Extraction and determination of total tannin from the euryale seed coat

The extracting processing of total tannin from the euryale seed coat was discussed for the comprehensive utilization of euryale seed coat by orthogonal,and content of total tannin from the euryale seed coat was determinated.The results showed that the best technology of extracting tannin from euryale seed coat at the room temperature was as follows:pH6 to the water as solvent extraction agent,soaked overnight after ultrasound-assisted extraction,ultrasonic power 300W,the ratio of material to liquid 1∶50,ultrasonic extraction 20min.The total tannin content was 3.62 percent,and this kind of euryale seed coat have a certain value.