Studies on Stem Bromelain and Stem Starch from Pineapple Plants

The authors have made an attempt to develop a practical method for the separation of bromelain and starch from pineapple stems. The bromelain was obtained either by the acetone method or by the tannic acid method. Results showed that most bromelain was precipitated in the 40-50% acetone concentration, also that most bromelain was precipitated when 2-4g of tannic acid were added per liter, under these condition the highest specific enzyme activity was obtained.The biochemical properties of crude enzyme were; optimal temperature 57℃; optimal pH 7.0; while Zn++ inactivated and Mg++ activated it to the highest degree.Crude bromelain was made to separate the components by means of dise-alectrophoresis. Six bands can be recognized in the zymo-graphs, whether the bromelain was obtained by the acetone method or tannic acid method.The pineapple stem starches are spherical granules of about 11μ in diameter. Although the granules are easily broken, a typical granule has a Y-shaped fissure in its central area. Using chloral hydrate technique to prepare amylase and amylopectin and direct scale readings of a mixture of amylase and amylopectin, the results indicated that the amylase content of pineapple stem starch is 36%.