Erimental Research Of High Voltage Pulsed Electric Field On Promoting Incense Effect To The Pu’er Ripe Tea

As one of the specialty tea produced in Yunnan, Pu’er Tea gets more and more attention and recognition for its special and unique flavorquality, and therefore the requirements for tea quality is increasingly high, while the aroma of tea is the principal element which influence the quality. As the progress of the analytical instrument and technique, in recent years, it has got great development in the area of aroma extraction and analytical investigation. The investigation results play an important role in raising the aroma quality, exploring the element of aroma and improving the tea processing. Non-thermal food processing of High Intensity Pulsed Electric Field (HPEF), has become one of the popular research topic in the food industry, for it has many impressive qualities like:short processing time, small temperature rise and low energy cost etc.. This paper aims at studying on the effect of HPEF to the aroma composition of Pu’er ripe tea, mainly from the following aspects:Primarily, selected the five-star Pu’er ripe tea (2005vintage) of Fuyuanchang, which was produced in Lincang of Yunnan Province, as the experimental subject. Select the HPEF of different voltage (12kV/18kV/26kV), frequency (120Hz/150Hz/180Hz) and time (30min/45min/60min) to process the ripe tea by orthogonal test, maked3factors and3levels orthogonal test table and test the aroma by using the electronic nose system, extract the original data of aroma composition from the mass data collected by the transducer, the result proves that the content of aroma composition changed prominently after HPEF processing. The3kind of aroma component which include alcohol, organic sulfide and Short-chain alkane increased significantly. In the condition of18kV/180Hz/30min,3kinds of aroma composition increase the most, and the average increase is12.5%; and under the condition of12kV/150Hz/45min, the increase comes second, the average is11.1%.Secondly, Conducted Principal component analysis(PCA), Linear Discriminant Analysis(LDA) and Loadings Analysis(Loading) by using system-provided Winmuster combining response curve peak comparison of the transducer. analysis the result got from the experiment processing by using the orthogonal test. Then got the Optimization conditions of HPEF18kV/120Hz/60min,12kV/120Hz/60min and18kV/120Hz/30min respectively within the scope of the experiment which has the promotion effect on the alcohol, organic sulfide and Short-chain alkane, Optimization conditions of HPEF which has the promotion effect on the3kinds aroma composition is18kV/120Hz/60min, the electric field voltage is the essential determinant which effect the variation of aroma composition among them.