Training Report Training on Quality Control of Dairy Products
Submitted by: (Name of Student) (College) (Course enrolled in)
Parag Dairy
Pradeshik Cooperative Dairy Federation Ltd. Lucknow-226001
Pradeshik Cooperative Dairy Federation Limited Lucknow-226001 Telephone: +91-522-2236466
Fax: +91-522-2266472
Certificate This is to certify that the report entitled 'Quality Control of Dairy Products' is a brief summary of the work done by Ms. (name of student) under the Training Program at the Quality Control Laboratory of the Dairy during the period of _________________________
(Coordinator) :
(In-charge Quality Assurance) :
(Coordinator) :
Acknowledgement It gives me colossal pleasure and satisfaction to state that my project program has been a success. I want to extend a vote of gratitude towards the in-charge of Quality Control (QA) of Parag Dairy, Mr. H.S. Verma for giving me this oportunity to work in the NDDB(National Dairy Development Board) quality-certified laboratory of PCDF (Pradeshik Cooperative Dairy Federation Limited) under the brand name 'Parag'. I want to thank the Chemist, Mr. M.K. Srivastava for his wise guidance and suggestions. I want to thank Mrs. Rekha, Assistant Chemist for being a guide and friend which kept me going. My thanks to Mrs. Kalpana, Assistant Chemist, for being a friendly support. And the achknowledgement will go waste if I do not mention the help and support of Lab Assistants, Mr. Surendra Singh and Mr S. C. Yadav. I would also give thanks to my family for giving me strength and encouragement to complete this work and hope their gracious blessings will continue. I would also like the teachers of my institute for their encouragement. At last i indeed feel honored to have worked in this laboratory which enhanced my academic knowledge and creativity in gentle ways.
(Name of Student)
CONTENT Topic
Page 5
•
About
NDDB
•
Company
•
Objectives
•
Fundamental
•
Milk
•
Process
Flow
•
Quality
Control
•
Effluent Water Treatment
6
Profile
of
the
Knowledge
Products
of
9
Company
of
10
Milk
11
Parag
13
Charts
–
Chemical
Analysis
&
Microbiologica
24
Analysis
17
National Dairy Development Board (NDDB) The National Dairy Development Board (NDDB) was designed in 1969 on Anand Dairy Cooperative outlines of creating district cooperative of milk producers at village level which aim at collection of whatever amount of milk they produce and payment to them according to the quality of milk they supply. Then this milk is processed and supplied to the people at metropolitans and other cities at nominal charges. For about 5 yr., NDDB was dormant till the time they received presents of Whole Milk Powder and Butter Oil from European Union and came into action with the help of Indian Dairy cooperation. Operation flood was started in 1970 under the guidance of Dr. Kurein, Chairperson NDDB, Anand and Mr. Jamnadas Patel in Khera, Gujarat. The objectives of Operation Flood are: ü To buy the milk from the farmers and villagers as much milk as they could
supply at reasonable prices and keep the price of milk stable whole year. ü To operate, procure, process and market milk and milk products. ü Production of good milk after its qualitative and quantitative estimation. ü System to eliminate middleman. ü Providing technical inputs and services to yield of milk animals. ü Organizing an efficient transport system to collect milk from villagers. ü Set up of balancing dairies and storage system to convert excess milk to
milk powder and butter oil. ü Train personnel to plan and manage the system as well as operate the
services described. ü To meet out these objectives, NDDB started dairy plants all over India and
Mother Dairy was one of them. It was set up in 4 major cities at Delhi, Mumbai, Chennai and Kolkata. Operation flood was a major dairy development program. Funds were generated by the sale of dairy commodities donated by the World Food Program (FAO-UN) which assisted project to carry out its mission. This included establishing dairy cooperatives in rural milk sheds, setting of animal husbandry units, constructing modern dairies in cities, organizing storage and long distance transportation and project planning with manpower development. The first phase of operation flood was completed in 1979, followed by second phase (1979-1988), assisted by European Economic Community. Its third phase ended in 1996.
Profile of the Company Name of the Organization
Lucknow Producer's Cooperative Milk Union Ltd.
Address of the Organization
22. Jopling Road, Lucknow
Established
1938
Registration
23 March, 1938
First Dairy Inspector
N. K. Bhargava
Place of Establishment
Initially at Charbagh, shifted to Ganesh ji, presently at 22, Jopling Road , Lucknow.
Founder
Raj Bahadur Gopal Lal Pandya
Board of Directors
Mr. Gopal Pandya Mr. N. C. Charturvedi Mr. Tej Shankar Mr. Pushkar Nath Bhatt
Per Day Production of Milk
Initially 4000 lts.
Location
Initially Charbagh, presently, 22, Jopling Road, Lucknow
Area of Distribution
Initially-Bakshi ka Talab, Tewari ganj, at present-entire district.
About the Company The common brand name of the company is “PARAG” the meaning of PARAG is the pollen
of flower the slogan in the logo is: PURE NATURAL & GOOD HEALTH
Parag milk shed is situated in the Lucknow, the capital of Uttar Pradesh since independence it has formed part of the traditional supply line of agriculture products from the village to the big cities rich in its milk potential the milk shed has, in the source of last few decades been thoroughly exploited by small traders and powerful contractors and well organized private dairies. Thus, while such intermediaries were retaining large profits the rural milk producers found their position deteriorating day by day. In 1950-a co-operative milk supply union was organized in Lucknow , which started collecting milk from village and supplied to Lucknow and local markets. This milk union continued function for about a decade, in the mean time Lucknow milk scheme was established by government of India in 1959-60 to ensure cheaper milk to the local pollution of Lucknow. The scheme started operating through 12 chilling centers in Eastern Uttar Pradesh. These chilling centers were mainly coated in thither district of Lucknow , Barabanki, Raebareli , Kanpur, Unnao, Sitapur etc . The milk was mainly collected through contractors. 10 milk unions were also found almost at the same time, around each chilling center. These continued functioning in a rather lop-sided manner till 1977.
Gradually all the milk union almost become defunctioning and was supplying very little quantity of milk during the years 1970-77. Obviously contractors had monopoly and collected major share of milk which was either supplied to Lucknow or to the local population of the city.
This programmer was launched in Uttar Pradesh in 1972 and the implementing agency in the wa pradeshik cooperative dairy federation limited which was framed in the year. The basic idea was
to replicate anand pattern societies in Uttar Pradesh. In august September 1972 organization of societies in Lucknow district was taken up bar out, Mohanlalganj,Amausi blocks. A spear head team from national dairy development board was posted in Lucknow , which started functioning from April 1978 with a team of 27 employees drawn from Lucknow milk 198 milk procurement cooperative societies by the year 1981, when the operation fllod-14 programme ended. Feeded balancing dairy, Lucknow Producer’s Co-operative Milk Union Ltd was set up under operation flood-1 programmer with the specific purpose of supplying milk of local markets and other districts. Dairies and conversion surplus milk into various dairy products. This dairy is situated in the middle of Lucknow . The dairy was commissioned in April 1978 and processed the liquid milk procured from the then milk shed comprising Lucknow, Raebareli, Barabanki and Unnao. The purpose of establishing feeder balancing dairy, Lucknow co was to provide remunerative market for milk produced in the milk shed comprising district of Lucknow , Barabanki, Raebareli, Kanpur and Sitapur as envisaged under operation flood-1 scheme. Thus feeder balancing dairy was oblized to receive entire surplus milk from the rural areas, through a network of milk coop. In 197879 the average handing of milk per day at fbd-Lucknow Producer’s Co-operative Milk Union Ltd was 49,300kg. With peak handing of 1, 04,950kg in the feb. In April 1981 Lucknow Producer’s Co-operative Milk Union Ltd launched pasteurized whole milk packed in polythene sachet for local consumers. The supply of milk was gradually extended to other local markets. As the basic idea of establishing FBD-Lucknow Producer’s Co-operative Milk Union Ltd was to convert surplus milk into various dairy-products, this activity started in sept. 1978 with manufacture of skimmed milk powder and ghee. The manufacturing of table butter was started from April 1981. In view of milk production procurement and marketing potential of Lucknow Producer’s Cooperative Milk Union Ltd , and expansion programme has been undertaken by N.D.D.B. On turn basis. The target set is as under: Increasing processing capacity from 1 lack to 3.5 liters per day. Increasing powder plant capacity from 10 tones to 40 tones per day. Increasing the capacity of ghee plant from 1.m.t. to 4.m.t. per day. Increasing the capacity of butter manufacturing up to 16.m.t. per day The work of expansion has been complete in 1989.
The work of expanded dairy started functioning on full capacity in 1991-1993 year. The liquid milk and products are selling in the market in the brand name of PARAG. The milk product has been marketed by P.C.D.F. luck now. The sale of liquid milk has been carried out Lucknow Producer’s Co-operative Milk Union Ltd, Lucknow. In the year 1983 P.C.D.F. Ltd. started working under Operation Flood – II (White revolution) scheme. Mostly unit milk Sahakari Board where connected under Operation Flood – II, having the name Dugdh Utpadak Sahakari Sangh (D.U.S.S.) Ltd. P.C.D.F. Ltd. takes royalty of common brand name PARAG and all the important policy taken by Pradeshik Cooperative Dairy Federation Ltd. Who monitors to all the D.U.S.S. Ltd. i.e. Lucknow , Kanpur, Varanasi. PARAG provides hygienic, nutritious milk and milk product. In the year 1983 Operation Flood – II scheme was launched, the main objectives of the Operation Flood were following – · To collect the milk directly from the producers (Villagers through society). · To insure the supply of quality milk collected from the villagers which being sold in the market area of city. · To save the producers, villagers and the customers from the middle man. · The milk is collected firstly to the society level then it comes to D.U.S.S. level finely it comes under the state level i.e. Federation.
Objectives of the Company OBJECTIVES
PCDF’S front-end objective was to see that there was enough milk for everyone in town. Marketing is simply the PCDF’S tool to achieve their ultimate objective and delivering the pure parag milk to every home.
PURPOSE
PCDF’S aims to build a system to ensure that individual farmer got a fair price for the milk he sold.
Management System Policy
We firmly believe that the path to progress can only be through procurement and production o superior quality milk & milk products, timely deliveries & total customer satisfaction. We will bring in qualitative change in the lives of our milk producers by ensuring profitable returns to their produce and offering quality & safe products at competitive price to consumers through proffesional excellence. We will create a vibrant work environment, continuously imroving upon our production, marketing ans service operations through application of quality, food safety & environmental management systems.
Fundamental Knowledge of Milk
Milk is the secretion derived after complete milking of healthy milk animal, excluding that obtained within 15 days before or after 10 days of calving.
Composition of Milk 01.
Milk Fat
Milk fat is the mixtures of 19 fatty acids. The bulk of fat in milk exist in the form of small globules with size approx. 0.1 to 22microns. It is an oil-in-water type emulsion. 02.
Proteins Protein is the most complex organic substances. They are vital for living organisms as they constitute an indispensable part of the individual body cell. The protein of milk consists of Casein, Lacto globulin and Lacto albumin. It is in colloidal state. Casein is only found in milk. It is easily coagulated by heat treatment.
03.
Water It provides the medium in which all the milk constitutes are either dissolved or suspended. Most of it is free and only a small portion is in bound form, being firmly by protein and phospholipids.
04.
Lactose(Milk Sugar) It is found only in milk. It exist in true solution phase and is fermented by bacterial to yield lactic acid. It is very important for cultured milk products. It can also cause souring in milk and its products.
05.
Mineral Matter: Although it is present in small quantity, it is very essential for human body. These are mostly salts like Mg, Na, P, N etc. It influences physio-chemical properties of milk and also affects the nutritive value.
06.
Phospholipids: There are three types of phospholipids (Lecithin, Cephalic and Sphingomylein). Lecithin is important constituent as it helps in the formation of outer membrane of fat globules.
07.
Pigment: There are two type of pigment present in milk, Fat Soluble and Fat insoluble. Carotene is fat soluble and is responsible for the yellow color of milk. The other two are Xanthophylls and riboflavin. Carotene also acts as an anti oxidant and as a source of Vitamin A.
08.
Milk Enzymes The important milk enzymes and their specific action are as follows:
-
Anise (diasterase) Lipase Phosphatase Protease Catalase
Starch Fat splitting, leads to rancid flavor It is capable of splitting certain phosphoric esters. It is capable of splitting proteins. decomposed hydrogen peroxides.
09.
Vitamins
Vitamins are present in minute quantities in milk or any other food but play a very important role in vital functioning of human body. There are 25 vitamins present in milk. These are fat soluble e.g. Vit. A, D, E,K. apart from fat soluble there are water soluble vitamins as B-complex(B1, riboflavin or B2, pantothenic acid, niacin, pyridoxine or B6.)
Milk Products of Parag 1. Packaged Milk: Pasteurised and standardised packaged milk is available in 500 ml and 200 ml packs of four types, viz., Parag Gold (full cream milk), Parag Taaza (toned milk), Parag liter (skimmed milk), Double Toned Milk. Flavored Milk is also available in 200 ml packs. 2. Butter: It contains less than 80% milk fat and more than 15% moisture and high acidity. It is prepared exclusively from milk cream of curd of cow or buffalo milk without the addition of salt, color or any preservative and is intended for cooking or for preparation of Ghee. Parag Butter is avaialble in 20 gm, 100 gm and 500 gm packs. 3. Ghee: About 43% of total quantity of milk produced in India is manufactured first into butter and then converted into Ghee. Bulk of Ghee is derived from buffalo milk because it is richer in fat that cow milk. In Parag surplus butter is mutted in steam jacket kettles. Which are equipped with mechanical stirrers and heated with steam till the moisture is removed. 4. Dahi: Commonly known as Yoghurt. Two type of dahi is avaialble viz., curd and sweetened curd (Mishti Dohi) in 200 gm packs. 5. Paneer: Commonly called as Cottage Cheese. In Parag, Paneer is produced by the traditional method in which citric acid is added to the boiled milk and the milk immediately
gets adulterated and water is separated and paneer is obtained. It contains less than 50% fra of more than 60% moisture. 6. Others: Other Parag products avaialable in the market are: Peda, Cream, Ice-cream, Kheer ( chhena and rice), Rasogulla, Gulab Jamun, Besan laddu etc.
Future Products: Some new products like coffee powder, ready to make ice-cream powder, baby food and other milk drinks are in the testing stages.
Process FlowCharts Process Flowchart for liquid milk Packaging
Milk Reception in Cans and Tankers Grading,Sampling,Testing Weighment Unloading through online Strains Chilling Raw milk storage tank Balance tank of pasteurizer Recombination & Homogenisation
Pasteurisation (78 deg. Celsius for 15 sec) Milk Chiller
Seperation
Sampling & Testing Cream Storage Tank
Pasteurized Milk Storage Tank sampling & chiller testing Sampling & Testing Pouch machine balance tank Tanker Pouch Filling Crating
Polyfilm Sampling & Testing
Cold Storage Dispatch _________________________________________________________________________
Standard Operating Procedure for Flavored Milk Pasteurised Milk Standardization Testing in QC Taken in Presanitized Tank Addition of Sugar (7% of Milk) Filteration Sugar Syrup made in different tank or vessel heated upto 80 deg. Chilled upto 7 deg. Addition of Color & Flavor Testing in QC Packaging (PoplyPack) Stacked in Milk Crates Stored at 4 deg. Celsius testing in QC Dispatch
______________________________________________________________ Process Flow Diagram for Dahi Plain/ Sweetened Dahi Standardised Milk from Storage Tank Boiled Sugar Solution
Heating of Milk at 95 deg. Celsius approx.
(In Case of Sweetened Dahi) Culture at 1.0-1.5%
Cooling Milk to 44 deg. Celsius (Inoculant and Milk) Filling Cups (Earthern and Plastic)
Fixing Lid and Sealed
Placed in Corrugated Trays & then in Crates Transferred to Incubation Room maintained at 42 deg celsius Transferred Crates to Cold Storage maintained at < 5 deg celsius Dispatch _______________________________________________________________________
Process Flow Diagram for Ghee Pasteurised Cream Churning
Removal of Butter
White Butter in Trolleys/20 kg in cartons Butter Melting vat Ghee Kettle (110 +- 2 deg. Celsius) Transfer to Settling/Storage tank Sampling and Testing
Classification Storage Tank Filteration Ghee Filling Tank Filling
Filling and Soldering of Tins
PolyPack Filling/lined Cartons
Monocartoning and cartooning Storage Dispatch ________________________________________________________________________
Process Flow Diagram of Butter Pasteurization of cream Storage Tank loading to churn Churning Pasteurised Water
Removal of Butter Milk
Washing with pasteurized water Preworking Unloading in Trolleys
Packing in Ploythene liner & c.box hardening in Cold Store Storage for Self Consumption
Quality Control Quality control is an essential and most important department for any manufacturer. Today every organization has efficient quality control system. Quality control is depend upon only practical (Survey Analysis and Right Procedure). In D.U.S.S. Ltd. LUCKNOW at reception point of milk
from different societies (Producers Villagers) Milk is collected and basic test are carried out quickly
after cleaning it is send for further processing. Finally after pasteurization three type of milk obtain that is Full cream milk. Toned Milk, Janta Milk. Milk procedure out through some stages---------------------1. Organo Leptic Test It passes through three stages. This is the first stage: Seeing Smelling Testing 2.
MBRT (Methyl Blue Reduction test) It is done to check the hygenic quality of milk. It gives an idea about the becterial load in milk. 10 ml milk is taken ina test tube along with 1 ml of Methyl blue. It is kept for observation at 37 deg. Celsius. Bacterial load is inversely proportional to disappearnce of blue color.
3. Gerber Method It is done for fat content of milk 10 ml mik is taken in milk butyrometer. 10 ml conc. H2SO4(1.0-1.182 specific gravity) is added to it. 1 ml Amyl alcohol (0.85 specific gravity) is added. Lock stopper is put on butyrometer and it is centrifuged for 3-5 mins. Scale reading is observed. 4.
SNF(Solid not Fat) Analysis SNF=CLR(Corrected Lactometer Reading)/4 + 0.2*Fat + 0.29 (This formula is used for Big lactometer) SNF=CLR/4 + 0.2*Fat + 0.50 (for small lactometer)
5. Acidity test This is done to find out the pH of milk. Acidity of milk should be between 0.10 – 0.15. Curdling occurs at 0.18. 9ml milk is taken in a beaker. 1% Phenophtahlein indiactor is added. 0.1N NaOH is take to be titrated against. Acidity=9*N*V(vol of NaOH)/w(milk)
Milk Adulterants Soda
2 ml of milk is taken in a test tube. 2ml rosalic acid solution (0.05N) is added t it. If red color appears – soda +ve If pale ornage color appears – soda -ve Urea
2 ml milk is taken in a test tube. 2 ml DMAB (dimethyl benzaldehyde) solution is added to it. If light color (yellow) – urea -ve If dark color (yellow) – urea +ve
Salt
1 ml of milk is taken in a test tube. 5 drops of salt detecting sol.(Potassium chromate)added 5 ml AgNO3(0.1342%) is added. Yellow color – salt +ve Brown color – salt -ve Glucose
1 ml milk is taken in a test tube. 1 ml gluscose detection sol. A(Barfold sol) added Gave boiling water bath for 3 mins. Immediately dipped in cold after 3 mins Added 1 ml Solution B(Phosphomonolytiv acid) dark blue color – gluscose +ve Light blue color – glucose -ve Precaution-
In this test the test tube should not be subjected to heat for more than 3 minutes while giving wate bath. This can result in a false positive result.
Sugar
1 ml milk is taken in a test tube 2ml sugar detecting sol.(resorcinol) is added Kept in water bath for 1 – 3 mins Brick red color – sugar +ve Light color – sugar -ve Starch
3ml milk is taken in a test tube It is boiled and then cooled 4-5 drops of starch detecting sol(iodine sol.)added Yellow color – starch -ve Blue color – starch +ve
Ammonium Compound
5ml milk is taken 1ml amm. Comp. Detection sol. Light shade – test -ve Dark shade – test +ve
Product Testing Curd
Acidity of Curd: 9gm curd is weighed. 10 ml distilled water is added It is titrated against 0.1 N naOH. As per experiment, 9.7 ml naOh was consumed, hence acidity of curd was 0.97. Butter
Moisture in Butter: Empty Beaker was weighed: 51.7036 gm 10 gm butter was taken. Butter was melted and moisture was boiled off. Weight if butter = 59.743-51.7036=8.040 gm Implies, misture % = 13.57 % Standard moisture should not be more than 16%. Acidity of butter: 20 gm butter is weighed. 90 ml d.w. Is added to it. Butter is melted. Acidity = 9*N*V/w = 9*0.02*1.5/20 = 0.01 Standard acidity should not be more than 0.05 Salt in Butter: Vapor is boiled off from 10 gm butter. Petroleum etehr is added due to which fat seperates. The seperated fat is weighed: 16.8693 gm. 250 ml distilled water is added. The salt dissolves in water. 17.6ml of solution is taken in a seperate beaker. 5 drops of K2Cr2O7 (0.1204 N) is added. 0.04 ml of AgNO3 is added. Standard salt content should not be more than 2-2.5%. Paneer
Acidity of paneer: 9 gm paneer is taken and distilled water is added to it. 1 ml phenophthalein is added to it and it is then titrated against 0.1 N NaOH. 1.3 ml NaOH is consumed, hence acidity is 0.13.
Moisture content of Paneer: Beaker is weighed: 53.9982 gm Weight of beaker with ghee: 69.643 gm Weight if beaker with paneer: 74.6433 gm Weight after boiling off moisture: 71.6669 gm Implies, 74.6433-71.6699=2.9764 moisture is present in 5 gm paneer. Implies, Moisture content is 59.52%, thus in 100 gm, 40.480 gm is dry weight. Fat test: Same as gerber method of fat analysis.
Microbiological Analysis of Milk Purpose:
To test the liquid milkStandard Plate Count (SPC) Equipment used:
1) Laminar Air Flow 2) Sampling Bottle 3) Auto pipette with tips 4) Dilution Blank (9 ml or 99 ml) 5) Test Tube/Culture Tube 6) Plating Media 7) Durham’s Tubes 8) Petri Dish 9) Hot Air Oven 10) Autoclave 11) Incubator 12) Colony Counter 13) pH Strips 14) Refrigerator Sterilization: Sterilize sampling and plating equipments whenever possible with dry heat in a hot
air oven at 170°C for two hours. Sterilize the media and materials that are likely to be charred in dr oven, by autoclaving at 15 psi (127°C) for 20 minutes. After sterilization all media should be stored in hygienic condition.
Collection of sample:
Milk sample received should be stored in refrigerator below 7°C till tested. General Precautions:
a) Use only sterilized bottle to collect sample b) Collect all samples aseptically. c) Stoppers or lid of the bottles should not be removed from the bottles unless necessary. d) Replace the stopper or lid immediately after the sample is obtained. e) Do not fill the bottle more then three fourth of its capacity. f) Clearly label each sample bottle indicating the source, date etc. g) Keep the sample immediately in refrigerator below 7°C. Composition And Preparation Of Media:
Plate Count Agar (Tryptone Glucose Yeast Agar) For S.P.C. : Ingredients:
1) Tryptone
5.0 Gms. / litre
2) Glucose (Dextrose) 1.0 Gms. / litre 3) Yeast Extract
2.5 Gms. / litre
4) Agar
15.0 Gms. / litre
5) Final pH
7.0 ± (0.1)
Preparation: Suspend 23.5 gm of ready made Plate Count Agar in 1000 ml distilled water, add 6.5
gm NaCl, dissolve and adjust the pH 7. Boil to dissolve the medium completely and fill it in flask or bottles. Sterilization: Sterilize by autoclaving at 15 lbs pressure for 20 minutes. At the time of use
completely melt the media, then cool it in water bath set at 45°C. Standard Plate Count Test: Materials required:
1) Plating chamber 2) Petri plates 3) Plate count agar 4) Auto pipette with tips (1.0)/pipette 2.2 ml. 5) Dilution tubes containing 9 ml of batch phosphate buffer solution. Procedure:
1-Transfer 1 ml of well mixed sample to 9 ml diluents (phosphate buffer solution).Mix Well and transfer 1 ml of this suspension to second tube to make second dilution.
Similarly make third and fourth dilution as per requirement 2-Arrange the Petri plates for each dilution to be tested, mark them with sample no. and Date. 3-Transfer 1 ml in each plate from respective dilution of sample being tested. 4-Melt the plate count agar, cool it about 45°C and pour 10 ml of this medium into the Petri dishes. Mix the agar by rotating the plate. 5-Allow the agar to set, invert and incubate the plates at 37°C for 48 hours. 6-At the end of 48 hours remove the plate from the incubator and count the colonies. 7- Also prepare a control plate with 15 ml media for checking its sterility Counting and Expression Of results:
Count the colonies grown in Petri plates. Count only those plates, which have 30 -300 colonies. Computation:
Count the colonies developed in each plate for respective dilution. Multiply colonies per plate by dilution used and report the arithmetic average as plate count per milliter/gram. Recording / Reporting Of Results:
Record and report the result as – Standard Plate Count/ml/gm---Or SPC/ml/gm EFFLUENT WATER-TREATMENT
Water is used for chilling the milk so that bacterial action in milk can be reduced. There are many impurities present in the water. There is several treatment of water for reduce these impurities & turbidity from the water. EFFLUENT TREATMENT PLANT (E T P)
Dairy effluent are organic in nature which have high BOD when it is discharge as such in water bodies the bacteriological action will deplete the oxygen content of stream which is not good for animals ,fishes & plants. Life which depend on oxygen . Therefore, it is necessary to remove the organic matter content prevent in the effluent before discharging it in to the environment. The ETP have following stages:1: Oil collection sump/ fat removed unit:It is a devices which is used to remove out fat, oil,other greasy substances and floating materials from the effluent water coming out from the dairy industries. 2:-Equalization tank /Neutralisation tank :-
Diffused aeration line provided in the equalization tank .Diffused aeration prevention the formation
of lactic acid and reduced BOD about 50%. Neutralization tank are meant for to control the pH of effluent. Due to this, the acidity of effluent water is reduced and it becomes harmless for the next stage treatment. 3:-Aeration Tank:-
In this tank extended are provided. In this tank, with the help of micro-organism , in the presence o air the organic matter is converted into simpler material through floculation process and water
becomes less harmfull. In this tank activated sludge takes place. The sludge digestion takes through aerobatic process. The sludge new active microbial cell here which are common by referred as mixed liquour suspended solids which is golden brown in colour, and a part of the sludge with the old cell in sent for clarifier /sludge setting tank.
4:-clarifier:-In this, sludge is separated and is collected in sludge drying beds with the help of pump and the rest of liquid material is repumped into aeration tank for purification. 5:-Sludge Drying Beds:- In this, with the help of Solar radiation sludge in a very good fertilizer which contain good amount of carbon, moister, inorganic material and metals contents, which can used for agricultural purpose.
6:-Vee notch chamber:- In this chamber a sample of treatment water is tested and if treatment wate have all the standards of UPPCB then it is drained into water bodies. TOTAL SOLIDS(T.S.)
PRINCIPLE:- Total solids are determined as the residue left after evaporation of the unfiltered sample. PROCEDURE:1:-Take an evaporating dish of suitable size and weigh. 2:-Evaporate 250-500 ml unfiltered sample in the evaporating dish on a water bath. 3:- take the final weight of the dish after evaporation of the sample. CALCULATION:TOTAL SOLIDS,g/l=A-B*100/v
where, A=final wt. of the dish in g B=initial wt. of the dish in g C=volume of sample taken in ml TOTAL DISSOLVED SOLIDS (TDS)
PRINCIPLE:-Total dissolved solids are determined as the residue left after evaporation of the filtered sample.
PROCEDURE:1:-take an evaporating dish of suitable size & wt. 2:-evaporate 250-500 ml filtered sample in the evaporating dish on a water bath. CALCULATION :-
TDS, g/l=A-B*1000/V
Where, A=final wt. of the dish in g B=initial wt. of the dish in g V=volume of sample taken in ml. TOTAL SUSPENDED SOLIDS (TSS)
Determine total suspended solids as the difference between the total solids and total dissolved solids.
TSS=TS-TDS
pH
PRINCIPLE :- pH is the negative log of the hydrogen ion concentration in a solution. It can be measured by colorimeteric methods using various indicators or paper strips. However, the use of colorimeteric methods are less convenient and less accurate. For accurate measurement of pH , electrometeric methods are used employing the hydrogen ion sensitive electrodes. APPARATUS:-There are a number of makes and models available for pH meters. Portable pH meters operated by battery can also be obtained. The accuracy of pH can vary from 0.01 to 0.1
depending on the make. Some pH meters employ two electrodes , an indicators glass electrode, and a calomel reference electrodes. Most pH meters also have a temperature compensation system to avoid the differences arising due to the difference temperatures. PROCEDURE:1:-Follow the instructions given by the manufacturer to use the pH meter.
2:-Essential aspect to use all the pH meters is to calibrate it with suitable buffer. Ready buffer of pH values are also available in the market. See the pH meter with a buffer whose values near to the expected pH of the sample. 3:-Buffer of different pH values can also be made in the laboratory in the following manner. A. Potassium hydrogenphthalate buffer
Dissolve 10.2g of potassium hydrogenphthalate in Water to prepare 1000ml of buffer. B. Phosphate buffer
Dissolve 3.40g of KH2PO4 and 4.45g of Na2HPO4.2H20 in water to prepare 1000 ml of buffer. C. Borax buffer
Dissolve 3.81g of Na2B4O7.10H2O in water to prepare 1000ml of buffer. The values of the above buffers at various temperatures are as follows: Temp 0’c
phthalate
phosphate
borate
0
4.01
6.98
9.46
5
4.00
6.95
9.39
10
4.00
6.92
9.33
15
4.00
6.90
9.27
20
4.00
6.88
9.22
25
4.01
6.86
9.18
30
4.01
6.85
9.14
DISSOLVED OXYGEN 1.Winkler’s Iodometric Methods
PRINCIPLE :- The manganous sulphate reacts with the alkali (KOH or NaOH) to form a white precipitate of manganous hydroxide which in the presence of oxygen, gets oxidized to a brown colour compound. In the strong acid medium manganic ions are reduced by iodide ions which get
converted to iodide equivalent to the original concentrated of oxygen in the sample. The iodine can be titrated against thiosulphate using starch as an indicator. REAGENTS A. Sodium thiosulphate, 0.025 N
Dissolve 24.82g of Na2S2O3.5H2O in boiled distilled water and make up the volume to 1 lt. Add 0.4g borax or a pallet of NaOH as stabilizer. This is 0.1 N stock solution. Dilute it to 4 times with boiled distilled water to prepare 0.025 N solution (250->1000 ml). Keep in a brown glass stoppered bottie. B. Alkaline Potassium iodide solution Dissolve 100g of KOH and 50g of KI in 200ml of boiled distilled water. C. Manganous sulphate solution Dissolve 100g of MnSO4.4H2O in 200ml of boiled distilled water and filter. D. Starch solution Dissolve 1g of starch in 100ml of warm(80’c-90’c) distilled water and add a few drops of formaldehyde solution. E. Sulphate acid H2SO4.conc(sp. Gr.1.84) PROCEDURE: 1. Fill the sample in a glass stoppered bottle (BOD bottle) of known volume (100-
300ml),carefully, avoiding any kind of bubbling and trapping of the air bubbles in the bottle after placing the stopper. 2. pour 1ml of each MnSO4 and alkaline KI solution (in case, the volume of the sample is about 300ml, instead of 1ml of reagents add 2ml solution of each), well below the surface from the walls. The reagents can also be poured at the bottom of the bottle with the help of special pipette syringes to ensure better mixing of the reagents with the sample. Use always, separate pipettes for these two reagents. A ppt. will appear. 3. Place the stopper and shake the well by inverting the bottle repeatedly. Keep the bottle for some time to settle down the ppt. If the titration is to be prolonged for few days, keep the sample at this stage with the ppt. 4. Add 1-2ml of conc. H2SO4 and shake well to dissolve the ppt. 5. Remove either the whole contents, or a part of them (50-100ml) in conical flask for titration. Prevent any bubbling to avoid further mixing of oxygen. 6. Titrate the contents, within one hour of dissolution of the ppt. against sodium thiosulphate solution using starch as an indicator. At the end point, initial dark blue colour changes to colourless. CALCULATION: When whole contents have been titrated: Diss. Oxygen, mg/l = (ml*N)of titrated*8*1000/V1-v When only a part of the contents has been titrated: Diss. Oxygen,mg/l = (ml*N)of titrant*8*1000/V2(V1-v/V1) Where, V1=volume of sample bottle after placing the stopper . V2=volume of the part of the contents titrated v=volume of MnSO4 and KI added In occanography , the unit ml/l is preferred over mg/l. It can be obtained by dividing the value in mg/l. AZIDE MODIFICATION OF WINKLER METHOD Principle The presence of certain oxidizing and reducing material may effective interface with the determination of oxygen by converting iodide ions to iodide or vice-versa. The azide modification removes the interference of such substances especially nitrite. Nitrite is destroyed by sodium azide. The method, therefore ,is suitable particularly in polluted waters, biologically treated waters and in BOD samples. Reagents
A. Sodium thiosulphate ,0.025N See winkler’s method B.
Alkaline iodide azide solution a) Dissolve 500g of NaOH or 700g of KOH and 150g of distilled water to make 1 lt. of solution. b) Dissolve 10g of NaN2 in 40ml of distilled water. Mix the two solutions (a)&(b).
C.
Manganous sulphate solution See winkler,s method
D. Starch solution See winkler’s method E. Sulphate acid H2SO4. conc. (sp. gr.1.84) PROCEDURE Follow the same Winkler’s method except that , add alkaline iodide azide solution instead of alkaline potassium iodide in the same quantities. CALCULATIONS Same as for Winkler’s iodide method. BIOCHEMICAL OXYGEN DEMAND(BOD) Principle:
Biochemical oxygen Demand (BOD) is the measure of the degradable organic material present in a water sample, and can be defined as the amount of oxygen required by the microorganisms in the stabilizing the biologically degradable organic matter under aerobatic conditions. The principle of the methods involves, measuring the difference of the oxygen concentrated between the sample and after incubating it for 5days at 20’c APPARATUS & REAGENTS A. BOD bottles B. BOD incubator Having temp. control at 20’c C. Phosphate buffer Dissolve each 82.5g KH2PO4. 21.75g K2HPO4. 33.4g Na2HPO4.7H2O and 1.7 g NH4CL in distilled water to prepare 1 lt. of solution. Adjust pH to7.2. D. Magnesium sulphate Dissolve 82.5g MgSO4.7H2O in distilled water to prepare 1 lt. of solution. E. Calcium chloride
Dissolved 27.5g of anhydrous CaCl2 in distilled water to prepare 1 lt. of solution. F. Ferric chloride Dissolve 0.25 g FeCl2.6H2O in distilled water to prepare 1lt. of solution. G. Sodium sulphite solution, 0.025 N Dissolve1.575g Na2SO4 and dilute to 1000ml. Solution should be prepared freshly. PROCEDURE:1:- Prepare dilution water in a glass container by bubbling compressed air in distilled water for about 30 minutes. 2:- Add 1ml each of phosphate buffer, magnesium sulphate, calcium chloride, and ferric chloride solutions for each lt. of dilution water and mix thoroughly. 3:- Neutralize the sample to pH around 7.0 by using 1N NaOH or H2SO4. 4:- Since the DO in the sample is likely to be exhausted ; it is usually necessary to prepare a suitable dilution of the sample acc. to the expected BOD range. See the table for the dilution of the sample. 5:- Prepare dilution in a bucket or a large glass trough , mix the contents thoroughly . fill 2 sets of BOD bottles. 6:- Keep one set of the bottles in BOD incubator at 20’c for 5 days , and determine the DO contents in another.
References
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Expanding
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www.parag.co.in
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www.nddb.co.in
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www.scribd.com
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Biochemistry
by
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B.D.Singh
J.L.Jain
Microbiology by Prescott .
