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A white to light brown powder, is a heteropolysaccharide derived from the cell wall of higher terrestrial plants. It is mainly used in food as a gelling agent in jams and jellies. Today it is also used in fillings, sweets, as a stabiliser in fruit juices and milk drinks and as a source of dietary fiber in foods. Pectin is a heterogeneous grouping of acidic structural polysaccharides, found in fruit and vegetables and mainly prepared from ‘waste’ citrus peel and apple pomace. Pectin has a complex structure. Preparations consist of sub-structural entities that depend on their source and extraction methodology. Commercial extraction causes extensive degradation of the neutral sugar-containing side chains.

Pectin was first isolated and described in 1825 by Henri Braconnot, though the action of pectin to make jams and marmalades was known long before. To obtain well set jams from fruits that had little or only poor quality pectin, pectin-rich fruits or their extracts were mixed into the recipe. During industrialization, the makers of fruit preserves soon turned to producers of apple juice to obtain dried apple pomace that was then cooked to extract pectin. Later, in the 1920s and 1930s, factories were built that commercially extracted pectin from dried apple-pomace and later citrus-peel in regions that produced apple juice in both the USA and in Europe. At first pectin was sold as a liquid extract, but nowadays pectin is often used as dried powder that is easier to store and handle than a liquid

Fruit and vegetables play an important role in human nutrition. They are vital source of essential minerals, vitamins and dietary fibre and supply complex carbohydrate and protein. They are good source of calcium, phosphorus, iron and magnesium and contribute over 90% of dietary vitamin C. Green and yellow fruits and vegetables are a rich source of vitamin A (β-carotene). Thiamine, niacin and folic acid, which are required for normal functioning of the human body, are also present in significant qualities. Fruit is an important food in diet designed to reduce the risk of coronary heart disease in developed countries. It is not surprising, then, that certain fruit components exert pharmacological or therapeutic effect. The antioxidant properties of β -carotene may also a role in prevention of some forms of cancers. Packing and handling systems have been developed to move the product from farm to consumer expeditiously in order to minimize quality degradation. Food irradiation is a physical process like drying, freezing, thermal processing (canning and pasteurization) that can be used to disinfest, sterile and preserve food. The use of chemical preservatives to inhibit the growth of spoilage bacteria in modern food system has been recognized as deterrent to health. The present day, customer demands food products with no chemical preservatives, free from additives, natural with assured safety and better long shelf life.

The deterioration in foods during storage may include loses in organoleptic desirability, nutritional value, safety and aesthetic appeal. Food is subjected to physical, chemical and biological deterioration. Heat, cold, light, humidity, other radiation, gas composition, moisture, dryness, natural food enzymes, micro and macro organism, and industrial contaminants are adversely affect the food quality and their shelf life. The practice of drying, curing and fermentation are among the conventional methods of preservation used for thousand years.

The paddy grain contains a rough outer covering called husk. It accounts for about one-fifth to one - fourth of the weight of paddy. The inner kernel, called brown rice or dehusked rice, again contains some soft outer layers, jointly called bran. It accounts for about 6-8% of the brown rice weight, including the small germ (1-2% by weight) located in one corner. Rice milling is the process of removing the husk and a part of the bran from paddy in order to produce edible rice. Rice milling system ranges from the home-scale to the large, complex modern rice-processing installations. They include hand-pounding equipment, single hullers, emery sheller-cum-huller mills, emery sheller-cum-cone polisher mills and the modern rubber – roller rice mills. Rice milling industry does not only mill rice but it also carries many other essential functions, such as cleaning and grading, drying, storage, quality control etc. for the production of better quality rice. All these processes are discussed in this paper.

Unlike other food grains, rice is mostly consumed as cooked whole grain, Milling technology is therefore geared to obtain maximum outturn of milled rice and to reduce breakage to the minimum. The single huller mills are by and large located in villages or in localities where paddy is custom milled for produces and they still handle the bulk of the country’s production. The large-capacity rice mills located in urban or semi-urban areas for commercial milling are of ½ to 4 tones per hour capacity and handle the rest of the paddy milled. Some battery hullers are still in operation as large commercial mills, specially for milling parboiled paddy.

Foods are classified into three groups on the basis of ease of spoilage. Spoilage meant a condition produced by the excessive growth of microorganisms leading gradually to decay or decomposition. The stable or non perishable foods like sugar, flour, grains and dry products do not ordinarily spoil unless handled carelessly. The semi-perishable food like potatoes, onions, apples, waxed fruits, fruits and vegetables having thick skin can be protected from spoilage if properly handled and processed. The perishable foods, like livestock products, seafood, and poultry items, dairy products, and most fruit and vegetables spoil readily unless special preservatives methods are used. The spoilage of foods may be caused by molds, yeast, bacteria, enzymes, food constituents and insects. The use of food additives have become necessary to prevent spoilage other wise caused by the growth of bacteria, yeasts and molds.

Food spoilage usually refers to undesirable changes occurring in food due to the action of micro-organisms, insects and enzymes. The original nutritional value, texture, flavour of the food are damaged, the food become harmful to people and unsuitable to eat. Today however, preservation has used such factors as temperature, water activity, pH, gases, organic acids, salts, antibiotics, irradiation, packaging and various combinations of these factors. Foods vary greatly in the length of time for which they can be held in their natural form without spoilage. Preservatives retard product spoilage caused by mold, air, bacteria, fungi or yeast. Bacterial contamination can cause food-borne illness, including life-threatening botulism.

In India, people are mostly vegetarian, depending largely on cereals and pulses, as their staple foods, which provide the main source of dietary proteins and calories. The proteins from pulses are known to be inferior quality, due to the deficiency of sulphur containing amino acids as well as due to other factors like digestibility, availability of amino acids, anti-nutritional factors, etc. The anti-nutritional factors present in this type of food, including their contents of enzyme inhibitors, lectins, flatulence factors, tannins, phytic acid and saponins. Anti-nutritional factors can cause detrimental effects to humans and animal growth and performance by impairing intake, uptake, or utilization of other food and feed components, or by causing discomfort and stress to humans and animals. The anti-nutritional factors mainly occur in pulses and grain legumes and foods and feed material prepared from grain legumes and pulses.

Substance which, from nutritional point of view, interferes with normal growth, reproduction or health when consumed regularly in amount existing in a normal component of diet should be considered as harmful and toxic. A significant part of human population relies on legumes as staple food for subsistence, particularly in combination with cereals. They are unique foods because their rich nutrient content including starch, protein, dietary fibre, oligosaccharides, phytochemicals (especially the isoflavones in soybean) and minerals. Their nutritional contents contribute to many health benefits to human.

Food technologies now have more sweeteners from which to choose than ever before. With the obesity epidemic and the public attention it currently receives, plus the increasing interest in foods with added benefits sweeteners that allow for consumer appealing labeling are of particular interest. These sweeteners fall into basic categories, those that are essentially calories free, often referred to as low-calories or intense sweeteners, and those, which are significantly reduced in calories, which may be referred to as reduced calories-sweeteners, bulk sweeteners, or sugar replaces. These sweeteners when used alone or in combination may permit such labeling as ‘low-calories’, ‘reduced-calories’, ‘light’ ‘sugar-free’ and ‘dose not promote tooth decay’.

The ideal sweeteners does not exist, it would be at least as sweet as sucrose and provide the same properties to a product as sucrose, with processing parameters similar to those of sucrose so that existing equipment can be used. It would be colourless, odourless and noncariogenic, with a clean, pleasant taste and have immediate onset and not much lingering. Solubility and stability are important. The ideal sweetener must be compatible with a wide range of food ingredients because sweetness is but one element of a complex food flavour system. Even sucrose is not perfect, being unsuitable for some applications.

Extrusion cooking is an emerging technology having advantages of low production cost, capable of producing end products in various shapes and sizes, from a variety of food materials with easy digestibility, maintaining hygiene and high product quality and leaving no effluents or hazardous materials. Minimal energy consumption and processing costs and possibility of flavour addition are the added advantages of technology. The process/technique has the versality and ability to constituently produce a given product in continuity at a given set of pre – determined specifications. It destroys fat splitting enzymes to avoid rancidity and thus extends the shelf life of products considerably. Microorganisms present in food materials are destroyed. It can be effectively utilized to develop functional and designer foods by using several locally available under-utilized food materials. However, it leads to increased package cost as puffed or expanded food products have low bulk density. R & D studies are further needed for co – extrusion of variety of cereals with high fibre content foods and micronutrients.

Fruit jelly is an important part of diet of all human being. It is easily digestible, highly refreshing, appetizing and nutritionally far superior to many foods. Today, a wide variety of fruit jellies are consumed in the home, at work place and sport stadium. There has been considerable increase in the consumption of fruit and vegetable jellies in the world during last few years. Jelly is a semi-solid product prepared by boiling a clear strained fruit extract free from pulp after the addition of required amount of sugar, citric acid and pectin. It should contain minimum 65 percent of total soluble solids and minimum 45 percent of fruit portion (Dhawan, 1998). Guava is rich source of pectin and acid content and have thick flesh is preferred for jelly making. For getting good quality jelly, mix under-ripe fruits give better pectin content and ripe fruits provide the flavor. Winter season fruits yield better quality jelly (Singh and Dhawan, 1983). It is a clear or translucent fruit spread made from sweetened fruit (or vegetable) juice and set using naturally occurring pectin. Additional pectin may be added where the original fruit does not supply enough. Jelly can be made from sweet, savory or hot ingredients. It is made by a process similar to that used for making jam, with the additional step of filtering out the fruit pulp after the initial heating.

Jellies are the products used as bread spreads all over the world. These are made from fruits rich in pectin. Guava, because of its rich pectin content, is processed into jelly. Processing of guava into jelly is practiced by processors all over the world. Colouring of jams and jellies has been an age old practices colorants. Great attention is being paid now days to the usage of natural colours in view of the hazards that the synthetic colours pose to human health. Incorporation of carrot resulted in colour improvement over control. Jelly containing carrot as a colouring source was found slightly better than other vegetables. Jelly is a semi-solid product prepared by boiling a clear strained fruit extract free from pulp after the addition of required amount of sugar, citric acid and pectin. It should contain minimum 65% of total soluble solids and minimum 45% of fruit portion (Dhawan, 1998).

Much of the post-harvest losses of fruits and vegetables in developing countries is due to the lack of proper storage facilities. While refrigerated cool stores are the best method of preserving fruits and vegetables they are expensive to buy and run. Consequently, in developing countries there is an interest in simple low-cost alternatives, many of which depend on evaporative cooling which is simple and does not require any external power supply. India is the second largest producer of fruits and vegetables in the world after Brazil and China respectively. Storage of fresh horticultural produce after harvest is one of the most pressing problems of a tropical country like India. India’s total fruits and vegetables production is lost during harvest, storage, grading, transport, packaging and distribution in a year which reduces the growers share. Due to their highly perishable nature, about 20-40% of total fruit and vegetable production go waste during various steps of the post-harvest chain, smooth transport and insufficient cool storage space/ facility at farmer’s level and high cost of refrigerated storage so further enhances loss of fruits and vegetables. Temperature and humidity play major role in storage of fruits and vegetables Temperature can be controlled by using energy consuming methods such as air-cooling, hydro-cooling, vacuum-cooling, chilling, ice cooling, freezing, etc.

Food is a complex system of inorganic and organic compounds. These compounds are present in food in unique combination and uniquely organized structures, and therefore, every type of food has unique characteristics, nutritive value, sensory quality, texture, etc. Food items are always in physical, chemical and biological dynamics, however rate of change vary from food to food. Those highly perishable in nature undergo faster rate of spoilage as compare to those semi-perishable or stable. Foods are affected by nearly every variable of environment. Heat, cold, light or other radiations, oxygen, moisture/dryness, natural food enzymes, microorganisms, macro-organisms, industrials and agricultural contaminants, time, etc. - all adversely affect the foods resulting to its spoilage or deterioration. Spoilage may be referred to the losses in nutritive value, sensory desirability, safety and aesthetic appeal to the unacceptable level. Level of unacceptability is the subject of socio-economic status and policies of the state. A food which is of unacceptable quality for one society may be of acceptable quality for other society.

History reveals that food was the root cause of many wars and also the battles were won or lost over food spoilage and its control. Wars and the need to provide safe food to armies in the region far away from the areas of their production have always focused attention on the problem of food spoilage, and this valid today even. Some of the most important advancements in the technology of food preservation were made during the war-time. Of these, most important was the technology of preventing food from spoilage for months together developed by French scientist Nicolas Appert for French army. He won awarded money of 12,000 Francs in 1908 for this. The World learnt the art of canning foods in which the food is packed in a sealed metal container and heated sufficiently. He, however, could not explain the principle behind the preservation by canning. Some 50 years later, work of Louis Pasteur explained that the growth of microorganisms was the major cause of food spoilage which are killed in Appert’s method of preservation.

Fruits and vegetables are very important food commodities not only in developing country like India but all over the world. India, which is the most densely populated country in Asia continent, is still struggling to achieve self-sufficiency to feed about 135 crores people. For this purpose, fruits and vegetables have got their specific importance to provide a balance and healthy diet to the Indian people. Therefore, the reduction of post-harvest loss of fruit and vegetables is a complementary means for increasing production. It may not be necessary to considerably step up the production of fruits and vegetables with the growing demand if the post-harvest loss is reduced to a great extent. The cost of preventing losses after harvest in general is less than preventing a similar additional amount of fruit and vegetable crop of the same quality

Fruits are important source of Pro-vitamin A and vitamin C. In addition, vegetables also supply fair amount of carbohydrates, protein and energy and add colour, flavour and aroma to human diet. India is one of the largest producers of fruits and vegetables. Fruits and vegetables are an important supplement to the human balanced diet as they provide the essential minerals, vitamins and dietary fibre (roughage) for maintaining the tear and wear of the over body. Fresh fruit and vegetables have a short shelf life under ambient conditions of temperature and humidity due to their highly perishable nature. They soon lose their freshness and become subjected to mould and bacterial attack, and consequently decay and become useless as articles of human diet. Fresh fruits and vegetables are valued for their quick sources of available energy. Fresh fruits have high water content (70-96%), varying amount of carbohydrate (3-27%) and fibre (0.2-3.1%) and a low content of protein, fat and minerals. Ideal climatic conditions ensure round the year availability of broad range of fruit and vegetables in large quantities. The production of fruits and vegetables was 97.00 MT and 179.60 MT during the 2017-2018 in India

India is today the second largest producer of fruit and vegetable after China with a total annual production of 281.75 million tons in 2017-18. Fruit and vegetables are essential components of the human diet and nutrition constitute. Fruit and vegetable are also element of diversification in agriculture for additional income generating resource and employment generation area. Although India is the largest producer of fruit in the world, the production per capita is only about 100 g per day. Huge losses to the extent of 20 to 40% of the total production are reported due to lack of adequate infrastructure and transportation facilities and higher the transportation cost. Thus the per capita availability of fruits is further reduced to 60 -80 g per day which is almost half the requirement for a balanced diet. The fruit production in India has recorded a growth rate of 3.9%, whereas the fruit processing sector has grown at about 20% per annum. However, the growth rates have been extensively higher for frozen fruits and vegetables (121%) and dehydrated fruits and vegetables (24%).

Fruit and vegetables are mostly seasonal crops but they are demanded by consumers throughout the year. They are very highly perishable in nature, which is difficult to preserve for the longer period of time under ambient storage conditions. The low temperature storage retarded the activity of various biological and biochemical agents of spoilage and provides longer shelf life to the fruit and vegetables The temperature is brought down by taking out the heat with the help of mechanical refrigeration, This system is based on a liquid absorbing heat as it change to a gas. The more common mechanical refrigeration system use a refrigerant such as (Ammonia, Freon etc.,) takes out the heat from the chamber/ store as it is expand. The spoilage agents are microorganism such as (e.g., bacteria, yeast and molds etc.) and larva. Optimum storage temperature for most products is one slightly above the freezing point of the product. Some fruit and vegetables are particularly sensitive to storage temperature are susceptible to called storage disease when stored at temperature below as or above the critical temperature e.g.,

Packaging is essential for the safe and easy marketing of any food products and for the retention of their natural characteristics till consumed or utilized otherwise. Packaging is also an essential part of processing and distribution of foods. Packaging used for processed foods can contribute marketing to the retention of the quality characteristics. It must protect a variety of assaults including physical damage, chemical attack and contamination from biological vectors including microorganisms, insects and rodents. Environmental factors such as oxygen and water vapour will spoil foods if they are allowed to enter packages freely. Contamination of foods by microorganism can spoil foods or cause life-threatening diseases. With dehydrated food, packaging serves a multi protection role. Depending on the product being packed, packaging has to provide protection against moisture pick up, loss of volatile components, oxidation and damage of product itself. With the development of food industries, use of different types of plastic containers becomes widely popular owing to its several advantages.

Although packaging has, in recent years, been accused of using up valuable resources, it is nevertheless absolutely essential. Packaging is vital to protect and conserve the items contained within it. The dominant purpose of packaging is to protect the product so that it reaches the consumer in the same condition as when it was first made. However there is a lot more to the effectiveness and usefulness of packaging than just protection. When a consumer picks up their carton of freshly squeezed mango juice, they are not aware of the energy and money saved by the packaging they are grasping in their hands. In order to fully understand the essential role packaging plays in every day life, it is necessary to understand the guiding principles behind it.

Food is a major determinant of health, nutritional status and productivity of the population. It is, therefore, essential that the food we consume is wholesome and safe. Unsafe food can lead to a large number of food-borne diseases. It is necessary that the food available is safe, hygienic, wholesome and its quality must be assured. Quality of foods can be defined as the ‘composite’ of those ‘characteristics’ that differentiate individuals units of a product and have significance in determining the degree of acceptability of that unit by the buyer. In general, the quality control is the maintenance of quality at levels and tolerance acceptable to the buyer, minimizing the cost for the vender. But, from the scientific angle the overall quality refer to technical, physical, chemical, microbiological, nutritional and sensory parameters to achieve the wholesome food. These quality factors depend on the specific attributes such as sensory properties, based on flavour, colour, aroma, taste, texture, quantitative properties viz. percentage of sugar, protein, fibre etc and hidden attributes like peroxide, free fatty acids, enzymes etc. Though quality attributes are many, not all need to be considered for a particular product. It is imported to determine how far relatively the factor is in relation to the total quality of the product.

Hence, the quality attributes of a particular is based on the composition of the product, expected deteriorate reaction, packaging used, shelf required and the type of the consumer i.e., deployed in terrain conditions or in peaceful situation. With the ultimate goal of protecting the consumer, quality standardization systems have come into force for regulating the gamut of operations in food manufacture. In a broader sense, food laws and Regulation cover the related acts affecting the marketing, production, labeling, food additives used, dietary supplements, enforcement of General Manufacturing Practice (GMP), Hazard analysis and critical Control Point (HACCP), federal laws and regulations, factory inspections and important-export inspections.

The food is considered as one of the essential for the maintenance of life. Manufacturing of the food product is not enough form the food industry. It is necessary that the food available is safe, hygienic; wholesomeness and its quality must be assured. The food industry is an important segment of industries in India and has its own peculiarities unlike other industries. Food processing industry has been recognized by government as a major sector of growth. It must be free from harmful additives, microbes and remain so for a period, it is intended to be consumed. Therefore, the methods employed in quality and food safety assurance programme within the food industry will vary considerably in accuracy and sophistication according to the type of process and size and nature of resources available. Since the international market has become demanding in terms of quality, safety and delivery, installation of Hazard Analysis Critical Control Point (HACCP) in food industry would provide a competitive edge to food supplies in the international market. Food control refers to all activities carried out to ensure the quality, safety and honest presentation of the food at all stages from primary production through processing and storage, to marketing and consumption. The term has been used to describe a total national effort involving an integrated approach between government and all segment and sectors of the food industry. Food control is linked to improvement in the health of the population, potential of a country’s economic development and reduction of spoilage and food losses.

A wide variety of quality determinants is employed, including size, colour, maturity and extent of blemishes. Quality is a measure of the degree of excellence or degree of acceptability by the consumer. The marketing of fresh fruit and vegetables is aimed eventually ay appealing to the consumer for whom tradition plays a major role in determining the acceptability of a food item. The eating habits of people are conservative. The increase of direct market from producer to supermarket chains is leading to the imposition of standards to predetermined specification by the supermarkets. Important factors in quality for the consumers are: appearance, including size, colour, shape, condition and absence of defects, texture, flavour and nutritional value. Quality is the ultimate criterion of the desirability of any food product to the consumer. The overall quality of food depends on the nutritional and other hidden attributes. Quality of foods can be defined as the ‘composite’ of the ‘characteristics’ that differentiate individual units of a product and have significance in determining the degree of acceptability of that unit by the buyer.

The word nutrition first appeared in 1551 and comes from the Latin word nutrire, meaning “to nourish.” Today, we define nutrition as the sum of all processes involved in how organisms obtain nutrients, metabolize them, and use them to support all of life’s processes. Nutritional science is the investigation of how an organism is nourished, and incorporates the study of how nourishment affects personal health, population health, and planetary health. Nutritional science covers a wide spectrum of disciplines. As a result, nutritional scientists can specialize in particular aspects of nutrition such as biology, physiology, immunology, biochemistry, education, psychology, sustainability, and sociology.

Disease is defined as any abnormal condition affecting the health of an organism, and is characterized by specific signs and symptoms. Signs refer to identifying characteristics of a disease such as swelling, weight loss, or fever. Symptoms are the features of a disease recognized by a patient and/or their doctor. Symptoms can include nausea, fatigue, irritability, and pain. Diseases are broadly categorized as resulting from pathogens (i.e., bacteria, viruses, fungi, and parasites), deficiencies, genetics, and physiological dysfunction. Diseases that primarily affect physical health are those that impair body structure (as is the case with osteoporosis), or functioning (as is the case with cardiovascular disease). Mental illnesses primarily affect mental and social well-being.

The foods we eat contain nutrients. Nutrients are substances required by the body to perform its basic functions. Nutrients must be obtained from diet, since the human body does not synthesize them. Nutrients are used to produce energy, detect and respond to environmental surroundings, move, excrete wastes, respire (breathe), grow, and reproduce. There are six classes of nutrients required for the body to function and maintain overall health. These are carbohydrates, lipids, proteins, water, vitamins, and minerals. Foods also contain non-nutrients that may be harmful (such as cholesterol, dyes, and preservatives) or beneficial (such as antioxidants).

The foods we eat contain nutrients. Nutrients are substances required by the body to perform its basic functions. Nutrients must be obtained from diet, since the human body does not synthesize them. Nutrients are used to produce energy, detect and respond to environmental surroundings, move, excrete wastes, respire (breathe), grow, and reproduce. There are six classes of nutrients required for the body to function and maintain overall health. These are carbohydrates, lipids, proteins, water, vitamins, and minerals. Foods also contain non-nutrients that may be harmful (such as cholesterol, dyes, and preservatives) or beneficial (such as antioxidants). Nutrients that are needed in large amounts are called macro-nutrients. There are three classes of macro-nutrients: carbohydrates, lipids, and proteins. These can be metabolically processed into cellular energy. Micro-nutrients are nutrients required by the body in lesser amounts, but are still essential for carrying out bodily functions. Micro-nutrients include all the essential minerals and vitamins. There are sixteen essential minerals and thirteen vitamins.

A forest is a large area dominated by trees. Many definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing and ecological function. Although a forest is usually defined by the presence of trees, under many definitions an area completely lacking trees may still be considered a forest if it grew trees in the past, will grow trees in the future, or was legally designated as a forest regardless of vegetation type. According to the Food and Agriculture Organization, forests covered four billion hectares or approximately 30% of the world’s land area in 2006. Forests are the dominant terrestrial ecosystem of earth, and are distributed around the globe. Forests account for 75% of the gross primary production of the earth’s biosphere, and contain 80% of the earth’s plant biomass.

DEVELOPMENT OF MODERN FORESTRY

Systematic management of forests for a sustainable yield of timber began in Portugal in the 13th century when Afonso III, the king of Portugal planted the trees to prevent coastal erosion and soil degradation, and as a sustainable source for timber used in naval construction. His successor Dom Dinis continued the practice and the forest exists still today. Forest management also started in Germany in the 14th century and in Japan in the 16th century. The practice of establishing tree plantations in the British Isles was promoted by John Evelyn during second half of the 17th century.

During the late 19th and early 20th centuries, forest preservation programmes were established in British India, the United States and Europe. Sir Dietrich Brandis is considered the father of tropical forestry. He brought European concepts and practices to the tropical and semi-arid climate zones. The enactment and evolution of forest laws and binding regulations occurred in most Western nations in the 20th century in response to growing conservation concerns. Tropical forestry is a separate branch of forestry which deals mainly with equatorial forests that yield woods such as teak and mahogany. One of the applications of modern forestry is reforestation, in which trees are planted and tended in a given area.

Agroforestry is a new name for a set of old practices. The general concept of agroforestry is to integrate trees and agriculture so as to create a more diversified landscape, while providing the producers with new environmental and economic benefits. In other words, agroforestry is a method of farming that allows trees and shrubs to grow along with crops and/or livestock, therefore blending agriculture and forestry in the same production system. In fact, man’s association with forest is much older than with agriculture. First man was a food gatherer and hunter in forests. Then he realized that the seeds of the fruits he collected germinated, grew into plants and bore the fruits again and thus man started to cultivate foods. Man’s desire to live in a community created settled agriculture.

The pressure on the agricultural lands has increased manifolds due to the increasing population, expansion of urban area and the industrialization process. The environment has also been disturbed. Soil is losing its productivity and the biodiversity is threatened. Farming community is trying all means to increase the land productivity. Chemical fertilizers and pesticides are applied in higher proportion, causing environmental pollution hazards. Under all these circumstances agroforestry has shown that besides sustainable agriculture it can also help promote a better environment. Trees have always played an important role in mankind’s survival. This relatively young science known as agroforestry was brought from the realm of indigenous knowledge into the forefront of agricultural research four decades ago and was promoted widely as a sustainability-enhancing practice that combines the best attributes of forestry and agriculture.

Trees have been used in cropping systems since the beginning of agriculture. Throughout the world, at one period or another in its history, it has been the practice to cultivate tree species and agricultural crops in intimate combination. In the tropics, human beings underwent a transition from hunting/gathering to the use of domesticated plants and livestock. As a part of the process, they cut down trees, cleared the debris by burning and sowed crops in the ash-enriched soil. It was the ‘slash-and-burn’ agriculture, a primary forerunner of the present-day agroforestry and a practice that might have originated in the Neolithic period, around 7000 BC.

There are innumerable examples of traditional land-use practices involving combined production of trees and agricultural species on the same piece of land in many parts of the world. Trees were an integral part of these farming systems and they were deliberately retained on farmlands to support agriculture. These practices are now known as agroforestry. However, the ultimate objective of these practices was not tree production but food production.

The words ‘system’, ‘sub-system’ & ‘practice’ are commonly used in agroforestry literature. In a broad sense, a system is defined as a group of associated elements forming a unified whole and working together in a well-defined regular relation for a common goal. An agroforestry system refers to a type of agroforestry land-use that extends over a locality to the extent of forming a land utilization type of the locality. Sub-system and practice are lower-order terms in the hierarchy with lesser magnitudes of role, content and complexity. However, these terms are used loosely, and almost synonymously.

Classification of agroforestry systems is necessary in order to understand and provide a practical framework for evaluating systems and developing action plans for their improvement. Any classification scheme should satisfy the following criteria (Nair, 2008).

The word ‘social forestry’ was coined by Westoby and used in the ninth Commonwealth Forestry Conference at New Delhi in 1968. In India the term was first used by the National Commission on Agriculture, Government of India in 1976, to denote tree raising programmes to supply firewood, small timber and minor forest products to rural population. Prasad (1985) defined social forestry as forestry outside the conventional forests which primarily aims at providing continuous flow of goods and services for the benefit of people. This implies that the production of forest goods for fulfilling the needs of the local people is social forestry. Thus, conceptually it deals with the people to produce goods such as fuel, fodder, small timber, etc. to meet the needs of local community particularly the underprivileged section (Shah, 1988).

Urban forestry is not a new concept, but it is one which appears to have growing potential. With increasing urbanization in the 20th century, the incorporation of trees into urban settlements has also increased. The management of all trees within the urban area is considered a distinct discipline of forestry. Urban forestry was conceptualized in the late 1960s in North America, and grew out of what was initially termed environmental forestry. Trees and urban forests can make our cities cleaner, cooler, greener, safer, healthier, happier and nice places to live.

Management approaches to soil, including problems of soil degradation and low soil fertility, have recently undergone major changes. The earlier concept was to concentrate on achieving high levels of production from the more fertile areas, leaving the marginal lands for extensive use only. Steeply sloping and highly drought-prone areas were mostly left without any cultivation as production from these areas was hardly cost effective. Soil constraints were to be overcome by inputs like improved crop varieties, fertilizers, chemical control of pests and diseases, and the use of irrigation.

The approach of use of newly developed high yielding crop varieties, improved agronomic management practices, use of chemical fertilizers, efficient water management and timely plant protection measures has been successful in achieving large increases in crop productivity in recent years. On the other hand, continuous application of fertilizers at higher rates leads to environmental problems. Yield responses to fertilizers have declined because of soil physical degradation and micronutrient deficiencies. Above all, large numbers of poor farmers simply can neither afford high levels of fertilizers and other purchased inputs, nor do they have the capital to take on the risk involved in their use. Increasing the area under irrigation has also run into severe constraints in the form of limits to available freshwater resources.

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/ or animals interact. Interaction literally means influence or mutual or reciprocal action. So, component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

The success of an agroforestry system relies heavily on exploitation of the component interactions. In an ideal relationship, production of trees as well as crops or grasses in combination could be comparable to their sole performance. Agroforestry could be even more advantageous if the production of associated components is increased due to influence of trees. This is possible because trees are capable of improving productivity of soil in many ways. A large number of trees are known to fix nitrogen symbiotically. Nevertheless, instances of crop inhibition in association of trees are not uncommon. Such inhibitions are primarily caused by shade effect as well as competition for below-ground resources such as nutrients and water. In some cases, inhibitory effect may also result from allelochemicals secreted by some of the tree species.

Farmers have been growing trees for different purposes for thousands of years. Tree species that are grown to provide more than one significant function are called multipurpose trees. These functions may be productive such as producing fuelwood, timber, fibre, fodder, food, medicine, etc. and/or protective such as soil conservation, shade, shelterbelt, microclimate amelioration, land sustainability, biodiversity preservation, etc. All trees are multipurpose; some, however, are more multipurpose than others. Tree species can be multipurpose in two ways.

Agroforestry is a land use system that involves two or more plant species at least one of which must be a woody perennial. When perennial woody and herbaceous components are grown together on the same piece of land their performance would largely depend on their ability to share various growth resources in a given environmental situation. Due to difference in growth pattern and resource requirement of the components in agroforestry situation, a close interactive relation is obvious. Thus, careful management practices for the components are required to establish a successful agroforestry system. The characteristics of the trees and crops, and their interactions, can be modified with good management practices in order to take advantage of the positive characteristics and minimize the effects of the negative ones. Effective and efficient agroforestry management may be divided into two groups; tree management and agricultural crop management.

FACTORS AFFECTING THE SELECTION OF TREE SPECIES

Trees in an agroforestry system contribute significantly to the total output of the system and therefore, success of the system depends on the selection of the tree species. The following factors are to be considered to choose the best tree species for the agroforestry systems in a particular site.

Ecology of a place is influenced by a number of biotic and abiotic factors. An agroecological zone is broadly homogeneous in climatic and edaphic factors, but not necessarily contiguous, where a specific crop exhibits roughly the same biological expression. On the other hand, the characteristics of an agroecological zone influence the crops and cropping patterns of the zone. Thus, there are considerable variations in the types and management practices of agroforestry systems being followed in different agroecological zones.

AGROFORESTRY FOR HUMID AND SUBHUMID TROPICS

Humid and subhumid tropical regions have much variation in biological, social and economic parameters. The characteristics of humid tropics include high mean annual rainfall of more than 1500 mm, dry season of less than four months in a year and mean annual temperature of more than 22° C. Rainfall usually exceeds the evapotranspiration. However, demographic pressure has caused excessive deforestation and overgrazing which developed soil related problems like low soil fertility, low organic matter, high acidity and high rainfall erosivity. The agroforestry practices designed for this region should aim for improved fallows, soil fertility improvement and conservation, food production, etc. Thus, the common agroforestry systems in this zone are taungya, homegardens, alley cropping, plantation-crop combination, windbreaks, silvipastoral systems and various intercropping systems. Shifting cultivation is a common practice in tropics which should be discouraged as it causes environmental degradation and ecological imbalance, soil erosion and soil nutrient loss.

A watershed is a geohydrological unit or all the land and water area bounded by a divide which contributes runoff to a common point. Watershed is considered to be synonymous with ‘catchment basin’ and ‘drainage basin’. In watershed management approach, development is not only confined to agricultural lands but also covers the area, starting from the highest point of the land to the outlet of the natural stream. Watershed management becomes increasingly important as a way to improve livelihood of people while conserving and regenerating their natural resources.

Watershed management is the process of creating and implementing plans, programmes and projects to sustain and enhance watershed functions that affect the plant, animal and human communities within a watershed boundary. It implies the judicious use of all the resources, i.e., land, water and vegetation in an area to prevent soil erosion, improve water availability and increase food, fodder, fuel and timber on sustained basis.

India shares 17.4% of the world population, while its land is only 2.4% of the total geographical area of the world. Naturally, the pressure on the land is often beyond its carrying capacity. Therefore, the productive lands, especially the farmlands in India are in the constant process of various degrees of degradation and are fast turning into wastelands. At present, approximately 55.76 million hectare area of the land is lying as wastelands in India. Out of these lands, about 50% lands are such non-forest lands, which can be made fertile again if treated properly. In the last 60 years India’s lush green village forests and woodlots have been deforested to the maximum. To restore this ecological imbalance by developing the degraded non-forest wastelands, Government of India had created the Department of Wasteland Development during July, 1992 under the Ministry of Rural Development, which has been subsequently reorganized and renamed Department of Land Resources, with a broader mandate.

National Wasteland Development Board was established in 1985 mainly to tackle the problem of degradation of lands, restoration of ecology and to meet the growing demands of fuelwood and fodder at the national level. The Board was reconstituted in August, 1992 and was made responsible for development of wastelands mainly in non-forest areas in totality by involving local people at every stage of development. It aims at creating a scenario where the Government acts as a facilitator and the people at the grass root level become the real executioner of the programme. The degradation of environment in the fragile Indian subtropical ecosystem is basically attributed to the following factors.

Human societies over the ages have depleted natural resources in different ways and degraded their local environments. Indiscriminate cutting down of trees and accelerating the construction works lead to global warming and climate change. Climate scientists believe that human-induced deforestation is responsible for 18-25% of climate change. Accumulation of greenhouse gases in the lower atmosphere is the main cause of global climate change. The concentration of these gases in the earth’s atmosphere is increasing, mainly due to deforestation and the combustion of fossil fuels which release carbon dioxide.

The earth receives heat energy constantly from the sun through radiation. Some of the heat is absorbed and some is reflected. Carbon dioxide works like an invisible blanket that wraps around the earth and traps the heat inside, similar to the function of a greenhouse. A greenhouse is a structure that is used in colder climates to grow plants. Even when outside temperatures drop below freezing point, greenhouses are still warm enough inside to grow plants. Greenhouses are made of glass, which allows solar radiation to enter. The heat is trapped inside the greenhouse, allowing plants to grow all the year round. Increasing concentrations of carbon dioxide in the earth’s atmosphere insulate it like a greenhouse, leading to a gradual warming of the earth’s atmosphere. Carbon dioxide is the major greenhouse gas, but there are others as well, including methane and nitrous oxide.

Mitigation means addressing the causes of climate change, while adaptation attempts to tackle its effects. The Intergovernmental Panel on Climate Change defines mitigation as an anthropogenic intervention to reduce the sources or enhance the sinks of greenhouse gases and adaptation as the adjustment in natural or human systems to a new or changing environment (IPCC, 2007).

Greenhouse gas emission is likely to rise by 25-90% by 2030 relative to 2000 and the earth could warm by 3° C at the end of this century. Even with a temperature rise of 1-2.5° C, the Intergovernmental Panel on Climate Change predict serious disastrous effects, including reduction in crop yields in tropical and subtropical areas leading to increased risk of food shortage, spread of climate responsive diseases such as malaria, and an increased risk of extinction of 20-30% of all biodiversity present on earth (IPCC, 2007). Carbon dioxide is the most important among all greenhouse gases. Carbon sequestration may be defined as the process of removing C from the atmosphere and depositing it in a reservoir. It entails the transfer of atmospheric carbon dioxide, and its secure storage in long-lived pools (UNFCCC, 2007).

From the agroforestry point of view, carbon sequestration involves primarily the uptake of atmospheric CO₂ during photosynthesis and transfer of fixed carbon into vegetation and soil pools for ‘secure’ storage. It occurs in two major segments of agroforestry systems; aboveground and belowground. The total amount sequestered in each part differs greatly depending on a number of factors including the region, the type of system, site quality, and previous land-use (Nair, 2012). On average, the soil and aboveground parts are estimated to hold major portions, roughly 60 and 30%, respectively, of the total carbon stored in tree-based land-use systems (Lal, 2010). Sequestering CO₂ from atmosphere through natural techniques such as afforestation, reforestation, natural regeneration of forests and the adaptive agriculture is more economically and ecologically sound in increasing the carbon storage capacity of the terrestrial ecosystems (Dhyani, 2014). Although carbon sequestration through afforestation and reforestation of degraded natural forests has long been considered useful in climate change mitigation, agroforestry offers some distinct advantages (Murthy et al., 2013). The carbon in the aboveground and belowground biomass in an agroforestry system is generally much higher than the equivalent land use without trees. An agroforestry system has higher carbon sequestration potential than pastures or field crops (Kirby and Potvin, 2007).

In agroforestry systems the various components like tree, crop and pasture exist in different proportions and orientations. It is difficult to find out which agroforestry system is the best suited for a given land situation. Similarly, it is to be decided which technologies are required for refinement and improvement of the existing agroforestry practices. But without sufficient knowledge of the existing system in a particular land situation, it is very difficult to set the research priorities for modification and development of this system.

Diagnosis and Design (D & D) is a systematic and objective methodology developed by International Centre for Research in Agroforestry (ICRAF) to initiate, monitor and evaluate agroforestry programmes. D & D is based on the philosophy that knowledge of the existing situation (diagnosis) is essential to plan and evaluate (design) meaningful and effective programmes in agroforestry research for development. The methodology plays a strategic role in all the phases of the agroforestry research process. D & D in agroforestry is unique and it has been specially developed for the following purposes.

Agroforestry systems are more complex than the agricultural systems. The long-term nature of trials involving woody species and the varying objectives of agroforestry trials demand that adequate caution be exercised in their design. Several characteristics of the trees like slow growth, long-term effects on their surroundings, long life, age of trees, the area over which the influence of trees extend, etc. complicate the issue of designing experiments for these systems. Agroforestry experiments are often established on marginal sites which include sloping lands, and sites with infertile and degraded soils. It is thus difficult to find homogeneous sites of such problem areas, especially sloping lands where plots along contour lines are long and linear. Germplasm of many agroforestry tree species are usually collected from different origins which lack uniformity. Therefore, experimental materials in an agroforestry experiment may not be of uniform quality.

There are several features of agroforestry systems that require some modification of the methods usually used in agricultural experiments. Important issues related to agroforestry experiments include

Economic analysis provides a rational basis for making decisions in allocating scare resources among various options to achieve competing goals. If resources were not limiting, there would be no need for economic consideration. Some important basic principles of economic analysis are outlined below.

PRINCIPLES OF ECONOMIC ANALYSIS

Optimization criteria

The additional return obtained from using one additional unit of an input should be considered to optimize net income from several possible production options. If option ‘x’ gives a higher return to land than other options, then additional units of land should be allocated to option ‘x’.

Agricultural extension is a term that has long been used to describe a non-formal educational system aimed at improving the livelihood of farmers. Extension education aims at three main types of behavioural changes in relation to knowledge (things known), attitudes (things felt) and skills (how to implement the things). This can be achieved through persuasion and motivation for the changes. The core activities in extension are education and training. Extension is now being regarded as a much wider task of integrating indigenous and new skills and techniques, derived from study or research, into an overall framework of discussion and cooperation between the people and the extension organisation. The extension worker is primarily engaged in the ‘selling’ of ideas to bring about changes in the knowledge, attitudes and skills of the individual. Functions of extension in a broader sense include

Multipurpose trees and shrubs are defined as all woody perennials that are purposefully grown to provide more than one significant contribution to the production and/or service functions of a land-use system that they occupy. In agroforestry systems, different species of trees and shrubs can be planted with many types of crops in a variety of patterns. Thus, it is required to know about the methods of propagation and nursery raising, planting and other silvicultural management practices along with the diverse uses of multipurpose trees and shrubs of tropical and subtropical areas before their selection for forestry and agroforestry activities. It is important to select the most suitable tree species since it is not easy to replace them once they have been planted.

MANGIUM (Acacia mangium)

Acacia mangium is a single-stemmed evergreen tree that grows to 25-35 m in height and up to 60 cm in diameter. The bole is usually straight, often fluted near the base, free of branches for up to half its height. Mangium is native to Australia, Indonesia and Papua New Guinea. However, it tolerates varied site conditions and has adaptability to different planting objectives. Mangium shows most vigorous growth on well-drained, fertile soils in high rainfall areas in the humid tropics. It is valued for its rapid growth and has been planted throughout the humid tropics and is a major plantation species in the Asia-Pacific. Provenances from Papua New Guinea consistently show better growth in height and diameter.

Introduction

Fermentation is one of the oldest food preservation techniques that can be traced back thousands of years. Fermentation is referred as one of method of biopreservation as it leads to extending the shelf life of foods that involve the use of microorganisms and their metabolites. (Ross et al., 2002) For millennia, the fermentation of food by using micro organisms has been used as a technique for ensuring shelf life extension and improving the quality characteristics, texture and flavour of food products as well as to develop new innovative products. The major bacteria used in food fermentation worldwide are lactic acid bacteria (LAB). LAB is a multitude of genera including Lactobacillus, Lactococcus, Streptococcus, Leuconostoc, Pediococcus, and Enterococcus. Lactic acid bacteria constitutes a diverse group of bacteria that enjoys the status of “generally regarded as safe” (GRAS) and “qualified presumption of safety” (QPS) by the Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), respectively. In this respect, starter microorganisms are known to produce a wide array of antimicrobial and protein-acoustic compounds to inhibit the growth of undesirable flora in foodstuffs resulting in shelf life extension. (Hill et al., 2017).

Introduction

Commonly available food materials especially dairy products, cereals and fruits are perishable and require processing for long term storage. The methods of food storage has been known from the pre historic times and was mostly based on processing the food into a more stable form with a longer shelf life. Such processes increases the time range of food availability and in many cases improves the taste thereby, cumulatively improving the food value. One of documented method of food preservation is by fermentation and is age old. Other commonly used methods include drying, refrigeration, salting and fermentation (Luck 1985, Paulus, 1985, Christensen et al., 2003, Martindale and Schiebel, 2017).

Flavour and appeal of food has been considered as one of the important factors contributing to the demand of the food. Originally the flavours were largely plant derived, current industrial practices largely utilise synthesis by chemical reactions and subsequent extraction to achieve a uniform quality (Weckerle et al., 2006, Davidovich-Rikanati et al., 2008, Sethupathy et al., 2018). These chemicals referred to as “flavourings” are defined as compounds that enhance the taste, appeal and palatability of food. They are naturally derived or artificially synthesised compounds. Considering that many artificially synthesised chemical flavours might affect the health adversely. Industrial food research has now shifted their focus on flavourings that are naturally available (Cohen et al., 2018). Such naturally occurring flavourings are referred to as bio-flavours (de Billerbeck 2015). The ease of producing bio active compounds from microbial culture extracts has played significant role in industrial food biotechnology (Verachtert et al., 2005).

Introduction

Fermentation is the process in which edible microorganisms invade food substrates and convert them into fermented foods including beverages, using their enzymatic and metabolic processes. These end products will have nontoxic flavors, aroma and texture which enhance the palatability. The word “fermentation” is originated from a Latin word fermentare, defined as “to leaven” (Frias et al., 2016). It is one of the oldest food processing technologies used by humans to preserve perishable food materials for long time, dated back to ancient human civilization (Hutkins, 2008). Globally, more than 5000 varieties of fermented foods are currently in use which includes traditionally fermented dairy products such as Dahi in India to industrial production of wines from fruits (Tamang, 2010) (Table 1 and Figure 1). Biochemically, fermentation is a metabolic process in which energy is derived from organic compounds without the involvement of an exogenous oxidizing agent. Fermentation may result in the production of many by-products such as carbon dioxide, alcohol, organic acids (lactic acid, acetic acid), vitamins, enzymes etc. which are now having more importance in food industries (Caplice and Fitzgerald 1999).

Introduction

Fermented foods are those foods which have been subjected to the action of microorganisms or enzymes that cause desirable biochemical changes and significant modification of the food (Campbell-Piatt, 1994). Fermented foods are usually produced using ingredients of plants or animals in combination with bacteria or fungi. The bacteria or fungi are either sourced from cultures maintained by humans or from the environment. The origins of fermented foods go back many thousands of years, with early evidence of the alcoholic fermentations of barley to beer and grapes to wine. Evidence suggests that fermented foods were consumed 7,000 years ago in Babylon (Battcock and Azam-Ali, 1998).Throughout the world, the fermented foods are used by the people. It plays a major role in the diet in many developing countries. Several traditional fermented foods are prepared in rural areas of many countries.

Introduction

Fermentation has been an integral part of food processing throughout the history of mankind. In beginning, it was mainly preservation method, then it became key process in substantial sensory characteristic development and now it is utilized to improve overall properties of outcome from major industries like bakery, dairy, beverages, etc. The human understanding of controlled fermentation process changes its fundamental objective by exploring its success in development of rheological and texture characteristics.

The biochemical transformation of raw food due to fermentation affects the organoleptic as well as rheological properties of a product. The changes in rheological as well as sensory properties is related with the modification of major component by the action of microorganism. For example, transformation of polysaccharides in bread dough by action of yeast produce ethanol, CO₂ and other simple compound which modify sensory as well as rheology of dough. The major micro-structural, bio-compositional and bio-chemical changes are due to microbial action are frequently described to understand the effect of fermentation on rheological as well as sensory properties of food products. The rate and quality of these associated major changes mainly depends upon concentration of saccharides for growth of microorganism as well as nature and existing microflorae. Hence, a proper monitoring of changes in rheological and sensory properties is necessary to optimize the controlled fermentation as well as design of process parameters from engineering and consumer point of view.

The biochemical changes directly responsible for changes in basic rheological and sensory characteristic including flow behavior, consistency, viscoelastic properties, hardness, adhesiveness, color, aroma, flavor and mouthfeel. The food industry is so diverse and exploring new and possibilities to catch diverse consumer worldwide, a proper understanding of effect of fermentation on mentioned properties will be key to hold competitive market. Hence, the present chapter will cover the basics of rheology and its role in food industry, effect of fermentation on rheological and sensory attributes of major class of food.

Introduction

Fermentation of food dates back to ancient practice of wine making. Fermented foods reflect culture and tradition of folklore and emphasis their close association with nature. Various methods employed for fermenting foods aimed in food preservation to reduce wastage; however lactic acid fermentation enhanced nutrition content and improved organoleptic properties. Experimental evidences on benefits on health and wellness on consumption of fermented foods are being reported. Fermentation process used for preparation of indigenous or traditional foods often depend entirely on natural microflora on the surface of raw material and containers used; Practices of fermenting foods are passed on as traditional know how to generations as a legacy. The fermented food manufacturers rely on commercial starter cultures, and highly reliant on indigenous materials as microbial collections are unique and highly variable according to region and products. Therefore, isolation of novel organisms, development of newer products and interactions are being explored using variety of fermented foods obtained through traditional processes

Introduction

Cereals are grown over 73% of the total world harvested area and contribute over 60% to the world food production providing dietary fibre, proteins, energy, minerals and vitamins required for human health. Cereals like rice, maize, wheat, barley, sorghum, and oats are chiefly used in the preparation of traditional fermented foods and beverages. However, the nutritional quality of cereals and the sensory properties of their products are sometimes inferior in comparison with dairy products. The reasons behind this the lower protein content, deficiency of certain essential amino acids, the presence of determined anti-nutrients (phytic acid, tanins and polyphenols) and the coarse nature.

Introduction

Eradication of malnutrition and hunger (Sustainable Development Goal, SDG-2) are the major challenges to humanity. Availability of sufficient nutritionally balanced food is the prerequisite for ensuring global food security. Food security is also critical for achievement of SDG 1 (poverty eradication) and SDG 3 (health and well-being) (UNDP, 2019). Changing climatic conditions accompanied by global warming not only acts a major threat for achievement of SDGs but could actually lead to the reversal of the progress already made. The escalating global temperature has jeopardized the food security throughout the world. A great decrease in the global crop yield has been suspected even with a 2°C rise in temperature. On field, it is often associated with crop nutrient loss, less accumulation of micronutrients and low availability of micro-minerals like iron and zinc. Additionally, the effect of the rainfall and temperature has also been observed. The global food prices are projected to increase by 3–84% by 2050 due to the fluctuations in rainfall and temperature (Hoegh-Guldberg et al., 2018).

Millets are the small seeded grains which belong to family Grassacae/Poaceae. Traditionally, millets are used for the food and feed purpose and are among the oldest cultivated crops. The millet species of commercial importance are proso (Panicum miliaceum), foxtail (Setaria italica), barnyard (Echinochloa esculenta), finger (Eleusine coracana), little (Panicum sumatrense) and pearl (Pennisetum glaucum) in different regions of the world. In India, foxtail millet (priyangava), barnyard millet (aanava) and black finger millet (shyaamaka) have been mentioned even in the Yajurveda texts of 4500 BC (Morya et al., 2017). The records of consumption of foxtail and proso millet are as old as 2000 to 1000 BC in China. Cultivation of foxtail millet in Korean peninsula is documented around 3,500–2,000 BC. Foxtail millet is the oldest of all the cultivated millets and is believed to be originated in Southern Asia. From there, it was spread to Europian nations. In the west, cultivation of millets majorly started after 1850 (ICRISAT, 2019)

Introduction

Foods prepared by fermenting raw ingredients of plant or animal sources naturally or mixing it with the starter culture (s) containing functional micro flora is called fermented foods. The functional micro flora used in starter culture is responsible for biochemical and organoleptic alteration of the substrates into edible yields which are socially and culturally appropriate to consumers (Tamang et al., 2010a, Tamang et al., 2010b). Fermented food has its own characteristic microflora and this group of micro flora increases the nutritional value by increasing the levels of essential amino acids, vitamins, proteins, etc.

Fermented foods play a major role in meeting nutritional requirement and socio economic development of developing countries. They are important components of the diet as staples, adjuncts to staples, condiments and beverages. A wide variety of fermenting substrates are available such as cereals, pulses, soya beans, flowers, milk, fish, meat, etc. A wide majority of plants and their parts are often utilized in the preparation of starter culture (Deori et al., 2007, Deka and Sarma, 2010).

Introduction

One of the main properties of fermented foods whether alkaline or acidic is the presence and activity of beneficial organisms which themselves make these foods functional. These functional micro organisms have varied roles like conversion of the native constituents of raw materials to forms in which they are more bioavailable, formation of taste, colour and flavouring compounds thereby imparting pleasantness to foods, removal of anti-nutritive factors in food by converting them into much less harmful compounds or degrade certain native toxic elements present in food, formation of biopreservatives which will extend the shelf life of foods and provide microbial security, as pathogens and spoilage microorganisms fail to readily grow in such hostile conditions. These functional microorganisms also produce in foods certain health-promoting bioactive compounds like enzymes, vitamins, minerals or increase the digestibility which may not have been in the original food or raw material before fermentation. In other words they improve the nutrition profile of the foods or naturally fortify foods. Some of these beneficial effects may also lead to the formation of certain compounds which show antioxidant properties in foods. These very roles played by these functional micro-organisms form criteria in their selection for use in food fermentations when they are intentionally added to foods both to initiate and accomplish desired fermentations.

Introduction

Over the past few decades, probiotics have become the most promising and emerging field in human nutrition and health across the world including India and other developing countries. The global profit generated from the probiotic market is expected to reach approximately 12,753.4 million US$ by the end of 2026 (Probiotic market report, 2018). The factor fueling the demand for probiotics is the growing awareness among consumers about their health benefits. The association of probiotics with health benefits stretches back to a time before microbes were discovered. However, the scientific evidence of the health benefits of probiotic microorganisms on the wellbeing of the host was firstly proposed by Russian Nobel laureate Ellie Metchnikoff in 1905. He reported that consumption of fermented milk containing Lactobacillus spp. is responsible for the healthy and long life of Bulgarian people (Anukam & Reid, 2007). Afterward, several of scientific progressions were made to reach the current status where probiotics are not only the subject of food and medical research but also the source of a multi-billion dollar global industry.

The term probiotic is derived from the Greek words, which means ‘for life’. According to the Food and Agriculture Association of the United Nations (FAO) and World Health Organization (WHO), probiotics are defined as “live microorganisms which when administered in adequate amount promote the health of the host” (Joint, FAO, 2002). In 2014, International Scientific Association for Probiotics and Prebiotics (IPPA) did minor correction in the definition given by FAO-WHO and defined them as “Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”

Introduction

Food is the most vital prerequisite for sustenance of human life and provides adequate nutrients for the metabolism. Recently several hypothesis supports that, beyond meeting nutritional needs, they play beneficial roles in improving health, and minimize the risk of illnesses (Roberfroid, 2000a). In this way, a novel term “functional food” was introduced and plays an outstanding role in improving the overall conditions of the human body (e.g. pre- and probiotics), lessening the threat of some ailments (e.g. cholesterol-lowering products), and also as therapeutics for several diseases (Roberfroid, 2000a, Roberfroid, 2000b, Mollet and Rowland, 2002).

Recently throughout the world, an extensive array of functional foods were developed which includes prebiotics, probiotics, synbiotics, foods supplemented with anthocyanins, phytosterols, isoflavones, antioxidants, and fat, sugar and salt-reduced foods. Amongst them, probiotic functional food has exerted beneficial effects on the health and is comprised of both probiotic dairy foods and probiotic non-dairy foods. The demand for dairy probiotic foods are increasing as it attributes to the beneficial health effects on the host by improving the survival of gastrointestinal microflora, production of bioactive compounds and prevention of lactose intolerance. Consequently, production of these foods is a significant research importance for both food manufacturing units and research institutes.

Probiotics are the important ingredients for foods with a “healthy” image. It could be combined with other beneficial ingredients or simply used to supplement the natural functional qualities of whole foods. The amalgamation of probiotic bacteria with nutrient rich foods, like dairy products, will have the additional value of improving consumer nutrition.

Introduction

Fermented meat and fish products have been consumed all over the world since times immemorial and represent one of the most important groups of food. Meat offers its own natural microflora. Hence a wide variety of products have been prepared since ancient times by varying the mixture of meat and salt as well as by the addition of spices and seasonings. Thus, fermented meat products characterize a diversity of flavors and textures and are receiving increased interest from consumers all over the world. Most of these products still depend mainly on local, traditional manufacturing processes since little scientific information is available; but scientific knowledge is very important for consistent production of high quality and safe products.

Meat is an essential part of non-vegetarian diet. It is liked for its unique taste and is a rich source of nutrients like good quality animal proteins, essential amino acids and fatty acids, minerals, trace elements and particularly B-complex vitamins (Singh et al., 2013). The growing concern of consumers regarding health and safety issues has led to the development of functional meat products that promote health and well-being, beyond their nutritional benefits (Grasso, et al., 2014; Tyopponen et al., 2003). This has driven researches in the meat processing sector to increase their efforts in producing such functional meat products, which have incorporated functional ingredients, reduced salt, nitrates/nitrites, cholesterol and fat and modified product fatty acid profiles (Zhang et al., 2010). Fermentation of meat produces a wide range of physical, biochemical and microbial changes in the muscle-based product