eChapters

NAD/NADP (Nicotinamide Adenine Dinucleotide/ Nicotinamide Adenine Dinucleotide Phosphate): Coenzymes acting as carriers of hydrogen atoms and electrons in some oxidoreductases catalyzed reactions. Their oxidized and reduced states are NAD⁺ and NADH + H⁺/NADP⁺ and NADPH + H⁺

Nanotechnology: Nanotechnology refers broadly to a field of applied science and technology whose unifying theme is the control of matter on the molecular level in scales smaller than 1 micrometre, normally 1 to 100 nanometers, and the fabrication of devices within that size range.

Nastic movement: Nastic movements are non-directional responses to stimuli (e.g., temperature, humidity, light irradiance), and are usually associated with plants. The movement can be due to changes in turgor or changes in growth. An example of such a response is opening and closing of flowers. There are several types of nastic movements such as Epinasty, Hyponasty, Photonasty, Nyctinasty, Chemonasty, Hydronasty, Thermonasty, Geonasty/Gravinasty, Thigmonasty, etc.

Macromolecule: A molecule having molecular weight ranging from few thousand to millions.

Macronutrients: The essential elements which are required by plants in comparatively large amounts are called as major elements or macro nutrients. Examples: C, H, O, N, P, K, Ca, S, Mg. In this C, H, O, N, P, K are called primary elements and Ca, S, Mg are called as secondary elements.

Malate shuttle: A mechanism of transferring reducing equivalent of cytosolic NADH in the form of malate across the inner mitochondrial membrane by a specific ketoglutarate malate transporter for oxidation through electron transport chain in little animal tissue like heart muscle.

Malic enzyme: An enzyme that catalyzes the oxidation of malate to pyruvate and carbondioxide.

Lactate dehydrogenase: An enzyme that reversibly catalyses conversion of pyruvate to lactate by utilizing NAD as coenzyme. This operates under anaerobic respiratory condition.

Lactate fermentation: Lactic acid fermentation is a biological process by which glucose and six carbon sugars (also, disaccharides of six carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate. It is an anaerobic fermentation reaction.

Latent heat: The heat required to convert a solid into a liquid or vapour, or a liquid into a vapour, without change of temperature. It is also called as hidden heat.

Leaching requirement: (LR) The amount of water in excess of the plant requirement that is needed to remove salt from the root zone in order to prevent soil salinity from exceeding a specified value.

Leaf Area Duration (LAD): It is the functional leaf area or estimated photosynthetic area which contributed for the total biomasss. To correlate dry matter yield with Leaf area, Power et al., (1967) integrated the Leaf area with time and called as Leaf Area Duration. LAD taken into account, both the duration and extent of photosynthetic tissue of the crop canopy. The LAD is expressed in m². days.

Ketose: A simple sugar in which carbonyl group is a ketone.

Kinases: Enzymes that catalyse phosphorylation of an acceptor molecule such as protein molecule by ATP.

Jasmonic acid: Jasmonic acid is derived from the fatty acid, linolenic acid. It is a member of the jasmonate class of plant hormones. It is biosynthesized from linolenic acid by the octadecanoid pathway. The major function of JA and its various metabolites is regulating plant responses to abiotic and biotic stresses as a well as plant growth and development processes.

Ice nucleation: It is a process of reducing the formation of ice crystal under freezing stress, by some polysaccharides and proteins known as ice nucleators.

Imbibitions: It is a special type of diffusion when water is absorbed by solids-colloids-causing them to enormously increase in volume. The classical examples of imbibition are absorption of water by seeds and dry wood.

Immobile elements: The elements which get translocated slower inside the plant are called immobile elements. Examples: Ca, Fe and B.

Immunoassay: This is very sensitive method of identifying and or quantifying the hormones and other molecules which has antigen and antibody interaction.

Indeterminate growth: Plant growth in which the main stem continues to elongate indefinitely without being limited by a terminal inflorescence or other reproductive structure; also growth is characterized by sequential flowering from the lateral or basal buds to the central or uppermost buds.

Indole -3 acetic acid: It is naturally occurring auxin responsible for cell elongation, apical dominance and other physiological functions of auxins.

Induced dormancy: Induced dormancy in which dormancy develops as a response to external environmental factors.

Half life: The time required for the disappearance of one half of a given component of a system.

Halochromism: It occurs when a substance changes color as the pH changes. This is a property of pH indicators, whose molecular structure changes upon certain changes in the surrounding pH. This change in structure affects a chromophore in the pH indicator molecule.

Halomorphic soil : A suborder of the intrazonal soil order, consisting of saline and sodic soils formed under imperfect drainage in arid regions and including the great soil groups Solonchak or Saline soils, Solonetz soils, and Soloth soils.

Hatch-Slack pathway: It is one of the carbon fixation pathway used by certain group of plants (C₄ plants) where the first stable compound is oxalo acetate, a C₄ dicarboxylic acid compound. In the first carboxylation reactions, atmospheric CO₂ combines with phosphoenol pyruvate (PEP) to oxalo acetate and then to malate. These plants posses kranz anatomy with mesophyll and bundle sheath cells.

Gel: A semi-solid medium in to which proteins or nucleic acids are subjected to electrophoresis, to determine their size or to separate them from other components.

Gene family: A set of genes whose sequences differ only slightly that encode identical products; within a single species, a multigene family.

Gene tagging: The addition of a marker to a gene; often by the introduction of a transposon or insertion element.

Gene transfer: Transformation; the insertion of foreign DNA into a host conferring a trait not previously inherant in that organism.

Gene: The concise meaning might be the sequence of DNA that encodes a gene product (an RNA or protein), including all upstream and downstream sequences involved in the expression of the gene.

Genome: Sum of all genetic information of an organism, nucleus, organelle, or virus.

Geotropism (Barytropism or gravitropism): When a seedling is kept horizontally on the soil, the radicle always grows towards soil, and the plumule grows away from the soil. This type of growth movement of radicle and plumule is called positively geotropic and negatively geotropic respectively. But some runners and rhizomes grow parallel to the surface of the soil and this is referred to as diagiotropic. When the lateral roots grow obliquely into the soil, it is referred to as plagiogeotropic phenomenon.

Germination percentage: Germination percentage is an estimate of the viability of a population of seeds.

Facilitated diffusion: Facilitated diffusion is a movement in the direction of a concentration gradient; but it involves moving through a channel protein or a carrier protein. A channel protein is merely a pore in the membrane, and is often gated to control movement. A carrier protein has a binding site where the substance attaches and moved through the membrane.

Facultative CAM: Plants which behave as C₃ under conditions of normal water supply. However, switch over to CAM mode under conditions of water deficit.

FAD (Flavin adenine dinucleotide): A riboflavin containing co-enzyme of some oxidation reduction reactions.

Facultative long day plant: Facultative photoperiodic plants are more likely to flower under appropriate light conditions, but will eventually flower regardless of length of night.

FADH: In biochemistry, flavin adenine dinucleotide (FAD) is a redox cofactor, more specifically a prosthetic group, involved in several important reactions in metabolism. FAD can exist in three different redox states, which are quinone, semiquinone and hydroquinone. FAD is converted between these states by accepting or donating electrons. FAD, in its full oxidised form or quinone form, accepts two electrons and two protons to become FADH₂ (hydroquinone form). The semiquinone (FADH) can be formed by either reduction of FAD or oxidation of FADH₂ by accepting or donating one electron and one proton, respectively.

Ectodormancy: A kind of dormancy which is due to environmental factors.

EDTA: An important chelating agent often used in modern nutrient solutions. It forms soluble complexes with metal ions such as that of iron and prevents from precipitation in the solution.

Elaiosomes: Greek élaion means “oil” and sóma means “body” , are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaiosomes that attract ants, which take the seed to their nest and feed the elaiosome to their larvae and by which the seed get dispersed.

Electrical conductivity: Electrical conductivity is the measure of a material’s ability to allow the transport of an electric charge. It is used to measure the level of salinity in water or soil. When electrical conductivity is more, then salinity is more since as salt concentration is more in water or soil, then those salts will conduct more of electricity. Normally measured in μS/cm.

Electrical impedance: The application of alternating electrical current to pre-frozen or frozen plant tissues to predict damage or measure injury, respectively.

Dark reactions: It is light independent reactions occurs during daytime. This includes C₃, C₄ and CAM pathway involving the utilization of NADPH and ATP to fix CO₂ into carbohydrates. It is also called as stromal reactions.

Day neutral plants: The plants that flowers regardless of the length of the period of the light that is exposed to. They are called as day neutral plants.

DCMU (Dichlorophenyl dimethyl urea or diuron): An herbicide that inhibits non-cyclic photophosophorylation specifically blocks the electron flow at the quinone acceptors of PSII, by competing for the binding site of plastoquinone that is normally occupied by PQB.

DCPIP (Dichlorophenol indophenols): A dye often used as artificial hydrogen acceptor to demonstrate in Hills reaction in isolated chloroplast in laboratory. The oxidized form is blue in alkali and red in acid, while reduced form is colourless.

C₃ cycle or Calvin cycle: It is a process of dark reaction of photosynthesis. It is also called as photosynthetic carbon reduction cycle which results in the production of sugars. It occurs not only in C₃ plants but also in C₄ and CAM pathway also. It occurs in the mesophyll cells. It is described in three stages: (1) Carboxylation, (2) Reduction, (3) Regeneration.

C₃ plants: Group of plants with calvin cycle wherein the first stable product is 3-phosphoglyceric acid, a three carbon compound. e.g., rice, wheat, barley.

C₄ cycle: C₄ cycle may also referred to as the dicarboxylic acid cycle or Hatch and Slack Cycle. The first stable product is a C₄ compounds like oxaloacetic acid. Here CO₂ molecule is accepted by phosphoenol pyruvate in the carboxylation reaction. The main purpose of this cycle is carbondioxide enrichment.

C₄ plants: Plants with Hatch-slack pathway and kranz anatomy of leaves in which the first stable product is four carbon compound, oxaloacetic acid. These plants posses high photosynthetic efficiency and low photorespiration rate. e.g., sugarcane, maize, sorghum.

Bacteriochlorophylls: A group of light absorbing photosynthetic green pigments of anoxygenic photosynthetic bacteria.

Ballistic transformation: The use of a particle gun to insert foreign DNA into a host.

Beneficial elements: These are the elements that help to optimize the growth and development only in some species. It is not essential to all the plants. Aluminum is beneficial to some species that are adapted to acidic soils. Cobalt can have a number of beneficial effects, especially in leguminous plants.

Betalains: Highly coloured nitrogen containing glycosylated compound in the category of alkaloids imparting red-purple and yellow colour in plants of centropsermae (e.g., beet root).

Beta-oxidation: Breakdown of fatty acids into Acetyl co-A by successive oxidation. It is the first step of lipids breakdown.

Bidirectional transport: Simultaneous transport of solutes in opposite directions in the same file of sieve elements. Bidirectional transport may occur under some circumstances. For e.g., in a file of cell, as a result of cytoplasmic streaming.

Abiotic stress: Unfavourable situation created by non-living factors to the growth and development of plants. Factors include water, temperature, soluble salts, heavy metals, etc.

Abscissic acid (ABA): A plant hormone belongs to isoprenoid compounds. It is also known as stress hormone since it has relevance in stress tolerance in plants. Some of the physiological effects of ABA are closing of stomata, synthesis of osmolytes and seed dormancy.

Abscission layer: Distinct layer of cells with weakened cell walls in abscission zone.

Abscission zone: A region near the base of petiole of leaf which contain abscission layer.

Fermentation process is known to humans since ancient times. It involves the transformation of raw materials into value added or nutritional products as a result of microbial action or their growth. The fermentation as a science involves aspects of the biological action of microbes, biochemical changes in the substrates and metabolites formed and their effect on food, health and nutritional applications. While fermentation as technology, involves chemical engineering, food engineering and instrumentation aspects and commercialization of the products prepared keeping in view the consumer acceptability. The term fermentation is derived from the Latin word ‘Fervere - to boil’ thus describing the actions of yeasts on extracts of fruits or malted grain. Fermented foods and beverages enhance the pleasure of eating and their nutritional roles include indirect contributions through subjective enhancement of appetite. The instant mixes for fermented or fermentable products such as idli, dosai, dhokla and bhatura mix can reduce the overnight fermenting of the raw materials required for preparation of these products. The instant mixes for idli & dhokla are quite common in the market. However, instant mix for Jalebi and Bhatura are still emerging. Such products add convenience to the consumers and products can be prepared instantly. Certain other fermented foods include dairy products, pickles, sauerkrauts, Kanji, beverages, food supplements and nutraceuticals from fermented biomass.

In 1907, the Russian Nobel laureate, Dr. Elie Metchnikoff, fascinated by the unusual longevity of Bulgarian farmers, consuming beneficial lactic acid bacteria by way of traditional fermented milk products, suggested that regular intake of friendly microbes could benefit human health. Although Dr. Metchnikoff ’s recommended bacteria for the purpose proved largely ineffective, the theory was carried forward with moderate success until the war on bacteria began because of the advent of sulfa drugs and antibiotics (Scott, 2012). However soon after their rampant use and the realization of the rapid spread of antimicrobial resistance, researchers turned yet again to ecological notions and the time was fertile for the advent of probiotics. By the 1980’s the term had stabilized both in medical and veterinary literature. The mid 1990’s witnessed a surge of exponential studies on probiotics, the definition of Probiotics emerged in 2001 and the years thereafter saw tremendous progress in the science of probiotics.

Almost simultaneous was the study on the study of the intestinal microbiota when Alfred Nissile demonstrated that transferring members of the human gut microbiota to healthy typhoid carriers helped in Salmonella being cleansed from their system (Nissle, 1916). It was then, that the importance of the gut microbes in prevention of infection became evident. What followed was the advent of culture independent, modern biotechnological tools for whole genome sequencing and the successful launch of two most ambitious projects - Human Microbiome project (Turnbaugh et al., 2007) and the Met Hit project (Metahit, 2009; Qin et al., 2010). They provided fascinating insights into the highly complex microbial ecosystem harboured by the human body. The term Microbiome (refers to the collective genome of our microbial inhabitants) had entered literature in 2001 and the concept of gut microbiota in maintaining overall health gained wider attention.

Introduction

Since the last century, nutritional science has made a remarkable contribution to the biological sciences through identification of diverse nutrients and their sources, functions, requirement, deficiency symptoms and their remedial measures etc. The advent of high-throughput sequencing technologies together with bioinformatic tools identified the presence of 100 trillion of microorganism belonging to all forms of life in the gastrointestinal tract. In fact, the whole gut microbial consortia are considered as a virtual organ in human and animals and is responsible for the development and functioning of series of essential physiological activities including digestion, absorption, metabolism, immunity, homeostasis, brain and gut development, resistance against disease etc. According to the modern scientific dogma, the human being is in fact a “Superorganism”, carrying consortium of numerous symbiotic Eukarya, Bacteria, Archaea and Viruses. The gut microflora has been co-evolved with human and presumed to maintain an intricate balance among different microbial communities. Upon introspection about the functionality of the gut microflora, it is amply clear that a few of these microorganisms have the ability to make healthy state; while other members are responsible for health-related problems including food poisoning, diarrhoea, abdominal pain, indigestion, inflammatory bowel disease, predisposition to colon cancer, compromising immunity, allergy etc.

Preamble

Historically, food has been an integral part of human civilization and diet with varied food components has sustained human life on this planet over the centuries. Similarly, culturing of food with natural fermentation as means of preserving foods with extended shelf life for future use. In the background of sustaining food security, advances made in biotechnology and molecular biology has provided ample scientific platform to use the advances in increasing and expanding food production on a global magnitude, so as to meet the needs of an ever-growing world population.

The intestinal microbiota is a key component of both the metabolism and immunity of humans and animals. The desirable microbes do have a significant role to play in healthcare through control of digestive disorders and foodborne illnesses. The continued research in this area over the years has led to the identification of important molecules that regulate major functional attributes in the betterment of human health and wellness in the long run. The science and technique of genetic engineering through molecular biology approaches has enabled in enriching the beneficial molecules for the benefit of human life. The accuracy in targeting and designing of molecules will go a long way in developing genetically modified (GM) lactic acid bacteria (LAB) and GM probiotics to significantly rewrite the medical care with food-based approach in the form of targeted specific diets – “Dietomics”.

Introduction

Off late our understanding of the composition and functions of the human gut microbiota has increased exponentially and there is a great interest in producing healthy foods in particular that which have an impact in improving the gastrointestinal health such as probiotics, prebiotics and synbiotics. Many of these functional foods are dairy based and have been accepted greatly worldwide. Nonertheless, there has been a need for the development of nondairy probiotic, prebiotic and synbiotic products (Salmeron 2017). This has prompted food scientists and food industrialists to study the feasibility of applying other fermenting substrates such as cereals for the development of innovative nondairy fermented functional foods. The importance of including nanoscience and nanotechnology techniques for the creation of fermented cereal beverages that contain specific bioactive nanoparticles and their role in food packaging systems will be discussed.

Introduction

The entire living organism from the smaller creatures viruses to the advanced human beings are composed of a set up of biochemical reactions which form the metabolism. These set of metabolic reactions are responsible for the life of organism. The rate of these reactions is a major concern for effective working of organism which is governed by biocatalyst. These biocatalysts are known as enzymes, which accelerates rate of biochemical reaction. These are not utilized in reaction. In 1877, Wilhelm Friedrich Kuhne (Kuhne, 1877) proposed the term enzyme which means ‘in yeast’ and is derived from the Greek word; inzume “leavened” or “in yeast”. At the molecular level of study it is observed that enzymes are proteins which are functional as tertiary and quaratanary structures. Enzymes have active site for the binding to substrate. The active site has two positions; binding and catalytic site (Ogeston, 1948). The former help to bind the substrate with the enzyme followed by the catalysis of reaction by the catalytic site.

Introduction

Since long time fermentation process is in use for the production of functional food products for human welfare. SSF is a cost effective industrially important method that could be used by food industries to improve the nutritional profile of natural substrates (Salar and Purewal, 2016; Postemsky et al., 2017). The process is being carried out by trained microbiologists in the presence of aseptic conditions using suitable starter culture on steam sterilized substrates. Steam sterilized substrates possess minimal amount of moisture so as to support the microbial growth during the fermentation period. Growth of microbial strains on specific substrates during the fermentation time results in formation of koji (antioxidant rich fermented product). Selection of substrates and starter microbial strains is an important step in the fermentation process which will determine the nutritional properties of fermented product. One of the major advantages of SSF at industrial level is its potential to be utilized on cereal grains, fruits, vegetables and even agricultural wastes (Salar et al., 2012; Postemsky and Curvetto, 2015; Bhanja et al., 2009). Most common substrates that are being used as solid platform for the growth of microbial strains are cereal grains.

Introduction

Wine is a very unique fermented beverage. It was an essential part of various religious and cultural ceremonies in ancient civilizations; and continues to be considered as a ‘drink for elite’. The reason is that wine was considered as ‘Gift of God and ‘God’s nectar’ in religious text books, and medicinal value of the beverage is well supported by modern science. Wine is a beverage well tagged with its geographical origin. This concept originally comes from French concept of terroir; which explains that a varietal wine from a defined region possess distinctive qualities. Wine makers of the past enjoyed this definition of quality for better marketing opportunities. Today, globalization and advancement in wine science created empowered consumers who could clearly discriminate quality of wines. In addition to a product with high sensory qualities, consumers expect a healthful beverage produced in an environmentally sustainable manner. Enology research projects focus on such aspects; and this chapter is a glance on enology advancements and proven health benefits of wine, such as cardiovascular health gut health, dental health etc.

Introduction

Fermented foods and beverages comprise an indispensable part of the human diet. They can be generally defined as those foods and beverages produced via controlled microbial growth and conversion of various substrates using either enzymes or as whole cell itself, as shown in Figure 1.

Introduction

The improvement of the quality of foods can be made by fortification of foods nutrients quality and quantity in food. It can be a very cost effective public health intervention. As a result of the high consumption pattern of dairy products viz. yogurt, the fortification process will effectively diminish or prevent diseases associated with nutritional deficiencies (Gahruie et al., 2015). However, due to nutrients deficiencies in human population especially in certain stages of life, holding, importing, and consumption of fortified foods is increasing (Preedy et al., 2013). As a general rule, addition of one or more essential nutrients to a food and increasing their concentration in that particular food to levels higher than normal is known as fortification. This is intended at preventing and correcting shortages in one or more micronutrients in the society or specific population groups (Bonner et al., 1999). The major ways of food fortification are (1) commercial and industrial fortification for wheat flour, corn meal, cooking oils, (2) bio-fortification of crops to augment their nutritional value, which can include conventional as well as selective breeding, and genetic engineering and (3) house hold fortification like vitamin D drops. Fermentation has twofold outcome on glycemic index though there are conflicting results after consumption. The reduced glycemic index of fermented food has been featured to the production of short?chain organic acids during fermentation.

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

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

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

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

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

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

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

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

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

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 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

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 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).

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.

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

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’.

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

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.

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).

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).

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.

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.

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.

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.

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 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.