eChapters

1. Introduction

Medicinal plants are nature’s priceless gift to human. They have been used all over the world for the treatment and prevention of various ailments particularly in developing countries where infectious diseases are endemic and modern health facilities and services are inadequate. Medicinal principles are present in different parts of the plants such as root, stem, bark, heartwood, leaf, flower, fruit or plant exudates (Thenmozhi et al., 2010). Phytochemicals from medicinal plants serve as lead compounds in drug discovery and design (Sofowora, 2006).

Free radicals are chemical species which contain one or more unpaired electrons, due to which they are highly metastable and cause damage to other molecules by extracting electrons from them in order to attain stability (Chakraborthy and Ghorpade, 2010). Hyper-physiological burden of free radicals causes imbalance in homeostatic phenomena between oxidants and antioxidants in the body. This imbalance leads to oxidative stress that is being suggested as the root cause of aging and various diseases like diabetes, cancer, and liver damage (in severe conditions like cirrhosis and hepatitis) (Wagh et al., 2010).

1. INTRODUCTION

The medicinal plants have been used by humans from the pre-historical times. Traditional medicine based on herbal remedies has always played a key role in the health systems of many countries. In India, the native people are exploiting a variety of herbals for effective curing of various ailments. Medicinal plants are widely used by all sections of the population and country is richly endowed with a wide variety of plants of medicinal value, which represents the great national resource (Alok, 1991).

It is estimated that at least 70 percent of population relay on herbal medicines for primary health care in our country (Holley and Williams, 1996). In India, different classical medicinal systems such as Ayurveda, Siddha and Unani are being practiced in the country and in addition to innumerable local folk medicinal traditions exist. More than 8000 species of wild plants are known to be used in India for the treatment of various health problems (Ved et al., 2000). This rich medicinal wealth is mainly distributed in two biodiversity hotspots that are Eastern Himalayas and Western Ghats. Numerous studies have pointed out that many drugs that are used in commerce have come from folk-use and use of plants by indigenous cultures (Anon, 1994). Medicinal plants form a heterogeneous group in growth, habit, distribution, reproduction, phenology and their ecological requirements.

1. Introduction

Several herbs have been used traditionally to prevent and treat human and animal diseases. Recently, scientific evaluation of plants and preparations of plant origin medications have received more attention. Cassia occidentalis had been reported to be used as antidote of poison, blood purifier, expectorant, anti inflammatory agent and a remedy for the treatment of liver diseases (Ghani, 1920, Kabiruddin, 1951). C occidentalis was tested for antifeedant and insecticidal properties. It was studied successfully for its anti-parasitic (Tona et al., 1999), hepatoprotective activity (Jafri et al., 1999). Stimulation of the immune system is highly desirable for the treatment of immunodeficiency and infectious diseases. The  anti-inflammatory and hepato protective effects of C occidentalis may relate to an influence of plant compounds on immunocompetent cells. The present study was undertaken to find out the effect of methanolic extract of C occidentalis leaves on the humoral immune response in rabbits.

1. Introduction

Pyrus malus Linn. commonly called as ‘apple’ in English and ‘seb’ in Hindi locally, is a well known tree belonging to family Rosaceae. It is indigenous to Europe and West Asia and grow wild in N.W. Himalayas and also cultivated. The leaves and young aerial parts are useful medicinally1. Leaves contain phloretin which is a natural antibiotic. Crushed leaves are used as temporary treatment for wounds. In Homoeopathy, its use is mentioned for labyrinthine vertigo by Dr. Cooper, in Boericke3.  The plant is a tree growing up to 20 to 40 feet, with spreading branches. The leaves are ovate or oblong ovate, serrate, 2-3’’ long; Petioles ½ to 1’’ in length. The flowers are large, fragrant, pale rose in colour and borne in sub umbellate corymbs. Fruit is a pome and edible.

Chemically the plant is  reported to contain patulin, campesterol, stigmasterol, b- sitosterol, nicotinic acid, phloretin 2- O-glucoside, phlorizin, Gibberellin A 62, melibiose, ostreasterol, 1,28-octacosanediol, pomonic acid and 1,24-tetracosanediol.

1. Introduction

Inflammation have been linked with pathogenesis of many diseases like Cancer, Atheriosclerosis, Neurodegenerative diseases, Diabetes Mellitus, Obesity, Arthritis, Cardiovascular diseases, Parkinson’s disease and other deadly diseases (Lee and Weinblatt, 2001). Inflammation can result to genetic defects and immunoregulation and mechanism defects which lead to tissue damage (Jones, 2006). Anti-inflammatory drug was serendipity discovered without thorough investigation and even not effective in term of controlling inflammation and now record several side effect just like other synthetic drugs, thus, safe biological sources are now been considered. Biological sources for active compounds that have medical importance are increase in recent time (Kaboli, 2001). Also, due to the residual side effects of synthetic compounds that form bulk of the materials used for the production of pharmaceutical products. Aspirin can cause stomach bleeding, acetaminophen can cause liver damage Cox-2 inhbitor Vioxx and Celebrex can cause heart problem and non-steroidal anti-inflammatory drugs (NSAID’s) was reported to contribute to numerous death (Clegg et al., 2006; Wolf et al., 1999; Sing, 1998).

1. Introduction

Plant-derived substances have recently become of great interest owing to their versatile applications. Medicinal plants are the richest bio-resource of drugs of traditional systems of medicine, modern medicines, nutraceuticals, food supplements, folk medicines, pharmaceutical intermediates and  chemical entities for synthetic drugs Medicinal value lies in certain chemical substances that have its physiological action on the human body. Many indigenous medicinal plants are used as spices and food plants. The general techniques of medicinal plant extraction include maceration, infusion, percolation, digestion, decoction, hot continuous extraction (Soxhlet), aqueous-alcoholic extraction by fermentation,  counter-current extraction, microwave-assisted extraction, ultrasound extraction (sonication), supercritical fluid extraction, and phytonic extraction (with hydrofluorocarbon solvents). For aromatic plants, hydrodistillation techniques (water distillation, steam distillation, water and steam distillation), hydrolytic  maceration followed by distillation, expression and enfleurage (cold fat extraction) may be employed.

1. Introduction

Phytochemicals are biologically active compounds found in plants, which act as a resistance system for host plants and protect them from biotic and abiotic stresses. Phytochemicals act as antioxidants, which react with the free radicals present in the cell. Free radicals are formed in the cell as a result of aerobic metabolism and these radicals are biologically active that damages the macromolecules like DNA, proteins and lipids resulting in oxidizing chain reactions (Moussa et al., 2011). Oxidative stress damage leads to various disorders like autoimmune disorders, cancer, rheumatoid arthritis, cataract, aging, cardiovascular diseases and other neurodegenerative disorders (Uttara et al., 2009). The major actions of antioxidant in the cells are to protect them against the damage caused by reactive oxygen species (ROS).

Medicinal plants are good sources of antioxidants such as vitamin E, ascorbic acid and carotenoids. There are huge numbers of medicinal plants that are veiled in the environment. In ancient times, different plant species have been used for the treatment of human ailments from fever to cancer (Devendrakumar et al., 2009).

Toxicology is defined as the study of chemical or physical agents which interact with biologic systems to produce a response in the organisms. Toxicity is the relative ability of a substance to cause injury to biologic tissue. Given the broad range of toxicities any substance might eventually invoke in an organism, it is easy to understand the wisdom of Paracelsus (1493-1541) when he said, “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy”.

Toxicology is the study of the harmful effects of chemical compounds on biologic systems, including their properties, actions, and effects. The toxic agent is referred to as a toxicant or poison. The term toxin refers to poisons produced by a biologic source (eg, venoms, plant toxins); the redundant term biotoxin is occasionally used. Toxicosis, poisoning, and intoxication are synonymous terms for the disease produced by a toxicant. Toxicity (sometimes incorrectly used instead of poisoning) refers to the amount of a toxicant necessary to produce a detrimental effect. Hazard describes the likelihood of poisoning under conditions of use.

Definitions
 
    •    Toxicology: Knowledge (or science) of poisons, including their chemical properties, identification, biological effects, and the treatment of conditions they cause.

    •    Poison: Any solid, liquid, or gas that, when introduced into or applied to the body, can interfere with the life processes of cells of the organism - by its own inherent chemical properties - without acting mechanically and regardless of temperature.

    •    Poison = Toxicant: The term poison is now used less often. Reason: Historical application of the term (malicious) vs. a compound used as a feed additive, agricultural, or other chemical - manufactured to fulfill a perceived human need.

Arsenic
General Information

    1.    Exists in elemental form (-3), trivalent As+3 and pentavalent As+5 oxidation states
    2.    Arsenic is an essential element for rats, chicks, mini-pigs and goats
    3.    The second most important pollutant for livestock. 

Source

Inorganic form is used in paints.
Pasture near smelters may be contaminated. 
Industrial effluents released into nearby water body.
Insecticides (arsenic trioxide, lead arsenate).
 

Nitrate – Nitrite Poisoning
Sources

Accidental ingestion/grazing of
Plants which are Nitrate accumulators

Introduction

Plants are the main source of nutrition to farm animals for their maintenance and production.  But, under certain conditions, plants intoxicate farm animal life due to the presence of some deleterious substances called phytotoxins. Such plants include a variety of fodder plants (Jowar, wheat straw, Lucerne), grasses (Millet grass), ornamental or fencing plants (Crotons, Nerium sps) and weeds.

(Tribulis) in the farm premises.
Generally, farm animals avoid such plants and weeds due to their unpleasant taste and offensive odor but during fodder scarcity caused by drought, floods or overgrazing, animals consume these plants. In addition, animals introduced into new areas, stall fed animals also sometimes lose their sense of discrimination and ingest such plants containing phytotoxins.

Introduction 

In the thirst of modernization and industrialization man has contributed pollution to the life and ecology of plants, animals and microbes. Increased demand for food and fiber has lead to the chemicalization of agriculture we have reached to such a stage that modern agriculture is dependent on high yielding varieties, which can only be grown under the influence of fertilizers and pesticides. Pesticides are the man made chemicals which are being used to produce enough cheap food. In India, 90,000 MT of technical grade pesticides are used annually to control pests and plant diseases. The pesticides are classified as insecticides, fungicides, weedicides, herbicides, nematodicides and rodenticides; of which insecticides constitutes 77% of the total pesticides used in different agricultural and animal husbandry practices and in public health operations.

Introduction

The word mycotoxin is derived from myco, meaning mold and toxin, a poison. A great number of mold metabolites have been identified as mycotoxins. Thus mycotoxins are secondary fungal metabolites (i.e., metabolites not essential to the normal growth and reproduction of the fungus) which cause pathologic, physiologic, and/or biochemical lesions in other species (may include animals, plants, other microbes, etc.).

Mycotoxicosis - Poisoning of a biological system by a mycotoxin.

Mycotoxins  are  defined as toxic metabolites released by moulds under certain conditions conducive for their growth. Acute or chronic toxicoses can result from exposure to feed or bedding contaminated with toxins that may be produced during growth of various saprophytic or phytopathogenic fungi or molds on cereals, hay, straw, pastures, or any other fodder. A few principles characterize mycotoxic diseases:

Introduction 

A toxin (Greek: ôïîéêüí, toxikon, lit. (poison) for use on arrows) is a poisonous substance produced by living cells or organisms that is active at very low concentrations. Toxins can be small molecules, peptides, or proteins and are capable of causing disease on contact or absorption with body tissues by interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor and acute (as in a bee sting) to almost immediately deadly (as in botulinum toxin)

A toxin is simply a poison that can affect the body by internal or external means. A toxin can be a chemical which occurs naturally or in synthetic form. More than 120,000 human-made chemicals have been introduced into the environment, in one form or another, and this number continues to grow each year at a phenomenal rate. At the same time, microbial toxins, being influenced by the vast numbers of chemicals, are mutating beyond belief.

Pollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the physical systems or living organisms they are in.  
Pollution can take the form of chemical substances, or energy, such as noise, heat, or light energy.

Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Sometimes the term pollution is extended to include any substance when it occurs at such unnaturally high concentration within a system that it endangers the stability of that system. For example, water is innocuous and essential for life, and yet at very high concentration, it could be considered a pollutant.

Definition 

Radiation poisoning, also called “radiation sickness” or a “creeping dose” is a form of damage to organ tissue due to excessive exposure to  radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure to low level radiation. Many of the symptoms of radiation poisoning occur as ionizing radiation interferes with cell division.

The clinical name for “radiation sickness” is acute radiation syndrome . A short exposure can result in acute radiation syndrome; chronic radiation syndrome requires a prolonged high level of exposure. A chronic radiation syndrome does exist but is very uncommon; 

Chemical warfare involves using the toxic properties of chemical substances to kill, injure or incapacitate an enemy.

Chemical warfare is different from the use of conventional weapons or nuclear weapons because the destructive effects of chemical weapons are not primarily due to any explosive force. The offensive use of living organisms (such as anthrax) is considered to be biological warfare rather than chemical warfare; the use of nonliving toxic products produced by living organisms (e.g., toxins such as botulinum toxin, ricin, or saxitoxin) is considered chemical warfare under the provisions of the Chemical Weapons Convention. Under this Convention, any toxic chemical, regardless of its origin, is considered as a chemical weapon unless it is used for purposes that are not prohibited (an important legal definition, known as the General Purpose Criterion)

Appendix - 1

Differential Diagnosis of Poisons based on Clinical Signs

Extension

Extension is that type of education which is stretched out to people in rural areas far and near, beyond the limits of education institutions to which the formal type of education is usually confined.

Education

Education is a process of bringing about desirable changes in the behaviour of human being.

Formal education: The hierarchically structured, chronologically graded ‘education system’, running from primary school through the university and including, in addition to general academic studies, a variety of specialised programmes and institutions for full-time technical and professional training.

Informal education: The truly lifelong process whereby every individual acquires attitudes, values, skills and knowledge from daily experience and the educative influences and resources in his or her environment - from family and neighbours, from work and play, from the market place, the library and the mass media.

Non-formal education: Any organised educational activity outside the established formal system - whether operating separately or as an important feature of some broader activity - that is intended to serve identifiable learning clientele and learning objectives.

OBJECTIVE OF EXTENSION EDUCATION

Objective

Objectives are expression of the ends towards which our efforts are directed.

The objective of extension is to develop the rural people economically, socially and culturaly by means of education. Overall, these objectives are divided into 4 types they are :

a)   Material objective

b)   Educational objective

c)   Social and cultural objective

d)   Developing leadership objective

a) Material objective

According to National Commission on Agriculture (1976). Agriculture extension aims at improving the efficiency of human capital, an effort to rapidly increase the rate of agricultural production. It also seeks to import necessary skill to farmer to understand the improved agricultural operation and improve the their own income, own resource and also the money value.

b) Educational objective

Extension education also aims at development of individual to change in behaviour by identifying their knowledge, skill, attitude and action. It aims at increasing the knowledge of people to analyse their past, present and expected future situation, to become aware of problem identification, solution and also realising their felt and unfelt need.

RURAL DEVELOPMENT

Meaning

The word “Rural” comes from the word “Rurale” which means close to nature and environment, and “Development” means growth or maturation.

Rural development is utilization, protection and enhancement of the natural, physical and human resources to make long-term improvements in rural living conditions. It involves provision of jobs and income opportunities while maintaining and protecting the environment of rural areas.

General Definition

1)     It is based on an operational approach with practicalities with the people covering maximum end users for maximum economic return.

2) Definition by Axinn

R.D. is a process of change among the rural people through change in environment, technology institutions and attitude to eliminate the poverty and improve the way of life.

3) Definition by Miller

R.D. is based on the following components

a)     Development of human resource - It includes the development of rural people by providing education to the rural children and employment to rural youth, socio-economic condition of village can be improved.

b)     Expansion of physical resources - Construction of infrastructures like roads, schools, colleges, post office, bank etc will improve the rural condition.

c)     Extension of communit’s control over the resources.

COMMUNITY DEVELOPMENT (CD)

Meaning of Community Development

Community development is an exclusive term. It is used frequently to encompash every efforts towards the advance of community interest.

Community

A community is a group of people who live in a particular geographical area and have an interest on each other and have a purpose of making a living.

Development

It means growth or maturation. It is gradual and sequencial phases of changes. Example: Life from child to death

Definition of Community Development

1. It is bringing forth the potential abilities and qualities of a group of people who live together in a common territory or region and who have an interdependent relationship with each other.

2. Community Development is a continuous process of social action by which the people of community do the following things.

(a)   Define their common and group needs.

(b)   Organize themselves formally and informally for democratic planning and action.

(c)   Make group and individual plans to meet their need and solve their problems.

(d)   Execute their plans with maximum reliance upon their own resources.

(e)   Supplement their resources from outside community when necessary with services and materials.

3. Carl Taylor’s Definition

Community Development is a method by which people in villages are involved in helping to improve their own economy through their own effort. Thereby, they are effective working groups in the programme or national development.

DEVELOPMENT OF WOMEN AND CHILDREN IN RURAL AREAS (DWCRA)

Objectives

  1.    To raise the income level of women poor households.

  2.    Formation of groups of 10-15 women in rural poor for developing of services.

Salient features

  1.    Each group is given one time grant of Rs.25,000/-as revolving fund for infrastructure, purchase of raw materials, marketing, child care etc.

  2.    Fund is in ratio of 50:50 between Central and State government.

  3.    Provision of setting up of District Supply and Marketing Society for women producers.

DISTRICT RURAL DEVELOPMENT AGENCY (DRDA)

Objective

To professionalise the DRDA so that they are able to effectively manage the antipoverty programmes of the Ministry of Rural Development and interact effectively with other agencies.

Salient Features

•   The DRDA is visualized as a specialized agency capable of managing the anti-poverty programmes and to effectively relate these to the overall efforts of poverty eradication in the district.

•   The DRDA role will be to facilitate the implementation of the programmes, to supervise, oversee and monitor the progress, to receive and send progress reports and maintaining accounts of funds received for various rural development programmes.

•   DRDAs also need to develop synergies among different agencies for the most effective results.

•   The Chairman Zilla Parishad would be the chairman of the governing body of the DRDA.

  1.    Gender Sensitization: Change of Attitude of people towards gender equality, gender roles etc.

  2.    Public-Private Partnership: Involvement of private stakeholders with public entreprises

  3.    Information and Communication Technology (ICT): Use of computer. fax, video, telephones in information sharing & transfer of technology.

  4.    Cyber Extension: Use of computers in extension management.

  5.    Broad Based Extension: Farming system use for maximum use of all available resource to maximize profit

  6.    Bottom-up Approach: Planning from lowest level of society.

  7.    ITK (Indegenous Technological Knowledge): Use of farm community knowledge for development

  8.    Market Led Extension: Transfer of technology basing on assured & confirmed market of the product.

Introduction
Remote sensing is the art and science of recording, measuring, and analyzing information about a phenomenon from a distance. Humans with the aid of their eyes, noses, and ears are constantly seeing, smelling, and hearing things from a distance as they move through an environment. Thus, humans are naturally designed to be remote sensors. In order to study large areas of the Earth’s surface geographers use devices known as remote sensors. These sensors are mounted on platforms such as helicopters, planes, and satellites that make it possible for the sensors to observe the Earth from above.

Definition
Remote sensing can be defined as any process whereby information is gathered about an object, area or phenomenon without being in contact with it. Our eyes are an excellent example of a remote sensing device. We are able to gather information about our surroundings by gauging the amount and nature of the reflectance of visible light energy from some external source (such as the sun or a light bulb) as it reflects off objects in our field of view. Contrast this with a thermometer, which must be in contact with the phenomenon it measures, and thus is not a remote sensing device.

Introduction

Although both maps and aerial photos present a “bird’s-eye” view of the earth, aerial photographs are NOT maps. Maps are orthogonal representations of the earth’s surface, meaning that they are directionally and geometrically accurate (at least within the limitations imposed by projecting a 3-dimensional object onto 2 dimensions). Aerial photos, on the other hand, display a high degree of radial distortion. That is, the topography is distorted, and until corrections are made for the distortion, measurements made from a photograph are not accurate. Nevertheless, aerial photographs are a powerful tool for studying the earth’s environment. 

Because most GISs can correct for radial distortion, aerial photographs are an excellent data source for many types of projects, especially those that require spatial data from the same location at periodic intervals over a length of time. Typical applications include land use surveys and habitat analysis. 

This unit discusses benefits of aerial photography, applications, the different types of photography, and the integration of aerial photographs into GISs.

Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing. It allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the buildup of noise and signal distortion during processing. Since images are defined over two dimensions (perhaps more) digital image processing may be modeled in the form of multidimensional systems. Introduction to image processing 
Image processing is a method to convert an image into digital form and perform some operations on it, in order to get an enhanced image or to extract some useful information from it. It is a type of signal dispensation in which input is image, like video frame or photograph and output may be image or characteristics associated with that image. Usually image processing system includes treating images as two dimensional signals while applying already set signal processing methods to them.
Image processing is a method to perform some operations on an image, in order to get an enhanced image or to extract some useful information from it. It is a type of signal processing in which input is an image and output may be image or characteristics/features associated with that image. Now-a-days, image processing is among rapidly growing technologies. It forms core research area within engineering and computer science disciplines too.

Introduction

The Global Positioning System (GPS) is a space-based navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. The US began the GPS project in 1973 to overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s. The U.S. Department of Defense (DoD) developed the system, which originally used 24 satellites. It became fully operational in 1995. Roger L. Easton, Ivan A. Getting and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
 
Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block IIIA satellites and Next Generation Operational Control System (OCX). Announcements from Vice President Al Gore and the White House in 1998 initiated these changes. In 2000, the U.S. Congress authorized the modernization effort, GPS III. In addition to GPS, other systems are in use or under development. The Russian Global Navigation Satellite System (GLONASS) was developed contem-poraneously with GPS, but suffered from incomplete coverage of the globe until the mid-2000s. There are also the planned European Union Galileo positioning system, China’s BeiDou Navigation Satellite System, the Japanese Quasi-Zenith Satellite System, and India’s Indian Regional Navigation Satellite System.

Introduction

A geographic information system or geographical information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present all types of spatial or geographical data. The acronym GIS is sometimes used for geographic information science (GIScience) to refer to the academic discipline that studies geographic information systems and is a large domain within the broader academic discipline of geoinformatics. What goes beyond a GIS is a spatial data infrastructure, a concept that has no such restrictive boundaries. In a general sense, the term describes any information system that integrates stores, edits, analyzes, shares, and displays geographic information. GIS applications are tools that allow users to create interactive queries (user-created searches), analyze spatial information, edit data in maps, and present the results of all these operations. Geographic information science is the science underlying geographic concepts, applications, and systems.

GIS is a broad term that can refer to a number of different technologies, processes, and methods. It is attached to many operations and has many applications related to engineering, planning, management, transport/logistics, insurance, telecommunications, and business. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis and visualization. GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y, and z coordinates representing, longitude, latitude, and elevation, respectively. All Earth-based spatial–temporal location and extent references should, ideally, be relatable to one another and ultimately to a “real” physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry.

Applications of Remote Sensing

The era of satellite remote sensing was open in the 1960s when cameras and electronic sensors were mounted on spacecraft. Nowadays there is a big assortment of satellite systems actively recording information about the Earth. A wide variety of imagery is available from satellites. Both active and passive sensors, operating from the microwave to the ultraviolet regions of the electromagnetic spectrum collect a large amount of information about the earth’s surface every day. Each of the systems vary in terms of their spatial, spectral, radiometic and temporal resolution. Those characteristics play an important role in defining which applications the sensor is best suited for. The main benefits of satellite remote sensing are the following:

SENSORY EVALUATION OF FOOD

When the quality of a food is judged or evaluated by the senses (taste, smell, sight, touch and hearing), it is said to be a sensory evaluation. Since food is prepared for the primary purpose of being eaten and enjoyed through the senses, sensory evaluation is most appropriate. No machine has yet been devised that can totally substitute for the human senses in evaluating the quality of human food. However, the human instrument used in sensory evaluation is very complex and many problems need to be managed as data are collected and analysed. Computers are generally used to analyse data from sensory evaluations and may also be used to collect information firsthand.

Flavour perceptions are difficult to characterise verbally, for example, think about how a strawberry tastes, then try to describe it some one else. In food research small groups of trained individuals called juding panels or sensory panels are commonly used to determine differences among food samples. These panels often consist of from 5 to 15 individuals who have had training and experience in testing the particular food products being evaluated.

INTRODUCTION

COLLOIDS :  The word colloids has actually been derived from Greek language where it means glue like. The science of colloids was founded about 1861 when Thomas Graham published a summary of his work on the diffusion of substances in solution. He classified substances into two groups, viz: crystalloids and colloids, depending on their ability to diffuse through parchment membrane. According to Graham, crystalloids readily passed through parchment membranes while colloids did not. According to modern concept, colloidal solution contain substances whose molecular aggregates possess a diameter greater than 1 mu  and less than 100 mu. If the particle size is greater than 100 mu, a suspension is obtained (Table 1).

CARBOHYDRATES AND SUGARS

Carbohydrates which include sugars and starches are among the most important of the food stuffs as well as the simplest of organic foods. They may be divided into three groups.

Group – I

Monosaccharides  : These are simple sugars that cannot be split into any simpler forms. The principal ones are glucose or dextrose, fructose and galactose. Glucose sometimes known as dextrose or grape sugar is found widely distributed in nature, especially in fruits and vegetables, and is one of the main constuents of honey.

It is in the form of glucose that sugar appears in the blood and is being burned continuously to produce energy. A certain amount of surplus glucose is absorbed from the digestive tract and stored in the liver as glycogen, which can be converted back into glucose when the need for more fuel arises. In the presence of yeasts, glucose undergoes fermentation and changes into alcohol.

STARCH : Starch is a complex carbohydrate that has been cursed by dieters in years past, but that now is praised by nutritionists as a particularly healthful source of energy. In food preparation at home starch is a very important as a thickening agent. However starch is but one of several polysaccharides that are used as thickners in the food industry.

STRUCTURE : Although starch is the name used by nutritionists this complex carbohydrate actually consists of two fractions amylose and amylopectin. The two fractions occur together in starch from most sources so the overall behaviour of starch is determined in large measure by the relative amounts of amylose and amylopectin. Each of the fraction has unique properties that contribute to the functionality of starch from various plant sources.

Milk is the one food for which there seems to be no adequate substitute. It constitutes almost the entire diet for the young of all mammals. Each species produces milk that is especially adapted to the growth of its own young, but milk from one species may be used as food for others. Since animals were domesticated centuries ago, the milk from various species such as cow, buffalo, goat and camel, has been used in the diets of people throughout the world. Only cows milk is of commercial importance in the United States, although small amounts of goat’s milk are sold.

Whole cow’s milk is approximately 88 percent water, 5 percent carbohydrate, 3.5 percent protein and 3.3 percent fat. Its nutrient content varies from species to species, from breed to breed, seasonally and even from the beginning of the milking to the end of the process. In the United States it is cow’s milk that is used commonly as a beverage and in food preparation. Therefore the milk discussed throughout this chapter is cow’s milk.

INTRODUCTION

EGGS : Eggs and egg products constitute an important part of family meals. The economic importance of the egg to agriculture and industry, its multiple uses in the preparation of many food products, and its excellent nutritive value have stimulated scientific scrutiny into the nature of the egg.

STRUCTURE : The chief parts of the egg are the yolk, the albumin (the white), and the shell and the shell membranes. The yolk is more complex structurally than may be thought at first glance. At the very center is a light coloured structure called the white yolk. The vitelline membrane serves as the enclosure or sac for the yolk. The strength of this membrane is important when yolks and whites needs to be separated in cookery. Two important rather twisted membraneous structures extend from opposite sides of the yolk into the white.

INTRODUCTION

Vegetables and fruits have many similarities with respect to their composition, methods of cultivation and harvesting, storage properties and processing. In fact many vegetables are considered fruits in the true botanical sense. But the difference between the two is that vegetables are derived from various parts of plants e.g. roots, leaves, stems, buds and so on whereas, fruits are the mature ovaries of plants with their seeds. The edible position of most fruits is the freshly part of the pericap or vessel surrounding the seeds. The other difference between the two is that those plant items that are generally eaten with the main course of a meal are often considered to be vegetables, whereas those that are eaten alone or as a dessert are considered as fruits. This is the distinction made by food processors, certain marketing laws, and the consuming publics.

Fats are obtained from both animal and vegetable sources. The principal animal fats are cream, butter, egg yolk, the fat of beef, mutton, pork, bone marrow, chicken fat, and codliver oil. Vegetable fats are those derived from fruits and seeds of plant, as olive oil, cottonsed oil, corn oil, peanut oil, soyabean oil and nut oils.

COMPOSITION AND NUTRITIVE VALUE OF FATS

Fats and oils, the most concentrated of fuel foods, were the first of the organic compounds or foods to have their composition determined. They are made up of same three elements which go to produce the carbohydrates, but the oxygen is less in proportion to the carbon. This explains the fact that fat yields more energy per gram than carbohydrates do.

INTRODUCTION

Pulses are edible fruits or seeds of food bearing plants belonging to the family of the leguminosae. The major pulses which find important place in our diet are redgram dhal, bengal gram dhal, black gram dhal, green gram dhal and masoor dhal. Some are used as whole grams cow pea, rajmah and dry peas also belong to leguminous family.

Legumes not only have dietary values but also play an important role in maintaining or even improving soil fertility through their ability to fix atomospheric nitrogen.

INTRODUCTION

Many people confuse fortification with the term enrichment. There is a big difference in between these two terms. Fortification means the addition of those ingredients not normally found in a food and it is added to achieve a particular dietary purpose. Lysine may be added to corn products to increase the biological value of the protein. Salt may be iodised to prevent the occurrence of goiter. Breakfast cereals may be fortified with an array of vitamins and minerals to ensure a completely balanced nutritional meal.

In enrichment, the amounts added are designed to meet specific legal standards of minimum and maximum levels of nutrients. It is recognised that in the processing of cereal products that the removal of bran and germ causes a large portion of the vitamins and minerals naturally found in the product to be lost. During World War II an effort was made to correct this deficiency by government endorsement of the enrichment of bread, flour, and cornmeal. Wheat flour, cornmeal, corn grits, bread, ready to eat and uncooked cereals, and macroni products have been enriched with thiamine, ribo-flavin, niacin, iron and in some cases, calcium and vitamin D.

W.H.O. has defined food fortification as “a process where by nutrients are added to foods to maintain or improve the quality of the diet of a group, community or population”.

INTRODUCTION

Meat is the flesh of animals that is used for food and consists of muscle, fat and bone. If the muscle which is commonly known as the lean meat, is examined under the microscope, it is seen to be made up of bundles of fibers held together by a thin membrane called connective tissue. Further study reveals that these fibers are in readily hollow tubes that vary in length in different animals and in different muscles in the same animals that are filled with a fluid, sometimes called muscle juice, which is known to contain protein, minerals and extractives. The forms of protein in the muscles are myosin (a globulin) and myogen (an albumen) and in addition, on red meats, hemoglobin.

INTRODUCTION

Adulteration of food consists of substituting it wholly or in part by any cheaper or inferior substance or of removing any of its constituents, wholly or in part, which affects adversely the nature, substance or quality of the food. According to the Indian Prevention of Food Adulteration Act (PFA) 1954, any ingredient which, when present in food, is injurious to health is an adulterant. Thus, according to the PFA definition, many of the food contaminants discussed in the previous section are adulterants and come under the purview of food adulteration.

Adulteration of foods was practised even in ancient times. It was not a serious problem then because business was on a small scale and the transactions involved a large measure of personal accountability. Later, with the increased centralization of food processing and distribution, and corresponding decline in personal accountability, intentional adulteration of food increased. Even in the early nineteenth century, many adulterants were used in articles like pepper, essential oils, vinegar, beverages (coffee, tea, beer, wines), butter, bread, etc. In recent years adulteration of foods has become a serious problem the world over. In western countries there is a rising concern over the safety of the food supply and many remedial actions, both voluntary and enforced, have been taken.

Materials Required

Equipments and machinery used in Postharvest Technology laboratory for processing, packaging and quality analysis.

Procedure

    1.    Identify the equipments and machinery, note down the typical features about its shape, size, colour etc.

Materials Required 

Fruits/vegetables, hand refractometers, fruit pressure tester, weighing balance, scale, chemicals and glassware required for analysis.

Procedure

    1.    Go to the orchard or vegetable field and collect samples of fruits and vegetables
    2.    Apply the specific maturity indices to the samples

Materials Required

Fruits/vegetables, thermometer, refractometers, NaOH, Phenolphthalein, glassware, weighing balance, plastic crates for storage of commodity, water cooling facility.

Procedure

    1.    Harvest the fruit / vegetable
    2.    Count No. of unmarketable fruits in every 100 fruits harvested
    3.    Record the internal fruit temperature in about 5-10 randomly selected fruits with the help of a thermometer
    4.    Pre-cool the commodity in cold water (<5ºC), air or refrigerator till the temperature reaches near its optimum storage temperature
    5.    Record the internal fruit temperature
    6.    Record the time required to pre-cool the commodity
    7.    Keep the product for storage at ambient conditions alongwith control
    8.    Record the difference in the shelf life and quality during storage

Materials Required

Fruits/ vegetables, washing tanks/ containers, size grader, fruit waxes, packaging material, neem based fungicides etc. 

Procedure

    1.    Take available fruits or vegetables 
    2.    Wash them in plain water or chemical solution as told by the teacher
    3.    Shade dry the fruits / vegetables
    4.    Prepare suitable wax solution
    5.    Apply wax on to the fruits as told
    6.    Record the fruit weight before packing
    7.    Pack the fruits properly in the trays / boxes depending upon the type and purpose
    8.    Do curing if required 
    9.    Do pre-packaging, if desired
    10.    Label the package for desired information
    11.    Keep the fruits for storage
    12.    Record the observations pertaining to weight loss and rotting periodically depending upon the commodity and its shelf life.

Materials Required

Fruits/ vegetables, weighing balance, plastic crates, CFB boxes or other packaging material fruit pressure tester, hand refractometer, markers etc.

Procedure

    1.    Harvest the fruits
    2.    Subject them to various pre-treatments (as discussed in previous exercise).
    3.    Record their initial parameters i.e. weight, firmness, surface colour, TSS, rotting etc. 
    4.    Place properly packed commodity in storage alongwith a check under ambient conditions
    5.    Record the observations regarding changes in quality during storage
 

Materials Required

Fruit, pulper, fruit mill, hydraulic press, screw type juice extractor, stainless steel pans, chemical preservatives, glass bottles, closures, crown corks, crown corking machine, plastic barrels.

Procedure

    1.    Select and weigh sound fruits/vegetables for extraction of juice/pulp.    
    2.    Wash and peel the fruits as required.
    3.    Extract the juice by hot or cold process.
    4.    Pasteurize the juice/pulp to inactivate the enzymes and partially kill microorganisms.
    5.    Preserve the juice/pulp by heat processing after hot filling and hermetic sealing or by addition of permissible quantities of suitable preservatives.
    6.    Label the bottles properly and keep them for storage

Materials Required

Fruit juice/ pulp, cane sugar, potable water, essence, citric acid, colours, preservatives, weighing balance, bottling and sealing facilities, hand refractometer, homogenizer etc.  

Procedure

    1.    Extract the juice as discussed in previous exercise.
    2.    Filter the fresh or preserved juice through muslin cloth.
    3.    Calculate the quantities of juice, sugar, water, acid (if required), preservatives, colour, essence etc. required for preparation of a known quantity of                      squash as per FPO specifications.
    4.    Prepare the beverage as directed by instructor
    5.    Pack the beverage in bottles 
    6.    Seal the bottles and label them
    7.    Take out one of the bottles and measure its TSS and titratable acidity.