eBook Chapters

The term pesticide includes fungicides, bactericides, nematicides, rodenticides, soil fumigants and herbicides. They cover a wide range of formulations: chlorinated hydrocarbons, organophosphates, metallic salts, acetic acid derivatives, thiocarbamates etc. They all have deleterious effects on humans, domestic animals, wildlife and plants.

Cheese is a milk product of ancient origin and portrays the ethos of civilization and its cultural evolution. Cheese is one of the oldest foods of mankind. It is commonly believed that cheese evolved in the Fertile Crescent between the rivers Tigris and Euphrates in Iraq some 8000 years ago. The so-called Agricultural Revolution occurred here with the domestication of plants and animals.

It seems that the cheese originated accidentally as a result of the activities of nomadic tribes. Since animal skin bags were a convenient way of storing liquids for nomadic people, these were used for storing surplus milk. Fermentation of the milk sugars in the warm climate prevailing would cause the milk to curdle in the bags. The swaying animals would have broken up the acid curd during journeys, to produce curds and whey. The whey provided a refreshing drink on hot journeys, while the curds, preserved by the acid of fermentation and a handful of salt, became a source of high protein food supplementing the meager meat supply.

This activity gave rise to the assumption that cheese was evolved from fermented milks. It is perhaps more probable that the crude fermentations progressed in two ways. In one direction towards the production of liquid fermented milks such as dahi, yoghurt, laban, koumis and Kefir and in the other direction through the drainage of whey through a cloth or perforated bowls, to leave solid curds which when salted became cheese.

It was a prominent article of the Greek and Roman diet as much as 2500 years ago. It is referred to in the Old Testament several times.

19.1 Introduction
Cheese is a product that is produced by coagulating curd from milk with rennet or similar enzymes in the presence of lactic acid produced by adventitious or added microorganisms. Following the shaping of the curd in a mould and the removal of a portion of the moisture, it is permitted to mature by being maintained at an appropriate temperature and humidity for a specified duration.The FSSAI defines cheese as soft, semi-hard, hard, or extra-hard products that are matured or unripened, have a whey protein to casein ratio that is not greater than that of milk, and can be coated with food-grade waxes or polyfilm. coagulating agents. During this procedure, flavor-producing bacteria and harmless lactic acid bacteria may be introduced. The separation of whey is facilitated by the coagulation that results, which also ensures that the cheesemaking process concentrates milk proteins, particularly casein. Consequently, the protein content of cheese is substantially higher than that of the initial milk material blend. Furthermore, cheese-making incorporates methods that result in a final product with comparable physical, chemical, and sensory attributes by coagulating milk proteins or milk-derived products. The ingredients of cheese are limited to those that are naturally present in milk, with the exception of certain additives such as coagulating agents, sodium chloride, and small quantities of calcium chloride, annatto or carotene colourants, and specific emulsifiers and stabilisers such as citric acid, sodium citrate, sodium salts of orthophosphoric acid, and polyphosphoric acid. The wax employed for coating must not present any health hazards, and if it is coloured, it must be made from only approved food colours. The moisture content of hard cheeses is determined by the presence of no less than 42% milk fat and no more than 43% moisture on a dry matter basis. Additionally, they may contain trace quantities of nisin and ascorbic acid or its salts.

Sauropus androgynus, also known as katuk, star gooseberry, or sweet leaf, is a tropical shrub that is used as a leaf vegetable in some areas. It’s known as Chinese Malunggay in China, and madhura cheera in Kerala, India. It has several upright stems that can grow up to 2.5 metres tall and dark green oval leaves that are 5-6 cm long. It’s known as ‘Multivitamin Greens’ because of its great nutritional value. Chekurmanis, which may be found in practically every household kitchen garden in Kerala, has not been cultivated for commercial use on a significant scale. As a result, there are no data on the area and production of these vegetables.

The term “chelate” comes from the Greek word “chel,” meaning “claw,” indicating that the element is tightly held or clawed by the ligand. The term was coined by Morgan and Drew in 1920, defining it as a chemical compound in the form of a heterocyclic ring with a metal ion attached by coordinate bonds to at least two non-metal ions, known as chelation. A chelate is a type of mineral complex, which is a mixture of a mineral and an organic compound like a protein or polysaccharide. Chelation refers to the bond formed between a metal ion (mineral) and a ligand (protein or amino acid chelating agent). Chelates are created by reacting a mineral salt with an enzymatically prepared mixture of amino acids and small peptides under controlled conditions. The ligand binds the metal at multiple points, forming a ring structure with the mineral, resulting in a chelate.
In animal feed, chelated minerals, such as iron, manganese, cobalt, copper, and zinc, are commonly used to enhance bioavailability and support metabolic functions. These trace elements are transitional elements on the Periodic Table, forming stable complexes or chelates due to their ability to form coordinate covalent bonds.
The primary goal of chelates is to improve mineral absorption in animals during periods of high nutritional demand, such as pregnancy, lactation, weaning, and environmental or disease stress. Chelates have been studied for their effects on immunity, reproductive performance, and overall herd health. To maximize mineral absorption, chelated compounds should be stable in the rumen.
Chelates are stable, electrically neutral complexes that protect trace minerals from chemical reactions during digestion, ensuring their availability to the animal. Chelated minerals are used to increase bioavailability and uptake, reaching the plasma intact and separating at the site of action. They can replace a portion of inorganic minerals in animal diets and are suitable for all species. Soluble chelated trace minerals are designed for use in drinking water supplies.

Objective
To determine the chemical composition of biomass in terms of cellulose, hemicellulose, lignin, and silica content using standard detergent fiber analysis and acid digestion techniques.
Principle
Chemical analysis of biomass helps in evaluating its structural and compositional characteristics, which influence its thermal behavior, degradation properties, and suitability for bioenergy applications. Biomass primarily consists of cellulose, hemicellulose, lignin, and pentosans, each playing a distinct role in the structure and energy potential of plant material:
Cellulose – A linear polymer of ß-D-glucose units linked by ß-(1?4) glycosidic bonds. It provides tensile strength and rigidity to plant cell walls and serves as the main carbohydrate source in biomass.
Hemicellulose – A heterogeneous branched polymer composed of pentoses (xylose, arabinose) and hexoses (mannose, glucose, galactose). It acts as a matrix surrounding cellulose microfibrils, providing flexibility and binding lignin and cellulose together.
Lignin – A complex three-dimensional polymer made up of phenylpropane units. It is highly resistant to microbial degradation, provides compressive strength, and acts as a natural binder in plant tissues.
Pentosans – Polymers of five-carbon sugars that contribute to carbohydrate storage and structural integrity.

Preparation of Samples

Before withdrawing portions for analytical determinations, bring the sample to a temperature of 26 to 28ºC and mix throughly by pouring gently into a clean dry receptacle and back, until a homogenous mixture is assured. If lumps of cream do not completely disappear, warm the sample to about 40ºC, mix throughly, then cool to 26 to 28ºC. In case a measured volume is required in a determination, bring the temperature of the sample to about 27ºC before pipetting. All samples shall be allowed to stand for three to four minutes after mixing to allow air bubbles to rise ; the sample bottle shall then be inverted three or four times immediately prior to taking the milk for analysis. If a sample is curdled, excessively churned or decomposed, the sample should not be taken up for analysis.

The chemical composition and digestibility of feedstuffs influence their nutritive value for animal production. Therefore, assessment of nutritive value of feedstuffs continues to be one of the top priority areas in animal production research. Although traditionally the feedstuffs were evaluated by performance studies and digestion trials, such techniques are expensive and requires more time and labour. Continued search for alternatives to animal feeding experiments have led to the development of feed evaluation systems that are rapid and economical.

In general, there are two kinds of laboratory analyses — Chemical analyses and Biological tests with rumen micro-organisms or purified enzymes. Biological tests give direct estimates of digestibility, but are lengthier and more expensive. Chemical analyses are cheaper and rapid, but do not give direct estimates of nutritive value. The statistical association between the chemical components and quality need to be established to predict the nutritive value.

Preparation and processing of samples for chemical analysis: The preparation of samples depends upon the purpose of analysis and the nature of the constituents that are to be determined. The preparation of samples for analysis is as important as the analytical procedure and hence, it should be done with utmost care. (A) Smpling of wet material: (1) Plant material; (2) Silage; (3) Cattle faeces; (4) Sheep / goat faeces; (5) Poultry excreta; (B) Sampling of air – dry material: (I) Hay or straw; (II) Concentrates.
Small quantities of feed samples are collected from several locations, all sides, in the middle and are mixed well after chaffing. Such mixture is subjected to quarter sampling, by spreading on levelled ground in circular form. This circle is now divided into 4 equal quarters. Any 2 diagonally opposite quarters are selected and other 2 are rejected. Selected portions are mixed properly and again spread on levelled ground in circular form. This mixture is again divided into 4 equal quarters and any 2 diagonally opposite quarters are selected, while remaining 2 are rejected. This procedure is repeated till required quantity of sample is obtained. This representative sample is brought to laboratory as early for drying in a hot air oven. Dried samples are ground to pass through 2 mm sieve in a Willey mill (large samples may be ground through hammer mill), as described in chapter 10. Sample is collected in an airtight plastic bag and stored in desiccator.

Abstract

The use of plants for treating diseases is as old as the human species. Popular observations on theuseandefficacyof medicinal plants significantly contribute to the disclosure of their therapeutic properties, so that they are frequently prescribed, even if their chemical constituents are not always completely known. Medicinal plants have therapeutic potential due to the presence of natural antioxidants functioning as reducing agents, free radical scavengers and quenchers of singlet oxygen. Majority of their antioxidant activity is due to bioactive compounds viz. flavones, isoflavones, flavonoids, anthocyanins, coumarins, lignans, catechins and isocatechins. They have been recognized to possess several medicinal properties (diuretic, expectorant, laxative, anti- bacterial, anti-pyretic etc.) and have been effectively used in the indigenous systems of medicine in India and other countries. Apart from the traditional use, a number of beneficial physiological effects have been identified by extensive studies. Among these are their beneficial effects on lipid metabolism, efficiency as antidiabetics, ability to stimulate digestion and to inhibit platelet aggregation, antioxidant, antilithogenic and anti-inflammatory potential.In this chapter an attempt has made to elucidate and understand the chemical and medicinal properties of Stavar and Safed musli those are using as medicine. These may also use as ingredients for preparation of herbal food products.

Chemistry of vegetable crops

Vegetables play an important role in human nutrition supplying some of the materials, which other food materials are lacking. Vegetables are important in neutralizing the acidity formed during digestion. They also serve as roughages in human nutrition and thus helping digestion.

They are the important sources of minerals like Ca, P and Fe. They also form an important source of vitamins, especially vitamin A. Green and yellow vegetables like carrot, turnip, spinach, beans, etc. contain appreciable amounts of vitamin A. Direct seed of beans, peas, and legumes contain appreciable amounts of proteins. Vegetables also contain sufficient amounts of vitamin C and also appreciable quantities of thiamine, niacin and folic acid. Tomatoes and potatoes contain fairly high amounts of vitamin C.

Life is fundamentally a complex interplay of chemical interactions and reactions. Chemistry examines the composition and properties of matter, the interactions between chemical components, and the mechanisms by which complex structures are formed. Biological chemistry, or Biochemistry, delves into these principles within the context of living systems, highlighting the intricate relationships between molecular structure and function. Understanding fundamental chemistry and its application to anatomy and physiology is crucial because the human body is composed entirely of chemical substances. Basic chemistry encompasses the study of matter, its various states, and energy in all its forms. In order to understand the basic chemistry of living let us start from the scratch of learning and remembering everything that we have learnt so far. Matter and Its Properties Anything with mass and occupying space is referred to as matter. Solid, liquid, and gas are its three main states. Mass, distinct from weight, represents the quantity of matter in an object and remains constant regardless of location. In contrast, weight depends on gravitational force. 

Introduction

Chemical communication between plants and insects is an essential part of mutual relationships, in which both partners benefit from the communication. The role of volatiles in pollination systems provides an excellent model for understanding the ecology and evolution of chemical communication between plants and insects. Infochemical:- A chemical that conveys information in an interaction between two individuals evoking in the receiver a behaviour or physiological response. Chemicals involved in interspecific communications were given the name of Allelochemicals by R. H. Whittaker in 1970. Allelochemicals affect the survival, growth & development of herbivorous insects as well as their natural enemies.

4.1 Introduction

The egg is made up of three primary components: the egg white, the egg yolk, and the egg shell. The calcite crystals of the shell are enmeshed in a protein and carbohydrate complex matrix. About 58% of the weight of an egg is made up of the viscous, colourless liquid termed egg white inside the shell. About 75% of the weight of an egg’s edible component is made up of water, although proteins and lipids make up the majority of its nutritional worth (Table 4.1). There are also trace quantities of minerals, often known as ash, and carbohydrates, which take the form of simple sugars including glucose, sucrose, fructose, lactose, maltose, and galactose.

I. FILL UPS

1. The major storage organ for cereals is _____ .
2. The major storage organ for legumes is _____.
3. The major storage organ in pine is _____.
4. The average protein percent present in soybean is _____.
5. The average oil percent present in oilpalm is _____.

The chemical composition of seeds is basically determined by genetic factors and varies among different species and seed parts (Table 1). However, it is influenced by environmental and cultural practices.

Cell walls mainly consist of cellulose, hemicellulose, and lignin in a 4:3:3 ratio. This ratio differs from sources such as hardwood, softwood, and herbs. Besides these three components, natural lignocellulosic materials contain a small amount of pectin, nitrogenous compounds, and the secret ash.

1. Cellulose

2. Hemicellulose

3. Lignin

Cellulose

Cellulose is a glucan polymer consisting of linear chains of 1,4-ß -bonded anhydroglucose units. Cellulose is the structural component of the primary cell wall of the green plants.About 33% of all plant matter is cellulose (the cellulose content of cotton fiber is 90%, that of wood is 40-50% and that of dried hemp is approximately 45%. Cellulose is a straight chain polymer.The number of sugar units in one molecular chain is referred to as the degree of polymerization (DP).Cellulose is insoluble in most solvents including strong alkali. It is difficult to isolate from wood in pure form because it is intimately associated with the lignin and hemicelluloses.

The volatile oil in the flower determines the odour and flavour of kewda and it has been of particular fascination to the chemists. There are only a few reports on the chemical composition of kewda essential oil (rooh or otto) Dhingra et al. (1954) distilled the kewda flowers collected from five places of Ganjam (Odisha) and Ghazipur (Uttar Pradesh) districts. He found the oil yield to vary from 0.015 to 0.031% and the compounds identified were methyl ether of β- phenyl ethyl alcohol (65.97%), d-linalool (18.70%), dipentene (8.31%), phenyl ethyl acetate (3.48%) and citral (1.82%). The oil was of light to golden yellow in colour having the following physico-chemical properties viz., specific gravity (d20o) 0.932-0.958; refractive index (n20o) 1.485-1.491; optical rotation ([α]D) + 1.350 to + 2.080; acid value 1.4 – 6.7; ester value 15.9 – 40.9 and soluble in equal volume of 80 % alcohol (Deshaprabhu, 1966). Sadgopal (1959) also reported the major constituent of oil as methyl ether of β-phenyl ethyl alcohol (65 – 80%) and minor constituents as dipentene, α-linalool, phenyl ethyl alcohol, citral and some terpene esters.

According to Chandra (1985), the oil contained dipentene (6.0%), d -linalool (19.0%), phenyl ethyl acetate (4.6%), citral (1.8%), caproic acid (0.5%) and stearoptene (0.2%) besides the major constituent methyl ether of β-phenyl ethyl alcohol (67.0%).

4.1 Introduction

Insecticides, biocontrol agents and resistant varieties are the three important pest management tactics in vogue across the globe. Though several biocontrol agents have been recorded on major pests of economically important crops, mass multiplication techniques for most of them are yet to be perfected, and in several instances, the inundative releases of natural enemies are costlier than chemical insecticides. Moreover, unlike perennial crop ecosystems, the annual crop ecosystems like rice, cotton, sugarcane, pulses, etc. are frequently disturbed and hence, inoculative releases of biocontrol agents are often impractical. Above all, in spite of sustained effort from dedicated plant breeders across the globe, the resistant varieties with outstanding yield potential are very limited in numbers. Genetic engineering of crop plants though paved the way for introducing insecticidal genes more precisely and efficiently, the poorly understood ecological and sociological implications of genetically engineered crops in their target environment resist their strong footing in the pest management programmes in most of the crops especially of food crops. In this backdrop, insecticidal interference is inevitable to manage the insect pests, and they are the only weapon whenever the pest population crosses the economic threshold level.

Acid soils occupy about 30 percent of the land area of the world out of which 67% acid soils support forests and wood lands and 18 percent are covered by grassland vegetation. Only 4.2 per cent (179 million hectare) of the acid soils across the globe is used for arable crops.

Soil acidity is a major constraint in crop production. The removal of basic cations especially Ca and Mg by leaching and their replacement by acidic cations, H, Al and Fe on exchange complex leads to soil acidity. Soil developed from granite parent material are more acidic than those developed from basalt, shale or lime stone. In acid soils, low pH leading to toxic concentration of H⁺, Al³⁺, Mn²⁺ influences nutrient availability, organic matter decomposition and microbial activity.

Efficient soil amelioration and nutrient management practices are necessary for crops susceptible to soil acidity.

Chemical ecology is the study of ecological interactions between organisms mediated by chemical produced by those organisms. In short it is considered as the ecological functions of the chemicals. An insect, in various stages of its life history, performs various activities like host plant location, host plant selection,  feeding and oviposition, mating, escape from its natural enemies etc. and the chemicals play a crucial role than visual and audio signals. Chemical ecology encompasses the studies of these chemicals based interactions.

Abstract

Organic farming, the state - of - art technology of the present era in agricultural cultivation, is not new to India. Green revolution in last four decades of Twentieth Century made farmers more dependants on chemical fertilizers and chemical pesticides for harvesting highest crop yield but side by side increased environmental pollution as well as health hazards and reduced soil productivity by increasing nutrient imbalance in soil. Indian farmers have almost forgotten their century old practice of preparation of compost from farm wastes and its use in next cultivation for getting pollution free healthy food materials. This articles deals with the problems of chemical farming in Indian context and their solution through organic farming.

Chemical immobilization of elephants needs an understanding of itís special features as a priority. Lungs are adhered to the chest wall by fibrous tissue and there is no pleural space. This fact must be taken into consideration when the elephant is cast or put into positions that may inhibit respiration.The trunk of the elephant is a vital organ. An injured or paralyzed trunk is a serious problem; if it cannot be corrected, the elephant will starve.

Chemical restraint is a form of animal restraint technique in which a drug or a chemical is used to restrict the movement (walking, running, aggression) of an animal or sometimes just to sedate or to calm down the animal. Chemical restraint is a safe and effective capture method when applied correctly and with due precaution.

Key facts

    
•    Arsenic (As) is a metalloid, with properties intermediate between those of a metal and a non-metal. Arsenic can exit in the environment and biological systems in various inorganic and organic forms (species). These are arsenite - AsIII, arsenate - AsV, monomethyl arsonic acid (MMAA), dimethyl arsinic acid (DMAA), arsenocholine, arsenobetaine and arsenosugars. 
    
•    Arsenicals have a wide range of toxicity. In general, inorganic arsenicals are more toxic than oragnoarsenicals to biota and trivalent arsenic (arsenite) is more acutely toxic than pentavalent (arsenate) form in the following orders:
    
    Arsenous acid (AsIII) ®  arsenic acid (AsV) ® MMAA ®DMAA ® arsenocholine ® arsenobetaine.
    
•    Under oxidizing and aerobic conditions, the predominant form of arsenic (As) in soil and water is arsenate (AsV), whereas under anaerobic and reducing/or waterlogged conditions, arsenite (AsIII) predominates.
    
•    Inorganic AsIII and AsV are the major As species in groundwater, soils, terrestrial plants, whereas the main species found in marine animals is Arsenobetaine (AsB), which is considered to be non-toxic.
    
•    The LD50 values of different arsenicals show that arsenite (AsIII) is most toxic (LD50 range 15-42 mg/kg) and arsenobetaine is least toxic (LD50 > 10,000 mg/kg).

Key facts

Freshwater biotoxins

    
•    Biotoxins are naturally occurring toxic compounds produced by some freshwater cyanobacteria (blue-green algae) and marine algal species (dinoflagellates, diatoms).
    
•    Cyanobacteria are now recognised as a serious water quality problem with regard to drinking water supply and recreational use.
    
•    Environmental conditions that can promote cyanobacterial/blue-green algal blooms are: excessive nutrients (phosphorus and nitrogen); warm water temperatures (15-30OC); sunlight for photosynthesis; and quiescent or stagnant water.
    
•    Outbreak of human poisoning attributed to cyanobacteria are neurotoxins (e.g. anatoxin-a, anatoxin-a(s), saxitoxins) and hepatotoxins (e.g. microcystins, nodularin) produced by some strains of the cyanobacteria including Microcystis, Anabaena, Aphanizomenon spp.

Key facts
    
•    Dioxins are the most dangerous and ‘super toxic’ chemicals so far known on the earth and three closely related families are collectively known as dioxins. These are Polychlorinated dibenzo-p-dioxin or dioxins (PCDDs), Polychlorinated dibenzofurans or furans (PCDFs) and polychlorinated biphenyls (PCBs).
    
•    2, 3, 7, 8-TCDD (or called TCDD) is the most potent of all the congeners. The toxicity equivalency factor or TEF of TCDD has been assigned as 1, while all other congeners assigned in order of toxicity ranking magnitude relative to TCDD.
    
•    There are 75 compounds/congeners in the dioxin family (PCDD), 135 compounds in the furan family (PCDF) and 209 possible compounds in the PCBs based on the possible number of chlorine atoms.
    
•    The toxicity of dioxins and dioxin-like compounds vary substantially among the different PCDDs, PCDFs and PCBs. It is generally accepted that only 29 out of the 419 congeners of dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls are toxic to humans and other organisms. The TCDD is most toxic and registered by the WHO as carcinogenic for humans.

Key facts

    
•    Endocrine disrupting chemicals (EDCs) are micropollutants with estrogenic or androgenic activities at very low concentrations and are emerging as a major concern for water quality.
    
•    EDCs include natural and synthetic hormones (Estrone or E1, 17b-estradiol or E2, Estriol or E3, 17a-ethynylestradiol or EE2); alkylphenols (nonylphenol or NP; octyphenol or OP), phenols (bisphenol-A or BPA), phthalates (Di-n-butyl phthalate or DBP, Di-2-(ethylhexyl)-phthalate or DEHP); organotins (tributyltin or TBT); and phytoestrogens (b-sitosterol, coumestrols, genistein). 
    
•    Wastewater treatment plants, intensive livestock effluents, industrial wastewaters, landfill, paper and pulp mill effluents and antifouling paints are important sources of EDCs in the environment.

Key facts
    
•    Pesticides are chemicals that are broadly used to protect crops, livestock and other animals and plants from pests and diseases. They are classified according to the type of pest to be controlled (algicides, herbicides, fungicides and insecticides).
    
•    Commercial production of DDT began in 1943. At that time, DDT was considered to be a wonderful invention. It was cheap to produce, very toxic to insects and much less toxic to mammals and its usage resulted in a sharp decline of mosquito borne diseases. In 1962, it was discovered that DDT was causing egg-shell thinning in bird eggs and thus was leading to the near extinction of bird species such as peregrine falcons and bald eagles.
    
•    Pesticides use has greatly helped to increase and improve the world food production. Use of pesticides also increases farmer’s profits by preventing crop losses due to pest attacks and weed infestation.

Key facts
    
•    Biotoxins are naturally occurring toxic compounds produced by some freshwater cyanobacteria (blue-green algae) and marine algal species (dinoflagellates, diatoms).
    
•    Tonnes of pharmacologically active substances are used annually in human and veterinary medicines, some of these substances are excreted (human and animal) non-metabolised or an active metabolites and enter into the environment since waste water treatment plant (WWTP) cannot degrade them.
    
•    In Europe, around 4,000 different pharmaceutically active compounds are used as human and veterinary drugs and the annual consumption is about several hundred tonnes.
    
•    European Union and the United States laws require an assessment of potential risks to the environment as part of license application processes for new medicinal products.

•    Pharmaceutical products are generally polar, water soluble and low volatile molecules, it means that they have high mobility in the environment.

Key Facts

    •    The heavy metals (HM) or trace metals in an aquatic environment can come from natural (e.g. geological minerals, wind blown silicate dust, volcanic emissions, sea spray and combustion) and anthropogenic sources (e.g. mining, industry and sewage treatment discharges as well as electronic waste and agriculture fertilisers). In aquatic systems, the heavy metals of greatest concerns are cadmium, copper, lead, mercury and zinc.
    •    Metals may exist in a number of physico-chemical states in aqueous systems such as particulate matter and dissolved forms. Metal speciation in freshwater is strongly influenced by hardness, alkalinity, pH, natural dissolved organic matter (DOM) and redox potential. 
    •    Water hardness is quantitatively related to metal toxicity in freshwater (i.e. toxicity of heavy metals decrease with increasing hardness and alkalinity; on the other hand, toxicity increases with decreasing salinity, dissolved organic matter and chelators). The uptake and toxicity of heavy metals of most metals in marine waters is low as compared to freshwater because metals are easily complexed with chloride ions.
    •    The toxicity of HMs is related to the dissolved ionic form of the metal rather than total concentration of the metal. Each different physico-chemical forms of an element has a different toxicity, for example, if the element (e.g. Cu) is absorbed on a colloidal particles it is expected to be of little or no effect on aquatic organisms, however,  if the copper is available as free Cu (II) ion, few aquatic organisms may survive.

INTRODUCTION

The use of chemical for protecting plants from the ravages of the pathogens is not an innovation of the 20th century. Chemicals have been used for over 200 years to protect plants against fungal diseases. At present about 150 chemicals belonging to different classes are used as fungicides in world agriculture. Most of the recommended treatments generally provide 90% or greater control of target diseses. Even when a crop has been grown from pathogen free soil and the crop seems superficially healthy, the use of fungicides in some circumstances become unavoidable. Resistant varieties of potato are attacked by late blight if rain occurs during tuber formation. To control this disease use of fungicides become vital to avoid any loss of the crop. Thus, even in the case of resistant varieties, judicious use of chemical protection will extend the life of resistance in the variety. For killing different groups of pathogens, different types of chemicals are required. The chemicals mainly used for controlling diseases are: fungicides for killing fungus, bactericide for killing barteria, nematicides for killing nematodes, and viricides for killing viruses.

Introduction and Concept

The word fungicide has originated from two Latin words: viz. fungus and caedo (to kill). So literally, a fungicide would be any physical or chemical agency which kills a fungus. However, the word is restricted to chemicals. Hence, the word fungicide should mean a chemical capable of killing fungi. However, there are a number of compounds which do not kill the fungus. They simply inhibit growth or spore germination temporarily. If the fungus is freed from such substances, it would revive. Such a chemical is called a fungistat. and the phenomenon as fungistasis. Some other chemicals, like certain phenantherene derivatives and bordeaux mixture may inhibit spore production without affecting vegetative growth. These are called antisporulants. There are other groups of chemicals which exhibit very poor or no antifungal activity in vitro condition but provide protection to the plants either by inhibiting the penetration of host surface by the fungi or by inducing the host defense system. The former type of chemicals are termed as antipenetrants and later as antipathic agents. Even though fungistats, antisporulants, antipenentrants, and antipathic agents do not kill fungi, they are included under the broad term fungicide because by common usage, the word fungicide has been defined as chemical substance which has ability to prevent damage caused by fungi to plants and their products. Fungicide which is effective only if applied prior to fungal infection is called protectants. On the other hand, fungicide which is capable of eradicating a fungus after it has caused infection, and thereby curing the plant, is called therapeutant.

Anti-pathogen Chemicals
The chemical substances that help to retard the activity of pathogens like fungus, bacteria and nematodes are said to be anti-pathogen chemicals.
Aim of use of chemicals in plant disease control
The aim and of use of chemicals in plant disease control are
• To create a toxic barrier between the host surface or tissue and the pathogen .
• To eradicate the pathogen present at a particular site on the host, such as seed, foliage, roots etc.
Functions of chemicals in plant disease control
• Reduction in inoculum density or eradication of inoculum from source of growth, multiplication and survival.
• Inactivaion or destruction of the pathogen when it lands on the treated surface, and
• Cure of the diseased plant.

Introduction

The metal particles in nanometer scale shows exciting optical and electronic characteristics when compared with respective bulk metals. Because of the inherent electronic properties of the metal and metal oxide nanoparticles these nanostructure materials are applied in various disciplines in recent days. Mostly these nanoparticles can be synthesized either top down or bottom up approaches. The conversion of bigger size particle or matter into tiny particles is called top down approach where as smaller particles or atoms joined together forming particles in regular shape within nanometer scale dimension is called bottom up approach. The formation of nanoparticles by chemical reduction is an example for the later one and the reduction size with the help of mechanical crusing leads to the formation of fine nanoparticles is named as top down approach. Mostly nanoparticles can be synthesized by chemical method because of its easiness to synthesis particles with uniform size and high purity.

In the previous chapter the physical methods of fruit and vegetables processing and preservation have been discussed. The present chapter deals with chemical method of fruit and vegetable preservation. In this method of preservation of fruits and vegetables, chemicals as preservatives are used to prevent the spoilage of fruit and vegetable products. These preservatives react with food (produce) constituents or microorganisms and create unfavourable conditions which hinder growth, activities and multiplication of microbes responsible for spoilage of food products. These chemical agents have maximum permissible limit of their use as law. They can be classified into two classes class I and class II.

Class I: Sugar, Salt and Oils

Class II: Sodium benzoate, Potassium metabisulphite (K M S) and Sorbic acid

Chemical synthesis is spontaneous organization of molecules into stable, structurally well-defined aggregates at the nanometer length scale. Chemical synthesis is largely an art form (i.e., theory often does not quantitatively predict how to make new materials from molecules).Yet, chemical synthesis can be quite powerful (e.g., proteins and complex organic molecules can be made from simple reagents) Semiconductor nanocrystals have been synthesized via “natural self-assembly” in two steps:

1.Capped cluster molecule forms spontaneously from molecular reagents in solution

2.Cluster molecules crystallize out of solution

18.1 Introduction

Recycling of industrial wastewater is not only environmentally beneficial, but it is typically more cost effective than conventional treatment and discharge. Through application of stream segregation and appropriate treatment technologies, high purity water is produced for continuous reuse where by metals are recovered and solid wastes reduced. Recycling of industrial effluent by chemical treatment includes many separation methods for getting pure waters. It is very essential to discuss about reverse osmosis, filtration, adsorption evaporation etc. This chapter includes the discussion about the methodology of chemical treatments.

18.2 Conventional Treatments

The oldest and most widely applied method of wastewater treatment involves the addition of chemicals and applications of aerators etc. to alter the make-up constituents of a waste. Although generally downsized, the process continues to play an important role in newer systems used today. Automated controls and advanced instrumentation have improved this technology in recent years. (Tomer et.al., 1997)

Introduction

Packaging of food material is an essential component of food industry since packaging provides protection, physical tampering resistance and unique appearance to the food products which attracts the customers (Robertson, 2006). The handling of food products would be inefficient and costly if they are not packed properly (Robertson, 2006). The style and design of packaging influence their sale as well as demand. The main aim of packaging is to corroborate the safety and quality of food by preventing microbial contamination (Lee K.M, 2010). Plastics, papers, glass and metals are the common materials used for packaging of food products (Arvanitoyannis and Bosnea, 2004). Among these plastics are most commonly used packaging material because of their low cost, light weight, design freedom and high durability (British Plastic Federation). Various additives are added to the plastics to achieve desired physical and chemical properties. These additives are stabilizers, plasticisers, lubricants and f lame retardants. These additives have potential to transfer from the packaging materials to the food stuffs(K Bunia et al., 2013).

The efficient food packaging solutions are the need of the hour for the Earth. The food losses including the production, post harvest, processing stages of the supply chain and food wastage includes loss of edible food occurring at the f inal stages of food chain that is during retail supply or ultimate consumption. The food born illnesses cannot be ignored which are a consequence of the contamination of food by bacteria, viruses, parasites, new chemical entities or toxicants. We need to optimise the food supply chain, increase food shelf life and consciousness amidst food producers to food consumers. The active and intelligent packaging may help the globe through sufficient food for the increasing population. Scavengers/ absorbers are important solutions which may absorb substances from the packaging inner atmosphere (ethylene absorbers, oxygen scavengers; emitters and antioxidants).

Nematodes are multicellular, unsegmented, bilaterally symmetrical roundworms belonging to pseudocoelomates class of creatures. Many of them are parasites of plants. Different crops species are susceptible to several species of plant parasitic nematodes which limits the yield and quality of the food harvest. Root-knot nematodes (Meloidogyne spp.), foliar nematodes (Aphelenchoides spp.), root-lesion nematodes (Pratylenchus spp.) reniform nematodes (Rotylenchulus spp.) and other ectoparasitic nematodes are the important nematodes species to infect the crop plants.

Weeds can be defined as plants which are undesirable, persistent, damaging and interfere with growth of other crop plants thus affecting agriculture, natural resources and economy of the country. These plants influence the produce of farmers in several ways.

It is used in the control of bacterial leaf spots, blights, and cankers mostly on fruits crops and ornamentals. The Bordeaux mixture, however, can cause burning of leaves or russeting of fruit such as apples when applied in cool, wet weather. The phytotoxicity of Bordeaux is reduced by increasing the ratio of hydrated lime to copper sulfate. Copper is the only ingredient in the Bordeaux mixture that is toxic to pathogens and, sometimes, to plants, whereas the role of lime is primarily that of a “safener.”

The algae associated with the plants belongs to the Order Trentepohliales (Ulvophyceae, Chlorophyta). These are filamentous green algae parasitic to higher plants, generally causing minor diseases characterized by negligible leaf spots, but on certain crops, in moist environments, these algal diseases can cause economic injury to plant leaves, fruits, and stems (Nelson, 2008).

Plant viruses cause severe crop losses worldwide. Conventional control strategies, such as cultural methods and biocide applications have limited success at mitigating the impact of plant viruses.

Introduction

The mammary glands of female mammals secrete milk, a necessary food that is liquid and meets the newborn’s nutritional needs. All mammals consider milk to be a complete food for their newborns. It is considered a necessary food for humans and can be consumed as a product or as liquid milk. It contains almost all essential nutrients except iron, which is very low in milk. In essence, milk is an emulsion of protein and fat in water, supplemented with carbohydrates, vitamins, and minerals.

Definition of Milk

• Milk is a complex biological fluid that differs from species to species in both composition and physical properties. It is the full lacteal secretion of a mammary gland that is obtained by milking mammals for a minimum of 72 h after calving or until the milk is free from colostrum.

• FSSAI defines milk as the normal mammary secretion derived from the complete milking of healthy milch animals. It should be free from colostrum.

From a chemical perspective, milk is a dynamically balanced mixture that comes in different forms such as emulsion, colloidal suspension, and true solution. It also contains varying amounts of proteins, fats, carbohydrates, salts, and water.

Gross Composition of Milk

Milk composition varies among different mammals. The average chemical composition of milk in various species is given in Table 1. Buffalo milk and sheep milk contain higher amounts of fat, while human milk comparatively has the highest lactose content. Human milk has lower protein content as compared to milk of other species.

Sixteen chemical elements are known to be important for a plant growth, their metabolic activities and survival. These can be divided in to two main groups

Chemical oxygen demand (COD) is measurement of oxygen demand of waste in terms of the total quantity of oxygen required for oxidation of the waste to carbon dioxide and water. This test is based on the fact that all the organic compounds, with few exceptions, can be oxidized The test is based on the fact that all organic compounds, with a few exceptions, can be oxidized by the action of strong oxidizing agents under acid conditions. Organic matter + Oxidizing agent = CO2 + H2O. The major advantage of COD test is the short time required for evaluation. The determination can be made in about 3 hours rather than the 5-days required for the measurement of BOD
Principle
The oxidizing agents like potassium permanganate and potassium dichromate is usually used to determine COD. Potassium permanganate is selective in the reaction like it reacts with carbonaceous on the other hand it shows nonreactive with nitrogenous matter. Estimating of COD with any method, oxidizing agent must be present to ensure that organic matter is oxidized completely. The organic matter and oxidisable inorganic substances present in water or wastewater get oxidised completely by standard potassium dichromate (K2Cr2O7) in the presence of H2SO4 to produce CO2 + H2O.The excess K2Cr2O7 remaining after the reaction is titrated with ferrous ammonium sulphate [Fe(NH4)2 (SO4)2]. The dichromate consumed gives the 02 required for oxidation of the organic matter.

Salinity is a measure of the total concentration of dissolved solids, which is usually expressed in parts per thousand (ppt). Chloride, sulphate, bicarbonate, and bromide are anions (- charged). Cations that are positively charged are sodium, magnesium, calcium, potassium, and strontium. The main solids are sodium and chloride.