DESIGN OF GUAR DEHULLING MACHINE FOR GUAR GUM SPLIT PRODUCTION

摘要

The guar seed contains 30-35% galactomannan located in endosperm. The conventional process for gum extraction from seed involves splitting the seed, separation of germ, dehulling, separation of hull, and grinding of the endosperm to different sizes and refining of the gum powder. Guar is subjected to heat (120-140�C) to overcome this difficulty in dehulling in the traditional process. In the present invention, a guar dehulling machine is designed, developed and tested for dehulling guar seed and better recovery of endosperm (refined guar gum splits). The pretreatment process before dehulling the guar seed is based on patent application (Application number: 1283/DEL/2007; Publication date: 03/04/2009) After pretreatment, the seed is immediately fed to the designed dehulling machine where hull of the pretreated guar seed is detached. The hull is removed from the dehulled lot using aspiration system built with the machine. The dehulled and unhulled seeds are separated using conventional grader. Dehulled seeds are dried using hot air to bring moisture content to about 10% (dry basis). Dehulled seeds are then split in to two halves using bun-mill or any other suitable device. Polishing of the splits removes traces of germ from cotyledon. The refined guar gum splits thus obtained are separated from the germs using grader. The neat endosperm (also known as refined guar gum splits), thus obtained free from hull and germ, can be used to make quality guar gum powder whereas the hull free germ can be utilized for suitable value added products.