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In spite of its high protein (CP, 34-36%) content, castor bean meal as such is not used as livestock feed due to the presence of toxic factors viz., ricin, ricinine and allergen. Of the three, ricin is the most detrimental to animals. In order to detoxify the castor cake, a number of physical and chemical methods are employed. The efficacy of the treatments is assessed, based on the qualitative and quantitative changes in ricin content. Of all the detoxification methods, autoclaving (15 p.s.i., 60 min) and lime (4% w/w) treatments completely destroy the toxin. (Anandan et. al., 2005).

Estimation of Ricin

The raw and detoxified samples can be analysed for the toxin, ricin as per the method of Kabat et al. (1947) with modifications as suggested by Waller and Negi (1958).

Extraction of Ricin

The solvent extracted castor cake sample of 500 g is extracted with 2.5 l of water acidified with HCl to a pH of 3.8 by shaking the contents in a conical flask for 6 h. The contents are allowed to settle and are then filtered trough Whatman filter paper No.1 . The residue is treated with 1.5 l of distilled water, shaken for 3 h and filtered through the same paper. A second treatment with water is given to the residue and filtered again through the same filterpaper.

This filtrate contains all the ricin and portions of ricinine that are soluble in cold, dilute HCI. It is evaporated to a small volume by vacuum distillation below 40 °C. The filtrate is saturated with sodium chloride and centrifuged at 4000 rpm for 20 min. to separate the precipitate containing only ricin.

Principle

In this method the estimation of pentose sugar is carried out. Acid hydrolysis of RNA releases ribose (a pentose sugar) which in the presence of strong acid undergoes dehydration to yield furfural. Orcinol, in the presence of ferric chloride as a catalyst, reacts with furfural producing a green colored compound which can be quantitatively estimated at A_{665 nm}. DNA gives a limited positive reaction with Orcinol test.

Materials and Reagents

1. Spectrophotometer
2. Boiling water bath
3. 5% chloroform (HClO₄)
4. Standard RNA solution : Dissolve yeast RNA (500ìg/ml) in 5% HClO₄ . make different dilutions to obtain solutions containing 100 – 500ìg RNA/ml with 5% HClO₄ .
5. Orcinol reagent : Dissolve 100mg of ferric chloride (FeCl₃.6H₂O) in 100 ml of concentration HCl and then add 3.5 ml of 6% solution of Orcinol prepared in alcohol.

Introduction

In India, the ground water recharge in arid and semi-arid regions is very important particularly as most of the population residing in these regions depend on groundwater for drinking and irrigation purposes. In such scenarios, to alleviate the problems of drinking water, the collection and storage of rainwater to supplement existing water supply sources should be implemented. The utilization of rainwater is one of the best methods that can aid in sustainable urban development (Kim et al., 2005). Every drop of rainfall should be utilized to cater the demand of an ever increasing population as the present system of water supply may not be sufficient in future. The rain water collection & its utilization, seems to be the only option to satisfy the demand of arid and semi arid regions. In most cases, the rain water is the purest water source & contains very low impurities. It is necessary to adopt rainwater harvesting methods in places where the conventional water supply has failed to meet the peak period demand of the people for drinking water. Rain water harvesting is one of the most economical and practical methods to provide supplementary water supplies for drinking purpose.

Principle

Nucleic acids leaving the rumen are mainly of microbial origin which are extensively digested in the small intestine and the purines liberated are absorbed. Only a small amount of absorbed purines are utilized by the host animal, the rest are metabolised forming hypoxanthine, xanthine, uric acid and allantoin. These metabolites are excreted mainly through urine. Therefore, with the understanding of how urinary excretion of purine derivatives (PD) respond to purine absorption i.e. the response curve of PD excretion to purine input into intestines, the microbial purine outflow from the rumen and the microbial N supply to the ruminant animal can be estimated by measuring the purine derivatives excretion through urine.

(Method of Hyden 1955a,b)
I. Use of Polyethylene Glycol (PEG)

These compounds are manufactured through the reaction of ethylene oxide with water, ethylene glycol or diethylene glycol to furnish functional  groups (in this case hydroxyl) for the propagation of the reaction. The process results in a mixture of diols of different chain lengths, in which the numbers of molecules of various sizes are presumed to be represented by Poisson’s distribution (Shaffer, Critchfield and Nair, 1950b). Polyethylene glycols 200, 300, 400 and 600 are fluids: compounds 1,000, 1,500, 4000, 6000 and 1,0000 are solids of increasing firmness. PEG compounds of molecular weight above 1000 are not absorbed from the gastrointestinal tract of the rat and man.

Polyethylene glycol has been used frequently as a water soluble marker in studies of absorption in man and animals (Sperber et al., 1953; Hyden, 1955a,b; Corbett et al., 1956; Gray et al., 1960; Weller et al., 1962; Ulyatt, 1964a,b; Walker and Hawley, 1965; Tulloh et al., 1965; Sinha et al., 1970; Nagel and Piatkowshi, 1972).

30.1. Aim

To estimate the salt contents in given samples by using Mohr method.

30.2. Theory and principle

Common salt is used during preparation of pickles, sauces, ketchup, fruit chutney and appetizers. Besides, imparting taste, the salt in appropriate concentration also acts as a preservative. In different products, it is estimated by using Mohr method. The sample is titrated with standard solution of silver nitrate for estimation of salt by using potassium chromate as an indicator. From the titre the concentration of salt is estimated by using a standard expression.

Sample Digestion

Dry ashing and wet oxidation are the two widely adopted methods for the release of mineral elements from plant tissues. Dry ashing is carried out usually at an ignition of 550 to 600 °C leads to loss of P and K by volatilization. Dry ashing being comparatively more time taking and also has a few drawbacks (such as S and Cl is lost by volatilization during ignition which can be prevented by adding Na2 CO3 ; a part of P and micronutrients also get occluded) is hence occasionally adopted. On the other hand, wet oxidation employs oxidizing acids like HNO3-HClO4 di-acid or HNO3-H2 SO4-HClO4 tri-acid mixture. The volatilization loss of K is prevented by the use of HClO4 and provides a clear solution while H2 SO4 helps completing oxidation. On heating HClO4 dissociates into nascent chlorine and oxygen, increasing the oxidation efficiency at high temperature. Explosion and fire may occur if there is direct contact of HClO4 with plant sample; hence the pre-digestion of samples is preferred. Digestion with HNO3-HClO4 instead of tri-acid mixture is also adopted specially when S is also to be determined in the same digest. The wet oxidation method being less time-consuming, easier and convenient is given below:

The levels of calcium (Ca), inorganic phosphorus (P) and magnesium (Mg) may help in early diagnosis of metabolic and deficiency disorders and for monitoring the herd health status of dairy cattle to maintain production and reproduction.

Estimation of Serum calcium

Calcium is present in 2 forms – inorganic and organic forms. Most of the functions of the calcium depend upon the ionized form. For estimation of serum calcium the most commonly used method is Clark and Collip method.

Sodium and potassium are the most important electrolytes of the body fluid. The sodium as sodium chloride is contained in body fluids. The potassium is also essential in body fluids and its concentration is controlled by the kidneys. The estimation of sodium-potassium balance makes an important contribution as component of metabolic profile test. Low level of Na occurs in early lactation of low grazing on summer pasture and also increasing age, depraved appetite, polydipsia and polyurea.

Total protein: (Biuret method)

There are several methods of estimating protein, in food, agricultural and clinical samples, each of them varying in sensitivity and applicability.

Principle
Biuret method is highly specific for protein and is based on the formation of the blue peptide-copper complex in alkaline solution. It is a method of choice in the clinical laboratory because of the simplicity accuracy and precision. The major limitation of the method is its poor sensitivity for many dilute solutions. The principle of this method is that the peptide bonds in protein react with biuret reagent to give a violet colored complex known as cupric potassium biuret. The colour intensity of which is proportional to protein concentration.

Abstract

The study of size, shape and pattern of various bones in the skull of vertebrate fossils constitutes the foundation of their taxonomy and plays a role in understanding their evolution as well. Size and shape change during lifetime, and the growth of an individual bone involves both isotropic enlargement of its boundary due to uniform growth and differential enlargement that changes its shape. This paper attempts to develop a methodology for quantitative assessment of the pattern of ontogenic shape changes for all the individual skull roof bones of a taxon (Benthosuchus) of an extinct amphibian (temnospondyl) from the Lower Triassic of Russia. Published diagrams depicting skulls of different ontogenic stages have been used. A measure for the degree of shape changes is also proposed. In this study, the skull roof bones in dorsal view were represented as polygons. The boundary of each polygon of a juvenile skull was compared with that of an adult. For comparative purpose, the polygons of the younger skull were placed optimally inside that of the older skull, under the assumption of maximised uniform (isotropic) growth. The variance of the distances between the two boundaries measured at a number of points along the boundaries was considered as a measure for the degree of shape change. The results obtained are in partial concurrence with the published observations traditionally obtained from anatomical studies for the above mentioned growth series.

31.1. Aim

To estimate the sodium benzoate contents in fruit and vegetable products.

31.2. Theory and Principle

Sodium benzoate is used as a class II preservative in preservation of pickles, sauces, squashes etc. Its estimation is important as the quantity of class II preservative shall not exceed maximum limit prescribed under FSSAI. In a sample containing NaCl, the benzoic acid is converted into water soluble sodium benzoate by addition of NaOH. When the Sodium benzoate solution is acidified with excess of HCl, water insoluble benzoic acid is formed which is extracted with chloroform. The chloroform is removed by evaporation and the residue containing benzoic acid is dissolved in alcohol and then titrated with standard sodium hydroxide.

Aim

To estimate the soil loss using universal soil loss equation

Universal soil loss equation

Wischmeir and Smith (1962) has been developed a predictive equation for estimating the soil loss taking into account following factors: Climatic characteristics, soil characteristics, crop management and conservation practices. It is called Universal soil-loss equation (USLE).

The Walkley-Black method is a widely used chemical procedure to estimate soil organic carbon (SOC). It involves the oxidation of organic carbon by potassium dichromate in the presence of sulfuric acid, followed by titration to determine the amount of unreacted dichromate. Here is a detailed step-by-step guide:

Materials Required

• Soil sample (air-dried and sieved through a 2 mm sieve)

• Potassium dichromate solution (1 N)

• Concentrated sulfuric acid (H2 SO4 )

• Ferrous ammonium sulfate solution (0.5 N)

• Orthophosphoric acid (H3 PO4 ) (optional)

• Diphenylamine indicator or N-phenylanthranilic acid (indicator)

• Distilled water

• Burette, pipette, and conical flasks

• Heating mantle or hot plate

The pH is defined as negative logarithm of hydrogen ion concentration or the log of the reciprocal of the hydrogen ion concentration (Sorenson, 1906).

Principle

A glass electrode in contact with hydrogen ions of the solution acquires an electric potential which depends on the concentration of hydrogen ions. This is measured potentiometrically against some reference electrode which is usually a calomel electrode. The potential difference between glass electrode and calomel electrode is expressed in pH units.

Two electrodes are used in the determination of pH. One is reference electrode which provides a standard voltage and is usually a saturated calomel electrode which has two layers of saturated solution of KCl and mixture of solid HgCl₂ and Hg. The outer tube is usually 5-15 cm long, 0.5-1 cm in diameter. The mixture of solid HgCl₂ + Hg paste is contained in an inner tube that is connected to the saturated KCl solution in the outer tube by means of small opening. The resistance developed by this type of electrode is 2000-3000 Ohms.

The outer electrode is glass electrode that consists of a tube enclosing a lead wire made up of Ag coated with AgCl. This wire is again enclosed in a wax insulation. To the tube at the bottom is attached a glass bulb made up of a special kind of glass which is sensitive to hydrogen ions. The thickness of the glass membrane varies from 0.03 to 0.1 mm and has a resistance of 50 to 500 mega Ohms.

When these electrodes are dipped in solution, the saturated solution of KCl comes out of reference through small holes and forms an invisible ionic bridge between electrodes through which current passes. The hydrogen ions are absorbed by glass electrode and depending upon the amount of hydrogen ions present in the solution, an electric potential develops between electrodes. This potential difference is measured in terms of pH units by suitable Galvanometer.

Object: Estimation of stomatal index and stomatal frequency with replica method.

Material required: Leaf sample, blue/red correction fluid, transparent finger nail polish, brush glass slide and microscope.

Principle: The number of stomata per unit area of the leaf is called as Stomatal Frequency. The stomatal index is defined as the percentage number of Stomata as compared to all the epidermal cells in a unit area of leaf i.e.

28.1. Aim

Estimation of reducing sugars in fresh fruits and processed products using Lane and Eynon method.

28.2. Theory

Sugars are inherently present in different fruits and vegetables or added during preparation of different products. They are added to the fruit products to improve the taste and also to act as a preservative. Glucose and fructose in the fruits represent reducing sugars while sucrose or cane sugar added represents the non-reducing sugar. They are estimated by using Lane and Eynon method which measures sugar as reducing sugar and total sugar as invert sugar.

32.1. Aim

To estimate the level of sulphur dioxide contents in fruit and vegetable products

32.2. Theory and principle

Sulphur dioxide in food product is added as class II preservative and may exists as undissociated sulphurous acid, as free bisulphate or sulphite ions or as combined SO2 in the form of hydroxy sulphonates. Sulphur dioxide is measured as free or total SO2. Estimation of SO2 in squashes, jam, RTS drinks is important as its presence beyond the prescribed FSSAI limits make the product not confirming to Indian Food Laws. Generally 2 parts of KMS (Potassium metabisulphite) releases one part of SO2 explained as under:

27.1. Aim

To estimate the titratable acidity of fresh and processed fruit and vegetable products.

27.2. Theory

Most of the fruit, vegetables and their products contain acid or mixture of acids. The acids may occur naturally in the fruit and vegetables or may be added during manufacture of different products or by lactic acid or acetic acid fermentation. Generally citric acid is added in most fruit products while in pickles, sauces and ketchup acetic acid is used. The acids are mainly responsible for the tartness or sour taste, thus estimation of acidity is used as the measure of tartness. They also help in preservation by lowering the pH of the finished products.

Principle
Total ash is the inorganic residue which remains after a feed stuff is ignited to carbon free at 550-600oC in a muffle furnace. In other words, ash is that part of the material which does not disappear at 550-600ºC, while all the organic matter (OM) gets burnet.

Requirement
    1.    Analytical balance
    2.     Asbestos sheet
    3.     Dessicator
    4.     Heater /gas flame burner
    5.     Metal tongs
    6.     Muffle furnace
    7.     Silica basin/crucibles