Research On Free Amino Acids Analysis Techniques Of Flue-cured Tobacco And Application

A high performance liquid chromatography method with OPA post column derivation was established for the determination of free amino acids. With this method 37 free amino acids can be separated in a single run with high accuracy and sensitivity and it can be used in many aspects. Eighteen free amino acids were analyzed in flue-cured tobacco with this method. The recoveries were in the range of 85.81-100.86% and the (relative) standard deviation was in the range of 2.06-5.39% which means good repeatability and recoveries. The sample was ground and passed through 60 meshes and ultrasonic extract was performed in 0.1mol/L hydrochloric acid for 30 min. and this is the optimal extract method.Seventy three cutters sample of different growing areas and varieties of Yunnan province collected in 2009 were determined with this method. The study of the difference content of free amino acid in different growing areas and varieties was carried out. There are significant difference in the content of glycin and arginine in Baoshan, Lincang and Wenshan. The content of methionine, cystine and aminoethanol has extreme significant difference and other amino acids showed no significant difference in different growing areas. There are extreme significant difference in the content of glycin, b-propylene and arginine in different varieties such as KRK26, K326 and yunyan87. The content of valine has significant difference and other amino acids showed no significant difference in different varieties.Canonical correlation analysis was performed between free amino acids and routine chemical composition, poly-atomic acids and volatile aroma compounds. The result showed that there are good correlation between free amino acids and these three kinds of compounds.