ABSTRACT
Separation of one or more components from a complex mixture is a requirement for many operations and extensively used in various applications in the food and biotechnology industries. Application of separation technologies is used either to recover high-value components from agricultural commodities, being an important operation for the production of food products such as oil and proteins, or especially for the development of healthpromoting food ingredients and high value-added food products such as antioxidants and avors. Separation processes are also used to remove contaminants, impurities, or toxins such as pesticide residue from food materials. Separation, often known as “downstream processing,” is totally devoted to the science and engineering principles of unit operation of separation and purication. Over the last 20 years, separation technologies in the food processing area have undergone an explosive growth. The competitive nature of the biotechnologies applied to the pharmaceutical and food industries for cost-effective manufacturing has provided much impetus for the development and use of new separation techniques on a large scale, but at a lower cost. Aside from the conventional separation techniques such as solvent and water extraction (solid-liquid contacting extraction or leaching),
CONTENTS
5.1 Introduction ................................................................................................ 159 5.2 Model Development .................................................................................. 162 5.3 Estimation Methods .................................................................................. 164
5.3.1 Weighted Linear Least-Squares ................................................... 164 5.3.2 Error-in-Variable Model ................................................................ 164
5.4 Experimental Verication ......................................................................... 166 5.5 Summary ..................................................................................................... 175 References ............................................................................................................. 175
crystallization, precipitation, distillation, and liquid-liquid extraction, etc., have already been incorporated in basic food processing and well established and commercialized. A number of newer separation techniques as promising alternative methods for improved application in food engineering have been implemented on the commercial scale, including supercritical-CO2 uid extraction, membrane-based separation, molecular distillation, pressured low-polarity water extraction procedures, etc. These newer techniques have made impressive advances in obtaining adequate segregations of components of interest with maximum speed, minimum effort, and minimum cost at as large a capacity as possible in production-scale processes. These techniques have been implemented for the purication of proteins, characterization of aromas, whey protein removal from dairy products, extraction of health-beneting sh oil, and clarication of beverages including beer, fruit juices, and wine. The separation processes and technologies for high value-added products are based on their polarity and molecular size. Many potential high-value products can be developed from natural resources by different separation technologies and processes. For example, carotenoids including lycopene, β-carotene, astaxanthins, and lutein make up a world market nearing $1 billion with a growth rate of about 3%. Therefore, efforts to utilize natural agricultural materials for the production of high valueadded products, especially health-promoting foods and ingredients, are of great interest to the food and biotechnology industries.
