Stability of White Wine Proteins: Combined Effect of pH, Ionic Strength, and Temperature on Their Aggregation
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- 作者：Marie Dufrechou ; C茅line Poncet-Legrand ; Fran莽ois-Xavier Sauvage ; Aude Vernhet
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：February 8, 2012
- 年：2012
- 卷：60
- 期：5
- 页码：1308-1319
- 全文大小：577K
- 年卷期：v.60,no.5(February 8, 2012)
- ISSN：1520-5118
文摘
Protein haze development in white wines is an unacceptable visual defect attributed to slow protein unfolding and aggregation. It is favored by wine exposure to excessive temperatures but can also develop in properly stored wines. In this study, the combined impact of pH (2.5鈥?.0), ionic strength (0.02鈥?.15 M), and temperature (25, 40, and 70 掳C) on wine protein stability was investigated. The results showed three classes of proteins with low conformational stability involved in aggregation at room temperature: 尾-glucanases, chitinases, and some thaumatin-like protein isoforms (22鈥?4 kDa). Unexpectedly, at 25 掳C, maximum instability was observed at the lower pH, far from the protein isoelectric point. Increasing temperatures led to a shift of the maximum haze at higher pH. These different behaviors could be explained by the opposite impact of pH on intramolecular (conformational stability) and intermolecular (colloidal stability) electrostatic interactions. The present results highlight that wine pH and ionic strength play a determinant part in aggregation mechanisms, aggregate characteristics, and final haze.