Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, Franje Kuhača 20, 31000 Osijek, Croatia.
Karlovac University of Applied Sciences, Josip Juraj Strossmayer Square 9, 47000 Karlovac, Croatia.
Molecules. 2020 Apr 9;25(7):1734. doi: 10.3390/molecules25071734.
Carbohydrates are important compounds in natural products where they primarily serve as a source of energy, but they have important secondary roles as precursors of aroma or bioactive compounds. They are present in fresh and dried (cured) tobacco leaves as well. The sugar content of tobacco depends on the tobacco variety, harvesting, and primarily on the curing conditions (temperature, time and moisture). If the process of curing employs high temperatures (flue-curing and sun-curing), final sugar content is high. In contrast, when air curing has a lower temperature, at the end of the process, sugar level is low. Beside simple sugars, other carbohydrates reported in tobacco are oligosaccharides, cellulose, starch, and pectin. Degradation of polysaccharides results in a higher yield of simple sugars, but at the same time reduces sugars oxidization and transfer into carbon dioxide and water. Loss of sugar producers will compensate with added sugars, to cover undesirable aroma properties and achieve a better, pleasant taste during smoking. However, tobacco carbohydrates can be precursors for many harmful compounds, including formaldehyde and 5-hydroxymethylfurfural. Keeping in mind that added sugars in tobacco production are unavoidable, it is important to understand all changes in carbohydrates from harvesting to consuming in order to achieve better product properties and avoid the formation of harmful compounds. This review summarizes current knowledge about tobacco carbohydrates, including changes during processing with special focus on carbohydrates as precursors of harmful compounds during smoking.
碳水化合物是天然产物中的重要化合物，它们主要作为能量来源，但也具有作为香气或生物活性化合物前体的重要次要作用。它们也存在于新鲜和干燥（熏制）的烟叶中。烟草的糖含量取决于烟草品种、收获情况，主要取决于熏制条件（温度、时间和湿度）。如果熏制过程采用高温（烘烤和晾晒），最终的糖含量就会很高。相比之下，如果空气熏制的温度较低，在过程结束时，糖含量就会较低。除了单糖外，烟草中还报告了其他碳水化合物，如低聚糖、纤维素、淀粉和果胶。多糖的降解会导致单糖产量增加，但同时也会降低糖的氧化和转化为二氧化碳和水的程度。糖的产生者的损失将通过添加糖来补偿，以弥补不理想的香气特性，并在吸烟过程中获得更好、更愉快的口感。然而，烟草中的碳水化合物可能是许多有害化合物的前体，包括甲醛和 5-羟甲基糠醛。考虑到烟草生产中添加的糖是不可避免的，了解从收获到消费过程中碳水化合物的所有变化非常重要，以便实现更好的产品特性并避免有害化合物的形成。本综述总结了关于烟草碳水化合物的最新知识，包括加工过程中的变化，特别关注碳水化合物作为吸烟过程中有害化合物前体的作用。
