5 Non-migratory bioactive polymers (NMBP)in food packaging M. D. Steven and J. H. Hotchkiss. Cornell University, USA 5.1 Introduction Non-migratory bioactive polymers(NMBP)are a class of polymers that possess biological activity without the active components migrating from the polymer to the substrate. This concept has existed for some time Bachler et al., 1970 Brody and Budny, 1995; Katchalski-Katzir, 1993)and has been applied primarily to immobilised enzyme processing(Katchalski-Katzir, 1993 Mosbach, 1980). It is only now becoming of interest in packaging applications (Appendini and Hotchkiss, 1997; Soares, 1998) Bioactive materials are based on molecules that elicit a response from living systems. The goal is to use bioactive materials for which the response is desirable from the standpoint of the package or the product, for example inhibition of microbial growth or flavour improvement. Enzymes are classic examples of bioactive substances, as are many peptides, proteins, and other organic compounds The definition, from the perspective of packaging, is based on function: the way the substance interacts with living systems. Purely physical processes, for example adsorption or diffusion, are excluded from this definition. Bioactive polymers can be formed by attachment of bioactive molecules to synthetic polymers, as in the case of enzyme immobilisation( Appendini and Hotchkiss, 1997, Soares, 1998),or may result from an inherent bioactive effect of the polymer structure, as with chitosan( Collins-Thompson and Cheng-An, 2000; Tanabe et al, 2002). They have potential applications in the packaging of food and other biological materials, in food processing equipment, on biomedical devices (Sodhi et al., 2001; Sun and Sun, 2002)and in textiles(edwards and vigo, 2001; Sun and Sun, 2002) Non-migratory polymers are defined to be those for which the bioactive ponent does not migrate out of the polymer system into the surrounding5.1 Introduction Non-migratory bioactive polymers (NMBP) are a class of polymers that possess biological activity without the active components migrating from the polymer to the substrate. This concept has existed for some time (Bachler et al., 1970; Brody and Budny, 1995; Katchalski-Katzir, 1993) and has been applied primarily to immobilised enzyme processing (Katchalski-Katzir, 1993; Mosbach, 1980). It is only now becoming of interest in packaging applications (Appendini and Hotchkiss, 1997; Soares, 1998). Bioactive materials are based on molecules that elicit a response from living systems. The goal is to use bioactive materials for which the response is desirable from the standpoint of the package or the product, for example inhibition of microbial growth or flavour improvement. Enzymes are classic examples of bioactive substances, as are many peptides, proteins, and other organic compounds. The definition, from the perspective of packaging, is based on function: the way the substance interacts with living systems. Purely physical processes, for example adsorption or diffusion, are excluded from this definition. Bioactive polymers can be formed by attachment of bioactive molecules to synthetic polymers, as in the case of enzyme immobilisation (Appendini and Hotchkiss, 1997; Soares, 1998), or may result from an inherent bioactive effect of the polymer structure, as with chitosan (Collins-Thompson and Cheng-An, 2000; Tanabe et al., 2002). They have potential applications in the packaging of food and other biological materials, in food processing equipment, on biomedical devices (Sodhi et al., 2001; Sun and Sun, 2002) and in textiles (Edwards and Vigo, 2001; Sun and Sun, 2002). Non-migratory polymers are defined to be those for which the bioactive component does not migrate out of the polymer system into the surrounding 5 Non-migratory bioactive polymers (NMBP) in food packaging M. D. Steven and J. H. Hotchkiss, Cornell University, USA