Cereals belong to the most important elements in the history of mankind. From the beginning of agriculture, cereals have been by far the most important staple food in the world. Although the cereal consumption decreased to a low level in the developed countries in Europe and North America, in the devel oping countries over two-thirds of the calorie and protein intake is based on cereals. A substantial quantity of cereals goes indirectly into food via feed to animals. Generally, cereal proteins are classified as proteins of lower biological value because of shortage in lysine and some other essential amino acids. Recent developments in the de termination and evaluation of the biological value of proteins and protein mixtures suggest that the oversimplified earlier evaluation of cereal proteins must be reviewed. This book contains the edited proceedings of the Inter national Symposium on "Amino Acid Composition and Biological Value of Cereal Proteins", held in Budapest, Hungary, Hay 31- June 1, 1983, under the sponsorship of the International Association for Cereal Chemistry, Hungarian Scientific Society for Food Industry and Grain Trust, Hungary, with supplemental invited contributions. Scientists (biologist, plant breeders, farmers, chemists, biochemists, engineers, food technologists and nutritionists) from 17 countries presented and reviewed, along with partici pants from 20 countries, the recent methodology and trends in the determination of the biological value of cereal proteins, v the amino acid composition of cereal proteins and factors in fluencing the composition and the role of cereal proteins in nutrition and animal feeding.

The nutritional quality of a protein depends on the proportion of its amino acids-especially the essential amino acids-their physio logical availability, and the specific requirements of the consumer. Availability varies and depends on protein source, interaction with other dietary components, and the consumer's age and physiological state. In many foods, especially those from plants, low levels of various essential amino acids limits their nutritive value. This is particularly important for cereals (which may be inadequate in the essential amino acids isoleucine, lysine, threonine, and tryto phan) and legumes (which are often poor sources of methionine). Moreover, these commodities are principle sources of protein for much of the earth's rapidly growing population. At the current annual growth rate of about 2 percent, the world population of about 4 billion will increase to 6.5 billion by the year 2000 and to 17 billion by the year 2050. Five hundred milliQn people are presently estimated to suffer protein malnutrition, with about fifteen thousand daily deaths. The ratio of malnourished to adequately nourished will almost surely increase. For these reasons, and especially in view of the limited availability of high quality (largely animal) protein to feed present and future populations, improvement of food and feed quality is especially important.

In the past decade, since the first edition was published, the study of cereal protein chemistry has grown and changed. New separation techniques have been introduced while the application of achievements of molecular biology and genetic engineering of proteins has progressed dramatically. This new edition includes these advances and updates the chemistry of cereal proteins for all specialists working in theory and practice of cereal grain production and processing.

Investigations on seed proteins have been intensively carried out during the past two decades. This is valid with regard to both their chemical composition as well as their nutritive value. The development of new biochemical and physical methods has resulted in obtaining deep insights into the structures of seed proteins and their mutual interactions. Intensive exchange of information between the scientists participating in national and international research programmes has given strong impulses for intensifying the research in this field. For the quantitative and quali tative investigations of seed proteins, not only some model plants were used; on the contrary, they were carried out on a large number of different crops important for different regions of the earth. In this way, a level of knowledge has been reached which could not be expected in this diversity within such a short period. This holds not only true for biochemical but also for physiological characters of the species of the limiting amino acids studied. With regard to nutritional aspects, the problem was of special interest, but also seed proteins acting as antinutritional factors were analysed in detail. Based on the knowledge of seed protein structures, it was possible to perform investigations on the genetic basis of their synthesis. This was done under two different aspects: The basic knowledge on the genes involved should be widened; moreover, it should be tried to improve the seed proteins quantitatively and qualitatively under the influence of mutant genes.

The aim of this book is to update knowledge and summarise recent research on pseudocereals, particularly regarding their botanical characteristics, composition, structure, use, production, technology and impact on human health. In the last few years, pseudocereals – in particular amaranth and quinoa – have acquired increased importance (which is also due to the increased demand for gluten ]free food). Worldwide, the demand for amaranth and quinoa has risen immensely, as seen in rising prices for amaranth and quinoa. At the same time, research in all relevant fields has intensified. At present there is some confusion surrounding the term ‘pseudocereals’ and what it does and does not include, for example kiwicha which is Amaranthus caudatus or kaniwa which is Chenopodium pallidicaule. Sometimes other grains are included in the pseudocereal group like chia (Salvia hispanica L), an oleaginous seed. One of the aims of the book is to clear up some of the confusion over what is included in the group of pseudocereals. The book will include: the origin, production and utilization of pseudocereals; structure and composition of kernels; carbohydrates/fibre/bioactive compounds of kernels; proteins and amino acids of kernels; lipids of kernels; pseudocereal dry and wet milling: processes, products and applications; food uses of whole pseudocereals; pseudocereals in gluten free products; and the nutritional and health implications of pseudocereal intake.

Yeast biomass is an excellent source of proteins, nucleic acids, and vitamins. It has been produced and consumed in baked goods and other foods for thousands of years and offers significant advantages when compared to other potential new microbial protein sources. Use of Yeast Biomass in Food Production provides up-to-date information regarding the chemical composition and biochemistry of yeasts, discusses the biotechnological basis of yeast production and possibilities for influencing yeast biomass composition using new techniques in molecular biology. The book examines techniques for producing yeast protein concentrates (and isolates) while still retaining their functional properties and nutritive values, as well as the various uses for these materials and their derivatives in different branches of the food industry. Finally, the book explores possibilities for the production and industrial use of other yeast components, such as nucleic acids, nucleotides, cell wall polysaccharides, autolysates, and extracts. Food microbiologists and technologists, as well as biotechnologists, will discover that this book is an invaluable reference resource.