Optimization of Preparation Process and Analysis of Functional Components of Compound Instant Tea Powder

In order to widen the utilization value of Dendrobium officinale flowers,the functional compound instant tea powder was developed with D. officinale flowers and green tea as raw materials. On the basis of single factor test and response surface test,the extraction conditions of D. officinale flowers were optimized,and then the mixture of D. officinale flowers extract concentrate and green tea extract were processed into compound instant tea powder. The results showed that the extraction rate of D. officinale flowers was 62.07% under the conditions of solid-liquid ratio at 1:25 (g:mL),ethanol concentration at 68%,ultrasonic temperature at 45℃ and ultrasonic time at 55 min. The compound instant tea powder with pleasant aroma and harmonious taste could be obtained by spray drying of the extracted concentrate and the same weight green tea extract,and its sensory score was 93.And the contents of amino acid,quercetin,taxifolin and kaempferol in the compound instant tea powder were 70.89,9.23,1.27 and 6.22 mg/g,respectively by high performance liquid chromatography(HPLC). Meanwhile,the compound instant tea powder had a certain scavenging effect on DPPH· and O₂^-·,and the inhibitory concentration 50%(IC₅₀)values were 0.0934 and 1.09 mg/mL,respectively. Therefore,the compound instant tea powder had excellent sensory characteristics and antioxidant activity.