Preface Milk has been the subject of scientific study for about 150 years and consequently, is probably the best characterized, in chemical terms, of our major foods. It is probably also the most complicated and serves as the raw material for a very large and diverse family of food products. Dairy science has existed as a university discipline for more than 100 years; it is the oldest sector of food science(and technology), with the exception of brewery science. Since dairy chemistry is a major facet of dairy science, it might be expected to have been the subject of numerous books. This is, in fact, not so. During the past 40 years, as far as we are aware, only six books or series on dairy chemistry have been published in English, i.e. Principles of Dairy Chemistry(Jenness and Paton, 1959), Dairy Chemistry and Physics(Walstra and Jenness, 1984), Fundamentals of Dairy Chemistry( Webb and Johnson, 1964: Webb, Johnson and Alford, 1974; Wong et al, 1988), Developments in Dairy Chemistry(Fox, four volumes, 1982, 1983, 1985, 1989), Advanced Dairy Chemistry(Fox, three volumes, 1992, 1995, 1997)and Handbook of Milk Composition(Jensen, 1995). Of these, Principles of dairy Chemistry and Dairy Chemistry and Physics were written essentially for senior undergrad uate students. The other four books/ series were focused principally on lecturers, researchers, senior postgraduate students and senior production management. Thus, at present there is a lack of books written at senior undergraduate/junior postgraduate level specializing in dairy chemistry/ cience. This book is intended to fill that gap and should be as useful to graduates working in the dairy industry as it is to those still studying The book assumes a knowledge of chemistry and biochemistry but not of dairy chemistry. As the title suggests, the book has a stronger biochemical orientation than either Principles of Dairy Chemistry or Dairy Chemistry and Physics. In addition to a fairly in-depth treatment of the chemistry of the principal constituents of milk, i. e. water, lactose, lipids, proteins (including enzymes), salts and vitamins, various more applied aspects are also covered, e.g. heat-induced changes, cheese, protein-rich products and the applications of enzymes in dairy technology. The principal physical properties are also described To facilitate the reader, the structure of various molecules mentioned frequently in the text are given in appendices but we emphasize that a good general knowledge of chemistry and biochemistry is assumed. The chemical composition of the principal dairy products is also includedPreface Milk has been the subject of scientific study for about 150years and, consequently, is probably the best characterized, in chemical terms, of our major foods. It is probably also the most complicated and serves as the raw material for a very large and diverse family of food products. Dairy science has existed as a university discipline for more than 100 years; it is the oldest sector of food science (and technology), with the exception of brewery science. Since dairy chemistry is a major facet of dairy science, it might be expected to have been the subject of numerous books. This is, in fact, not so. During the past 40years, as far as we are aware, only six books or series on dairy chemistry have been published in English, i.e. Principles of Dairy Chemistry (Jenness and Paton, 1959), Dairy Chemistry and Physics (Walstra and Jenness, 1984), Fundamentals of Dairy Chemistry (Webb and Johnson, 1964; Webb, Johnson and Alford, 1974; Wong et al., 19SS), Developments in Dairy Chemistry (Fox, four volumes, 1982, 1983, 1985, 1989), Advanced Dairy Chemistry (Fox, three volumes, 1992, 1995, 1997) and Handbook of Milk Composition (Jensen, 1995). Of these, Principles of Dairy Chemistry and Dairy Chemistry and Physics were written essentially for senior undergrad￾uate students. The other four books/series were focused principally on lecturers, researchers, senior postgraduate students and senior production management. Thus, at present there is a lack of books written at senior undergraduate/junior postgraduate level specializing in dairy chemistry/ science. This book is intended to fill that gap and should be as useful to graduates working in the dairy industry as it is to those still studying. The book assumes a knowledge of chemistry and biochemistry but not of dairy chemistry. As the title suggests, the book has a stronger biochemical orientation than either Principles of Dairy Chemistry or Dairy Chemistry and Physics. In addition to a fairly in-depth treatment of the chemistry of the principal constituents of milk, i.e. water, lactose, lipids, proteins (including enzymes), salts and vitamins, various more applied aspects are also covered, e.g. heat-induced changes, cheese, protein-rich products and the applications of enzymes in dairy technology. The principal physical properties are also described. To facilitate the reader, the structure of various molecules mentioned frequently in the text are given in appendices but we emphasize that a good general knowledge of chemistry and biochemistry is assumed. The chemical composition of the principal dairy products is also included