The Technology of Extrusion Cooking

1 Operational characteristics of the co-rotating twin-screw extruder.- 1.1 Types of extruders.- 1.1.1 Single screw.- 1.1.2 Co-kneaders.- 1.1.3 Counter rotating.- 1.1.4 Co-rotating.- 1.2 Process characteristics of the t.s.e..- 1.2.1 Feeding.- 1.2.2 Screw design.- 1.2.3 Screw speed.- 1.2.4 Screw configurations.- 1.2.5 Die design.- 1.2.6 Barrel temperature and heat transfer.- 1.2.7 Scale-up.- 1.2.8 Process flow charts.- 1.3 Ancillary processes.- 1.3.1 Preconditioning.- 1.3.2 Devolatilisation.- 1.4 Raw materials.- 1.5 Practical operation of the t.s.e.-start up, shut down and control.- 1.6 Glossary.- References.- 2 Raw materials for extrusion cooking processes.- 2.1 Introduction.- 2.2 Structure-forming raw materials.- 2.2.1 Structure-forming raw materials based on starch.- 2.2.2 Protein-rich raw materials.- 2.3 Raw materials acting as fillers in the extrudates.- 2.3.1 Proteins.- 2.3.2 Starches.- 2.3.3 Fibrous materials.- 2.4 Raw materials as plasticisers and lubricants.- 2.4.1 Water.- 2.4.2 Oils and fats.- 2.4.3 Emulsifiers.- 2.5 Raw materials acting as nucleants for gas bubble formation.- 2.6 Raw materials acting as flavours.- 2.6.1 Salt.- 2.6.2 Sugar.- References.- 3 Breakfast and cereal extrusion technology.- 3.1 Introduction.- 3.2 What is a breakfast cereal?.- 3.3 A closer look at the products.- 3.4 Breakfast cereal processes.- 3.5 Principles of cooking.- 3.6 Overview of cooking processes.- 3.6.1 Boiling water cookers.- 3.6.2 Steam cookers.- 3.6.3 Adiabatic extrusion.- 3.6.4 High shear cooking extrusion.- 3.6.5 Low shear, high pressure cookers.- 3.6.6 Low shear, low pressure cookers.- 3.6.7 Continuous steam pre-cooking.- 3.7 Breakfast cereal processes: traditional and extrusion methods.- 3.7.1 Flaked cereals.- 3.7.2 Extrusion puffed breakfast cereals.- 3.7.3 Oven puffed cereals.- 3.7.4 Gun puffed cereals.- 3.7.5 Shredded products.- 3.7.6 Pre-cooked hot cereals.- 3.8 Conclusion.- References.- 4 Snack food extrusion.- 4.1 Introduction.- 4.2 Ingredients.- 4.2.1 Cereals.- 4.2.2 Root crops.- 4.2.3 Process aids.- 4.3 Equipment review.- 4.3.1 Mixing equipment.- 4.3.2 Feeders.- 4.3.3 Conditioning cylinders.- 4.3.4 Extruders.- 4.3.5 Dryers.- 4.3.6 Fryers.- 4.3.7 Coaters.- 4.4 Direct expanded products.- 4.4.1 Process description.- 4.4.2 Fried collets.- 4.4.3 Baked collets.- 4.5 Co-extruded snacks.- 4.5.1 Process description.- 4.5.2 Formulation.- 4.5.3 Miscellaneous.- 4.6 Indirect expanded products.- 4.6.1 Pellets.- 4.6.2 Fabricated chips.- 4.7 Die and cutter design.- 4.7.1 Die plates.- 4.7.2 Die holes.- 4.7.3 Effect of expansion forces.- 4.7.4 Effect of viscoelastic forces.- References.- 5 Petfood and fishfood extrusion.- 5.1 Introduction.- 5.2 Raw material characteristics and selection.- 5.2.1 Protein sources.- 5.2.2 Starch sources.- 5.2.3 Fat, fibre and ash consideration.- 5.2.4 Minor ingredients.- 5.2.5 Typical formulations.- 5.2.6 Raw material preparation.- 5.3 Selection of hardware.- 5.3.1 Feeding devices.- 5.3.2 Preconditioning considerations.- 5.3.3 Extruder barrel selection.- 5.3.4 Die/knife design.- 5.3.5 Ancillary process equipment.- 5.4 Processing variables.- 5.4.1 Preconditioning.- 5.4.2 Extrusion.- 5.4.3 Process control.- 5.5 Final product specifications.- 5.5.1 Quality control.- 5.5.2 Troubleshooting techniques.- 5.6 Evaluation of operational costs.- 5.7 Conclusion.- References.- 6 Confectionery extrusion.- 6.1 Introduction.- 6.2 Processing.- 6.2.1 Pre-extrusion processes.- 6.2.2 Cooker extruder profiling.- 6.2.3 Addition and subtraction of materials.- 6.2.4 Shaping and forming at the die.- 6.2.5 Post-extrusion processes.- 6.3 Flavours and other special ingredients for confectionery extrusion.- 6.4 Liquorice.- 6.5 Toffees, caramels and fudges.- 6.6 Boiled sweets.- 6.7 Sugar crust liqueurs.- 6.8 Pressed tablets.- 6.9 Creams, pastes and lozenges.- 6.10 Gums.- 6.11 Jellies.- 6.12 Cocoa and crumb.- 6.13 Chocolate.- 6.14 Reaction chamber products.- 6.15 Aerated confections.- 6.16 Chewing gum.- 6.17 Frozen confectionery.- 6.18...