Measurement of Adjuncts in Hard Ciders Obtainable in the United States Using Carbon Isotopes

The carbon isotope compositions (δ13C values) of 23 hard ciders obtainable in the United States were analyzed to detect adjuncts, specifically added C4 sugars (i.e., corn syrup and cane sugar). In contrast, the main ingredient of hard ciders is fruit, mostly apple, juice which is derived from C3 plants. The labeled ingredients of ciders were found to be inconsistent with the carbon isotope ratios. A higher proportion of imported ciders studied had no isotopic evidence of added C4-based sweetener, while most domestic ciders had elevated δ13C values, indicative of C4-based sugar additives. European ciders could contain beet sugar, a common sweetener used in that region, which would not be detected as an additive because it is a C3-based sweetener. The δ13C values of the ciders were found to have no correlation with the amount of sugar in the cider, as reported on the nutritional information label, likely reflecting varying fermentation times. An increase in the amount of added C4 sugars did not correspond to a decrease in price, in contrast to what is found in beers.本研究对美国市售的23款硬质苹果酒（hard ciders）的碳同位素组成（δ¹³C值）开展分析，以检测其是否添加了辅料，具体为外加的C4类糖（C4 sugars，即玉米糖浆与甘蔗糖）。硬质苹果酒的主要原料为源自C3植物（C3 plants）的水果汁，其中以苹果汁为主。研究发现，此类苹果酒标注的配料信息与其碳同位素比率并不一致。在所分析的样本中，进口苹果酒的占比更高，且未检出添加C4基甜味剂（C4-based sweetener）的同位素证据；而多数国产苹果酒的δ¹³C值偏高，表明其添加了C4基糖辅料。欧洲地区的苹果酒可能含有甜菜糖——该区域常用的甜味剂，由于甜菜糖属于C3基甜味剂（C3-based sweetener），因此无法通过本同位素分析方法被识别为添加物。研究还发现，苹果酒的δ¹³C值与其营养标签上标注的含糖量并无相关性，这一现象或反映了不同样本间发酵时长存在差异。与啤酒领域的相关研究结论相反，本研究中添加的C4类糖含量提升并未对应价格的下降。