Much progress in the understanding and utilization of process flavors was made due to (1) advances in chromatographic separation and computer-related technology, (2) relentless investigation of a wide range of flavour precursors, (3) regulation that met consumer safety concerns , and (4) industry demand for better, complex and authentic products. The flavour industry is by far the largets user of knowledge from process and reaction flavour studies and had grown from approximately 2 billion 20 years ago, to about 8 billion dollars in annual sales today. Maillard reaction, lipid oxidation, degradation of suagrs, proteins, lipids, ribonucleotides, pigments and vitamins, and the interactions of degradation products are the chemical platform for generating many flavour compounds encountered in processed flavouring, flavours and foods. This book is organized to shed some light on the current state of science in process and reaction flavours, and to report significant findings.