Improvement of the Traditional Sago Starch Processing in the Philippines Through Mechanization

Abstract

 Sago (Metroxylon sagu Rottb.) is widely grown in the Philippines in waterlogged areas or near creeks and water embankments. The utility of the crop varies. Leaves are formed into shingles and used as roofing materials; leaf stalks are dried and used as firewood or fence material; the bark is dried for fuel wood; and the pith is extracted with the starch, roasted, and sold in the market in a dried and crumbly form that can be processed further into various foods. The traditional method of starch extraction requires at least 22 steps beginning with the harvest of the logs. It involves knife-stripping, drying and series of hand pounding and subsequent screening to reduce the size prior to sedimentation. The whole process is tedious and timeconsuming. Processing one whole sago log is estimated to require 10-12 man days and 5 to 6 days to completely extract the starch. The entire process was studied, and a sago-pith grating machine was developed.
 The developed grating machine eliminates the bottlenecks of the traditional starch extraction process, namely; knife-stripping, sun-drying of the stripped pith and repeated hand pounding and subsequent screening of the powdered pith. The number of steps in the traditional starch extraction process was reduced by as much as 50%. Splitting the sago logs into quarters is required prior to sago-pith grating. About 60-65 seconds is required to split a 32-cm diameter x 50-cm length sago log into four pieces. Only one person is needed to operate the machine with a grating capacity of 155 - 180 kg/hr depending on the skill of the operator. The parts of the machine utilized local and commercially available materials for easy repair and maintenance.