Low shear extrusion process for manufacture of quick cooking rice

Claim 1

A low shear process for the production of quick cooking rice products comprising the steps of: preparing a mixture comprising from about 60 to 80% by weight of rice material selected from the group consisting of rice flour and rice granules and mixtures thereof and from about 20 to 40% by weight of water in a preconditioner by mixing said quantity of rice material with said water and elevating the temperature of the mixture to a level of from about 150° F. to 210° F. and retaining said mixture in said preconditioner for a period of time of about 20 seconds to about 3 minutes, thereby partially cooking the mixture in the preconditioner; introducing said partially cooked mixture into the barrel of an extruder separate from said preconditioner, said barrel having therewithin a flighted, rotatable screw and an endmost extrusion die; rotating said screw to sequentially advance said partially cooked mixture along said barrel first through a cooking zone, then through a venting zone and a forming zone, and finally through said extrusion die, to yield an extruded product, said partially cooked mixture having a temperature of from about 180° F. to about 300° F. and is retained therein for a period of from about 10 to 25 seconds in said cooking zone, the maximum temperature of the mixture in said cooking zone being the highest temperature the mixture will experience in the extruder, said mixture having a temperature of from about 130° F. to about 250° F. and being retained from about 20 to about 60 seconds and being subjected to pressures in the range of from about 200 to 1200 psig in said forming zone; venting gaseous products from said mixture in said venting zone; and drying said extruded product at a temperature and for a period of time sufficient to yield said quick cooking rice products.