Rapid purification of catechins using soybean protein

For the rapid purification of catechins from tea leaves, soybean protein wa s applied. Amongst catechins [(-)-epigallocatechin (EGC), (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin 3 -O-gallate (EGCG), (-)-epicat echin 3-O-gallate (ECG)] in a tea leaf extract, the catechin gallates (EGCG and ECG) were specifically extracted by complex formation with soybean pro tein. The procedure is as follows : 1) Soybean protein was prepared from au toclaved de-fatted soybean. 2) The protein extract was mixed with a water e xtract of tea leaf and the pH of the mixture was adjusted to 4.5. 3) Catech in-protein complex, precipitated in the mixture, was filtrated and dried. 4 ) Catechins were extracted with acetone-water (I : 1) from the catechin-pro tein complex. The complex of the catechin and soybean-protein would be a ne w food and/or pharmaceutical product, which is attractive by its bio-activi ties originated from both catechins and soy protein.