Contents ◾ xvii
Organic Acids, Diacetyl, Hydrogen Peroxide, and Reuterine as Food Preservatives ........212
Organic Acids ........................................................................................................212
Diacetyl .................................................................................................................213
Hydrogen Peroxide ................................................................................................214
Reuterine ...............................................................................................................214
Bacteriocins of Lactic Acid Bacteria as Food Preservatives ..............................................215
Bacteriocin-Producing Strains ...............................................................................215
Characteristics of Bacteriocins ...............................................................................216
Genetics and Gene Organization .......................................................................... 220
Mode of Action......................................................................................................221
Bioengineered Bacteriocin .................................................................................... 222
Production and Purification.................................................................................. 223
Applications .......................................................................................................... 223
Encapsulation and Delivery of Bacteriocin .................................................................... 226
Food Packaging ............................................................................................................. 226
Liposomes ...................................................................................................................... 227
Nanoencapsulation ........................................................................................................ 227
Safety Concerns with Nanotechnology .......................................................................... 228
Yeast Metabolites as Preservatives .................................................................................. 228
Conclusion ..................................................................................................................... 228
References ...................................................................................................................... 229
18 Food Ingredients and Enzymes of Microbial Origin ................................................231
Introduction ...................................................................................................................231
Microbial Proteins and Food Additives .......................................................................... 232
Single-Cell Proteins (SCPs) ................................................................................... 232
Amino Acids ......................................................................................................... 232
Nutraceuticals and Vitamins ................................................................................ 232
Flavor Compounds and Flavor Enhancers .............................................................233
Colors ....................................................................................................................233
Exopolysaccharides (EPS) ..................................................................................... 234
Organic Acids ....................................................................................................... 234
Preservatives ......................................................................................................... 234
Microbial Enzymes in Food Processing ......................................................................... 234
Enzymes Used .......................................................................................................235
α-Amylase, Glucoamylase, and Glucose Isomerase ...................................... 236
Catalase ....................................................................................................... 236
Cellulase, Hemicellulase, and Pectinase....................................................... 236
Invertase ...................................................................................................... 236
Lactase ......................................................................................................... 236
Lipases ......................................................................................................... 236
Proteases ...................................................................................................... 236
Enzyme Production by Recombinant DNA Technology ...................................... 237
Immobilized Enzymes .......................................................................................... 238
Adsorption on a Solid Support .................................................................... 238
Covalent Bonding........................................................................................ 238
Organic Acids, Diacetyl, Hydrogen Peroxide, and Reuterine as Food Preservatives ........212
Organic Acids ........................................................................................................212
Diacetyl .................................................................................................................213
Hydrogen Peroxide ................................................................................................214
Reuterine ...............................................................................................................214
Bacteriocins of Lactic Acid Bacteria as Food Preservatives ..............................................215
Bacteriocin-Producing Strains ...............................................................................215
Characteristics of Bacteriocins ...............................................................................216
Genetics and Gene Organization .......................................................................... 220
Mode of Action......................................................................................................221
Bioengineered Bacteriocin .................................................................................... 222
Production and Purification.................................................................................. 223
Applications .......................................................................................................... 223
Encapsulation and Delivery of Bacteriocin .................................................................... 226
Food Packaging ............................................................................................................. 226
Liposomes ...................................................................................................................... 227
Nanoencapsulation ........................................................................................................ 227
Safety Concerns with Nanotechnology .......................................................................... 228
Yeast Metabolites as Preservatives .................................................................................. 228
Conclusion ..................................................................................................................... 228
References ...................................................................................................................... 229
18 Food Ingredients and Enzymes of Microbial Origin ................................................231
Introduction ...................................................................................................................231
Microbial Proteins and Food Additives .......................................................................... 232
Single-Cell Proteins (SCPs) ................................................................................... 232
Amino Acids ......................................................................................................... 232
Nutraceuticals and Vitamins ................................................................................ 232
Flavor Compounds and Flavor Enhancers .............................................................233
Colors ....................................................................................................................233
Exopolysaccharides (EPS) ..................................................................................... 234
Organic Acids ....................................................................................................... 234
Preservatives ......................................................................................................... 234
Microbial Enzymes in Food Processing ......................................................................... 234
Enzymes Used .......................................................................................................235
α-Amylase, Glucoamylase, and Glucose Isomerase ...................................... 236
Catalase ....................................................................................................... 236
Cellulase, Hemicellulase, and Pectinase....................................................... 236
Invertase ...................................................................................................... 236
Lactase ......................................................................................................... 236
Lipases ......................................................................................................... 236
Proteases ...................................................................................................... 236
Enzyme Production by Recombinant DNA Technology ...................................... 237
Immobilized Enzymes .......................................................................................... 238
Adsorption on a Solid Support .................................................................... 238
Covalent Bonding........................................................................................ 238