Study On Processing Technology Of Celery Leaf Tea

In order to make full use of processing waste of celery,improve the comprehensive utilization of celery processing,develop drink with health care function,celery leaves were used as raw material in this experiment,studying systematically on the processing technology of celery leaf tea,the process parameters including withering,stolling,Zuoqing,fixing,rolling and drying were optimized,developing celery leaf semi fermented tea;in addition,extraction and purification of polyphenols,the composition and content of polyphenols and NMR structure characterization of celery leaf and celery leaf tea were studied as well.The results are as follows:(1)Getting optimum parameters of semi fermented celery leaf tea from the study.(26±2)?,withering 25 min under the sun,then switch to stolling processing,stolling 10 min indoors,until the residual heat between the leaves is dissipated,then be in the process of Zuoqing,22~25 ?,70~80 % RH,medium Zuoqing,Yaoqing alternates with Tanqing,the time of Yaoqing is 2,3,8,12 min respectively,the time of Tanqing is 0.5,1,1,2.5 h respectively,after the process of Zuoqing,putting the leaves into the 190 ? pot,roasted 5min,leaves without cooling switch to rolling processing,rolling 4 times,5 min each rolling,after rolling,drying the leaves by hot-air under 55 ? until the moisture content reaches 5~8 %,getting celery leaf tea present dark green and coiled coil.Celery leaf tea according to solid-liquid ratio 1:100(g/m L),95 ? hot water brewing 8 min.Bioactive components such as polyphenols,flavonoids,free amino acids an so on in celery leaf tea are released pretty much,color of tea infusion is yellow-green,with typical celery aroma,taste mellow and the sweet after taste lasts long.(2)The two multinomial regression equation Y=15.43+X1-0.11 X2+0.13 X3+0.21 X1X2+0.11 X1X3-0.1 X2X3-0.62 X12+0.33 X22+0.013 X32 was obtained for the ethanol concentration X1,ultrasonic time X2 and liquid-solid ratio X3 by response surface,the model can be used to analyze and predict the yield of celery leaf tea polyphenols.The optimum extraction conditions was obtained: ethanol concentration is 79.92 %,ultrasonic time is 40.11 min,liquid-solid ratio is 48.89 m L/g,ultrasonic power is 350 W,ultrasonic temperature is 50 ?,yield of celery leaf tea polyphenols reaches 24.08 mg/g.Purification of celery leaf tea polyphenols by HP20 resin,the concentration of the sample is 5.94 mg/m L,loading amount is 400 m L,the flow speed is 1.0 m L/min;with 70 % ethanol as desorption agent,the flow speed is also 1.0 m L/min,after purification,the purity of polyphenols was up to 72.67 %.(3)Analysed by HPLC and NMR,8 kinds of phenolic compounds were detected in celery leaves and celery leaf tea,they are protocatechuic acid,chlorogenic acid,catechin,epicatechin,naringin,rosmarinic acid,hypericin and apiin,in which apiin,protocatechuic acid and Chlorogenic acid have high content among the polyphenols.Celery leaves turn to celery leaf tae by Semi fermentation,the total phenol content of 7 kinds of polyphenols except apiin decreased from 1459.13mg/100 g to 1199.27 mg/100 g,reduced by 21.67 %.