cooking oil and ghee processing

Internship Report

Prepared By: Abdul Rahim 2011-BT-CHEM-01 Chemical Engineering Department University of Engineering and Technology Lahore KSK Campus Lahore.

Internship Report

4 week internship report in Hoor Banaspati and cooking oil industry PVT LTD Vehari Road Multan.

Table of Contents

1. Introduction to Oil and Ghee.2. Percentage of oil in different seeds. 3. Preparation of Indicators.4. Manufacturing of Vegetable Ghee5. Flow Sheet Diagram of Ghee Manufacturing.6. Procedure of ghee manufacturing.7. Unit operation and unit process.8. Oil and Ghee analysis.9. Flow sheet diagram of extraction of oil.

Introduction to oil and Fats

• Natural oil and fats are the tri-ester of glycerol with long chain of carboxylic acid (12-20 carbon) known as tri-glycerol or tri acyl glycerides.

• Oil is an organic substance which contain higher %age of unsaturated glyceride ester , While fat contain higher %age of saturated glyceride ester.

Percentage of oil in different seedsSeed Name Oil Percentage

Alsi seed 30%-72%

Canola seed 40%-45%

Canola cake 10%-14%

Canola meal 0.80%-2%

Cotton seed 17%-18%

Cotton cake 6%-18%

Cotton meal 0.5%-1%

Caster seed 41%-86%

Palm seed 50%-60%

Peanut seed 30%

Popy seed 40%-50%

Popy seed cake 8.88%

Popy seed meal 1.78%

Percentage of oil in different seedsSeed Name Oil Percentage

Rape seed 30.33%

Rape seed cake 7%-10%

Rape seed meal 0.50%-1.50%

Sunflower seed 38%-40%

Sunflower cake 10%-13%

Sunflower meal 0.80%-1.50%

Soyabeen seed 17%-18%

Soyabeen cake 8%-10%

Soyabeen meal 0.50%-2%

Taramira seed 22%-27%

Taramera cake 10%-12%

Taramera meal 0.80%-2%

Preparation of Indicators

1. Phenolphthalein 1%:Dissolove 1 gm. of phenolphthalein powder in 100 ml ethyl sprit.

2. Methyl Orange:

Dissolove 2 gm. of dye in one liter of distill water.

3. Methyl Red: Dissolove 0.1 gm. of methyl red in 18.6 ml of N/50 NaoH solution and dilute to 250 ml with distill water.

4. Dimethyl Glyoxime 1%: Dissolove 1 gm. of salt in 100 ml of ethanol.


5. Phloroglucinol 0.1%: Dissolove 0.1 gm. of salt in 100 ml ether.

6. Antimony Tri chloride 25%: Dissolove 25 gm. of salt in 100 ml of chloroform.

7. Starch Solution: Take 1 gm. of starch with water in the thin paste. Pour it , in 100 ml of distilled water drop by drop and boil it for five minutes. Allow to cool. Decant of clear solution, prepare fresh solution when ever required.


8. Potassium Chromate:

Dissolove 4 gm. of solid pot-chromate in 100 ml of distill water.

9. Alcoholic potash: Dissolove 56 gm. of solid alcoholic potash in one liter distilled alcohol.

10. Pot- Iodide 15%:

Dissolove 15 gms of solid in 100 ml of distill water.11. Buffer Solution: Add 140 ml of conc. Ammonia solution (sp-Gravity 0.88-0.90) to 17.5 gm. Ammonium chloride and dilute it to 250 ml with water.


12. Hydroquinone Solution:Dissolove 5 gm. salt of hydroquinone in 500 ml of distilled water, dissolve it completely and add 0.3 ml of conc. H2So4.

13. Litmus Solution:It is prepared by dissolving 100 gms litmus powder in 100 ml water and add more 150 ml water. It is used where evolved co2.

14. Molybedate Solution: Dissolove 8.8 gm. of Ammonium molybedate in about 100 ml of distilled water then add 300 ml water and 38 ml of H2So4, then dilute to 500 ml exactly.


15. Carbonate sulphite solution: Dissolove 130 gms of anhydrous sodium carbonate and 24 gm. of sodium sulphite in 500 ml of distil water.

16. Ammonia Buffer solution ph 10: Add 70 gm. ammonium chloride in 568 gm. ammonia solution and make volume 1 liter with distil water in measuring flask.

Manufacturing of Vegetable Ghee

• Chemical formula of ghee: (C17H33 Coo)3 C3H5

• Chemical Reaction:(C17H31Coo)3 C3H5 + 3H2 (C17H33 Coo)3 C3H5

• Raw Material: Soya been oil, Sunflower oil, Cotton seed oil, Palm oil, Canola oil.

Ni

Flow Sheet Diagram of Ghee Manufacturing

N/10 NaoH Nacl 15bag/25ton fuller earth

steam soap stock Steam Fuller earth Fuller earth N/10 NaoH

Steam Steam Soap Stock Ni Catalyst Steam H2 gas

Vegetable oil storage

tank

Pre-neutrilization

40-50c1-1.5hrs

Pre-Bleaching85-100C

1-2hr

Plate & frame filter press

Hydrogenation150-190C

3-7hrsNi ½-2kg


Post-neutrilization

50-90C½-1.5hr

Post-Bleaching90-100C

15-20mm hg1-2hr

15-20mm hg


Fuller earth

De-

180-235C3-6hr

30mm hg

OdorizationCooler

Cold water

Hot water

Citric acid

Filter

Vitamin blending

A+D vitaminPackingMarket

Vitamins

Detail Pre- Neutralization: In this section , the crude oil after charging in a neutralizer is preneutralized. Following chemicals and conditions are required.Chem : N/10 NaoH solution , NaCl , H3Po4.Temp : 40C - 50CPressure: 760 mm of hgTime : 1 - 1.5 hrs.The main purpose of pre-neutralization is to decrease the free fatty acid. This is done by passing NaoH solution. Agitator is provided for complete neutralization. Steam is passed through steam coils , which play double role (1) agitation (2) heat transfer.Soap stock is obtained as by product.

Per-BleachingIn this section per-neutralized oil is bleached.Following chemicals and conditions are required for this purpose.Chem : 15 bags of 50 kg Fuller earth for 25 ton batch.Temp : 85C-100CPressure: 15 - 20 mm of hgTime : 1 - 2 hrs.In bleaching tank , first of all heat the oil up to 85C - 100C by steam coils. After heating close the steam valve and mix oil for 20 minutes by impeller. Now add 15 bags of fuller earth by blower and mix for 20 - 25 minutes. After mixing power off the impeller and allow to cool oil up to 100C and pump oil to plate and frame filter press to remove fuller earth. After filtering color of oil will be very good.

Hydrogenation It is very important and main step in ghee manufacturing. In this section oil is converted into ghee with the help of hydrogen gas. Following chemicals and conditions are required.Chem : Ni catalyst , H2 gas.Temp : 150C - 190CPressure : 50 - 250 PSITime : 3 - 7 hrs.Hydrogen gas is allow to pass through in the oil , in the presence of Ni catalyst. During the process the degree of hydrogenation is checked and controlled by refractrometer. Reading is indicate the physical properties i.e. Saturation and melting point of oil. The melting point of ghee is kept according to the season temperature. After the complete hydrogenation, it is pass through the filter to remove the Ni catalyst. Reaction in hydrogenation is takes place as:(C17H31Coo)3 C3H5 + 3H2 (C17H33 Coo)3 C3H5After the hydrogenation the oil is converted into ghee called molten ghee.

Ni

Post-Neutralization

The hydrogenated oil is introduced in this section. In this section following chemicals and conditions are required.Chem: N/10 NaoHTemp: 50C - 90CTime: ½ - 1.5 hrs.The main purpose of post neutralization is to complete removal of free fatty acid.

Post-BleachingPost bleaching is done in a same way as done before. Fuller earth is added to improve and absorb additional color particles. Following chemicals and conditions are required.Chem : Fuller earthTemp : 90C - 100CVacuume : 15 - 20 mm of hgTime : 1 - 2 hrs.After complete bleaching , Ghee is passed through filter to remove fuller earth. Then it is passed to the de- odorization section.

De- OdorizationThe filtered hydrogenated oil still contain un-pleasant odor. So it must be de-odorized. Citric acid is also added in the ghee which helps the digestion.Following chemicals and conditions are required.Chem: Citric acidTemp: 180C - 235CVacuume: 30 mm of hgTime: 3 - 6 hrs.Then ghee is passed through cooler to cool down its temperature at 60C.

Vitamin Blending

In this section , vitamin A+D are added in the ghee to meet the requirement of good quality ghee. Then it is checked in a test lab and then it is packed.

Unit operation and unit process

• Unit operation. transfer of oil to neutralization section. Addition of N/10 NaoH and NaCl in it. transfer of pre-neutralized oil in pre-bleaching section. pre-bleaching of oil. Filtration of oil. Addition of hydrogen gas in hydrogenation section. Addition of Ni-Catalyst. Post-bleaching of molten ghee. De- odorization of ghee. Addition of citric acid. Vitamin blending of A+D in ghee.

Unit Process

• Pre- Neutralization of oil.• Hydrogenation of oil.• Post- Neutralization of oil.

Oil and Ghee analysis Determine the percentage of oil in vegetable seeds , cake and meal. Apparatus: Thermostat water bath, Seed grinder, Electrical balance, Filter paper, Clamp, Beakers 250 ml, Hard plate.

Chemicals: Hexane solvent.

Procedure:1. Take approx. 250 gms of sample in grinder and complete grind the sample.2. Put the grinded sample on a paper.3. Power on the electrical balance.4. Now take a small piece of paper and put it on the balance pan, and make balance weight

less.5. Take 5 gm. of sample by electrical balance.6. Now make a thimble of filter paper and fill the sample in thimble and double it by another

thimble.7. Now power on the thermostat water bath and fill the hexane in extraction apparatus approx.

half measuring flask of 250 ml.

8. After heating the hexane , pour the sample thimble in extraction apparatus.9. Continue the process at least for 1:30hr - 1:45hr for cake and meal sample, while 3hr- 4hr for seed sample.10. During process hexane will extract the oil from sample.11. After completion of process take out the sample from extraction apparatus by clamp.12. Take out the measuring flask from apparatus and pour the sample(hexane + oil) in beaker and heat it on hard plate to remove hexane from oil.13. After removing the hexane take out the beaker from hard plate and allow to cool.14. Now calculate the oil %age in sample by following calculation. Empty beaker weight = YOil+ empty beaker weight = XOil weight = X - Y = ZOil percentage = obtained oil weight/ total sample weight 100Oil %age = Z/5*100

Determine the moisture percentage in vegetable seeds , oil , cake , meal and soap. Take a clean glass empty dish and note its weight. Now take approx. 10 gms of sample in glass dish and put it in oven at 100C

- 110C for 1hr - 1:15hrs. After 1 hr. take out the sample from oven and allow to cool at room temp. After cooling the sample , calculate the moist %age by following calculation. Let empty dish wt. = 50.00gm. Sample+ E.D.wt = 60.00gm. sample wt. = 10.00gm. Dry sample+ E.Dwt = 59.00gm. Moisture wt. = (sample+E.Dwt) - (dry sample+E.Dwt) = 60-59 = 1.00gm Moist %age = moist wt/sample wt 100 Moist %age = 1/10*100 = 10 %

Determination of FFA of oil/ghee.

Apparatus: Titration flask, pippet, burette, 10 ml cylinder.

Chemicals: Methyl sprit, phenolphthalein indicator.

Procedure: Take 50 ml methyl sprit in titration flask. Add 2 - 3 drop of phenolphthalein indicator. Fill the burette with N/10 NaOH solution. Titrate the solution with N/10 NaOH , until the first color light pink will

appear , now stop the titration. Now add 10 ml of sample oil/ghee in solution by measuring cylinder , and

shake , the solution will be colorless. Now note the initial reading of burette and again titrate with N/10 NaOH

solution, add drop by drop the NaOH solution and continously shake the solution sample.

Stop the titration when just light pink color will appear. Now note the final reading on burette and calculate the used volume of NaOH solution. Multiply the used volume of NaOH with 0.282 E.g. FFA = B.Reading * 0.282 FFA = 0.4 * 0.282 = 0.1128 % The range of FFA of oil/ghee should be in B/W 0.08 % - 0.19 %

Check the Bleachbility of oil.

• Apparatus: Colorimeter, thermometer, stirrer rod, beaker 250 ml, clamp, filter paper.

• Chemicals: Fuller earth.

• Procedure: • Take sample 120 125 ml in 250 ml beaker, and heat it up to 60C on hard

plate.• Now take sample in the cylinder of colorimeter.• Put the cylinder in colorimeter and check its color, match the color of

colorimeter with the color of oil and note the reading.• Now calculate the 1st index by adding color readings.• Now again heat the sample oil up to 100C on hard plate.• Add 1gm of fuller earth in sample oil and mix it well for five minutes, mix and

heat the sample very well.

• After heating and mixing , separate the fuller earth from oil by filter paper separating beaker.• Take filtrate oil in colorimeter cylinder and again put it in colorimeter.• Check the second color of oil in colorimeter and calculate 2nd index.• Calculate bleachbility of oil by following method.

• 1st index - 2nd index = X• X/1st index * 100 = bleachbility %age.

Determine the melting point of ghee.

• Apparatus: Magnetic pug mill, beaker, thermometer, Magnetic stirrer , capillary tube(1.1 1.2mm).

• Procedure: • Take cold water in 250 beaker and put the magnetic stirrer in beaker.• Put the beaker at magnetic pug mill.• Now dip the thermometer in the beaker by stand do not touch the thermometer at the

bottom of beaker.• Fill two capillary tubes with sample ghee approx. half inch.• Now attach the capillary tube with ice and liquid ghee will freeze in sold form.• Now attach the sample capillary tubes with the thermometer at its bottom.• Now power on the magnetic pug mill and starts to heat the water continuously , and

note temp on thermometer.• Heat the water continuously until solid freeze ghee just start to melt at this point note

the temp on the thermometer, it is the MP of ghee.• The MP of ghee should be same as the temp of season.

Rancidity Test of oil and ghee.

• Rancidity mean the chemicals which wee add in oil or ghee during processing, are remove or not?

• Chemicals: 0.1 % phyloroglucinol indicator. (0.1 gm. phyloroglucinol in 100 ml ether.)• Procedure: Take 5 ml sample in test tube , add 5ml conc. HCl ,

Now put your thumb on the mouth of test tube and shake it well. Now slowly remove your thumb and release the pressure. Now add 5 ml phyloroglucinol and shake it , and allow to settle down for 20 minutes. If pink color appear its mean till chemicals are present in sample oil or ghee, other wise has removed.

Phyloroglucinol always kept in refrigerator , because it is explosive. If we kept it in lab at room temp it will be explosive or damage rapidly.

Vitamin test

• Chemicals: 25% antimony tri chloride. ( mix 25gm of antimony tri chloride powder in 100ml chloroform.)

• Procedure: Take sample of oil or ghee in test tube.• Add one drop of vitamin solution.• Now add 2 - 3 drop of Antimony tri chloride

indicator , and blue color will appear , that showing vitamins are present in sample.

• If blue color not appear its mean vitamins are not present.

Determine the conc. of NaOH solution.

By weight method: Procedure: Take 1 - 2gm of NaOH solution in titration flask by electrical balance. Add 100 ml distill water in flask of sample. Add 1 -2 drop phenolphthalein indicator Initial color is pink. Titrate this solution with 1N HCl solution. Final color is colorless. Note B. Reading and calculate used volume. Calculate the %age of NaOH solution by using following formula. Ml of HCl used/ wt. of liq NaOH * 4 = NaOH percentage

Determine the conc. of NaOH solution.

By Bomimeter: Procedure: Fill the sample solution of NaOH in cylinder and dip the Bome

meter in cylinder. Note the reading of bome meter on graduated scale , It is the

% age purity of NaOH solution.

Extraction of oil.Flow sheet diagram.

Raw cotton seed

Cleaning & Screening

Compressed air

dust

De-linting

Mechanical expression

1700-2200PSI80-92% oil

recover

Flacking0.010”-0.014”

De-Hulling

Hulls

Solvent extraction

70-90CPressure

1atm

Roaster

Evaporator

Miscella (oil + solvent)

Oil refining

Oil storage

Meal

condenserHexane solventstorage

hexane

Hexane

Meal

Hexane

Lint