Abstract: A material consisting mainly of protein and water is supplied into an extruder through a supply port, mixed by screws and extruded from an extrusion port. The extrusion port is provided with a die including a plate having a plurality of holes. A mixture extruded from the extrusion port is provided with a fibrous orientation. The die has a cooling mechanism for cooling the mixture extruded from the extruder. The obtained protein material is heated and compression-molded by a pressing machine, and a protein food having a meat-like texture and mouth feeling is produced. Thus, a high-protein, low-calorie protein food having a meat-like complex texture and mouth feeling can be produced by a simple process.

Abstract: Transesterification involving a fat, or a fat and fatty acid, or a phospholipid is carried out with a lipase or phospholipase immobilized on a polymer carrier. The transesterification is preferably carried out in a system containing a very small amount of water such as 50 to 2,000 ppm. The phospholipase can be phospholipase A.sub.2. In a first embodiment, lipase from a microorganism of the genus Rhizopus, Mucor, Alcaligenes or Candida is immobilized on the surface of a hydrophobic, insoluble organic polymer carrier having pores of an average diameter of 10 nm or larger and having on the surface epoxy groups capable of covalently binding lipase. The immobilized lipase is dried under reduced pressure. In a second embodiment, lipase is immobilized on the surface of a polymer carrier such as a hydrophobic, insoluble organic polymer carrier having a pore diameter of 5 to 1,000 nm and having on the surface a functional group capable of binding lipase and an anion-exchange group.

Abstract: A material consisting mainly of protein and water is supplied into an extruder through a supply port, mixed by screws and extruded from an extrusion port. The extrusion port is provided with a die including a plate having a plurality of holes. A mixture extruded from the extrusion port is provided with a fibrous orientation. The die has a cooling mechanism for cooling the mixture extruded from the extruder. The obtained protein material is heated and compression-molded by a pressing machine, and a protein food having a meat-like texture and mouth feeling is produced. Thus, a high-protein, low-calorie protein food having a meat-like complex texture and mouth feeling can be produced by a simple process.

Abstract: An immobilized lipase is prepared for transesterification of oils, fats or phospholipids in a reaction system containing a very small amount of water such as 50 to 2,000 ppm. The lipase may be a phospholipase such as phospholipase A.sub.2. In a first embodiment, lipase from a microorganism of the genus Rhizopus, Mucor, Alcaligenes or Candida is immobilized on the surface of a hydrophobic, insoluble organic polymer carrier having pores of an average diameter of 10 nm or larger. A solution of lipase is contacted with the polymer carrier for 10 minutes to 40 hours to covalently bond the lipase to the carrier. The immobilized lipase is dried under reduced pressure to a water content of 0.5 to 30 wt %. In a second embodiment, lipase is immobilized on the surface of a polymer carrier such as a hydrophobic, insoluble organic polymer carrier having a pore diameter of 5 to 1,000 nm and having a functional group capable of binding lipase in a aqueous solution and an anion-exchange group on the surface.