The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia.
Midwest Grape and Wine Industry Institute, Iowa State University, 536 Farm House Lane, Ames, Iowa 50011-1054, USA.
Food Chem. 2022 Aug 15;385:132658. doi: 10.1016/j.foodchem.2022.132658. Epub 2022 Mar 9.
Protein is reportedly negligible in most red wines, due to its loss following co-precipitation with phenolic substances. A method for protein quantification in red wine was developed which overcame analytical interference from phenolic substances, based on ethanol precipitation, followed by acid-hydrolysis and amino acid quantification. Protein concentration was surveyed in a range of red wines produced from V. vinifera and interspecific (Vitis spp) hybrids, revealing higher than expected concentrations, ranging from 23 mg/L ± 2.57 to 380 mg/L ± 16. The results showed that tannin extracted from grapes remains soluble in wine in the presence of protein even at high protein (>100 mg/L) and tannin (>500 mg/L) concentrations. As a further consequence of this, the particle size and concentration of colloids within high- and low-protein wines were similar, independent of protein or tannin concentration. Higher wine tannin concentration was also correlated with increased heat stability of wine protein.
据报道，由于与酚类物质共沉淀，大多数红葡萄酒中的蛋白质含量可忽略不计。本研究开发了一种基于乙醇沉淀、酸水解和氨基酸定量分析的方法，可克服酚类物质对红葡萄酒中蛋白质定量分析的干扰。本研究调查了一系列由 V. vinifera 和种间杂种（Vitis spp）酿造的红葡萄酒中的蛋白质浓度，结果显示，蛋白质浓度高于预期，范围为 23mg/L ± 2.57 至 380mg/L ± 16。结果表明，即使在高浓度的蛋白质（>100mg/L）和单宁（>500mg/L）条件下，葡萄中单宁提取物仍能与蛋白质一起保持在葡萄酒中溶解。此外，由于这一原因，高、低蛋白葡萄酒中胶体的粒径和浓度相似，与蛋白质或单宁浓度无关。葡萄酒中单宁浓度越高，其蛋白质的热稳定性也越高。
