摘要
含硫化合物如谷胱甘肽、硫醇、硫化氢、二氧化硫等都是葡萄酒中重要的风味物质,这4类含硫化合物的含量和形态影响着葡萄酒的风味,且两者都与这4类含硫化合物的来源、检测方法及葡萄酒生产工艺有直接或间接的关系,但针对以上方面的结论仍不统一。基于此,本文整理了这4类含硫化合物在葡萄酒中的含量和存在形态、来源、检测方法、贮藏期间的变化及控制方法这5个方面的研究进展。就含量和存在形态而言,谷胱甘肽主要以还原型谷胱甘肽(GSH)的形式存在,含量不高于70 mg·L^-1;硫醇以游离态存在,或与金属离子结合,硫醇含量与具体种类相关,数量级从ng·L^-1到μg·L^-1不等;硫化氢主要以结合态存在,易与金属离子结合,总含量不高于30μg·L^-1;二氧化硫常以气体形式或亚硫酸氢根形式存在,或与含羰基化合物结合,总含量为64.8-166.5 mg·L^-1。在来源方面,这4类含硫化合物都与发酵期间酿酒酵母的代谢活动有关。谷胱甘肽主要来源于未发酵葡萄汁原料,少部分来源于氨基酸的发酵代谢;硫醇来源于含硫氨基酸、谷胱甘肽的发酵代谢及以硫化氢为底物的化学反应;硫化氢主要源于含硫氨基酸、硫酸盐和亚硫酸盐的发酵代谢;二氧化硫主要来源于外源添加剂,也有少部分源自硫酸盐的发酵代谢。检测这4类含硫化合物时,常采用化学检测方法或光谱法,此类方法检测快速但误差较大;色谱法精确度高,但是样品预处理复杂,仪器昂贵。在贮藏期间葡萄酒中的铁、铜等过渡金属离子和氧气引起的Fenton反应和氧化反应显著影响部分硫醇和硫化氢的含量。最后针对部分含硫化合物带来的异味,可以通过优化原料品质、筛选酿酒酵母菌株、改进二氧化硫添加工艺、添加金属盐等方法降低。在今后的研究中,可从优化检测方法、探究发酵和贮藏陈酿期间含硫化合物变化机理、改进葡萄酒生产环节等方面展开工作。
Sulfur compounds in wines such as glutathione, thiol, hydrogen sulfide and sulfur dioxide are the important flavor compounds, and their content and existing forms greatly affect the wine flavor. The four sulfur compounds are investigated based on the origin and analysis method as well as the winemaking process, while the results on the above aspects are not in agreement in many studies. In this paper, the research progress was summarized about the content, form, origin, analysis method, evolution during storage, and controlling means of the four sulfur compounds in wine. In terms of content and form, the glutathione mainly existed in the reduced form of GSH, and its content was no more than 70 mg·L^-1. Thiol might exist in the free form or combined with metal ions, and its content depended on the specific form ranging from ng·L^-1 to μg·L^-1. Hydrogen sulfide mainly existed in binding state and easily binds to metal ions, and its total content was no more than 30 μg·L^-1. Sulfur dioxide often existed in the form of gas or bisulfite(H2SO3-) or binds to the carbonyl compounds, and its total content ranged from 64.8 mg·L^-1 to 166.5 mg·L^-1. In terms of the origin, these four kinds of sulfur compounds were all related to the microorganisms’ metabolic activities during fermentation. To be specific, the glutathione mainly came from the un-fermented grape juice, and a small part came from the amino acid metabolism. Thiol was mainly from the metabolism of the sulfur amino acid and glutathione as well as the chemical synthesis with the hydrogen sulfide as substrate. Hydrogen sulfide mainly came from the sulfur amino acid metabolism, sulfates and sulfites. Sulfur dioxide came from the exogenous additives and the sulfate metabolism. In terms of analysis method, chemical or spectroscopy method was often used, which could be detected quickly to a certain extent, but causing a large error. Regarding the chromatography technique, it had a higher accuracy, but the sample preparation was complicated and the instrument was expensive. The Fenton reaction, i.e. the oxidation initiated by the oxygen and transition metal ions such as iron and copper ion might significantly affect the contents of thiol and hydrogen sulfide during the storage of wine. Finally, to reduce the unpleasant odor caused by some sulfur compounds, some measures could be conducted including optimizing the quality of grape and must, screening the beneficial yeast strains, improving sulfur dioxide addition process and adding metal salts. In conclusion, future researches could be focused on optimizing the detection method, exploring the changing mechanism of the four kinds of sulfur compounds during fermentation and storage, and improving the wine-making process, so as to provide a reference for the winery.
作者
张清安
陈博宇
ZHANG QingAn;CHEN BoYu(School of Food Engineering and Nutrition Sciences,Shaanxi Normal University,Xi’an 710119)
出处
《中国农业科学》
CAS
CSCD
北大核心
2020年第5期1029-1045,共17页
Scientia Agricultura Sinica
基金
国家自然科学基金(31101324,31972206)
陕西省重点研发计划(2018ZDXM-NY-086)
