Abstract: Using camellia seed cake as raw material,the effect of solid to liquid ratio,extraction time,ultrasonic time and volume fraction of ethanol on the yield of tea saponin was studied by using ultrasonic assisted ethanol extraction method.The optimal extraction was carried out using the response surface optimization experiment.The optimal conditions were as follows∶solid to liquid ratio was 1∶7 (m/V),extraction time 93 min,ultrasonic time 36 min,volume fraction of ethanol 55%,and the yield of tea saponin was 14.708% under these conditions.According to this optimization scheme,the testing results showed that the model had high reliability and can predict the actual situation.Meanwhile,the results of bacteriostatic effect showed that tea saponin had better bacteriostasis effect on Staphylococcus aureus,but had no bacteriostasis effect on Escherichia coli.

Key words: tea saponin, ultrasonic assisted ethanol extraction method, response surface optimization experiment, bacteriostatic effect