Preface   The food and nutritional security of about 6.7 billion population in the world depends upon the quantity and quality of cereals produced. Cereals are the cheapest source of energy and provide proteins, dietary fibre, minerals, vitamins and other nutritional factors to the human beings. Among cereals, rice, wheat and maize are the major sources of food and feed and contribute around 23%, 17% and 9% of the world calorie, respectively. These are grown across the world from temperate to tropical environments. Millions of people are involved in production, processing and marketing of these cereals. There are large numbers of wheat based products such as fermented pan bread, flat breads including chapati, biscuits, noodles and pasta products. Rice is generally cooked and eaten directly and also consumed such as breakfast cereals, baby food and in many other forms. Maize (known as corn) is the principal cereal crop in tropical and subtropical regions throughout the world. Virtually every part of maize has economic value as grains are used for human food, fermented to produce a vide range of food and beverages, fed to livestock and industrial uses in the production of starch, oil, sugar, cellulose and ethanol. Barley is used mainly for feed and malt purposes and little for human food. Recently cereals have been explored for their use in several industrial applications such as bio-fuels and biodegradable products. Therefore, improving quality of cereals for food, feed and industrial applications has paramount importance in world economy. This depends on understanding the chemical and genetic basis of industrial and nutritional quality traits. The chemical and molecular studies during the last 10 years have expanded the knowledge on cereal quality. This has demonstrated that there are some common genetic factors among cereals related to nutritional quality. However, the information is not accessible easily to the readers at different levels. Therefore, efforts have been made to provide information on quality of wheat, barley, maize and rice in this book for the benefit of researchers, students and industrial people. Keeping above facts in mind the book has been divided into 13 chapters of which 10 chapters are related to wheat quality. The first chapter is related to wheat production, consumption and utilization. Separate chapters are provided on starch and proteins because they are main storage components in the grain. Wheat gluten proteins impart unique characteristics to dough to make it suitable for different products. The allelic variation in gluten proteins has strong relationship with gluten strength and extensibility and thus suitable in predicting wheat grain quality. Starch pasting properties have strong relationship with noodle quality in wheat and cooking quality in rice. Separate chapters have been provided on soft wheat products, fermented and flat bread, and durum wheat products. Since there are two international market classes of wheat termed as soft and hard; extensive studies have been conducted on grain texture and thus a separate chapter is provided. Wheat based industry demands specific type of flour for which chemical and rheological tests have been developed to explain the suitability of wheat for different products. Since large amount of genetic information has been generated on nutritional quality traits, a separate chapter has been given on improving nutritional quality. Similarly good information has been generated on molecular aspects of wheat quality improvement; a separate chapter has been added on molecular breeding and transgenics. Individual chapter on rice, barley and maize has been provided to give a brief account of major traits covering both industrial and nutritional quality. Rice quality includes information on various types of rice available, cooking and eating quality traits and their molecular genetics as well as transgenic approach for improving nutritional quality. Recent studies demonstrated the utility of transgenic approach in improving bioavailability of micronutrients and also improving pro-vitamin A content in rice. The maize chapter includes information on milling, food and feed quality and maize as a source of biofuel. Detailed information is given on nutritional quality of maize including QPM. Chapter on barley includes information on malting and brewing quality and also food and feed quality. β-glucan content in barley has important role in food, feed and malting quality. Since β-glucans have health benefits, the relevance of barley in improving nutritional quality has been highlighted. Efforts have been made so that the readers understand quality of major cereal crops at chemical, molecular, genetic and processing levels. Important references have been collected and reflected at the end of each chapter along with summary. This publication may serve as reference material to plan research activities in different cereals for the improvement of processing and nutritional quality. This will also help students to understand cereal quality which is going to be focused globally in coming years. Authors are thankful to those who have contributed directly or indirectly in bringing this book in this form. Readers are requested to give suggestions to improve this book further to make it more useful for wide range of stakeholders and readers.

Introduction Wheat is an important cereal crop and is widely cultivated across the world. Wheat is consumed in different forms and major products are chapati, bread, biscuit, noodles and pasta products. Wheat has three groups of cultivated species namely bread, durum and dicoccum wheats. The common or bread wheats account for approximately 95% of world production. Nearly all of the remaining 5% cultivated varieties are durum wheats used for pasta products and couscous and dicoccums represent very little of the total wheat production. The bread wheat is divided into two broad classes based on grain texture; hard and soft. Hard wheats with high protein content and strong gluten are used for making bread and some noodles while soft wheats with lower protein content and weak gluten for biscuit, cakes and pretzels. Semi-hard wheats having some combinations of the above characteristics are utilized for making unleavened breads such as chapati, Asian steamed bread and some noodles. There can be large disparity within wheats of various classes; therefore to provide consistent quality, it is divided into grades. The grading is determined by the test weight, protein content, moisture and foreign material. The major wheat exporting countries have distinct grading patterns designed to provide wheat for specific purposes and consistent quality.

Introduction There are large numbers of wheat based products such as fermented pan bread, flat breads including chapati, biscuits, noodles and pasta products. Each product has its own specific requirements. For example fermented pan bread needs wheat with higher protein content, stronger and extensible gluten. Chapati requires hard wheat with high protein content and medium gluten strength. Waxy wheats have been found associated with improved shelf life of breads. White salted Japanese noodles need partial waxy wheats with soft grain characteristics and medium protein content and gluten strength. Partial waxy wheats with comparatively lower amylose content and higher starch paste viscosity improve texture of white salted noodles. Yellow alkaline noodles need comparatively harder wheat with medium strong gluten and without waxy trait. Pasta made from durum wheats requires stronger gluten, high protein content and higher content of yellow pigments. In this chapter detailed account of both fermented and flat breads will be given.

Introduction For many years it has been an elusive task to provide a precise definition as to what constitutes quality in wheat. Each country has its own traditions in bread and other bakery products. Quality will mean different things to a miller, a baker, a grain handler or a plant breeder. As the baking industry becomes increasingly specialized, specific qualities are sought. Even among those wheat varieties generally recognized as having desirable quality traits, the influence of environment can be substantial, and this necessitates a high level of skill on the part of grain buyers to survey the current year’s crop and blend the wheat for a specific end-use. This genotype X environment effect on quality also limits the capacity of end-users to source identity-preserved wheat from a narrow geographic area. Those of us engaged in the field of plant breeding are concerned primarily with those traits that can be manipulated genetically, and we study their stability under a range of climatic conditions. Constraints in time, cost, and sample availability usually necessitate the use of predictive tests during early generations, followed by milling and baking tests on advanced lines that have met a number of agronomic, disease and predictive quality criteria.

Introduction Durum or macaroni wheat (T. turgidum var. durum) is an important crop used chiefly for the production of pasta in Western Europe and North America, and two layered bread, single layered bread, burghul, couscous, pasta, frek and feed in other parts of the world (Table 1). In North Africa and the Middle East, durum is also used for producing flat breads. On a global basis only a small amount of durum wheat is used for baking of pan-style and hearth-style bread. Also, durum wheat for baking is often used in blends with common wheat. In India, durum occupies approximately 2.0 mha area and production is estimated to be around 2.5-3.0 million tones annually amounting to 3-4% of the total wheat production. The consumption of pasta is increasing at the rate of around 5% annually and currently it is estimated to be around 10 Lakh tones. The demand for pasta products may increase further due to increasing population and improving standard of living.

Introduction Dough is a complex mixture of flour constituents, water, salt and other ingredients depending upon the requirements of end-products. It is the principal intermediate stage in the transformation of wheat into different end-use products. Rheological properties of dough determine the behaviour of dough during mixing, rounding and molding used in making different products and also effect on the quality of finished product. Therefore, understanding the various features of dough rheology and their relations with product quality is important. The importance is enhanced further because of mechanization and automation of baking industry. Dough is composed of continuous phase in which gas cells are dispersed. The continuous phase is called “dough phase”. It consists of starch granules embedded in protein matrix along with some lipids, cell remnants and yeast cells in fermented dough. Gas production and retention is the most comprehensive quality requirements of the dough for bread making. The ability of the wheat dough to retain gas during fermentation and oven rise is unique. This depends on the ability of the dough to be stretched into thin membranes because of protein phase.

Introduction Wheat is the most important cereal crop to the human kind. It is the main source of energy and nutrition in human diet. Wheat is consumed in the form of large number of end products as chapati, bread, biscuit, cakes, pretzels, noodles and pasta products. Millions of people are involved in milling, baking and pasta products industry with huge turnover per annum. However, each end-use product of wheat has it’s own specific requirement for example basically hard wheats along with strong gluten and high protein content are used for bead making. Soft wheat with weak gluten and low protein content are required for biscuit making Souza et al. (1994). Durum (tetraploid) wheat is used for pasta products as macaroni, vermicelli and spheghatti and Dicoccum for therapeautic purposes. Often chemical improvers are used to improve the dough properties for these products. Most of these chemicals have been banned because of their toxic effects. Therefore, only alternative is to develop varieties suited to meet the requirements of these end-use products. This needs better understanding of molecular basis of grain quality to accelerate breeding for producing wheat varieties for each end-use product separately. Storage proteins are the major component of grain which determines end-product quality. In this chapter detailed structure, genetics and functionality of gluten proteins are described.

Introduction Bread wheat (Triticum aestivum L.) is one of the most widely cultivated and consumed crops in the world. Wheat is perhaps best known for its different end-use baking properties as determined by grain texture, protein content and quality. Wheat is generally traded by and classified into “hard” and “soft” market classes on the basis of grain hardness or texture of the wheat kernel (caryopsis). Soft wheats have softer endosperm texture that fractures easily, therefore requiring less energy to mill, yields smaller particles, and has less starch damage after milling when compared to hard wheats. Hard and soft are used with slightly different connotations in different parts of the world. In Western Europe, hard is applied primarily to durum wheats and the soft applied to bread wheat. Elsewhere the term is applied to different cultivars within the species Triticum aestivum. In general, hard wheats are used for bread baking, while soft wheats are used for cookies and cake making. Hard wheat requires more force to crack the kernel, maintains a larger particle size, passes through sieves more easily and has more damaged starch MacRitchie (1980). Higher starch damage is required for good bread making quality Tipples et al. (1994) but is detrimental to the biscuit making quality.

Introduction Carbohydrates constitute nearly 80% of the total dry matter of wheat kernel. Starch is the predominant form, with cellulose, hemicellulose and pentosans present in lesser amount. Starch is present in discrete granules within the cells of the endosperm. Starch content is available in the range of 65% to 75% and generally related negatively to the protein content. Starch structure is a crucial determinant of many end-product uses of wheat. While the amylose /amylopectin ratio is a useful descriptor of starch structure, a more complete analysis of the population of the molecules which constitute a particular starch is considerably more revealing. The molecules range from the high degree of polymerization (107 – 109 glucose units) and heavily branched amylopectin population, to the lower degree of polymerization (103 -106 glucose units), and infrequently branched amylopectin population. Starches with widely differing structures are suited to particular end uses. For example, starches with no amylose, the so called waxy starches are particularly suited to use as thickeners or gel forming agents because they form a clear stable gel with little retrogradation. In contrast, starch with high amylose content form hydrogen bonded insoluble aggregations which are suited to use in adhesives, plastics and as a source of dietary-fibre starch. The size and branching pattern of starch are also important determinants of the suitability of starches for particular end-uses due to the effects these parameters have on gelatinization temperature, starch swelling and viscosity.

Introduction Nutritional value of food stuff is defined by its ability to provide nutrients required by the body. Proteins, carbohydrates, fats, minerals and vitamins are main ingredients in food stuffs. Wheat is an important source of these nutrients. The distribution of nutrients within wheat kernel is typical of many cereals. Nutrients are generally found in the highest concentrations in the germ or embryo and in the aleurone cells surrounding the starchy endosperm followed by bran, whole wheat flour and white flour in decreasing order. Of special importance is that it contains the entire B complex, except for vitamin B12. B vitamins function as cofactors in many metabolic reactions involved in the release of energy. The germ, which includes the scutellum, is especially rich in vitamins B and E, high quality protein, unsaturated fats, minerals, and carbohydrates. The bran consists mostly of the insoluble carbohydrate cellulose, and contains incomplete protein, traces of B vitamins, and minerals including zinc and iron. The endosperm is the largest part of the grain, and consists mostly of the carbohydrate starch, incomplete protein, and trace amounts of vitamins and minerals. Significant variations in the content of grains occur because of variety, crop year, area, fertilizer, and soil type.

Introduction Improvement of wheat grain quality depends on the knowledge of quality requirements of different end-use products and the genetic components controlling different quality traits. In previous chapters we have dealt in-depth with quality requirements of different end-use products and their genetic components. Depending upon the goal of quality improvement, different strategies are adopted to improve wheat quality. It depends upon the number of genes controlling the traits as well as the availability of the simple methods for phenotyping the traits especially during early segregating generations. In addition stability analysis of the traits across the environments is essential before we go for breeding. Constraints in time, cost, and sample availability usually necessitate the use of predictive tests during early generations, followed by milling and baking tests on advanced lines that have met a number of agronomic, disease and predictive quality criteria. Knowledge of germplasm lines having specific quality traits is needed to initiate breeding for the improvement of wheat grain quality for different end-use products. The quality requirements of different major end-use products are provided in the following table (Table 1).

Introduction Barley is an important cereal crop grown all over the world and is used mainly for feed and malt purposes and little for human food. Barley is the world’s oldest grain, as evidenced by discoveries in ancient cities in the Middle East and North Africa. It has been cultivated for about 8,000 years, and today is the world’s fourth largest cereal crop. Considerable evidence is available that points to the role of barley as sustaining food source in the evolution of humans. Additionally, alcoholic beverages of various types and fermented foods prepared from barley are commonly referred to in the ancient literature. As other food crops (wheat, rice, corn and rye) became more abundant, barley was relegated to the status of “poor man’s bread”. In the United states, barley used as food is 1.5%, as animal feed 65% and in malt and alcohol production 30% (Newman and Newman, 2006). In 1991, barley used as food in European countries was even lower (0.3%) than the United States. In contrast, during the same time period food was the largest for barley in Morocco (61%), China (62%), India (73%), and Ethiopia (79%). However, current consumer interest in nutrition and human health may help restore barley’s status in the human diet. Nutritional qualities of barley have been known since ancient times. For example, Ajgaonkar 1972 described how ancient Indian physicians effectively stabilized type II diabetics some 2400 years ago. Treatment was remarkable simple and not really different from recommendations that are given to diabetic patients today, i.e., lose weight, change diet, and increase exercise.

Introduction Rice is grown in more than 100 countries in the world and is an important crop for nutritional security of large part of the population. World rice production in 2007 was approximately 645 million tones. Around 50 countries have an annual production of more than 1 million tones. Ninety percent of the total rice is produced in Asian countries, with two countries, China and India, growing more than half the total crop. Top ten rice producing countries are China, India, Indonesia, Bangladesh, Vietnam, Thailand, Myanmar, Japan, Philippines, and Brazil. In Bangladesh, Cambodia, Indonesia, Lao PDR, Myanmar, Thailand, and Vietnam, rice provides 50-80% of the total calories consumed. Major part of the rice is consumed locally where produced and only 6-7% of world rice production is traded internationally.

Introduction Maize (Zea mays, or corn as it is known in some countries) is the principal cereal crop in tropical and subtropical regions throughout the world. The increasing use of maize as a staple food reflected the much higher yields per hectare, compared with wheat, rye and barley. Because maize was cheap, it became the dominant food and main source of dietary energy and protein for poor people, particularly those in rural and underprivileged segments of society. Maize is considered to be a native of the Americans. There are different views about the introduction of maize in India. One view is that maize was introduced into India by the Portuguese during the seventh century. Other view is that maize was introduced in Pre-Colombian era through the Atlantic Arabian trade route. This is supported by the more recent variability that has been observed in the maize collections made from the north eastern Himalayan region. However, the historic records regarding the cultivation of maize in India date back only to the Maratha Empire.

INDEX A Abrasive whitener 258 Alkali 254 Alkali spreading value 258 Amylose 254, 258 Amylose content 258 Amylose groups 254 B Brokens 254, 258 C Chalky 254 Characteristics 254 Chemical characteristics 254 Colorimetric 254, 258 Cyclone mill 258