Correlations between Amadori compound contents and quality of flue-cured tobacco leaves from different ecoregions

In order to measure the contents(mass fraction)of Amadori compounds in flue-cured tobacco leaves from various ecoregions, 249 tobacco leaf samples from 8 flue-cured tobacco ecoregions with different flavor types were selected and their contents of Amadori compounds in leaves were analyzed. Correlations of the Amadori compounds with chemical quality indexes from different ecological regions were determined. The results showed that: 1) The contents of total Amadori compounds in leaves from different stalk positions in the 8 ecoregions were in the order of upper leaves>middle leaves>lower leaves, all of which were normally distributed, and the content of Fru-Pro was the highest. 2) Most Amadori compounds in the flue-cured tobacco were positively correlated with leaf sensory properties. 3) According to heat map analyses, the 8 ecoregions in the order of the contents of Amadori compounds were Region Ⅷ>Region Ⅵ>Region Ⅴ>Region Ⅰ>Region Ⅱ>Region Ⅲ>Region Ⅳ>Region Ⅶ. The contents of Fru-Pro, Fru-Gln and Fru-His in the leaves from southwest plateau ecoregion-fresh sweet flavor type (RegionⅠ) were higher. Among them, Fru-Pro content significantly negatively correlated with nitrogen/nicotine ratio; the contents of Fru-Phe, Fru-Ser, Fru-Val, Fru-Thr and Fru-Leu extremely significantly negatively correlated and the contents of Fru-Tyr, Fru-Ile and Fru-Aba significantly negatively correlated with potassium/chlorine ratio.