Quantitative and structure analysis of pectin in tobacco by 13C CP/MAS NMR spectroscopy

摘要

A new method utilizing 13C CP/MAS NMR spectra was developed for the simultaneous quantitative and structure analysis of pectin in tobacco. The conditions of acid extraction of tobacco samples and the parameters of spectral instruments were optimized. The C-6 carbon regions of NMR spectra were studied in detail, and the chemical shift and the area of peaks were applied for the calculation of polygalacturonic acid (PGA) content, degrees of methylation (DM) and degrees of acetylation (DAc). The quantitative results showed that the average recovery was 92.5% with a RSD of 4.4a€“4.9%. Therefore, this NMR method could provide important information about both the amount and structure of pectins.