The Research Of Promoting The Pu’er Raw Tea Alcohols Aroma With High-voltage Pulsed Electric Field

The Pu’er tea is very popular at home and abroad because of its special role in human health and its aging storage character. The quality of Pu’er tea has become a key factor of consumption indicators and price. The Pu’er tea aroma is an important factor determining the original tea’s quality, and alcohols aroma is its characteristic aroma. High Voltage Pulsed Electric Field (HPEF) is a hot spot research in non thermal processing technology, in which not only can sterilize medium and keep food fresh but also can improve the quality of food. In this paper, biological effect of HPEF was studied in Pu’er raw tea alcohol aroma as following:First of all, the arbor tree’s tea produced in2012had been selected as No.1test samples and the arbor tree’s tea produced in2011had been selected as No.2test samples, which were representative tea in the major tea producing area of Yunnan province. According to the principle of orthogonal test, the experimental conditions including voltage of12kV/18kV/26kV, frequency of120Hz/150Hz/180Hz, and time of30min/45min/60min, the three factors and three levels orthogonal test table had been produced. Then we conducted a series of experiments with No.1and No.2test samples in HPEF, tested the samples by using electronic nose and received original data from ten sensors of the electronic nose. The result showed that the alcohols aroma content of No.1tea had increased by21.8%under the condition of18kV/120Hz/45min, and the alcohols aroma content of No.2tea has increased by20.7%under the condition of26kV/120Hz/60min.Secondly, the alcohols aroma data was analyzed in principal component analysis (PCA), linear discriminant analysis (LDA) and the difference between the contribution rate of sensor analysis (Loadings) by Winmuster software. Having extracted the G/GO data of the number eight sensor conductivity ratio in50seconds, a analysis of orthogonal test table had been made. According to the results, we found out that No.1tea alcohol aroma could be improved under12kV/120Hz/30min conditions in HPEF, and compared with voltage, time is the main factor. On the other hand, No.2tea alcohol aroma could be improved under26kV/120Hz/60min conditions in HPEF, and compared with time, frequency is the dominant factor.