Application of Immobilized Cells and Enzymes in the Food Industry
Immobilization of whole cells or enzymes means fixation to a support, or support-free crosslinking of enzyme aggregates. Immobilized cells and enzymes can be used in continuous systems without the loss of the biocatalyst through leaching. There are several techniques used for immobilization: entrapment in a gel matrix, adsorption to different, mainly porous surfaces, encapsulation, or covalent binding. Immobilization has the advantages of enhanced stability and catalytic activity of the used biocatalysts. In the food industry, immobilized cells are used for biomass production of starter cultures in dairy industry, in winemaking, in brewing processes, and in acetic acid fermentation. Immobilized enzymes, especially carbohydrases, are used during starch processing, for the production of sugar syrups, for lactose hydrolysis in milk, in the production of prebiotics, and for liberation of antioxidants from their glycosidic form. This chapter will give a short summary about the different immobilization techniques and the use of immobilized cells and enzymes in the food industry, and provide an overview about the properties of the immobilized biocatalysts.