Carbohydrates—Key Players in Tobacco Aroma Formation and Quality Determination

Abstract

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.

The ultra-structural, metabolomic and metagenomic characterisation of the sudanese smokeless tobacco ‘Toombak’

“…Hexose may also contribute to the taste of Toombak. Low sugar content may however, allow bacterial growth and prevent acid metabolites from occurring, thus keeping Toombak at alkaline pH [ 80 , 81 ]. At least, in part, the low sugar content of Toombak should not contribute to the risk of caries development from extrinsic sugars, amongst Toombak users.…”

Molecular composition of soil organic matter (SOM) regulate qualities of tobacco leaves

“…The carbohydrate content, such as sugar and starch is also crucial in evaluating the quality of tobacco and research found that consumers preferred high-level sugar tobaccos 37 mainly because the sugar can improve the taste of tobacco 38 . The sugar and starch contents in JS, QX and WN2 were higher than the standard and led to their low quality (Fig.…”

Impact of nicotine pathway downregulation on polyamine biosynthesis and leaf ripening in tobacco

“…The glucose concentrations in the PMT‐RNAi leaves increased more rapidly and to higher values than in the WT so that the PMT‐RNAi plants contain nearly three times as much glucose compared to the WT at harvest. Burley tobacco is characterized by low sugar concentrations in the leaves (Banožić et al., 2020) so an increase in glucose presents a potentially negative influence on the tobacco quality. It is known that while higher sugar concentration often increases the quality of a tobacco, there needs to be a balance among sugars, waxes, and resins (Mendell et al., 1984).…”