eChapters

Abstract

Drying is a very important unit operation in food processing. Being an energy intensive unit operation, drying process demands improvement to make it energy efficient. Beside this operating conditions used in drying affect product quality substantially; however, traditional dryers do not allow enough flexibility to meet quality requirements for several products. This has resulted in development of number of new drying techniques, to cope with both energy efficiency and product quality.

Abstract

In recent years microwave processing have attained increasing recognition in food industries particularly in drying and dehydration. During microwave processing, electromagnetic energy is supplied directly to the food material for volumetric heating. This provides rapid temperature rise throughout the material with reduced thermal gradients. This unique heating mechanism reduces processing time and saves energy. In-spite of advantages of microwave heating it leads to overheating in food material and formation of cold and hot spots if applied improperly during drying. To overcome these challenges different microwave assisted hybrid drying technologies have been developed by many researchers. These techniques are microwave assisted hot air drying, microwave assisted osmotic dehydration, microwave assisted vacuum drying, microwave- infrared assisted hot air drying, microwave assisted rotary drying. This chapter comprises the fundamentals of microwave and provides comprehensive update of microwave assisted hybrid drying processes for food and agricultural materials.

Abstract

Hot air circulation is the most common industrial method of drying foods which has its own inherited disadvantages. Microwave drying can be an alternative method for removing moisture from foods and there has been a surge of interest in the application of microwave to process the foods, in past few years. The reason being that there is worldwide energy crisis and the growing acceptance and familiarity with domestic microwave ovens. It is well known that conventional means of heat processing irreversibly alter the flavor, colour, and texture of many foods. From the point of flavor alone, it is desirable to improve our present methods of processing foods. Some improvements have been made in this direction with a number of food products by use of high-temperature short- time processing.

Abstract

Spray drying is one of the most preferred methods of converting food and pharmaceutical solutions into powder form. Very high product throughput, hygienic and highly automated process and relatively benign thermal and dehydration stress on products associated with this process has made it ubiquitous in powder manufacture. Compared to freeze drying, spray drying is significantly less expensive both in terms of operation and capital costs. In this chapter, key features of spray drying such as underlying operational principle, types of spray nozzles used, the flow pattern of droplets/particles and drying medium within the drying chamber, the particle formation process of individual droplet are discussed in considerable detail. The modelling aspect of a single droplet subjected to spray drying environment has also been included. Finally, the most commonly considered characteristics of spray dried powders including morphology, crystalline/amorphous nature and solubility are highlighted and discussed.  The content presented in this chapter will be very useful for practising engineers, technologists, researchers as well as postgraduate and undergraduate students.

Abstract

Osmotic dehydration is gaining popularity due to several energy and product quality related advantages it offers. It has huge potential as a complementary process step prior to operations such as air-drying, microwave drying, freezing, frying etc, if not an alternative one, in the food process chain. It can be easily integrated with other processing steps in order to improve the overall efficiency of a given food process. Application of additional driving force either prior to or during osmotic dehydration can enhance the mass transfer rates in the osmotic dehydration. Role of mathematical modelling both in osmotic dehydration and rehydration have been discussed. Current limitations for the adaptation of osmotic dehydration in the food processing industry and possible solutions are also discussed in detail.

Abstract

Classification of the hundreds of possible dryers is essential to the logical selection of appropriate dryer for a given application. Diverse criteria for classification as well as selection of dryers are presented and discussed briefly. The advantages and limitations of different dryer types must be taken into consideration. Initial capital cost is often the key deciding criterion in industrial dryer selection. This is not a good strategy as the user must pay for the operating costs over a long period of life of the dryer. In general several different dryer types are suitable for a given product. Careful selection is essential for cost-effective operation of the dryer.

Abstract
 
Food products can have moisture content as high as 90% which needs to be lowered to acceptable limits to prevent microbial growth and deteriorative reactions. Drying is one of the most common and cost effective techniques for removal of excess moisture from the food by application of heat. In addition to its role of extending the product shelf life and providing stability, drying also helps to produce variety of products from agricultural, horticultural and industrial products. But to obtain the desired quality product, adequate drying is essential which depends on type of dryer and drying technique employed which further requires proper understanding of drying process. Despite being important unit operation in food processing industry, appropriate scientific knowledge of the drying process is still limited. So, the fundamental principles and associated terminologies with drying has been discussed in detail in this chapter to have thorough understanding of the drying process. In addition, different models and calculation procedures for drying of different types of commodities has also been reviewed.

India

Milk legislation and regulations are designed to prevent fraud and adulteration. But they now cover many factors that affect sanitation and public health. Milk generally is classified into grades according to the care with which it is produced.

Introduction

Numerous characteristics of food determine its acceptability to consumers and to regulatory officials. Before accepting a food for consumption, it must be attractively presented, must have desirable odour and flavour characteristics and other qualities and must be free from potential pathogens or their toxic products. The ultimate nutritive qualities, flavour and appearance have been preserved and no harmful organisms or substances are present to affect the consumer adversely. If the quality of the product is good, its keeping quality is also likely to be substantial. Conversely, there are more chances of spoilage of an inferior quality food product during storage.

Dairy equipment and utensils with which milk and milk products come into contact are the main sources of contamination in the products. By the use of effective equipment cleaning and sterilization methods on routine basis, milk of high bacteriological quality can be consistently produced. In composite milk plant, a variety of equipment and utensils are used. The use of stainless steel for the fabrication of dairy utensils and equipment provide highly polished and hard smooth surface that can be cleaned readily, apart from showing resistance to corrosive action of detergents and bactericidal solutions. Utmost care is taken to avoid dents and scratches, which could be the possible focal points of subsequent contamination. To overcome all these problems aluminium and stainless steel vessels and equipment present an ideal situation.

Normally raw milk contains different levels of inhibitory substances, which restrict the normal development of bacteria and some times may even kill them. The degree of inhibitory activity varies considerably in milks of different species, viz, cow, buffalo, human. Maximum activity present in human milk, variations occur in the milks of individual animals and some times even at different milking or from different quarters of the udder of the same animal.
There are two groups of antimicrobial substances present in milk:
    1.    Inherent or naturally occurring substances in milk. 
    2.    Non- inherent compounds secreted into milk from other sources.

Tuberculosis

Tuberculosis has been recognized as one of the most important infectious diseases in the world because of its high global impact and its chronic debilitating character, particularly in the poor section of society. Milk-borne tuberculosis is directly or indirectly related to the consumption of raw milk from infected dairy herds.

According to International Dairy Federation(IDF),1980, Mastitis also called as ‘mammitis’ is defined as an inflammation of the udder, almost always of microbial origin and is the outcome of a local or a general infection. The common symptoms are related to inflammation, viz., swollen, hot, red, and painful udders. Mastitis can be classified based on symptoms or on the causative organism.

A) Forms of mastitis based on symptoms

    1.    Acute or clinical
    2.    Sub-acute or subclinical
    3.    Chronic.

The significance of milk in human nutrition is now well established as it is considered as the best, ideal and complete food for all age groups. However, in spite of being so, milk can also serve as a potential vehicle for transmission of some diseases under certain circumstances. Moreover, by virtue of possessing almost all the essential nutritional factors, milk can also serve as an excellent culture and protective medium for certain microorganisms, which may include potential pathogens capable of causing serious health problems to the consumers. In this way, milk may serve not only as a vehicle of transmission of disease causing organisms, but it can also allow these pathogens to grow, multiply and produce certain toxic metabolites, thereby making itself an extremely vulnerable commodity from public health point of view.

Bacteriophage is the term applied to bacterial viruses. Bacteriophage having the ability to lyse certain sensitive living cells. Phages are small particles, which can only be seen in the electron microscope after the application of suitable staining techniques. All phages have a head and most have a tail. The head may be isometric or prelate with a hexagonal outline.

There are two types of phages virulent and temperate which enter a different relationship with the host, the lytic and lysogenic cycles respectively.

Milk fermentation is process by which a change is produced in milk through the activity of microorganism. As milk leaves the udder it serves as a medium for the growth of many species and accordingly undergoes a series of changes, the processes producing these changes constitute the milk fermentation.

Fermentation of organic compounds, especially in the lack of oxygen leads to the rapid break-down of ‘biopolymers’ to produce ‘anaerobic food chains’.

Starters are selected strains of micro-organisms deliberately added to milk during conversion into cheese, dahi, yoghurt and other fermented dairy products to bring about specific changes in the appearance, body, texture and flavour characteristics of the desired final products.

Functions of Starters

The primary function of almost all starter culture is to develop acid in the product. The secondary effects of acid production include coagulation, expulsion of moisture, texture formation and initiation of flavour production. In addition to these, the starters also help in imparting pleasant acid taste, conferring protection against potential pathogens and providing a longer shelf life to the product. These bacteria convert 1% of lactose in milk approximately to lactic acid with very little by-products such as acetic acid, ethanol, CO2 and normally with no substances causing taints and hence leading to a clean and wholesome milk souring.

In India, the collection, transport and distribution of raw milk involves a number of agencies and persons at rural and urban level – village producers, milk collectors, halwais (Sweet-makers), milk vendors, dairies, producer-retailers and wholesale or retail markets.

1. Collection

Usually, the milk collectors approach the small village producers to collect milk and the same is sold directly or indirectly (through agents) to a dairy (milk procurement centres) or halwais or city milk vendors or consumers. The producer – retailers themselves, in some cases, supply the milk to the above said parties. The production of milk in small, scattered holdings in village causes problems during its collection. It involves visits to many villages, some of which are not easily accessible for the purpose.

The Concept of ‘Clean Milk’ Production

Although milk is nature’s most ideal and perfect single food both for the newborn and the mature human beings, the possibility of it being a source of biological and chemical hazards cannot be excluded. In view of the immense dietary importance of milk, the need for production of safe, clean and wholesome milk is emphasized. The term ‘clean milk’ does not mean milk in which all visible dirt is absent or milk from which it has been removed; rather it does denote raw milk from healthy animals, that has been produced and handled under hygienic conditions; that contains only small number of harmless bacteria and that possesses a good keeping quality without being treated by heat. In other words, the unhygienic production of milk may lead to inferior keeping quality as a result of rapid microbial multiplication under favourable storage conditions apart from serving as a potential health hazard. These microorganisms cause the milk to sour quickly, putrefy and develop undesirable flavours, colour defects, ropiness and bitterness. On the other hand, the pathogenic microorganisms, which may gain entry through various sources, may cause many diseases to the consumers.

The sources of contamination of milk on the farm can broadly be categorized as

    a)    Interior of the Udder
    b)    Exterior of the Udder.
The interior reflects the health of the animal, while the exterior depends on the farm condition, equipment, persons, water etc.

a) Interior of the Udder
The animal by itself is one of the most significant contributors of microorganism in milk. The bacteria in the udder usually enter from the teat opening and get distributed internally by their own growth and physical movement. In the normal healthy udder, the types encountered in milk are most predominantly Micrococci, followed by Streptococci, Corynebacterium and others. Most of the bacteria are excreted in fore milk.

The term growth as applied to higher organisms such as animals commonly is concerned with increase in protoplasmic mass and does apply to reproduction or to increase in number. In microbiology the term refers to increase in the number of organisms. Bacteria increase in number by a process of simple binary fission. Each cell increase in size and redivide into two similar cells. Each of the divide cells may in turn divide to become two cells. Each division produces what is termed as new generation of cells, theoretically there are 2,4,8,16,32,64,128,256 cells in the 2,3,4,5,6,7,8,& 9th generation, this is known as logarithmic growth – the population doubles with each successive generation. Under favourable conditions, bacteria produce generation within 15min. Under unfavourable conditions 24 hours of more may be needed for each generation. Generation time for E.coli is 17 to 20 minutes.

Life forms are composed of one of two basic cell types : Eukaryotic or Prokaryotic. Generally, eukaryotic cells are larger and more complex than the prokaryotic cells and possess a membrane-enclosed nucleus; eukaryotic means ‘true nucleus’ (eu=true; karyon = nucleus). All plants, animals, fungi, protozoa and algae are composed of eukaryotic cells. Only the microorganisms classes as bacteria and the archaea are prokaryotic cells. Prokaryotic cells have no nuclear membrane and therefore lack a true nucleus. The latin prefix pro means ‘early’ and in this instance suggests the somewhat primitive nuclear structure found in bacterial cells. Eukaryotic microorganism are sometimes simply referred to as eukaryotes, and the prokaryotic microbes as prokaryotes.

Veterinary public health deals with the contributions of veterinary medicine to public health. It is concerned, in the first instance, with the control and elimination of zoonoses and also with the following areas of activity:
    ·    Food hygiene (production, processing and distribution of foods of animal origin)
    ·    Environmental contamination and degradation by animal wastes and animal products
    ·    Comparative medicine (eg. Studies in animals on naturally appearing cancer, cardiovascular disease, metabolic and other disorders encountered in humans)
    ·    Laboratory animal medicine
    ·    Education and training in VPH and communication with the public
    ·    Reproduction biology
    ·    Aspects of mental and societal health
    ·    Emergency veterinary functions in natural disasters and other catastrophes.

Introduction

The economic choice of any process is the criterion for efficient utilization of the by-product that is produced along side of main product. During manufacture of major dairy products, the dairy industry also ends up in producing different by-products. Various by-products of dairy industry are skim milk, butter milk , whey and ghee residue. Dairy industry is particularly confronted with the problem of economic utilization of whey and ghee residue. The techno-economical problems associated with utilization of these by-products, is now receiving considerable attention. More efficient, cost effective and sophisticated technologies have opened up new vistas for manufacture of number of derived by-products. Further more the market for dairy by-products, as an ingredients in other consumer food products like snacks, ready meals and microwavable food products, has been growing.

Introduction

In the recent past there has been a great deal of questioning regarding role of milk fat in cholesterol metabolism and other body functions. The enormous wave against cholesterol containing foods has damaged the image and market growth of fat rich dairy products. This trend is due to presence of saturated fats and cholesterol that are known to increase the incidence of coronary heart diseases one of the common cause of heart attack. The educated and urban society is more health conscious about the presence of cholesterol in their diets. This has led to the greater demand of cholesterol free foods. Ghee being a saturated fat and containing little amount of cholesterol, is suspected to contribute towards coronary heart diseases. However, critically surveyed scientific literature indicates that there is no evidence of any association of milk fat with increased risk of coronary heart diseases. Age old and proven Ayurvedic system of medicine has proved the usage of ghee to induce several beneficial effects on human health and used extensively for therapeutic purpose like in treatment of skin allergy, respiratory diseases, curative for ulcers and eye diseases. This suggest that ghee is a valuable form of dietary fat.

Introduction
Ghee is the pure clarified butter fat prepared chiefly from cream and/or desi butter (Makhan) to which no colouring matter is added.  Ghee manufacture has great significance and relevance to Indian masses and the dairy industry. Ghee is a very popular product since ancient time and has greater demand during festival and other ceremonial functions where use of ghee in food has been considered to delicacy due to its pleasing flavour and aroma. There are sufficient recorded evidence to prove that the manufacture of ghee originated from India and has been used extensively for religious and dietary purposes since Vedic times. Presently about 28% of total milk production is utilized for manufacture of about 1 million tones of ghee per annum. It is the traditional product with an established market. Cow ghee is golden yellow in colour, and is attributed unique therapeutic value.  The colour of buffalo ghee is greenish yellow due to presence of pigments called billirubin and billiverdin. Ghee is characterized by its pleasant, cooked and rich flavour. The preferred texture is of larger uniform size from grains having non-greasy consistency.

Introduction

The demand for butter as table spread has declined due to high cost, poor spreadability at low temperature, high saturated fat and cholesterol content, changing life style and increased demand for healthy products. Today food industry is actively involved in new product development, this includes new formulations and imitation of foods being designed to compete with or replace existing products based on their superiority in convenience, cost and quality. The wide acceptance of bread in regular diet among urban consumers (75 percent of all household) reflects around 8 percent rate of growth in bread consumption. With this increase, the requirement of a suitable spread to complement has also increased. Table spreads include a variety of spreadable semi-solid products such as fat spreads, cheese spread, peanut butter etc. Butter has also been blended with vegetable oils/fat to produce a product that retains dairy qualities of butter with enhanced spreadability.

Butter is one of the leading milk product in developed countries of the world. It serves as a balance wheel of dairy industry. Surplus milk is generally converted into butter to be used during the times of scarcity. It is an article of commerce and a sign if wealth. Butter is a fat concentrate, which is obtained by churning cream, gathering the fat into a compact mass and then working it for proper distribution of moisture and salt. The art of butter making has a long history. The manufacture of butter was confined to colder regions where gravity creaming was successful. The milk was allowed to stand undisturbed for 10-12 hours until layer of cream collects at the top.

Introduction
Makkhan (Makhan) is an indigenous(desi) butter obtained by hand churning of dahi using wooden beater (mathani). It is traditional unsalted butter characterized by its delectable and rich flavour. It is white in colour with slightly greenish tinge and has typical soft body and a smooth grainy texture with pleasant aroma. This product has been extensively used for dietary and religious practices since vedic times. The entire quantity produced forms an intermediate product for preparation of ghee (clarified butter fat). Nearly 30% of the total milk production goes for desi butter manufacture. The average yield of the product is very low ranging from 5.5-7.0% for every 100 kg milk used for the purpose. The chemical composition of the product is variable depending upon the method of manufacture. It is difficult to achieve the uniform standard of 20% moisture in the final product due to limitations in the technique adopted for its manufacture. The non fatty solids and lactic acid are derived from the method of preparation and preservation. Higher non fatty solids in makhan indicates use of self soured milk, while a high lactic acid content indicates prolonged storage and in sanitary conditions of manufacture.

Definition

It is one of the important portion of milk which forms a fatty layer on top of milk when left un-disturbed. It is a prime component of milk and comprises mainly of milk fat. It may be defined as “that portion of milk which is rich in milk fat” meaning portion of milk into which larger portion of milk fat has been gathered.  According to FSSAI, 2011 Malai and Cream are defined as –

Malai means the product rich in butter fat prepared by boiling and cooling cow or buffalo milk or a combination thereof. It shall contain not less than 25.0 per cent milk fat.

Several centuries ago, perhaps as early as 6000-8000 BC, ancient man learned to domesticate species of animals for obtaining milk for their consumption. These included cows, buffaloes, sheep, goats, and camels, all of which are still used in various parts of the world for the production of milk for human use. The significance of milk as the most wholesome single food available in nature has never been debated. It is as ancient as mankind itself. The role and consumption pattern of milk in the traditional diet varies widely in different regions of the world. The tropical countries have not been traditional milk consumers, whereas in Europe (especially Scandinavia) and North America, milk and milk products have been traditional parts of the diet.

13.1. Introduction

Diseases of dairy cattle cause huge economic losses. The losses are associated with lower productive and reproductive performances as well as mortality of the valuable animals. The high producing animals are susceptible to various infectious and contagious diseases. The diseases may permanently affect the performance of the animal e.g., mastitis may permanently damage the quarter(s) of the udder. Thus the culling rate of the herd may increase which affects the profitability of the farm. The occurrence of diseases in cattle is preventable. So, steps are needed to prevent the occurrence of diseases as prevention is better than cure. A number of factors are associated with the occurrence of diseases in animals. Disease prevention and control involves measures designed to prevent or reduce as much as possible the incidence, prevalence and consequences of the disease. These measures can be applied to control the reservoir of infection, break route of transmission or reduce the numbers of susceptible. Various new and environment friendly methods have been developed by modification or refinement of the old methods of disease control and prevention.

12.1. Introduction

Milking is the crucial operation in a dairy farm, as milk is the main source of revenue of a dairy farm. Milking is a labour intensive operation. About 50-60 percent of the total time of farm operation is required for milking and allied activities. Milking is an art which requires skill, patience, efficiency and experience. It should be handled quietly, quickly, gently, cleanly and completely, by avoiding any type of pain, annoyance or inconvenience to the animals. Possession of high yielding animals or good managemental conditions will not generate profit if the milking operation is inefficient.

1.1. Introduction

A typical dairy farm consist of different classes of dairy animals like calf, heifer, breeding heifer, pregnant, milch and dry animals and bull. The systems of management for the different classes are not same. They need some routine as well as periodical farm practices, some of which are common for all categories of animals (i.e., identification, dehorning, grooming etc.), while some categories need special farm operations (e.g., castration in males, milking etc.). Also there is need of routine disinfection of animal sheds and farm premises to prevent and control occurrence of diseases and maintaining the animals healthy. Further for proper execution of all these operations there is need of keeping farm records.  Keeping in view the above points, this section deals with some important farm management practices.

10.1. Introduction

During last few decades dairy animal production has been intensified several folds, along with this reproductive problems have also increased. For efficient dairy animal production, the cow should show regular reproductive activities like cyclic breeding activity, pregnancy at appropriate time, give birth of a live healthy calf and again pregnant after sometimes. If any of these activities are inadequate, then it substantially affects the profitability of the farm. There is an ample scope of improvement of these reproductive setbacks through traditional breeding, feeding and management. However, reproductive problems can be minimized by the use of recently developed reproductive techniques. It not only minimizes reproductive problems, but also improves the reproductive efficiency of the dairy herd and better exploitation of the genetic potential of high merit animals.

9.1. Introduction

Reproduction is an important event in the life of an animal (both male and female). The success of a dairy farm depends on the reproductive efficiency of cattle which depends on the efficient reproductive management. The animals should be reproductively sound. The cow should be a regular breeder with calving interval of 12-13 months to minimize the generation interval and to increase the profitability of the dairy farm. The bull should have high libido, produce good quality semen with high fertility rate.

8.1. Introduction

Providing appropriate nutrition is an elementary step in dairy animal production. Improper nutrition prevents cattle to express full genetic potential for milk production and reproductive efficiency. Nutrition helps in maintaining good health condition of the animal.

Therefore, one should know the basic digestive physiology, various types of nutrients and their requirements in different categories of animals present in a dairy herd. As feed cost contributes principal expenditure of a dairy farm, balanced ration should be prepared in a cost effective manner. Proper understanding of feeds and rations also help to explore alternative feeds and supplements without hampering the health as well as productivity of the animals. Effective dairy farming requires converting feed into milk which worth more than the total cost of production (mostly contributed by feed cost).

7.1. Introduction

The lactating cows are important assets of a dairy farm. The profitability and viability of the dairy farm mainly depend on the overall milk production. The lactation cycle of the cow can be divided into different phases for efficient management as milk production, DM intake and body weight vary considerably during the different phases. In the early lactation, lactating animals loose body weight drastically and they are prone to various metabolic disorders. Efficient nutritional management during lactation is required to support the high milk production, persistency of lactation and health of the cows. Another most important event is the post partum oestrus and subsequent conception, which depends on the care and management of the cows during this period. Therefore, proper care and management of the lactating cows are essential to harvest maximum amount of milk from healthy cows in a sustainable way.

6.1. Introduction

Care of cows at and after calving is vital for successful birth and maintaining the cow and calf in proper health condition. Calving is a high risk event in terms of both cow and calf health, and is associated with most of the health problems. New born calves are born sterile and it gets infection from the surroundings which depends on the maintenance of hygienic environment and care of the just after birth. The fresh cows are susceptible to a number of metabolic diseases and infections due decrease immune status of the cow. Preparation and care during this period will minimize sickness and death of the cow and calf.

5.1. Introduction

A dry cow is a cow that is not producing milk. Usually cow remains in-milk for about 305 days (average lactation length), after that it remains for a period of about 60 days in dry condition (not giving milk) called dry period. Dry period is critical for a cow for regeneration of her udder and reserve nutrients for the next lactation, otherwise, milk production will not be upto the mark and the cow may suffer from several metabolic diseases after parturition. A dry cow is just as valuable as a lactating cow, therefore should be not neglected. A dry cow management programme includes nutrition, general management and health control programme.

4.1. Introduction

Heifers are young female cattle from 12 months of age to first calving. Heifer management is important as they are future cow of the herd. Proper growth and body condition of the heifers are associated with their early sexual maturity and age at first breeding, and their later productive and reproductive performances, when they become cow. Thus, proper care and management of the heifers is necessary to establish a good dairy herd.

3.1. Introduction 

Calves are the future replacement stock of dairy farm. The raising of calves, an important operation of the dairy farm requires a great deal of managemental skill, application and constant attention. Any negligency results in increased calf mortality, poor growth and development of the calves. So, care of the calves is important for success of the dairy farm.

2.1. Introduction

A system of housing is more or less synonymous to the system of management of dairy cattle. Housing is essential to protect the animals from extreme climatic conditions, wild animals and theft. Housing also helps to maintain normal health of the animal by proper feeding, watering and reducing environmental stresses. An efficient housing system ultimately leads to an efficient management and reduce labour requirements to the minimum.

1.1. Introduction

Dairy animal production in the last few decades witnessed tremendous growth throughout the world. The remarkable success of the dairy animal production can be attributed to the constant efforts of researcher, planner as well as producer. At present dairy farming is becoming a commercial activity. Hi-tech dairy farms produce high quality milk for making value added milk products for competitive markets around the world. The management of the dairy farming enterprises is crucial for the sustainability and profitability of it. The effective management of dairy animals essentially emphasizes the following areas:

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.

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

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

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

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

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.