Martinelli Luiz A, Moreira Marcelo Z, Ometto Jean P H B, Alcarde André R, Rizzon Luiz A, Stange Erik, Ehleringer James R
Cena, Av. Centenário 303, 13416-000 Piracicaba, SP, Brazil.
J Agric Food Chem. 2003 Apr 23;51(9):2625-31. doi: 10.1021/jf026088c.
Sparkling wines have become a popular beverage in recent years, and the production of these wines is subject to adulteration during fermentation. This study investigated the stable carbon isotopic composition (expressed as delta(13)C) of the wine and of the CO(2) bubbles produced during the second fermentation for a number of sparkling wines produced in different countries around the world. Carbon isotope ratio analyses were used to estimate the addition of sugar obtained from C(4) plants (sugar cane or corn). The average delta(13)C values of the Brazilian brut, demi-sec, and doux sparkling wines were -20.5 +/- 1.2 per thousand (n = 18), -18.1 +/- 1.3 per thousand (n = 9), and -15.8 per thousand (n = 1), respectively. These values were statistically heavier (more positive carbon isotope ratio values) than the average delta(13)C of sparkling wines produced in other parts of South America (Argentina and Chile, -26.1 +/- 1.6 per thousand, n = 5) and Europe (France, Germany, Italy, Portugal, and Spain, -25.5 +/- 1.2 per thousand, n = 12), but not statistically different from sparkling wines produced in the United States or Australia. The most likely explanation for differences in the carbon isotope ratios of wines from these different regions is the addition of C(4) sugar during the production of some sparkling wines from Australia, Brazil, and the United States. The isotopic composition of the CO(2) bubbles (delta(13)C-CO(2)) followed similar trends. The average delta(13)C-CO(2) of most of the Brazilian and Argentine sparkling wines was -10.8 +/- 1.2 per thousand (n = 23), indicating that the likely source of carbon for the second fermentation was sugar cane. Conversely, the average delta(13)C-CO(2) of most of the sparkling wines produced in Chile and Europe was -22.0 +/- 1.2 per thousand (n = 13), suggesting that a different sugar (most likely sugar beet) was most used in the second fermentation. It was concluded that in many cases, the carbon isotope ratios of sparkling wine and CO(2) bubbles can provide valuable information about the sugar sources.
起泡酒近年来已成为一种受欢迎的饮品，并且这些葡萄酒在发酵过程中容易受到掺假影响。本研究调查了世界上不同国家生产的多种起泡酒在二次发酵过程中葡萄酒及其产生的二氧化碳气泡的稳定碳同位素组成（以δ¹³C表示）。碳同位素比率分析用于估计从C₄植物（甘蔗或玉米）中获得的糖的添加情况。巴西的天然型、半干型和甜型起泡酒的平均δ¹³C值分别为-20.5±1.2‰（n = 18）、-18.1±1.3‰（n = 9）和-15.8‰（n = 1）。这些值在统计学上比南美洲其他地区（阿根廷和智利，-26.1±1.6‰，n = 5）和欧洲（法国、德国、意大利、葡萄牙和西班牙，-25.5±1.2‰，n = 12）生产的起泡酒的平均δ¹³C值更重（碳同位素比率值更正），但与美国或澳大利亚生产的起泡酒在统计学上没有差异。这些不同地区葡萄酒碳同位素比率差异的最可能解释是，澳大利亚、巴西和美国的一些起泡酒在生产过程中添加了C₄糖。二氧化碳气泡的同位素组成（δ¹³C-CO₂）遵循类似趋势。大多数巴西和阿根廷起泡酒的平均δ¹³C-CO₂为-10.8±1.2‰（n = 23），表明二次发酵的碳的可能来源是甘蔗。相反，智利和欧洲生产的大多数起泡酒的平均δ¹³C-CO₂为-22.0±1.2‰（n = 13），这表明二次发酵中最常使用的是另一种糖（很可能是甜菜糖）。得出的结论是，在许多情况下，起泡酒和二氧化碳气泡的碳同位素比率可以提供有关糖源 的有价值信息。
