This book presents the theory behind extrusion technology, as used for food and feed products, in a way which can be readily applied in practice. It provides good fundamental understanding, but presented in the context of practical application, so that readers can understand how it applies in a real manufacturing situation. This book is relevant to all types of extruded human foods and animal feeds, and all types of equipment used to produce them: single- and twin-screw extruders, and specialised snack food machines. It considers how the equipment and processes operate, and how the process conditions interact with the ingredients used. Understanding the theory behind the process - and how it applies in practice - means that formulations and processes can be designed to be more robust, appropriate equipment can be selected for the required duty, and effective operating procedures and guidelines can be developed - leading to reliable processes and consistent product. The authors bring decades of industry and research experience to this book. This Second Edition includes a new chapter on the development of optimal screw profiles, as well as other additional material and updates to the text and format.