and with satisfactory analytical recovery, was validated. The limits of detection and quantification of this method meet the current laws for the four proteins studied, albumin, alpha-casein, beta-casein and lysozyme, even being below the minimum reference criteria of the OIV. The detection limit values were 0.05 mg.L-1, 0.10 mg.L-1, 0.10 mg.L-1 and 0.005 mg.L-1, and for the limit of quantification were 0.10 mg.L-1, 0.25 mg.L-1, 0.25 mg.L-1 and 0.01 mg.L-1, respectively. Regarding the average analytical recovery, the results meet the limits recommended by AOAC (2016), with 96.7%, 101.2%, 100.5% and 96.2% for albumin, alphacasein, beta-casein and lysozyme, respectively. In this work it was developed a method of analysis of albumin, casein and lysozyme simultaneously by LC-MS/MS, which can be used for the purposes of wine inspection and labeling. [resumo fornecido pelo auto]