Bromelain is a sulfhydryl protease extracted from pineapple juice and peel. Light yellow amorphous powder, slightly peculiar odor. The molecular weight is 33000. The optimum pH values for casein, hemoglobin and baee were 6-8 and 5.0 for gelatin. It is slightly soluble in water, but insoluble in ethanol, acetone, chloroform and ether.