Catechins are isolated through an initial hot water extraction with ethyl acetate, and then separation by
chromatography, followed by spray-drying.39 The spray-dried catechins may be recrystallized. Two other processes for the
extraction of catechins from C. sinensis leaves are conducted with or without enzymatic treatment with tannase. The initial
extract is further extracted with water and ethanol, and then filtered through multiple media. The product of the process
without tannase is sterilized above 100°C, whereas the product obtained with the tannase treatment is sterilized below 100°C.