Maskan M., Altan A. (eds.) Advances in Food Extrusion Technology

CRC Press, Taylor & Francis Group, 2012. — 398 p.This book was written principally as a reference for graduate and undergraduate students, researchers, and extruded product manufacturers, with special emphasis on some recent extrusion works. However, food technologists, and scientists and technicians in the extrusion processing industry may also find the contents useful. This book will serve as a source of information to all involved with food and feed extrusion. For a person who is new in this area, this book will serve as a guide for understanding and properly selecting the raw material and an extruder.
Chapter 1 introduces the extrusion technology; its history, nomenclature, and working principles; and overview of various types of extruders, and parts and components of an extruder for design considerations. Chapter 2 discusses extruder selection and design, fluid flow problem with different types of raw materials, and heat transfer and viscous energy dissipation, with advantages and limitations for particular cases. Chapter 3 addresses the raw materials used in extrusion cooking with respect to chemical composition and particle size. It discusses the raw materials with specific reference to the products. Also, it discusses preparation or preconditioning of raw material for extrusion. Among these are grinding and particle size selection and moisture equilibration of raw material. Several review articles have addressed chemical and nutritional changes in extruded foods. Chapter 4 emphasizes recent research while providing an overview of trends previously reported in the literature. Chapter 5 focuses on a methodology to take a successful product (solution cast whey protein films) and create a similar extruded product. In particular, in-line viscosity measurements and extrudate rheological properties were examined to evaluate the similarities and differences between the extruded films and their solution-cast counterparts. The next four chapters present the extensive literature that currently exists on feed but mainly on food extrusion, with special emphasis on developments over the past decade. Examples are given for a number of important works such as utilization of food industry by-products for the development of extrudates, production of breakfast cereals, snack products, confectionary products, extrusion of pulses and feeds, and extrusion processing of pet foods and aquatic feed blends containing DDGS.
Chapter 10 covers the coinjection of food substances into an extruder die with the objective of creating defined colored patterns, adding internal flavors, and achieving other food injection applications into cereal-based extruded products. This chapter also deals with development of half-products or third-generation snacks (pellets). Focus is given to processes for producing corn masa– and potato-based pellets and to the identification of critical process parameters for providing precise control in hydration, as well as gelatinization levels, and overcoming variations in the characteristics of starting raw materials. Chapter 11 covers thermal and nonthermal extrusion of protein products and nonthermally extruded whey protein products.
Chapter 12 focuses on the experimental methods that are commonly used to determine extrudates’ quality parameters and the most important quality properties of an extrudate. It is the objective of Chapter 13 to show the potentialities of process modeling based on continuum mechanics in the field of twin-screw extrusion for food applications through a common approach that was developed for several years. In this chapter, two main aspects are considered in twin-screw extrusion modeling. The whole process, from feeding of the raw materials in the hopper to the exit of the transformed product at the die, or just a focus on a limited portion of the extruder, is considered. Troubleshooting is the identification or diagnosis of “trouble” in an extrusion system caused by a mechanical failure or misapplication of extrusion processing parameters. Therefore, a chapter on troubleshooting the extrusion process completes the book.