the sustainability of dam construction through environmental management

8/10/2019 The Sustainability of Dam Construction Through Environmental Management

1/48

IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT)ISSN: 2319-2402 Volume 1, Issue 1 (Sep.-Oct. 2012), PP 01-05www.iosrjournals.org

www.iosrjournals.org 1 | Page

The Sustainability of Dam Construction through Environmental

Management

Adeniji Olawale Aladelokun (Phd)Department of Geography, College of Education, Ikere-Ekiti, Ekiti State. Nigeria.

Abstract: Thispaper examines dam construction in relation to positive and negative socio-economic impacts.It is affirmed that Environmental Impact Auditing (EIA) holds the key to lowering negative impacts. It is a well

known fact that dam construction impacts are multi-disciplinary as climatology, geology, biodiversity, etc areaffected, with each having feedback effects. Environmental managers and planners must therefore seek tocombat negative impacts of dam construction with the use of cognate Environmental Management Plans

(EMPs).

I. Introduction

Water management projects have a long history as their desirability was recognized even in earlycivilization especially in regions of insufficient rainfall (Adams, 1975). As observed by Garbrecht (1983) suchgreat civilizations as those in the valley of the Nile, the Tigris and Euphrates, the Indus and Hong-ho were ableto develop on the basic of complex and advanced water management systems. Going by the report of Odihi(1991), it is possible by such means as Advanced Water Management System for many to ensure adequatesupply of water in time and in space which will result in meaningful improvement of the quality of life forcommunities hitherto trapped in poverty and misery brought about by lack of potable water.

All living things on the earth depend on water and the earth is the only confirmed planet where water is

present in liquid form, falling as precipitation and flowing through the landscape (Bruce, 1992). As there is along history of water management projects, so also, are there numerous reports and publications of dams andtheir impact on the environment and life in general. This paper focuses attention on the various aspects of dams

at global, regional and local levels. The discussion includes the functional aspects or justification for damconstruction, dam impacts on socio-economic activities as well as history of water development projects. Effort

is equally made to highlight the importance of the Environmental Impact Auditing (EIA).

II. An Overview on Dam ConstructionA Dam according to Chorley (1969) is a barrier constructed across a stream or river to impound water

and raise its level. Mcgraw-Hill Encyclopedia of Science and Technology (1960) defines a dam as a structure

that bars or detains the flow of water in an open channel or watercourse. In the same and manner, EncyclopediaInternational (1980) describes dam as an artificial barrier across an open channel of water to create a reservoir orraise water level. It is a barrier built across a river to create a lake (Hornby, 2000). However, Iwena, (2000) seesa dam as an extensive area occupied by water trapped on a river course. From the foregoing, therefore, a dam

can generally be defined as barrier built across a water course to hold back or control the flow of water forstorage, diversion or detention.

The construction of dams have been going on from early mans period of civilization as evidence areavailable in the region of Bacelonia around Euphrates and Tigris in present-day Iraq. The construction ofbarrier across streams channels for the purpose of impounding water goes back to about 5,000 years from now(Sharma and Sharma, 1990).

In most cases, the ideas for which these dams have been constructed have to a great extent beenaccomplished at both individual and societal levels. According to Ayoade (1988), large projects in historicaldevelopment have been undertaken in Africa not for power but as multipurpose schemes. The first modern damscheme was the Gezira project developed from 1913 to 1950. It consists of a system of irrigation canals and

sehar dam, which direct water from the Blue Nile into the main canal.WCED (1987) observed that in the Republic of Cameroon, in addition to Lagolo Dam, other dams

including Song-Loulon and Edea Dams on the Sanaga River are respectively the third and fourth largest dams in

West Africa after Kanji Dam on the River Niger in Nigeria, and the Akosombo Dam on the Volta River inGhana.

NEST (1991) documented that, dams have been built in Nigeria since about 1918 notably for domestic

water supply. Hamadou (1997) reported that in Nigeria, right from 1920, hydro-electric power was generatedon the Jos Plateau. In 1964, the first major hydro-electric power project in Nigeria started with the building of adam across the Niger River at Kainji. In 1967, the first phase of the project was completed. At present, the


2/48

The sustainability of dam construction through environmentalmanagement


Federal Government of Nigeria has spent billions of Naira to construct many dams for potable water supply andhydro-electric power generation. The Bakolori Dam built in mid 70s on River Sokoto in the North Western part

of the country floods 30,000 hectares of arable land with irrigation water. In a village Bugauda, South of Kano,the Tiga Dam in Kano State was built. Also, the Shiroro Dam and Kanji Dam in Niger State were constructed in1993 and 1964 respectively with the purpose to serve industries with electricity.

The number of dams and irrigation projects according to NEST (1991) has been increasing rapidly and

feasibility studies are being carried out for most of larger rivers in Nigeria. Hamadou (1997), however,observed that besides the Hydro-Electric Power (H.E.P) these dams serve in the development of water supply,irrigation agriculture, control of floods etc.

III.

Types of DamsIwena (2000) classifies dam on the basis of structural form and material used. Dams are also often

classified according to their mode of impoundment and the use for which they are built. To this end, dams areclassified into four major types viz: gravity dams, arch dams, buttress dam and earth-filled dams. The Gravitydams are solid concrete structures with triangular cross sections. The dam is thick at its base and thinner

towards its tops. When view from the top, it is either straight or only curved and the upper stream is nearlyvertical. It is described by Encyclopedia International (1980) and Babalola (2003) as roughly triangular dams incross section. The broad based gravity dam holds water by the brute force of its weight. An example of thistype is found on Columbia River in Washington.

Arch Dams are those that employ the same structural principles as the arch bridge. Arch dam is a typewhereby the upper stream curve of the slender dam directs water pressure through the abetment to the retainingcanyon walls. It is normally built in the form of up ended arch with bases on the walls of canyon. Arch dams

are thinner and therefore require less material than any other type of dam. Arch dams are good for sites that arenarrow and have strong abutments. They are usually made of concrete and more often in the shape of a V than Ushape. The gorge is often in the shape of a V, less often it is a U-shape. They use much less of concrete thangravity dams. The best design is a double-curved arch. Arch dams are generally classified as thin, medium andthick, depending on the ratio of the width of the base (b) to the height (h). Examples of this type of dam are theKariba Dam in Rhodesia; the Glen Canyon Dam on the Colorado River in Arizona, which is 216m high, and

475m long; the Vallon de Baume in France which is 12m high and 18m long and curved with a radius of about14m; and the Monte Novo dam in Portugal which is about 5.7m high and 52m long, including the wing walls atboth ends.

Buttress Dams are watertight upstream face and a series of buttresses that support the face and the

water pressure and the weight of the structure to the foundation. (Encyclopedia International,1980). Anexample is the Pidima Dam built in 1953 in Greece.

Encyclopedia International (1980) describes Earth-filled Dam as those that utilize natural materialswith minimum of processing and may be built with primitive equipment under addition where any otherconstruction materials would be impracticable. They are the earliest known dams and seem to be the easiest toconstruct. However, numerous failures of many earth-filled dams that are poorly designed make it an apparentthreat. Earth-filled Dams require much more engineering skill in their conception and construction that any

other types of Dam. The highest earth-filled embankment dam in the world is the Oroville Dam in California.Embankment Dam is the type of dam with earth materials, rock and dirt. It is the oldest form of Dam. Itgenerally costs less than those concrete dams. It is interesting to note that Ero Dam in Mobal Local GovernmentArea of Ekiti State falls into this category.

IV. Environmental Impact Auditing for Sustainable Management of DamsEnvironmental Impact Auditing is simply the assessment of the potential impacts of proposed projects

on the environment. It is an environmental management tool used to determine the impacts of a project oroperation on the environment (SPDC, 1994). EIA is a process or study in which the potential physical,biological, economic and social impacts of a proposed infra-structural development on the immediate and more

distant environment are identified, analyzed and predicted (Canter, 1977 and Odiette, 1993)Environmental Impact Auditing (EIA) is a process based on current scientific knowledge used to

predict the environmental consequences of a proposed action, project or programme and to provide decision

makers with systematic information presented in such a way that the impacts as well as mitigating needs can bepresented in spatio-temporal perspective (Stromgquist and Tathamn, 1992).

The history of EIAs in developing countries dates back to the late 1970s when the first EIAs mostlyfollowed the criteria and procedures practised in the donor country (Kakonge and Imevbore, 1993) which might

have hampered the development of EIA in the individual countries by not taking into account the localenvironment and associated environmental problems.

Historical legacy of sustainable development dates back to 1972 at the Stockholms environmentaldebate and in 1992 at the Environment and development crusade in Rio de Janiero and also in 2002 at Durban


3/48



sustainable development summit. The Durban Summit added poverty alleviation to the theme of the discourse.This was however based on the premise of the Stockholm Summit which states that the resources of the world

are limited and its ecosystem fragile and vulnerable to change.Agenda 21, the central document of the United Nations Conference on Environment and Development

(UNCED) in Rio de Janerio in 1992, defined sustainable development as a global partnership foreconomically

viable socially equitable, ecologically sound development not only for today but also for the future: Among the

major point of discussion of the Rio conference are gradual elimination of ozone depleting substances, GreenHouse gas reduction, biodiversity conservation and protection of international waters.

Sustainable development requires that environmental resources should be used functionally and

judiciously. It requires adequate planning of developmental activities so as to enhance long term resources use.From the foregoing, a clear understanding of the concept shows that sustainability does not mean that resourcesshould not be used at all. In this regard, sustainability borrow support from the concept of preservation whichimplies that resources be exploited in such a way that is renewable or regeneration is assured.

Development itself was noted by Brechery (1992) to depend on what social goals are being advocatedby the development agency, Government, analyst or adviser. That is, a list of attributes which society seeks toachieve or maximize. Drawing from this, therefore, development can be conceived as the utilization of naturalresources. Therefore, the sustainable use of resources means the ability to seize opportunities in managingenvironmental problems.

Houghton (1999) noted rightly that sustainable development means the long term survival of the planet

earth and its process of dynamic evolution, including the wide range of species which currently lives on it, notleast the human kind. For human kind, it specifically requires achieving a position which allows for living inharmony with nature, that both life and resources are managed efficiently for optimum support of man and other

life- forms. From the stand point of Houghton (1999), it can be asserted or inferred that vandalisation anddestruction of cherished biodiversity are environmentally hazardous and deleterious to human habitation as wellas to the environment.

Further, on development and sustainability the World Commission on Environment and Development

(1987) defines sustainable development as a process of change in which the exploitation of resources, thedirection of investments, the orientation of technological development, the institutional change are all inharmony and enhance both current and future potentials to meet human needs and aspiration.

From the foregoing, it is obvious that UNCED (1992) prescribes antidote for wasting resources as aprocess for integrated activities and actions aimed at re-cycling value- added resources through use. That is,such an approach does not only meet the need of the present but will not compromise the needs of future

generations. Sustainability means that the present generation must not rub the coming generations. Rather, wemust leave an ecological footprint of judicious use of environmental resources in such a way that they becomerenewable. This could otherwise be regarded as socio- cultural and economic sustainability. From theenvironmental point of view, sustainable development means the use of environmental resources in such a way

that the action is not hazardous or deleterious to the environment and the components therein.Whatever is the nature and type of project in supra-urban space, certain changes are imminent in the

environment as well as in the socio-economic life of the people as a result of these interventions. Hence, thenecessity of the Socio-economic and EIA to be carried out in order to identify, quantify and evaluate the natureand magnitude of impacts of these changes in the biological, bi-geophysical, economic and politicalenvironments in which such projects are located and more importantly, in which humanity must operates(Olokesusi, 1994).

Studies on environmental impact of dam construction have demonstrated that dams and reservoirs havesignificant impacts on the environment in their drainage basin while providing solution to water and power

deficiency most especially in drought prone areas of Nigeria (Olofin, 1980). This implies that such impacts caneither have adverse or beneficial effects on the quality of the environment or on the sum total of the resourcescomprised within it. Aladelokun (2010) working on Ero Dam in Ekiti State asserted that impacts may beprimary or secondary, short-term or long-term, irreversible or quasi-permanent. The primary impacts are causedgenerally by project input. These include change in land use, land ownerships, vegetative speciescomposition, noise of equipment, dust during land clearing, and more importantly, a change in electricity output.The secondary impacts on the other hand are usually caused by project output. They are indirect or inducedchanges and typically these include the associated investments and changed patterns of social and economic

activities that are stimulated or induced by the project.Short-term impacts are those that have immediate impacts of short-duration such as noise, dust, erosion

and flood, application of herbicides to remove undesirable species, while the long lasting or cumulative effects

of these agents may permanently damage other vegetative growth or result in disruption of ecological balance.The importance of giving special consideration to both short-term and long-term effects is to enable us to assess

the cumulative impacts of the project, which either significantly reduce or enhance the state of the environmentfor future generations.


4/48



The irreversible impacts apply primarily to non-renewable resources. Endangered species, fossilfuels, minerals or wildlife situation through sub-soil exposure often involve irreversible effects.

Irretrievable effects on the other hands are the adverse effects on some value that will be lost andcannot be restored. These among others, include an endangered or threatened animal that may become extinctor destruction of unique habitants for wildlife, increase freshwater flow into water bodies changing the balance

in coastal/marine environment, change of flow of water in river due to impoundment and irrigation scheme

downstream, change in labour and capital investment.

V. ConclusionThe rate of development has increased since the world entered 21

stcentury. Closely associated with

the trend of development are socio- economic and environmental problems like flooding, bio-diversity loss,pollutions etc. There are isolated and non-integrated approaches for combating these problems. Each problem

requires its own strategy of reduction or prevention. However, for environmental sustainability to be achieved,the problems must be combated at the stage when the impact is least felt. Then an integrated holistic approachmust be adopted.

The prevention of adverse consequences of Dam construction requires the application of differenttechniques. Specifically, this could be achieved through environmental design to ensure sustainability. Ameaningful strategy therefore should not end in the planning studio or on the drawing board. Sustainabledevelopment requires adequate implementation monitoring. It requires advocacy planning as well as citizen

participation. Naresh and Richard (1996) advocate an integrated strategy to meet the needs of people, theeconomy and ecosystem through proper decision making.

There seems to be greater consensus among those advocating sustainable development that greater

emphasis must be place on full and true valuation of the natural, built and cultural environment. With theforegoing as a background, one can rightly say that the issue of sustainability is very important in combatingnegative consequences of Dam construction through environmental design. For it to be achieved, localcommunities should have inputs in potential Dam construction consequences and possible reduction measures.

The campaign for the prevention of negative consequences of Dam through environmental design is anattempt to reduce and eliminate environmental and social-economic destruction and to correct the damages of

the past. It is sustainable and futuristic in its perspective. It is a kind of development that offers a vision of theneed of the present generation without undermining the integrity of the environment, and without equallyjeopardizing the interest of the future generation (Sousan, 1992).

The struggle for environmental sustainability entails the availability of effective and environmental

friendly technologies. Sustainability on this note requires the utilization of economical resources withoutchanging it, secure adequate resources for sustainable human consumption, and support fairness, cooperatingand well-being in the effort towards human development and social health. Which satisfies the basic needs ofhumanity, ensuring survival, healthy human development, and the expression and free pursuit of the full rangeof human aspiration ( Naresh and Richard, 1996).

In other development, NERC (2004) posited that environmental cost accounting will help us inachieving the goals of the much needed environmental sustainability. It is stressed that EIA help us to avoid or

restore the effect we have on the environment. It is equally noted that even though, science and technology ismore needed for the development of sustainable development, the growth of science and technology is equallyposing some environmental footprint. The publication referred to EIA as a management tool that can help us toimprove our performance and plan for dealing with risk and liabilities.

According to the World Bank (2003), the core challenge for sustainable development is to ensure abetter quality of life for all the people while meeting everyones aspiration for social well being. To achieve this,

it is necessary to sustain critical ecosystem services and strengthen the social fabric that underpinsdevelopment.

This paper helps to establish the fact that tangible improvement in peoples living condition in thethematic spheres mention above will no doubt reduce the rate and extent of negative Dam consequences and

tendencies. The challenges ahead therefore have triggered the preparation of the environment strategy that willbetter align the management of environment and natural resources with sustainable development.

References[1] Adams, W. M. (1975) The Downstream Impacts of Dams Construction, Nigeria Transactions. Institute of British Geographers.

New Series. No 10 Pgs. 290-307

[2] Aladelokun, A.O. (2010) Some Socioeconomic and Environmental Impact of Ero Dam in Moda Local Government Area of Ekiti

State. A Ph.D. Thesis, Department of Geography and Environmental Management. University of Abuja, Abuja.

[3] Babalola, A.I. (2003) Economic Impacts of Dam Construction in Ekiti State. N.C.E. Long Essay, College of College of Education,

Ikere Ekiti.

[4]

Brecchery, M.J. (1992) Towards sustainable Urban Development in Marinas, A.M. and S.R. Bowlty (eds). Environmental Issues inthe 1990s. Chichester, John Wiley.

[5] Bruce, J.O. (1992), Meteorology and Hydrology for Sustainable Development. World Meteorological Organization.


5/48



[6] Center, L.W. (1977) Environmental Impacts Assessment, New york Mc Graw Hill.

[7] Charley, R.J. (1969) Introduction to geographical hydrology U.S.A. Harper and Row publishers.

[8] Encyclopedia International (1980) Lexicon publication. Vol. 5. pgs 425 427.

[9] Garbrecht, C.J. (1983) An Environmental Evaluation System for Water Resource Planning. Water Resource Research, 9, 523 532.

[10] Hornby, A.S. (2000) Oxford Advanced Learners Dictionary of Current English. Edited by sally Wehmeir and Michael Ashby. New

york, Oxford University Pres

[11] Houghton, G. (1999) Environmental Justice and the Sustainable City. In David, S. (ed) Sustainable Cities. Condoms Earth scan, 62-

79.

[12]

Iwena, O.A. (2000) An Essential Geography For Secondary Schools. Ikeja, Tonad Publishers Nig. Ltd.[13] Kakonge, J.O. and A.M. Imevbore (1993) Constrains of Implementing Environmental Impact Assessment in Africa. Environ Impact

Assessment 13. 299308.

[14] Mcgraw- Hill Encyclopedia of Science and Technology (1960) Library of Congress. Vol. 4. Pgs 8 10.

[15] Naresh, C.S. and S. Richard (1996) From Legacy to Vision: Sustainability, Poverty and Policy Adjustment. Winningpeg, Canada.

International Institute for Sustainable Development (IISD).

[16] NEST (1991) Nigeria: A Threatened Environment. A National Profile, Ibadan. Macmillan. 3 2.

[17] Odiette, W.O. (1993) Environmental Impact Assessment for Sustainable Development. Environmental News. Oct Dec.

[18] Odihi, J.O. (1991) Downstream problems of Dammed Rivers in Nigeria. A Case Study of Water Resources Development. A paper

presented at Nigeria Geography Association conference.

[19] Olofin, E.A. (1980) Some Effects of Tiga Dam on the Environment D

[20] Olokesusi, F. (1994) The Environmental Impact Assessment Process Initiating it and making it work for Nigeria. Proceeding of the

NNPC Seminar on the Petroleum Industry and the Nigerian Environment. Lagos, Nigeria. NNPC

[21] SPDC (1994) Environment, Newsletter.

[22] Stromquist, L. and S. Tathamm (1992) A practical Approach to Environmental Impact Assessment in Developing Countries. In

Stromquist , I (ed) Environmental Impact Assessment: Notes on Applied Research, UNGI report N0 82. Uppsala University,

Uppsala, Suredem. Pgs 143[23] UNCED (1992) United Nations Conference on Environment and Development.

[24] W.C.E.D. (1982) Our Common Future: London Oxford University Press.


6/48

IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT)

ISSN: 2319-2402 Volume 1, Issue 1 (Sep.-Oct. 2012), PP 06-10www.iosrjournals.org


Use of Buffers in Spectrophotometric Determination of N-

Phosphonomethylglycine by the Ninhydrin Colour Reaction

1Lami A. Nnamonu*,

2Nnadozie N. Nkpa

Centre for Agrochemical Technology, Department of Chemistry, University of Agriculture, Makurdi Nigeria.

Abstract: The aim of this work was to develop a spectrophotometric method of glyphosate assay that isconsistent and reproducible over a wide range of concentrations. The use of two buffer systems 4M CH3COOLipH 5.2/Hydrindantin/DMSO and 0.2M sodium citrate buffer pH 5.0/Ascorbic acid/DMSO which have not been

used before for ninhydrin quantification of glyphosate is hereby reported. The absorbance of the resultingpurple derivative was measured at 570 nm with molar absorptivity of 5.79910

4and 1.97510

4L mol

1cm

1.

Linear relationships between concentration and absorbance were observed over Beers law range from 0.3 to

4.5g/ml. For the citrate system, R2 =0.982, SD = 0.3744, N= 9 and P < 0.0001; while R

2 =0.984, SD =

1.0956, N= 8 and P < 0.0001 for the acetate system. The citrate buffer/ascorbic acid system was employed

successfully in adsorption studies of glyphosate unto kaolin and starch. Limits of detection and quantificationwere 0.6159 and 0.699 g/ml respectively for citrate buffer and 1.802 and 5.5465 g/ml respectively for thelithium acetate buffer system. The method was applied to quantification of glyphosate adsorption to kaolin andstarch, where the citrate buffer gave R2 values of 0.803 (Freundlich) and 0.964 (Langmuir) for kaolin.

Keywords:Buffer, Glyphosate, Ninhydrin, Spectrophotometric determination

I. IntroductionN-Phosphonomethyl glycine (glyphosate or NPMG) is the worlds most popular broad -spectrum, non-

selective, systemic herbicide used for post-emergence control of annual and perennial weeds. Its impact on theenvironment is becoming more significant by the day [1, 2]. The same properties that make it very effective also

make simple methods for its determination and quantification, especially at residue levels, difficult to establish.Its polar nature and high water solubility make extraction difficult and restrict the options for using standardderivation techniques often employed for gas chromatographic (GC) analysis [3]. The absence of a chromophore

or fluorophore in NPMG also necessitates derivation techniques for the determination of glyphosate residues byliquid chromatography. The use of chromatographic methods and emerging techniques in glyphosate analysishas been reviewed [4]. These methods involve the use of sophisticated and expensive equipment, requiring

lengthy clean up procedures, giving less than ideal recoveries. In spite of numerous published methods, it hasbeen noted that the analysis of glyphosate at residue levels has tested the patience of many experienced analysts[5]. The increasing load of literature on methods of analysis of glyphosate is indicative that a robust, reliable

method is still being sought.A method of analysis that can be used in simple laboratories, the type in developing countries, is the

spectrophotometric method. The reaction of glyphosate with carbon disulphide to convert the amine group into

dithiocarbamic acid has been used as basis of a spectrophotometric determination of glyphosate [6]. Thedithiocarbamate group was used as chelating group for reaction with transition metal ion, Cu (II). The resultantyellow complex was measured at 435 nm. Another UV-VIS spectrophotometric method of glyphosate analysisbased on the transformation of amino group of glyphosate in aqueous acetonitrile to the correspondingdithiocarbamate derivative has been reported [7]. The derivative is reacted with copper (I) perchlorate to form ayellowish green colored complex with absorbance measured at 392 nm. Spectrophotometric determination of

glyphosate using ninhydrin has been done in neutral aqueous medium in the presence of sodium molybdate at100

oC to give a Ruhemanns purple adduct[2]. However, at the concentrations investigated in this work, the

Ruhemanns purple adduct formed decomposed (as evidenced by fading of the rich purple colour) on standing

for a few minutes at 18oC while measurements were going on, thereby giving inconsistent results. We wanted

therefore, to make the ninhydrin assay reproducible over a wide range of concentrations.The similarity of NPMG and its principal metabolite, aminomethyl phosphonic acid (AMPA) to

naturally occurring amino acids and amino sugars contributes to the difficulty in determining residues of these

compounds in crops and animal products. In this paper, this similarity is exploited and the buffers used in aminoacid analysis are employed in the spectrophotometric determination of glyphosate. Buffers were utilized becauseit was reported that buffers and the presence of reduced ninhydrin are essential for the performance ofreproducible and sensitive assays of amino acids [8, 9] The use of two buffers 4M CH3COOLi pH5.2/Hydrindantin/DMSO and 0.2M sodium citrate buffer pH 5.0/Ascorbic acid/DMSO in the reaction of

ninhydrin with glyphosate was explored and the Ruhemanns purple product obtained(stabilized by the buffers)


7/48

Use of Buffers in Spectrophotometric Determination of N-Phosphonomethylglycine by the Ninhydrin


was isolated and confirmed by 1H-NMR. This method was used in quantifying glyphosate adsorbed to kaolin

and starch.

II. Materials and methodsII.1 Materials

N-phosphonomethyl glycine 96%, ninhydrin, lithium hydroxide monohydrate, anhydrous citric acid,

sodium citrate dihydrate, hydrindantin dehydrate, corn starch and kaolin were obtained from Sigma Aldrich, UKand used as received. All reagents were of analytical grade purity. Absorbance at 570 nm was measured on aCary 50 Bio PCB 150 Water Peltier system UV-visible spectrophotometer. Plastic vials were used for the

experiments to obviate the binding of glyphosate to glass. All solutions were prepared in high purity water thatwas obtained from a Milli-Q water system (Millipore, Billerica, MA, USA).

1H-NMR was taken on a Bruker

400. FTIR was run on Perkin Elmer Spectrum 100 spectrophotometer (PIKE Technologies 16077).

II.2 Buffers

II.2.1 Lithium acetate buffer.M lithium acetate buffer pH 5.2 was prepared with 168 g (4 mol) lithium hydroxide monohydrate and

293 ml glacial acetic acid [10]. The alkali was weighed in the fume hood (to avoid breathing in the dust), pouredinto 200 ml high purity water in a 500 ml conical flask and placed on a vortex mixer. When it was about halfdissolved, the acetic acid was added. After vigorous effervescence subsided and the solution cooled to about

25oC, it was poured into a 1000ml volumetric flask, properly rinsed in and water added close to the mark. Theflask was corked, filtered through a sintered glass funnel and the pH taken. When pH was lower than 5.2, it was

adjusted with LiOH.H2O (1g gave a 0.01 rise in pH units). When it was higher than 5.2, pH was adjusted byadding glacial acetic acid (1 ml acid equal to a 0.01 rise in pH unit). The solution was made to the mark.II.2.2 Citrate buffer.

0.2 M citrate buffer pH 5.5 was prepared by sonicating 3.412g (17.76 mmol) anhydrous citric acid and

0.6588 g (2.24 mmol) sodium citrate dihydrate, C6H5O7Na3 .2H2O, in 60 ml high purity milli-Q water in a100ml volumetric flask. 2.0 cm3of 12.5 M NaOH was added and the solution made up to the mark [11].

II.3 Ninhydrin reagentsII.3.1 Ninhydrin Reagent I.

This reagent solution was prepared by adding 1.6 g (8.99 mmol) ninhydrin with vigorous stirring to 60ml DMSO in a 250 ml round bottom flask. 0.24 g (0.745 mmol) hydrindantin was added into the deep vortex

created by the stirrer (for fast dissolution) and stirring continued for 5 minutes till it was completely dissolved.20 ml lithium acetate buffer pH 5.2 was then added and stirred for another 3 minutes [9, 10]. The golden-yellowmixture was poured into an amber-coloured bottle and stored under nitrogen in the refrigerator.

II.3.2 Ninhydrin Reagent II.This reagent was prepared by a modification of the method of Yokoyama and Hiramatsu [12] that used

ascorbic acid/ninhydrin/methyl cellosolve in the determination of glutamic acid. In this work, methyl cellosolvewas replaced by DMSO as advocated by Moore [10]. Into 30 ml of DMSO in a 100 ml conical flask was added

0.25 g (1.4 mmol) ninhydrin with stirring. 7.5 mg (0.043 mmol) ascorbic acid was then added and stirringcontinued for another 3 minutes to ensure complete dissolution. The lightyellow reagent was corked and stored

in an amber-coloured bottle under nitrogen in the refrigerator.

II.4 Stock solutions

20 mg N-phosphonomethyl glycine was weighed and sonicated in 20 ml water to give a 1000 g/ml(5.917x10

-3M) stock solution. 1ml of this solution was diluted to volume in a 100ml volumetric flask, to give a

10 g/ml solution of glyphosate. Working calibration solutions of 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 and 0.3g/ml were made by serially diluting this solution. The concentration of glyphosate in these solutions was

determined using ninhydrin in the proposed buffer systems and calibration curves plotted.

II.5 Derivatization with ninhydrin reagentsInto 2 ml glyphosate sample solution in plastic screw cap bottles was added 1ml of the ninhydrin

reagent I. To use ninhydrin reagent II, 2ml of the reagent was added to 1ml of glyphosate sample and 2 mlcitrate buffer pH 5.5. The vials were immersed to a depth of about 2 inches in a boiling water bath for 30 mins.

The rate of heat applied to the bath was sufficient to bring the bath back up to 99 - 100oC within two minutes

after insertion of a full rack of 20 vials. The vials containing the Ruhemanns purple derivative were thencooled rapidly under running water and the absorbance measured at 570 nm.

II.6 Adsorption to starch and kaolin


8/48



Adsorption experiments were done using the batch equilibration method [13]. 2 ml water was added

into 250 mg sorbent (i.e. starch or kaolin) samples in capped plastic vials. 5 ml of standard herbicide solutionswith concentrations ranging from 0.05 mmol to 0.7 mmol were added. These were equilibrated by shaking on amechanical shaker (250 rpm, shaking amplitude 12.5 mm, orbital) for 24 hrs at room temperature (18oC). After

equilibration, the suspensions were centrifuged (4500 rpm for 10 mins) and 3ml of the supernatant was drawnfor analysis of glyphosate, using the proposed buffers.

III. Results and discussion

III.1 MechanismThe reaction of ninhydrin with glyphosate is likely similar to that of the alpha-amino acids [14], where

nucleophilic type displacement of an OH group of ninhydrin by the amine group of glyphosate takes place. Thisis followed by decarboxylation, hydrolysis (to eliminate phosphoric acid) and the addition of a second ninhydrin

molecule to form the Ruhemanns purple adduct (2). Theproposed mechanism is shown in Scheme 1:

O

O

OH

OH + NH2

OH

R

O

O

O

OH

NO

O-

R

H

O

O

NO

O-

R

R=CH2PO2H

O

O-

N H

R

O

O

N H

R

O

O

NH H

R OH

O

O

NH2

H

O

O

OH

H

O

O

OHO

O

OH

O

OO

O-

N

+ CO2

+ RCHO

+ NH3

2 Scheme 1 Mechanism of reaction of Ninhydrin andN-Phosphonomethylglycine

1H-NMR of the isolated ninhydrin-glyphosate adduct showed one peak at 7.65. Structure 2 as written

should give two peaks (7.65 and 8.00) of equal intensity due to the aromatic protons of the two non-equivalent indanetrione rings. However, resonance stabilization of the negative charge of (2) renders the twobenzene rings equivalent, thereby resulting in the absence of the second peak expected at 8.0, similar topreviously reported observation [15]. IR (cm-1): 3445, 3094, 1702, 1150-1180.

III.2. Analysis

Using the buffers at optimum conditions, a linear dependence of absorbance on concentration wasobserved over Beers law range from 0.3 to 4.5 g/ml with a molar absorptivity of 5.79910

4L mol

1cm

1for

the citrate and 1.975104

L mol1

cm1

for the acetate buffer system. The calibration curves are presented inFigs. 1 and 2.

Fig 1 Acetate Buffer Calibration Curve

Fig 2 Citrate Buffer Calibration Curve

0.0 0.5 1.0 1.5 2.0 2.5 3.0

0

1

2

3

4

5

P ar ame te r V al ue Er ro r

------------------------------------------------------------

B 1.97533 0.09293

------------------------------------------------------------

R SD N P

------------------------------------------------------------

0.98236 0.37435 9


9/48



The limit of detection (LOD) was estimated by dividing the relative standard deviation (RSD) of the

blank with respect to water by the slope of the calibration curve (m) and multiplying by a factor of 3.0. The limitof quantification (LOQ) was calculated by dividing the standard deviation (RSD) of the blank with respect towater by the slope of the calibration curve (m) and multiplying by 10. The limit of detection, limit of

quantification, correlation coefficient (R), RSD and slope were calculated and summarized in Table 1.

Table 1 Quantification ParametersParameter Values

CH3COOLibuffer system

Citrate buffer system

Molar absorptivity () L mol cm 1.97510 5.79910

RSD 0.3744 1.0956

Correlation Coefficient (R) 0.982 0.984

Slope 1.9753 5.799

Limit of Detection (g/ml) 1.802 0.6159

Limit of Quantification (g/ml) 5.5465 0.699

It is noteworthy that the citrate buffer /ascorbic acid system gave higher R2values in addition to the fact

that it is economically more viable, similar to earlier reported results [12]. The cost of hydrindantin is about 100times higher than that of ascorbic acid. Also, about 10 20 times more hydrindantin than ascorbic acid isrequired to prepare the same volume of ninhydrin reagent.

II.3. ApplicationThe method of buffers was applied in quantification of glyphosate in adsorption studies of glyphosate

unto corn starch and kaolin. Aliquots of the extract were analysed by the proposed method giving stable

Ruhemannspurple adduct at the ambient temperature.Glyphosate adsorption isotherm data have been obtained using the batch technique, where variousconcentrations of herbicide solution were added directly to aqueous suspensions of the adsorbent. After

equilibration, the concentration of pesticide remaining in solution was determined in the centrifugedsupernatant.

The amount of NPMG adsorbed, qe (mg/g) was calculated on the basis of a mass balance principle

according to Eq.1:qe= (Co- Ce) * V /w ...1where Co and Ceare initial and equilibrium concentrations (mg/L) of herbicide in the aqueous phase, V is thealiquot volume (L) of aqueous solution taken and w is the mass of adsorbent (g).The Langmuir isotherm is mathematically expressed as follows:1/qe = 1/ KL.b (1/Ce) + 1/KL ...2

Where KL is the maximum adsorption at the monolayer (mg g-1

), Ce is the equilibrium amount ofglyphosate (mg/L) in the aqueous phase, qe is the amount of herbicide adsorbed per unit mass of adsorbent , b isthe Langmuir constant related to the affinity of binding sites (mg g-1) for the sorbate molecules, and is a measure

of the energy of adsorption.A plot of 1/qeagainst 1/Cewas used to calculate the Langmuir constants KLand b.

The widely used empirical Freundlich equation based on sorption on a heterogeneous surface is given

by:

log qe = log KF+ (1/n)log Ce ...3where KFand n are Freundlich constants indicating sorption capacity (mg g

-1) and intensity respectively. KFis a

measure of the amount of pesticide sorbed for an equilibrium concentration of 1 mg/L. The constant, n, is ameasure of the intensity of adsorption and reflects the degree to which adsorption is a function of theconcentration. KFand nFwere determined (using the least squares method) from a linear plot of log q eagainst

log Ce.The nFvalue can be considered as an index of site energy distribution (i.e., the higher the nFvalues, the

less heterogeneous the sorption sites) [16]. Also 1 nF 10 has been interpreted as indicative of favourableadsorption [17].

The regression coefficient, the calculated Langmuir constants KLand b, and the Freundlich constants

KFand nF, are shown in Table 2.


10/48



Table 2 Derived Langmuir and Freundlich Isotherm Constants

Adsorbent

Langmuir Freundlich

KL b R KF n R

Kaolin 6.711 0.160 0.964 2.355 2.132 0.803

Starch 0.837 2.609 0.722 1.905 2.882 0.591

IV.

ConclusionA spectrophotometric method of determination ofN-phosphonomethyl glycine using ninhydrin, where

the Ruhemann purple adduct is stable enough to allow measurements over a wide range of concentrations hasbeen developed. The method, which uses two buffer systems (lithium acetate and sodium citrate) was applied to

quantifiaction of the herbicide adsorbed unto kaolin and starch giving good results. It could be extended todetection and quantification of glyphosate in environmental samples.

V.AcknowledgementAnalytical Services Chemistry Department, Durham University, United Kingdom is acknowledged. We

are grateful to the Association of Commonwealth Universities (ACU) for sponsorship for L.A. Nnamonu.

References

[1] T. V. Nedelkoska, G. K. C. Low, High-Performance Liquid Chromatographic determination of glyphosate in water and plantmaterial after pre-column derivatization with 9-fluorenylmethyl chloroformate, Anal. Chim. Acta.,511, 2004, 145153.

[2] B. L. Bhaskara, P. Nagaraja, Direct sensitive spectrophotometric determination of glyphosate by using ninhydrin as a chromogenic

reagent in formulations and environmental water samples,Helvetica Chimica Acta, 8(11), 2006, 2686269.

[3] P. L.Alferness, Y. Iwata, Determination of glyphosate and aminomethyl phosphonic acid in soil, plant and animal matrices and

water by Capillary Glass Chromatography with mass-selective detection J. Agric. Food Chem. 42, 1994, 2751-2759.

[4] C. D. Stalikas, C. N. Konidari, Analytical methods to determine phosphonic and amino acid group-containing pesticides, J.

Chromatography, 907, 2001, 1-19.

[5] FAO/WHO, Food and Agriculture Organization of the United Nations, Joint FAO/WHO Meeting on Pesticide Residues (FAO Plant

Production and Protection Paper 78).Pesticide residues in food1986, Evaluations1986, Part IResidues. 1986, Rome.

[6] M. R. Jan, J. Shah, M. Mohammed and B. Ara, Glyphosate herbicide residue determination in samples of environmental

importance using spectrophotometric method,Journal of Hazardous Materials169, 2009, 742745.

[7] D. K. Sharma, R. Kashyap and N. Kumar, Spectroscopic method for determination of glyphosate in relation to its environmental

and toxicological,Arch. Environ. Sc. 6, 2012, 42-49.

[8] A. C. Beckwith, J. W. Paulis and S. Wall, Direct estimation of lysine in corn meals by the ninhydrin color reaction, J. Agric. Food

Chem., 23 (2), 1975, 194-196.

[9] S. Moore and W. H. Stein, A modified ninhydrin reagent for photometric determination of amino acids and related compounds, J.

Biol. Chem., 211, 1954, 907.

[10] S. Moore, Amino acid analysis: aqueous dimethyl sulfoxide as solvent for the ninhydrin reaction. J. Biol. Chem.,243, 1968, 6281-

6283.

[11] S. Moore and W. H. Stein, Photometric ninhydrin method for use in chromatography of amino acids, J. Biol. Chem., 176, 1948,

367-388.

[12] S. Yokohama, J-I, Hiramatsu, A modified ninhydrin reagent using ascorbic acid instead of KCN, J. of Bioscience & Engineering,

95(2), 2003, 204-205.

[13] M. Cruz-Guzmn, R. Celis, M. C. Hermosin, W. C. Koskinen and J. Cornejo Adsorption of pesticides from water by functionalized

organobentonites, J. Agric. Food Chem., 53 (19), 2005,7502.

[14] ] M. Friedman, Applications of the ninhydrin reaction for analysis of amino acids, peptides, and proteins to agricultural and

biomedical sciences,J. Agric. Food Chem., 52 (3), 2004, 385-406.

[15] D. C. Wigfield, G. W. Buchanan and S. Croteau, On Ruhemanns purple, 58(3), 1980, 201-205.

[16] B. Xing, B. Sorption of naphthalene and phenanthrene by non-amended soils and humic acids J. Environ. Qual. 26:12641270

Environ. Pollut. 111, 2001, 303309.

[17] F. E. Okieimen, F. I. Ojokoh and R. A. Wuana, Preparation and evaluation of activated carbon from rice husk and rubber seed shell

ChemClass J.,2004, 191-196.


11/48

IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT)ISSN: 21019-2402X Volume 1, Issue 1 (Sep.-Oct. 2012), PP 11-18www.iosrjournals.org

www.iosrjournals.org 11 | P a g e

Effect of Thermal Processing on Shelf Stable Canned Salted Beef

with Tomato Gravy

Ankur Singh1, T. R. Genitha

2, Rongen Singh

3, B. R. Shakya

4

1M.Tech Student, 2,3Assistant Professor, 4Associate Professor, Department of Agricultural Process and Food

Engineering.Allahabad Agricultural Institute- Deemed University, Allahabad-211 007 U.P. India

Abstract: Studies were conducted to analyze the characteristics of shelf stable canned salted beef with tomatogravy involving the effect of thermal processing. Product standardization was done by traditional methodutilizing tomato gravy along with salted beef for making shelf stable canned meat. After that the optimizedpreservative concentration and thermal treatments were given to it at different temperature time combinations

viz., 1100C 115

0C and 121

0C for 20,30 and 40 minutes respectively in order to interpret the effect of thermal

processing and salt as a preservative. Samples were evaluated initially and after that at the intervals of 0, 15,

30, 45, 60, days for sensory analysis. Microbiological, chemical and sensory studies were conducted after each15 day interval up to other 60 days in order to depict the increase in shelf life stability due to application ofcurd as an emulsifier (i.e. effect of preservative and thermal processing). It was found that the thermalprocessing of shelf stable canned salted beef with tomato gravy done at 121 0C for 40 minutes had significantlysuperior acceptability and the adequate protein, fat, moisture content was found significantly superior in 110

0C

for 40 min.

Keywords:Product Standardization, Thermal processing, Canning, Sterilization, Shelf life study.

.

I. INTRODUCTIONIndian meat industry has emerged as the most dynamic and rapidly expanding segment of livestock

economy as in evident from the production level of 4.9 million tonnes with recent export of 0.27 millions tones

fetching worth about Rs.1400 crores of foreign exchange. Meat is recognized as highly nutritious food being anexcellent source of high quality protein. Containing a good balance of the essential amino acids and having high

biological value. (Rastogiet al.1978). Buffaloes are exported for slaughter from India and Pakistan to theMiddle East and from Thailand and Australia to Hong Kong. Demand for meat is so great that Thailand'sbuffalo population has dropped from 7 million to 5.7 million head in the last 20 years, a period in which thehuman population has more than doubled. (Charles and Johnson1972).

Ready-to-eat foods have also been defined as the status of the food being ready for immediate

consumption at the point of sale. It could be raw, cooked, hot or chilled and can be consumed without furtherprocessing. Ready- to-heat foods are fully cooked with long shelf life, up to 2-3 years and beyond dependingupon the storage condition. Most commonly RTE foods have been defined as those foods which are ready forconsumption, only to be reheated and consumed. For example Indian curries, deserts, frozen heat and eat

products like chicken and mutton curry, canned beef meat etc. which are generally retorted and are shelf stable.(Mann and Breashers 2007). Unlike pasteurized cooked meat products where the survival of heat resistantmicroorganisms is accepted the aim of sterilization of meat products is the destruction of all contaminatingbacteria including their spores. Heat treatment of such products must be intensive enough to inactivate/kill the

most heat resistant bacterial microorganisms, which are the spores of Bacillusand Clostridium. Temperaturesabove 100C, usually ranging from 110-121C (Hanet al.2004).

II. Materials And MethodsThe experiment was conducted in self fabricated A 2 size can in the laboratory at the Department of

Agricultural Process & Food Engineering, AAI-DU. Product development & thermal Processing of ready to eatSalted Beef with Tomato Gravy was conducted in a tin can.

2.1. Materials used: Meat, vegetables, refined oil, common salt, curd, meat masala, dry spices, lemon.

2.2. Method for the preparation of Salted Beef with Tomato Gravy

2.2.1.Salted Beef with Tomato Gravy PreparationMeat brisket (meat cut from the chest of the animal/buffalo) was washed properly with tap water; the

raw meat was placed in the pan of (5 liters) capacity, cover with cold water and brings gently to the boil. Afterthe cooking was done properly to get the soft tendering texture in the product, the surface of the beef loaf wascovered with salt, lemon and sugar, and leave for several hours. Meat was turned regularly during the next six


12/48

Effect of Thermal Processing on Shelf Stable Canned Salted Beef with Tomato Gravy


days salt was rubbed into the beef loaf each time and spoon the brine over the beef. Then, after six days, thebeef was ready to be cooked.

2.2.2. Preparation for the gravyAll vegetables and spices were grinded properly onion, tomato, garlic, green chilly, salt, cloves, cumin

seeds, black cardamom, green cardamom, bay leaves, black pepper corn and meat masala. The above mentionedgrinded ingredients and the putted into the gently boiled refined (sunflower) oil and cook it until the required

taste was developed.

2.3. Final preparation of the Salted Beef with Tomato GravyThe chopped meat loaves were deeply fried in the refined oil. These fried pieces were filled into the

empty cans with the prepared tomato gravy.Product standardization(By traditional method)

Filling

Exhausting

Liding

Thermal processing

(Autoclaving at 110, 115 & 121oC for 20, 30 & 40 min)

Cooling (tap water)

Storage

2.3.1.

Process flowchart for the thermal processing of Salted Beef with Tomato Gravy in cans.

Flatten can unit

Cylindrical formation by can reformer

Flange end preparation by flanger

Can lid fixed with double seamer

Can examination with water

Can ready for processing

2.3.2. Can fabrication flow chartSterilization of can

Filling the contents in the can

Exhausting of filled can in water bath done at 800C for 10 minutes


13/48



Can lid is fixed with double seaming machine (2 revolution)

Sterilization

Cooling

Storage in a cool and dry place

2.3.3. Schematic flow chart for the canning process.

2.4.1.Microbiological analysisPDA and NA media was prepared and standard plate count, yeast and mould count was taken at the

intervals of 15 days (0, 15, 30, 45, and 60 days).

2.4.2. Chemical analysisFat, protein, moisture content, and pH was determined according to (A.O.A.C) method at the intervals

of 15 days (0, 15, 30, 45, 60 days).

III. Results And Discussion

3.1.Product standardizationThe product standardization of salted beef with tomato gravy was done by using finishing technique,

by maintaining low vacuum in the can inspite of the filling temperature and by maintaining head space (1.10) ofthe salted beef with tomato gravy because all the cans were filled to constant weight for maintaining theconsistency of the tomato gravy depends on the emulsification. Proper filling resists the breaking of emulsion.No significant variation in the consistency was achieved, because proper emulsification was achieved by using

proper composition during finishing. The product standardization was done by maintaining adequacy of thermalprocessing at temperatures and time treatments (110

0C, 115

0C, 121

0C) for 20, 30, and 40 minutes. The product

standardization of the salted beef with tomato gravy was done by organoleptic evaluation of the product

consisted of offering the curry prepared using the concentrated gravy to a panel of judges drawn from the staffindicate that there was a definite maturation and improvement during storage of salted beef with tomato gravy.The product stored at room temperature 25-300C and 370C and thermally processed at 1210C for 40 min, up to

60 days was acceptable.

Similar results were interpreted during the acceptance of sensory, microbial, and chemical analysis of cannedmeat based on mutton curry and beef curry (Madhwaraj et al. 1979.)In this canned meat also sensoryevaluation was carried out on 9 point hedonic scale and all analysis were conducted similarly .(Pflugg and

Esselen, 1963).The salted beef with tomato gravy was standardized by traditional recipe. The nutritional and other

compositions of the product are given below:

3.1.1. CompositionBeef muscle pH (5.4), fat (3.4%), moisture (76.6%), protein (19%), and ash (1%).Meat cuts considered for each can weighs: 250 g

Tomato gravy with all essential ingredients for each can weighs: 250 gWeight of empty can : 100 gWeight of each packed can : 600 g

(500 g : Salted beef with tomato gravy, 100 g : can weight)

3.2. Chemical characteristics of salted beef with tomato gravy3.2.1. Effect of thermal processing on protein percentage of salted beef with tomato gravy.

ProteinStatistical analysis of protein percentage at 0 days storage was shown that the mean value at temperature

TE1, i.e., 17.51 was significantly superior to the mean value at temperature TE2, i.e., 17.36 which again wassignificantly higher than TE3 i.e., 17.23.Similar trend was observed by the statistical analysis of protein percentage at 0 days storage, was shored thatthe mean value at time T1, i.e., 17.64 was significantly superior to the mean value at time T2,i.e., 17.30 which

again was significantly higher than T3,i.e., 17.16.The same table shows the results during interaction analysis of protein percentage at 0 days storage was shoredthat the interaction at TE1+T1, i.e., 17.85 was significantly superior to the interaction at TE2+T1, i.e., 17.62

which again was significantly higher than TE3+T1, i.e., 17.45.


14/48



It was observed significantly by the findings of the analysis that protein was denaturated at higher temperaturesduring thermal processing of salted canned meat with tomato gravy and decreases the biological value of

protein and physical properties of protein were affected due to high temperature and time treatments.Protein is one which is highly digestible and absorbable and which supplies the organism with

adequate amounts of the amino acids which it needs. Roasting and canning may affect the physical properties of

meat protein adversely by changing the linkages so that they are not as susceptible to enzymatic digestion

(Howkeret al., 1976).(Morgan and Kern 1934) found that during canning of meat the biological valuedecreased in proportion to increase in severity of the heat treatment .

3.2.2. Effect of thermal processing on fat percentage of salted beef with tomato gravy.

FatStatistical analysis of fat percentage at 0 days storage was shored that mean the value at temperature

TE2, i.e., 4.45 was significantly superior to the mean value at temperature TE1, i.e., 4.35 which again wassignificantly similar to TE3, i.e., 4.37 (table 4.2).Whether at time treatments it was observed by the statistical analysis of fat percentage at 0 days storage was

shown that the mean value at time T3, i.e., 4.42 was significantly superior to the mean value at time T1, i.e.,4.37 which again was significantly similar to T2,i.e., 4.39 (table 4.2).The same table shows the results during interaction analysis of fat percentage at 0 days storage. It was observedthat the interaction at TE3+T1, i.e., 4.52 was significantly superior to the interaction at TE2+T1, i.e., 4.34

which again was significantly superior to TE1+T1, i.e., 4.24 (table 4.2).High temperature cooking of the meat in a vessel or sealed jars and cans, where the meat is roasted, sliced and

sealed in jars. The layer of fat not only protects the meat from contamination but also excludes oxygen. Thisseparation of fats results in fat embedding. As temperature increases it affects the physical properties of meatfat. (Reiser and shorland, 1990).Similar findings were depicted during the fat estimation of canned meat (Madhwaraj et al.1979).

3.2.3.Effect of thermal processing on pH of salted beef with tomato gravy.pH

Statistical analysis of pH was shored that at temperature TE3, i.e., 5.59 and TE2, i.e., 5.58 wassignificantly superior to the mean value at temperature TE3, i.e., 5.55.Whether at time treatments it was observed by the statistical analysis of mean value of pH at time T3 i.e., 7.67was significantly superior to the mean value at time T2,i.e., 6.47 and T1,i.e., 6.07.

It was shown that the results during interaction analysis of pH at TE3+T3, i.e., 5.61, TE2+T3, i.e., 5.61, andTE1+T3, i.e., 5.57 were insignificant.The pH of meat never reaches such high acid values, but the high temperature reached during the heat treatmentabout 112to 113C might favor the reaction. (Morgan and Kern, 1934)), studied that during canning or roasting

if the pH of canned meat lies between 5.4-5.8, the canned meat will be under edible conditions.These conditions apply to foods of low acidity (pH above a value of 5.5) and medium acidity (pH - 5); withmore acid foods the spores of micro-organisms are less heatresistant. Meat products are mostly low-acid, while

meat and vegetable mixtures are medium -acid. In practice once the F-value (thermal treatment at 1210C) has

been determined for a batch of food according to the size of the container the heat treatment required to treatsubsequent batches is the same (Bender and Zia, 1976).

3.2.4. Effect of thermal processing on moisture percentage of salted beef with tomato gravy.

Moisture content

Statistical analysis of moisture percentage at 0 days storage was shown that mean value at temperatureTE3, i.e., 73.66 was significantly superior to the mean value at temperature TE2, i.e., 73.83 which again wassignificantly superior to TE1, i.e., 74.02.Whether at time treatments it was observed by the statistical analysis of moisture percentage at 0 days storage

was shored that mean value at time T3, i.e., 73.61 was significantly superior to the mean value at time T2, i.e.,73.86 which again was significantly superior to T1,i.e., 74.04.The same table shows the results during interaction analysis of moisture percentage at 0 days storage wasshown that interaction at TE3+T3, i.e., 73.38 was significantly superior to the interaction at TE2+T3,i.e., 73.58which again was significantly superior to TE1+T3, i.e., 73.87.

It was observed by the findings of the statistical analysis that moisture content of meat was decreasedduring canning, roasting as the temperature increases the moisture content was decreased during high thermal

time and temperature treatments. High moisture content results in growth of microorganism during meatcanning by using different gravys moisture content decreases as the temperature increases . (Reiser and

shorland, 1990).


15/48



3.3. Microbiological characteristics during storage periodStandard plate count of canned salted beef with tomato gravy after thermal processing at 121 0C for

similar time combinations showed significant and prominent reduction in the microbial population of cannedsalted beef with tomato gravy. The microbial load was reduced to optimum level which clearly depicts the shelfstability of salted beef with tomato gravy. But the maximum decrease in the microbial population of the cannedsalted beef with tomato gravy thermally processed at 121 0C for 40 minutes.

Statistical analysis of microbial count at 0 days storage was shown that the mean value at temperatureTE3, i.e., 29.22 was significantly superior to the mean value at temperature TE2, i.e., 42.89 which again wassignificantly superior to TE3, i.e., 52.22.Whether at time treatments it was observed by the statistical analysis of microbial count at 0 days storage was

shored that mean value at time T3, i.e., 24.78 was significantly superior to the mean value at time T2,i.e., 41.78which was significantly superior to T1,i.e., 57.78.The same table shows the results during interaction analysis of microbial count at 0 days storage. It was shown

that the interaction at TE3+T3, i.e., 14.33 was significantly superior to the interaction at TE2+T3, i.e., 28.00which again was significantly superior to TE1+T3, i.e., 32.00.


16/48



At high temperatures thermal treatments thermally processed cans of meat under gravy preparation have lowestdecline at microbial load and a longer shelf life than other types of food packets such as sachets, pouches, glassjars.(Madhwaraj et al, 1979).

3.4. Sensory characteristicsThe sensory characteristics of the canned salted beef with tomato gravy were analyzed after 0, 15, 30,

45, and 60 days were done and tabulated in table.

After comparing the mean sensory score it was found that the significant mean sensory score wasobserved in salted beef with tomato gravy thermally processed at 121

0C for 40 minutes after comparing with the

mean sensory score of control. Hence clearly depicts the shelf stability of the canned salted beef with tomatogravy and its maximum acceptability.

3.4.1. Effect of different temperatures and time of thermal processing on overall acceptability

characteristics of salted beef with tomato gravy.Same trend as above was observed in mean sensory scores of overall acceptability at temperature TE3,

i.e., 6.87 was significantly superior to the mean value at temperature TE2, i.e., 6.53 which again wassignificantly superior to TE3, i.e., 6.40.

Whether at time treatments it was observed by the statistical analysis of mean sensory scores of overallacceptability at time T3, i.e., 7.53 was significantly superior to the mean value at time T2,i.e., 6.60 which againwas significantly superior to T1,i.e., 5.67.The same table shows the results during interaction analysis of mean sensory scores of overall acceptability at

TE3+T3, i.e., 8.00 was significantly superior to the interaction at TE2+T3 i.e., 7.40 which was significantlysuperior to TE1+T3, i.e., 7.20.

Results in consonance with the acceptability and nutritional quality of gravy based canned meat on

beef curry and mutton curry (Madhwaraj et al 1979). Results are in confirmation with the the development ofinstant ready to eat mutton curry was organoleptically acceptable(Das and Radhakrishna 2001).Similar results were interpreted during statistical analysis of colour, taste, aroma, flavour, sensorycharacteristics.


17/48



IV. Summary And ConclusionsThe results summarized and drawn after the present research entitled effect of thermal processing on

shelf stable canned salted beef with tomato gravyare given below

1. Beef meat chunks and tomato gravy was used for development salted meat with tomato gravy. Meat chunksconsidered for each can weighs, 250g weight of each chunk, 25g.2. The product standardization of salted beef with tomato gravy was done by using finishing technique, by

maintaining the filling temperature, at 800C and by maintaining head space (1.10cm) of the salted beef with

tomato gravy. Curd was used as an emulsifier to maintain the consistency of the gravy.3. The product standardization of salted beef with tomato gravy was done by maintaining the consistency of the

tomato gravy depends on the weight with all essential ingredients for each can, 250g. Proper filling resists thebreaking of emulsion. Proper emulsification was achieved by using curd (50ml for each can) as an emulsifier.4. Microbiological analysis was carried out to depict the shelf stability of canned Salted Beef with TomatoGravy and was carried out after every 15-day time interval up to 60 days. It was observed by the statistical

analysis of microbial count that the canned meat at 1210C for 40 min having mean values at temperature TE3,

i.e., 15.67, at time T3,i.e., 14.00 and the interaction at TE3+T3,i.e., 4.00 were significantly superior to othersamples.5. Similarly the chemical analysis was done. After the chemical analysis it was observed in the protein, fat, pHand moisture content percentage at 110

0C for 40 min had the significant mean values at temperature TE1, i.e.,

17.51, at time T1, i.e., 17.64 and the interaction at TE1+T1, i.e., 17.85 was significantly superior than othersamples.

6. Thermal processing was done at three different temperature time combinations. From the mean sensory scoreit was predicted that canned meat which was thermally processed at 121

0C for 40 minutes had significantly the

superior acceptability.

4.1. ConclusionThe present study also revealed that application of thermal treatments, emulsifier, proper fillingtechnique and the microbial stability as well as the sensory, and the nutritive characteristics of the canned Salted

Beef with Tomato Gravy were retained. Salted Beef with Tomato Gravy which was thermally processed at121oC for 40 minutes had significantly superior acceptability and the adequate protein, fat, moisture contentwas found significantly superior in 1100C for 40 min. Similarly the maximum decline in the microbial load was

depicted after the canned Salted Beef with Tomato Gravy was thermally processed at 121oC for 40 minutes.

V. References[1] Association of Official Analytical chemists, 1975 Official methods of analysis, Washington

[2] Bender, AK. and Zia, M. 1976 Meat quality and protein quality. 1. Fd. Technol. 11. 495498

[3] Charles, D. D., and Johnson, E. R., 1972, Carcass composition of the water buffalo (Bubalus bubalis). Australian Journal of

Agriculture Research 23:905-911.

[4] Das, Himanish and K., Radhakrishna, 2001, Preservation of mutton as ready-to-eat curry by hurdle technology, defence food

research laboratory, Siddarthanagar, Mysore, India.

[5]

El-Koussy, H. A., Afifi, Y. A., Dessouki, T. A., and El-Ashry, M. A. 1977, Some chemical

and physical changes of buffalo meat after slaughter. Agriculture Research Review 55:1-7.


18/48



[6] Han. Jun, Ma and Ledward, D. A. 2004, High pressure/thermal treatment effects on the beef muscle, Meat Science 68 (3): 347-

355

[7] Howker, John J. ; Shults, Gary W. Wierbicki, Eugen, 1976, Effect of Combined Irradiation and Thermal Processing on Canned

Beef. Army Natick Research And Development Command Mass Food Engineering Lab, . Agriculture Research Review 30 (1):

44-48

[8] Madhwaraj, M. S., S. B. Kadkol, Nair, P. R., Dhanraj, S., Govindarajan, V. S., Baliga, B. R., 1979, Central Food Technological

Research Institute, Mysore, India, manuscript.

[9] Mann, J. E. and Brashears, M. M. 2004, Contribution of Humidity to the Lethality of Surface-Attached Heat-Resistant Salmonella

during the Thermal Processing of Cooked Ready-to-Eat Roast Beef, Research Note, Journal of Food Protection, 70(30):762-765[10] Morgan, A. F., Andg. E. Kern. 1934, The effect of heat upon the biological value of meat protein. J. Nutrition, 7: 367.

[11] Pflugg, J., Esselen, W. B., 1963 in food processing operations, the AVI publishing co., Inc. 410.

[12] Rastogi, R., Youssef, F. G., and Gonzalez, F. D. 1978, Beef type water buffalo of Trinidad-Beefalypso. World Review of Animal

Production 14(2):49 -56.

[13] Reiser, R. and Shorland, F.B. (1990), Meat Fats and Fatty Acids , journal of food science and technology, (2)5: 21-62
http://www.sciencedirect.com/science/journal/03091740http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235114%232004%23999319996%23509198%23FLA%23&_cdi=5114&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b8780dbaacd6e11876eb45927a6be15dhttp://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235114%232004%23999319996%23509198%23FLA%23&_cdi=5114&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b8780dbaacd6e11876eb45927a6be15dhttp://www.sciencedirect.com/science/journal/03091740


19/48



Taxonomic Redescription of Messor Himalayanus Forel

(Hymenoptera: Formicidae), New Report from South India

Presty John1& K A Karmaly2

1s.H College, Thevara, Cochin, India2St.Xaviers College For Women Aluva. India

Abstract: Ants are dominant insects and highly developed social animal. They are widely distributed

throughout the world. Currently there are 28 subfamilies and 408 genera. (Bolton et.al, 2007) The speciesMessor himalayanus Forel belongs to the subfamily Myrmicinae of family Formicidae. The present study wascarried out in three places of Kollam district viz. Kuriottumala, Punalur and Yeroor. The ecology of this speciesie; nesting pattern, habit, habitat, food preferences, active involvement in day timings and colonial behavior are

observed. The species Messor himalayanus Forel resdescribed, compared with other species of Messor andsimilarities and dissimilarities are also provided. Currently there are only two species of Messor reported from

India and only one from South India and the species Messor himalayanus Forel adds a new report to SouthIndia.

Keywords: Messor himalayanus, Myrmicinae, New report, Resdescription, South India.

I. IntroductionThe genusMessor was established by Forel in 1890 as subgenus ofAphaenogaster. In 1892d Emery

synonimised as Cratomyrmexbased on the type-species Cratomyrmexregalis by monotypy, 1895 as subgenus

of Stenamma.In 1903 Bingham raisedMessoras genus based on the type species Formica Barbara,, in 1917Veromessor byForel as subgenus of Novomessor. The genus Veromessor was recently synonymised withMessor(Bolton, 1982). Currently there are 112 species, 49 subspecies in world (Bolton, 2012) . In India thereare only two species ofMessor. (Himender Bharti,2011)

The genus Messor is commonly known as Harvester ants. Harvester ants are species that regularly storecollected seeds in underground granaries (Hlldobler and Wilson, 1990), thus shaping the physical, chemical

and hydrological properties of the soil (Cammeraat et al., 2002). The colonies can be often seen in grassy areaswhere seeds are available. This kind of land forms a suitable place for Messor himalayanus Forel for nest

construction. Most of them construct the nest behind the roots of grass.

II. Materials And Methods2.1 Study site

The study was performed in a typical grassland area ie; Kuriottumala (Kollam). The soil is mainlysandy. The typical vegetation is composed of herbaceous plants, mostly dominate by grasses.

Specimens were collected by all out search method on the ground. Collected specimens were mountedon rectangular cards and pinned with Asta insect pins of size 38 mm x 0.53 of 3 (made by Newy Goodman LtdU K). Ants up to the genus level by using Stereoscopic binocular microscope (Getner 40x) and species levelidentification is carried out using Leica MZ6 stereo zoom microscope (Germany),based on taxonomic keys of(Bingham, 1903, Hlldobler & Wilson, 1990; Bolton, 1994). The unmounted specimens were stored in 70%

alcohol in eppend off tubes and kept in refrigerator for further studies.

III. MeasurementsAL: Alitrunk length .the diagonal length of the Alitrunk in profile from the point at which the pronotum meetsthe cervical shield tho the posterior base of the metapleuron

ED Eye diameter: maximum diameter of compound eye measured in oblique lateral view.F1-F12: Funicular segments, Length of the antennal segments (funnicles) except scapeHL: Head length: maximum distance from the mid-point of the anterior clypeal margin to the mid-point of theposterior margin of the head, measured in full-face view;.HW:Head width: measured at widest point of the head, in full-face view behind eye-level.PW: Pronotal width: maximum width of pronotum measured in dorsal view.

SL: Scape length: maximum scape length, excluding basal condyle and neck..


20/48

Taxonomic Redescription Of Messor Himalayanus Forel (Hymenoptera: Formicidae), New Report


IV. IndicesCI: Cephalic index (HWx100)/HLSI: Scape index (SLX100)/HW

V. Results5.1 Worker measurements & indices

5.2 Worker minorTL= 6.5 mm; HL= 2 mm; HW= 2 mm; CI= 100 mm; SL= 1.5 mm; SI=75 mm; ED= 0.25 mm; PW= 1 mm;AL= 2 mm5.3 ColourHead, thorax and abdomen black; antennae, legs reddish brown.

5.4 Sculpture and hair patternYellowish white, abundant, appressed hairs are present all over the body.Head anteriorly, pronotum above, abdomen, smooth, polished and shining; mesonotum above in profile and

laterally, very densely transversely striated; pronotum laterally, head posteriorly, nodes of pedicel rugulose;mandibles longitudinally striated.

5.5 Head

Excluding mandibles head square; posterior region of head distinct, emarginated , vertex anteriorly

little truncated; antennae 12 segmented with indistinct club, antennal groove distinct, scape of the antennaeshort, slender, cylindrical, reach upto 3/4th from its insertion to the top of the head; eyes small, round, mid-laterally located; ocelli absent; frontal carinae short, distinct, widely divergent; clypeus triangle, slightlyemarginated posteriorly, transverse anteriorly; mandibles curved inwards, strong, massive, dentition obsolete.

5.6 ThoraxPronotum and mesonotum forming a single convexity, pronotum forming a shield above, promesonotal

groove distinct; mesometanotal groove deep; mesopleuron with single impression in the middle; metanotal

spiracle, metapleural gland bulla distinct, metanotum unarmed; coxa of legs rectangular; trochanter thickened inmiddle, narrowed posteriorly; femur slender not dichromatic.

5.7 Abdomen

Two nodes of pedicel distinct, first node anteriorly attenuated, emarginated above, conical; helicium

present; second node of pedicel rounded above, as long as broad. Gaster opaque, broadly oval.

5.8 Plesiotype:Worker major N 8 29' 18.2872" E 76 55' 7.7743", INDIA: Kerala, Trivandrum (Veli) Presty: 20.IV.

2011 [DZSXCA).

5.9 Other materials examined:2 W:INDIA: Kerala, Kollam (Kuriottumla) Presty John 07. X. 2011,. 2W: INDIA: Kerala, Kasargod (Bekkel)Presty John, 20.I.2011, 2 W: INDIA: Kerala, Kollam (Yeroor) Presty John 26.I.20121W: INDIA: Kerala,

Kollam (Punalur) Presty John 19.IV.2012.5.10 Distribution: INDIA [Kerala: Kollam; Trivandrum; Kasargod);5.11 Biology: Unknown.5.12 Habit:Granivorous.

5.13Habitat:Collected from grassy plains.

VI. DiscussionMessor himalayanusForel closely resembles with Messor barbarous Linnaeus in having 1. Sides of

thorax transversely striate. 2. Abdomen highly polished, smooth and shining.3. Mandibles longitudinallystriated. HoweverMessor himalayanusForel differs fromMessor barbarous Linnaeus in having 1. Meatnotum

unarmed (in Messor barbarous Linnaeus metanotum is dentate). 2. Pilosity wanting ((in Messor barbarousLinnaeus Pilosity abundant). 3. Head with scattered punctures ((in Messor barbarous Linnaeus head is withoutpunctures).


21/48

Taxonomic Redescription Of Messor Himalayanus Forel (Hymenoptera: Formicidae), New Report


VII. AcknowledgementWe also wish to thank KSCSTE Trivandrum, Kerala for providing the fund for carrying out the work.

Also thankful to the Principals of S.H College Thevara and St. Xaviers College for Women, Aluva forproviding necessary facilities for carrying out the work.

References

[1] Bingham, C. T. The Fauna of British India, including Ceylon and Burma.Hymenoptera, Vol.II. Ants and Cuckoo-wasps.. Taylorand Francis, London (1903) 506 pp

[2] Bolton, B. Afrotropical species of the myrmicine ant genera Cardiocondyla, Leptothorax, Melissotarsus, Messor and Cataulacus

(Formicidae). . Bull. Br. Mus. Nat. Hist. (Ent.), 45, . (1982) 307-370 pp.

[3] Bolton, B.Identification Guide to the Ant Genera of the World:. Cambridge, Mass (1994) 222 pp.

[4] Bolton, B. Catalogue and Synopsis, inhttp://gap.entclub.org/(2012)

[5] Bolton, B., Alpert, G., Ward, P. S. and NeskereckiI, P. BOLTONS CATALOGUE OF ANTS OF THE WORLD, 1758 2005.Compact Disc Edition, Harvard University Press.

[6] Cammeraat L.H., Willott S.J., Compton S.G. and Incoll L .D. 2002. The effects of ants nests on the physical, chemical andhydrological properties of a rangeland soil in semi-arid Spain. Geoderma (2007).105: 120

[7] Emery, C. d. Voyage de M. Ch. Alluaud dans le territoire d'Assinie (Afrique occidentale) en juillet et aot 1886. Formicides.

Annales de la Socit Entomologique de France 60 (1891): (1892) 553-574 pp.

[8] Emery, C.. Beitrge zur Kenntniss der nordamerikanischen Ameisenfauna. (Schluss). Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere, (1895) 8: 257-360 pp.

[9] Forel, A. Fourmis de Tunisie et de l'Algrie orientale rcoltes et dcrites par Auguste Forel. Annales de la SocitEntomologique de Belgique. Comptes-rendus (1890) 34: lxi-lxxvi

[10] Forel, A.. Cadre synoptique actuel de la faune universelle des fourmis. Bulletin de la Socit Vaudoise des Sciences Naturelles(1917) 51: 229-253.

[11] Himender Bharti, List of Indian Ants (Hymenoptera:Formicidae), Halters, (2011) Vol 3 79- 87pp.

[12] Hlldobler B. and Wilson E.O The Ants. The Belknap Press of Harvard University Press, Cambridge, Massachusetts. (1990). 732

pp.
http://gap.entclub.org/http://gap.entclub.org/http://gap.entclub.org/http://gap.entclub.org/


22/48



Effects of Sublethal Concentrations of Diazinon on Total Protein

in Tilapia Fish (Oreochromis Niloticus)

A.A. Soyingbe1, O.O. Ogunyanwo

1, T.B. Hammed

2, and A.O. Adesope

3

1Dept. of Environmental Health Sciences, Ogun State College of Health Technology, Ilese-Ijebu, Nigeria.2Alesinloye Market Environmental Health Project, Alesinloye Market, Jericho Road, Ibadan, Oyo State,

Nigeria.3Department of Medical Laboratory Sciences, Ogun State College of Health Technology, Ilese-Ijebu, Nigeria

Abstract: This study assessed the influence of organo-phosphorus (OP) Diazinon pesticide on adult tilapia fish(Oreochromis niloticus) in a semi static renewal bioassay for 30 days. Adult fish were acclimatized tolaboratory conditions for 7days and then exposed to varying sub-lethal concentrations of diazinon (1.0, 2.5, 5.0,

7.5 and 10.0 mg/l) for 30 days and compared with control (untreated). Total protein was determined in plasma,muscle, gills, liver and kidney. The water quality used for the study showed pH 7.05, dissolved oxygen 6.7 mg/l,

temperature 26.00

C, alkalinity 16.25 mg/l, conductivity 106.12ps/cm and turbidity 0.46 NTU. The 96h LC50 ofdiazinon was 7.65mg/l. At various concentration of diazinon, fish showed uncoordinated behaviour such assomersaulting, convulsion and erratic swimming. The levels of total protein in plasma was significantly lower(P


23/48

Effects of Sublethal Concentrations of Diazinon on Total Protein in Tilapia Fish (Oreochromis


Unconsumed feed and feacal waste were removed and water was regularly replenished as recommended byOyelese and Faturoti [12]. Sub-lethal concentrations of diazinon for assay (1.0, 2.5, 5.0, 7.5 and 10.0mg/l) were

determined based on the range finding test [13]. These were prepared by transferring 0.02; 0.13, 0.25, 0.37 and0.5 ml, respectively of the original concentration of diazinon and making it up to 30L with distilled boreholewater in the test aquaria. Also, 30L of the diluents water was used as control. Four replicatesof each treatment

level (concentration) and control were set up and fishes were introduced individually into each aquarium.

The exposure period lasted for 30days during which the exposure media were renewed daily. The waterquality parameters such as pH, dissolved oxygen, temperature, alkalinity; conductivity and turbidity of the test

media were determined and recorded following the standard method on water quality assessment, [14]. After the30 day exposure period, blood samples for biochemical analysis were collected from each fish with 23G sizeneedle and syringe. Fish were not fed prior to blood sample collection. Samples were preserved in heparinsedbottles. Fishes were sacrificed after blood collection and dissected for the collection of their gills, liver, kidney

and muscle. Thereafter, 0.5g of each organ was macerated (grounded) with pestle and mortar. Physiologicalsaline was used for preservations and stabilization. Samples were centrifuged at the rate of 300 rpm for 10minutes. The supernatants were then removed and stored in plain bottles at 200C for analysis of the total

protein levels (Lowery et al; 1951). The results obtained were subjected to Analysis of Variance (ANOVA),where difference exist, Duncan Multiple Range Test (DMRT) were used to test for pair wise significantdifferences (P


24/48

Effects of Sublethal Concentrations of Diazinon on Total Protein in Tilapia Fish (Oreochromis


Fig 1: Acute toxicity test of diazinon in tilapia (Range means 95% confidence interval)

Sudden changes in the frequency of movement of the fish subjected to different concentrations ofdiazinon were physically observed. Behavioral changes like somersaulting, convulsion, excess secretion of

mucus, erratic swimming, sudden quick movement and darkening of fish were observed during the exposure offish to diazinon.

IV. Discussion

The results of the media quality used in this study were within the optimal range reported in theprevious studies [16, 13] as optimal requirement for most aquatic organisms. Thus, this suggested that the

parameters did not seem to alter the toxicity of the insecticide to the test fishes. However, temperature, hardness,pH, alkalinity, sex, age and other physiological status of the test animals were reported to have profound effectson the toxicity of agro-chemical [17, 18]. Toxicity of diazinon to O. niloticus is relatively lower when comparedwith other species of fishes. The 96hL50 value (7.65 mg/l) obtained in this work was lower than the valuesreported in

the sustainability of dam construction through environmental management

Documents