Analysis of Aroma Components of Raw Pu'er Tea in Lincang City Based on Multivariate Statistical Analysis

In order to accurately evaluate the aroma quality of raw Pu'er tea in Lincang City, the aroma components of 16 raw Pu'er teas were systematically analyzed and comprehensively evaluated by multivariate statistical analysis. A total of 48 aroma components were detected, with 11 aroma components were more than 2.00% content. Among them, linalool was the most abundant component and the content was 24.68%. For the aroma types, the alcohols were accounted for the largest proportion with a mean of 46.55%, followed by aldehydes with a mean of 26.81%, while ketones, esters and other components were responsible for little proportion. Multivariate statistical analysis showed that the raw Pu'er teas obtained form in southern region were clearly distinguished from those in northern region. The concentration of alcohols and esters was significantly higher in southern region than those in northern region, whereas aldehyde, ketones and other components were remarkably lower. Altitude may be an important reason for the difference of aroma components of Pu'er raw tea in the south and north regions. Furthermore, 23 aroma components were identified based on variable importance in projection (VIP) score>1, which might be responsible for the discrimination of raw Pu'er teas in southern and northern region. Linalool, isoflolone, ketones, alcohols, aldehydes, β-cyclocitral, α-cyclocitral, 2,2,6-trimethyl-cyclohexanone, nerol and β-ionone play siginificant role in the differentiation of raw Pu'er tea harvested from different regions. This study would provide some theoretical basis for accurately understanding the aroma quality of Lincang Pu'er raw tea, and also provide ideas and methods for the study on the quality evaluation and origin determination of Lincang Pu'er raw tea.