title: The challenging SO2-mediated chemical build-up of protein aggregates in wines.
abstract: Despite the extensive research performed during the last decades, the multifactorial mechanism responsible for white wine protein haze formation is not fully characterized. A model is proposed, which is essentially based on two postulates: the experimental identification of sulfur dioxide as the non-proteinaceous factor, and the inference from reliable data available in the literature of the dynamic chemistry played by wine protein sulfhydryl groups. Unlike other reducing agents, addition of SO2 to must/wine upon heating cleaves intraprotein disulfide bonds, hinders thiol-disulfide exchange during protein interactions, and leads to formation of novel interprotein disulfide bonds. These bonds are ultimately responsible for wine protein aggregation following a nucleation-growth kinetic model, as shown by Dynamic Light Scattering experiments. The model was tested in wine model solution (using total and fractionated wine proteins) and validated under real wine conditions. The results achieved may open the way to develop techniques that will find wide application in the wine industry.
authors: LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Portugal; LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Portugal. Electronic address: rchagas@isa.ulisboa.pt.
authors: Ricardo
authors: R
authors: Chagas
authors: LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Portugal.
authors: Luísa M
authors: LM
authors: Ferreira
authors: LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Portugal.
authors: César A T
authors: CA
authors: Laia
authors: LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Portugal; CEV, S.A, Zona Industrial de Cantanhede/Biocant Park, Cantanhede, Portugal.
authors: Sara
authors: S
authors: Monteiro
authors: LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Portugal.
authors: Ricardo B
authors: RB
authors: Ferreira
mesh_terms: D004220:Disulfides / Q000737:chemistry; D000067493:Dynamic Light Scattering; D005511:Food Handling / Q000379:methods; D066329:Protein Aggregates; D011506:Proteins / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D004220:Disulfides; D066329:Protein Aggregates; D011506:Proteins; D013438:Sulfhydryl Compounds; D013458:Sulfur Dioxide
keywords: DLS; Protein aggregation; Protein haze; Sodium bisulfite (PubChem CID: 23665763); Sulfur dioxide; Sulfur dioxide (PubChem CID: 1119); TCEP hydrochloride (PubChem CID: 2734570); Wine; Wine proteins; l-(+)-Tartaric acid (PubChem CID: 444305)