Separation Processes in the Food and Biotechnology Industries: Principles and Applications

From the Editors' Preface

This book concentrates on the more recent methods and techniques for separating food components and products of the biotechnology industry. Each chapter deals with a specific type or area of application and includes information on the basic principles, industrial equipment available, commercial applications, and an overview of current research and development.
Much of the emphasis is on extraction of macromolecules, increasing the added value of foods and recovering valuable components from by-products and fermentation media. Many of the methods discussed are now in commercial practice, while others are being vigorously researched.

Separation and filtration technology is of major importance in food processing and biotechnology. This new book provides a very detailed examination of the most important, advanced separation processes now in use. Each chapter is prepared by a specialist or specialists in the type of separation discussed. Each separation method is related to practical commercial applications.

Each chapter ends with a section of references.
Preface
Separation processes-an overview
Foods-the raw material
Separation techniques: Introduction, Separation from solids, Separations from gases and vapors
Water treatment

Supercritical fluid extraction and its application in the food industry
Introduction
The supercritical fluid state: Physical properties of NCF CO2
Properties of NCF solutions: Solubilities in NCFs, Theoretical models (equations of state (EOS), Diffusion coefficients
Factors determining the efficiency of NCF extraction: Extraction stage, Separation stage
Equipment and experimental techniques used in NCF extraction and fractionation: Extraction, fractionation
Applications: Decaffeination of coffee and tea, Seed oil extraction, Purification of lecithin, Lowering cholesterol levels in foods, Fractionation of high-value oils and fats, Extraction of flavours and fragrances

Pressure-activated membrane processes
Introduction
Terminology
Concentration factor and rejection
Membrane characteristics
Permeate rate
Transport phenomena and concentration polarisation
Membrane equipment: Membrane configuration
Safety and hygiene considerations
Reverse osmosis applications: Introduction, Water treatment, Milk processes, Fruit and vegetable juices, Other applications

Ultrafiltration
Introduction
Processing characteristics: Rejection or retention factors, Yield, Average rejection, Practical rejection data
Performance of ultrafiltration systems: Transport phenomena and concentration polarisation, Fouling, Factors affecting flux
Diafiltration: Washing out at constant volume, Diafiltration applications, Protein fractionation
Ultrafiltration applications: Dairy applications, Oilseed and vegetable proteins, Animal products, Biotechnology applications, Medical applications: serum fractionation

Microfiltration
Introduction
Theory, materials and equipment: Membrane configurations and characteristics, Performance of microfiltration systems and membrane fouling
Applications in the food and biotechnology industries: Food industry, Applications for biotechnology
Conclusions

Ion-exchange and electrodialysis
Ion-exchange: Theory, materials and equipment, Applications of ion-exchange in the food and biotechnology industries
Electrodialysis: Theory and equipment, Applications of ED in the food and biotechnology industries

Innovative separation methods in bioprocessing
Introduction
System characteristics: Physiochemical basis for separation operations, Kinetics and mass transfer
Liquid-liquid extraction: introduction: Aqueous two-phase separation, Reverse micelle extraction, Perfluorocarbon affinity separations, Liquid membrane separations
Solid-based separations: Adsorption systems: expanded bed adsorption, Continuous adsorption recycle extraction, Membrane chromatography, Chromatographic and adsorption materials
Other developments: Electrically enhanced separations, Genetic approaches to protein purification, Purification of intracellular proteins

Fractionation of fat
Introduction: Crystallisation: nuclei formation and crystal growth, Polymorphism, Quality of edible oils
Dry fractionation: Flat-bed vacuum band filter, Rotary drum filters, Membrane filters
Detergent fractionation: The Lipofrac process, Crystallisation
Solvent fractionation

Solids separation processes
Introduction
Physical properties of solids: Classification of powders, Particle size and particle size distribution, Particle density, Forces of adhesion, Bulk properties, Bulk density and porosity, Flowability
Separation of particulates and powders: Size reduction, Sieving
Air classification: Introduction, Commercial air classifiers, Process characterisation, Applications, Cereal separations, Legumes, Other applications
Wet separation processes: Protein recovery, Soya processing, Wheat protein, Other applications
Some miscellaneous solids separations: Dehulling, Peeling, Cleaning of raw materials, Sorting and grading

Index
30 tables, 103 figures

Illustrations and Tables
This new text is well illustrated with schematics, photographs and microphotographs. Tables provide reference data in convenient form. Here is a small sampling of this material.
Figures: Pressure-temperature phase diagram for CO2 showing isochores - Schematic of an NCF CO2 pilot plant - An NCF fractionation column . . . Spiral wound configuration - UF plant: batch operation; continuous, internal recycle or feed and bleed; commercial scale - Schematic of electrodialysis process - Scheme of enzyme purification by liquid-liquid extraction - Lipofrac fractionation process
Tables: Biochemicals extracted from foods and by products - Examples of physical properties of foods, and separation processes to which they relate - Criteria determining implementation of SCF CO2 extraction - Physiochemical basis for the development of separation processes