Abstract
Polyphenols are chemicals found in tobacco that are affected by the method used to cure the leaf and, as a result, can be useful in the characterization of tobacco products. The purpose of this work was to develop an analytical method to investigate the levels of six polyphenols found in tobacco leaves and tobacco products: 3-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid (cryptochlorogenic acid), 5-O-caffeoylquinic acid (neochlorogenic acid), kaempferol 3-O-rutinoside (nicotiflorin), quercetin 3-O-rutinoside (rutin), and 6-methoxy-7-hydroxycoumarin (scopoletin). Extraction conditions for sample preparation using PLE and instrument conditions for analysis by UPLC-MS/MS were optimized and validated. Results from the analysis of 30 cured tobacco leaves are presented and discussed in the context of each curing method represented. Results from the analysis of various tobacco products are also presented and trends observed across product types are discussed in the context of the applicability of the validated method. Total polyphenol levels for flue-cured, Oriental, and air-cured leaves were determined to be in the ranges of 18–41 mg/g, 5–27 mg/g, and 0.5–3 mg/g respectively. Similarly, cigarette polyphenol levels were found in the range of 4–16 mg/g and cigar polyphenol levels were less than 1.5 mg/g. The trends observed in the results for the tobacco leaf samples are consistent with expectations regarding the fate of polyphenols under the conditions commonly used in curing procedures. The results for the tobacco products demonstrate that the validated method can be used to study polyphenol content in cigarettes and a variety of cigar types including pipe tobacco cigars.