Quality assessment/Quality control of edible/cooking oil.

Quality control/Quality assessment of raw materials and products use in edible/cooking oils:

Qualitative analysis :

A qualitative analysis determines the presence or absence of a particular compound, but not the mass or concentration. By definition, qualitative analyses do not measure quantity.

Quantitative analysis :

Gravimetric analysis

Gravimetric analysis involves determining the amount of material present by weighing the sample before and/or after some transformation. A common example used in undergraduate education is the determination of the amount of water in a hydrate by heating the sample to remove the water such that the difference in weight is due to the loss of water.

Volumetric analysis

Titration involves the addition of a reactant to a solution being analyzed until some equivalence point is reached. Often the amount of material in the solution being analyzed may be determined. Most familiar to those who have taken chemistry during secondary education is the acid-base titration involving a color changing indicator. There are many other types of titrations, for example potentiometric titrations. These titrations may use different types of indicators to reach some equivalence point.

CRUDE OIL QUALITY

Crude oil is normally defined in terms of moisture and dirt, phosphatide content normally expressed as ppm phosphorus, free fatty acids (FFA) or acid value and also in terms of color, oxidation characteristics, and trace components such as iron and copper.

*Moisture contents

Temperature 105C and sample 60ml

Initial weight of empty beaker? (W1)

Beaker + sample weight? (W2)

Sample weight =   W2-W1=W?

Weight after heating =W2-W3=W*

Moisture content =    W*/W *100= ?%

Procedure:

Weigh in a previously dried and tared dish about 5 - 10g of oil or fat which has been thoroughly mixed by stirring.

Loosen the lid of the dish and heat, in an oven at 105±10C for 1 hour. Remove the dish from the oven and close the lid.

Cool in a desiccator containing phosphorus pentoxide or equivalent dessicant and weigh.

Heat in the oven for a further period of 1 hour, cool and weigh.

Repeat this process until change in weight between two successive observations does not exceed 1 mg.

*MELTING POINT :

·        Take a sample (oil%Ghee) in capillary  two tubes.

·        Cool the capillary tube with ice.

·        First heat the sample in a beaker and take the sample in capillary tubes.

·        Take cold water in a beaker and put the capillary tube and thermometer in cold water beaker.

·        Start the sprit lamp and turn the light.

·        Shake continuously the water by stirrer when the first bubbles appear in the capillary tubes the sample start motion note the temperature at that point it will be its MP.

*FREE FATTY ACID (FFA*)

Titration method:

·        Take 40ml spirt in flask.

·        Add few drops of 1% phenolphthalein indicator.

·        Start the burette in which the solution of NaOH is present till the color become pink.

·        Then put 11ml sample in the flask and shake the flask well that the pink color disappear.

·        Then heat the flask for 3mint up to 22C in steam bath.

·        Again start the burette in which the (0.01N) NaOH is present till the color become pink  note the length of burette used (ml)

·        FFF% = ml used *0.288 =?

    Or

FFA= (V*N(NaOH)*25.6)/W

Where

V is the volume of NaOH used in the blank sample until the pink color persisted(mL)

N(NaOH is the normality of NaOH

W is the weight of the cooking oil sample(g).

NOTE :    FFA% <0.22.

RANCIDITY TEST :

In routine work apart from the free fatty acids determination, the analysis should include the determination of peroxide value, Kries test and ultra-violet absorption at 234 nm and 268 nm to establish rancidity.

PRESECENCE OF RANCIDITY INDICATION

·        5mL oil sample in flask or test tube

·        5mL conc HCl (hydrochloric acid).

·        0.1% phloroglucinol solution in diethyl ether.

·        Shake the 5ml sample with 5ml of 0.1% phloroglucinol solution in diethyl ether and then add 5mL conc HCl (hydrochloric acid).

·        Alow to stand for 10minutes.

·        A pink color indicates incipient rancidity means if pink color appear the rancidity present and if not appear than not present.

*Per oxide value (PV) :

This is an indication of the extent of oxidation suffered by an oil.

Reagents:

i)                    Acetic acid - chloroform solvent mixture (3: 2). Mix 3 volumes of glacial acetic acid with 2 volumes of chloroform.

ii)                    Freshly prepared saturated potassium iodide solution.

iii)                   0.I N and 0.0I N sodium thiosulphate solutions. Weigh 25 g of sodium thiosulphate and dissolve in 1 L of distilled water. Boil and cool, filter if necessary. Standardise against standard potassium dichromate solution.

iv)                   Starch solution - 1% water-soluble starch solution

 Procedure:

·        Weigh 5 g (±50 mg) sample into a 250 ml stoppered conical flask.

·        Add 30 ml acetic acid chloroform solvent mixture and swirl to dissolve.

·        Add 0.5 ml saturated potassium iodide solution with a mohr pipette.

·        Let stand for 1min in dark with occasional shaking, then add about 30 ml of water.

·        Slowly titrate the liberated iodine with 0.1 N sodium thiosulphate solution, with vigorous shaking until yellow colour is almost gone.

·        Using Add about 0.5 ml starch solution as indicator and continue titration shaking vigorously to release all I 2 from CHCl3 layer until blue colour disappears.

·        . If less than 0.5 ml of 0.1 N Na2S2O3 is used repeat using 0.01 N Na2S2O3. Conduct blank determination ( must be less than 0.1 ml 0.1 N Na2S2O3).

 OR

·        20ml sample of ghee/oil

·        20ml solvent mixture ( 2 vloume (100ml) of glacial acetic acid + 01 volume(50ml) of chloroform

·        10ml of 5% KI solution is given shake before heat

·        Heat for few minutes

·        Few drops of starch solution is added

·        Black color appear

·        In titration flask (burette ) there is Na2S2O3 5H₂O is used till the original (white) color appear

·        The volume used in titration is the Peroxide Value (initial reading  of burette –final reading)

OR

Calculation:

Peroxide value expressed as milli equivalent of peroxide oxygen per kg sample (meq/kg):

Peroxide value = Titre X N X 100/ Weight of the sample

Where,

Titre = ml of Sodium Thiosulphate used ( blank corrected)

N = Normality of sodium thiosulphate solution.

Fresh oils usually have peroxide values well below 10 meq/kg. A rancid taste often begins to be noticeable when the peroxide value is above 20 meq/kg. (between 20 – 40 meq / Kg). In interpreting such figures, however, it is necessary to take into account the particular oil or fat.

Mixture preparation for PV test

(1)              Solvent mixture

2 volume 100ml glacial acetic acid and 1 volume  50ml chloroform.

(2)              5% KI solution

100ml distill water and 5 gm of KI is taken

(3)               Starch solution

500ml distill water (heated) after cooling

Nasheshta or floor(atta) 1to2 spoon is added

(4)              Sodium thio sulfate  (Na2S2O3 5H₂O) solution

3.19gm of sodium thio sulfate

250ml distill water.

*Nickel test :

Reagents

·        Cocentrated HCL  

·        Saturated Bromine Water  

·        0.1% Dimethly glyoxime soluction in 95% alcohol /2% furfural solution in alcohol

·        Nickel Sulphate

Procedure

·        5ml sample oil and ghee.

·        Heat the sample on flame  and ventilation.

·        Some amount of Cocentrated HCL  is added to the sample.

·        Add few drops of furfural solution.

·        Shake the mixture  2 to 3 minutes.

·        Allow the mixture to settle down for about 2 minutes.

·        If pink color appear show that nickel is present.

*SOAP TEST /Saponification test for lipids

*  5mL sample in test tube (oil and ghee)

* Few drops of phenopthlene indicator  .

* Give heat to sample

* If pink color appears soap is present in the sample

               OR

Requirements

Glass ware, test tubes2 ,popette4, beaker 5

Apparatus

Heating mantle, test stand ,watch glass

Chemical

Ethanol NaOH/KaOH 20%w/v

Given sample oil ghee etc.

Procedure

·        Take 0.5ml/0.5gm(soild) of sample.

·        Add 1ml NaOH(20%w/v) to the sample.

·        Add 0.5ml ethanol to sample(ethanol is used to dissolve the fats in the sample).

·        Keep in boiling(hot @100C) water bath for 15 minutes.

·        Take out the test tube after 15 minutes.

·        Keep in test tube stand.

·        Than add 5ml of distil water to test tube.

·        Shake the test for few seconds.

·        The bubble for indicate the soaps.

 Determination of Colour :

Principle:

The method determines the colour of oils by comparison with Lovibond glasses of known colour characteristics. The colour is expressed as the sum total of the yellow and red slides used to match the colour of the oil in a cell of the specified size in the Lovibond Tintometer.

Apparatus:

(a) Lovibond Tintometer

 (b) Glass cells (cell size 0.25 inch, 0.5 inch. 1.0 inch, 5.25 inch or 1.0 cm, 2.0 cm, 5.0 cm as required)

Procedure:

Melt the sample if it is not already liquid and filter the oil through a filter paper to remove any impurities and traces of moisture.

Make sure sample is absolutely clear and free from turbidity

. Clean the glass cell of desired size with carbon tetrachloride and allow it to dry.

Fill it with the oil and place the cell in position in the tintometer.

Match the colour with sliding red, yellow and blue colours.

Report the colour of the oil in terms of Lovibond units as follows :-

Colour reading = (a Y + 5 b R) or ( a Y + 10 b R) in ( * cell)

Where, a = sum total of the various yellow slides (Y) used

 b = sum total of the various red (R) slides used

 Y + 5R is the mode of expressing the colour of light coloured oils; and

 Y + 10 R is for the dark-coloured oils

Although the yellow and red slides required to match the colour shade of an oil in a tintometer are assessed separately, it is found that to a certain extent these slides are mutually compensatory.. Consequently different workers may report different values for the yellow and red units for the same oil and the same workers may report different values for the yellow and red units for the oil examined at different times. To obviate such personal errors a composite factor is used for checking the colour comprising the sum total of the yellow(Y) units and 5 or 10 times the total of red units as specified for the oil or fat.

*Vitman test:

·        Take 100ml oil or ghee sample

·        Give heat for some time

·        Add  few drops of antiamonia trichloride (SBCl3) made in chloroform

·        Blue color indicate the presence of vitamin

Solution:

20%SBCl3 in 100ml chloroform.

*CHEMICAL USED IN EDIBLE OIL lab:

·        Acetic acid glacial (CH₃SO₄).

·        Sulphuric acid (H₂SO₄).

·        HCl.

·        Chloroform (CHCl₃).

·        Ethanol(C₂H₅OH).

·        Ammonium solution 32% (ammonium hydroxide).

·        Potassium hydroxide (pellet).

·        Sodium carbonate (Na₂CO₃) or natrium carbonate.

·         Sodium hydroxide ( NaOH) also called caustic soda (solid form).

·        Sodium thiosulfate (Na₂S₂O₃.5H₂O).

·        Phenolphthalein indicator.

·        Oxalic acid (C₂H₂O₄).

·        Pholoroglucinal( powder form).

·        Methyl orange (C₁₄H₁₄N₃NaO₃S).

·        Antimony trichloride (SbCl₃).

·        Methyl red (C₁₅H₁₅N₃O₂).

·        Potassium iodide (KI).

·        Sprit.

·        Vitamin ( A &D) (0.18ml/T).

·        Starch solution.

Di ethyl ether.

Da GHANI khan baba janat.program ADABI Taroon.(SM Riaz)

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                       Part 3, video below.

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ما د ګلونو د رنګونو دلداري کړې ده ما.شاعر : استاد صابر

Dost Muhammad dilsoz sb yadoona da saib shah sabir sara

مسلمانه چرته لاړي۔۔وه جانانه چرته لاړي۔۔ pashto poetry

process involved in edible/cooking oils industries.(refining process)

                                

                                        Edible Oil Processing

Raw martials :

·        RBD , SOYBEAN OIL , SUNFLOWER , RAPESEED OIL (RSO) ,PALM OIL

·        COOTEN SEED OIL , CANOLA ,OLIVE ,CORN OIL  ,PALM KERNOL OIL

·        COCONUT OIL ,GROUNDNUT OIL ,LINSEED OIL.

Introduction:

 Vegetable oils are an important part of the human diets world-wide and their production by extraction processes greatly increased in the last century due to higher request and consumption, the increase in world population and the progressive availability of more efficient process technologies and equipment. Edible oils are widely used by food industry due to their nutritional properties and their influence on the smell and taste of food products.

During the industrial production of vegetable oils and oil is assigned to oil that is not processed after being extracted from the animal or plant material. In order to become suitable for human consumption, crude oils are generally refined to remove the majority of these unwanted components to produce a stable product with desired color and a pleasant taste, with the least possible damages on desirable components and with the least possible loss of oil (Suliman et al., 2013). In general, refined oil is clear, odorless, and resistant to rancidity.

Process :

The traditional refining process of crude vegetable oils generally includes the steps of

* DEGUMMING,

*NEUTRALIZATION,

* BLEACHING AND

*DEODORIZATION.

Explanation of process :

The fats and oils obtained directly from

rendering or from the extraction of the oil seeds are:

termed “crude” fats and oils. Crude fats and oils contain

varying but relatively small amounts of naturally

occurring non-glyceride materials that are removed

through a series of processing steps. For example, crude

soybean oil may contain small amounts of protein, free

fatty acids, and phosphatides which must be removed

through subsequent processing to produce the desired

shortening and oil products. Similarly, meat fats may

contain some free fatty acids, water, and protein which

must be removed.

It should be pointed out, however, that not all of

the nonglyceride materials are undesirable elements.

Tocopherols, for example, perform the important

function of protecting the oils from oxidation and

provide vitamin E. Processing is carried out in such a

way as to control retention of these substances.

*Degumming

Crude oils having relatively high levels of

phosphatides (e.g., soybean oil) may be degummed

prior to refining to remove the majority of those

phospholipid compounds. The process generally

involves treating the crude oil with a limited amount of

water to hydrate the phosphatides and make them

separable by centrifugation. Soybean oil is the most

common oil to be degummed; the phospholipids are

often recovered and further processed to yield a variety

of lecithin products.

A relatively new process in the United States is

enzymatic degumming. An enzyme, phospholipase,

converts phospholipids, present in crude oil, into

lysophospholipids that can be removed by

centrifugation. Crude oil, pre-treated with a

combination of sodium hydroxide and citric acid, is

mixed with water and enzymes (phospholipase) by a

high shear mixer, creating a very stable emulsion. The emulsion allows the enzyme to react with the phospholipids, transforming them into water-soluble lysophospholipids. This emulsion is broken by centrifugation, separating the gums and phospholipids

from the oil. This process generates a better oil yield than traditional degumming/refining. Enzymatic degumming is currently not widely commercialized.

Refining/Neutralization :

The process of refining (sometimes referred to as “alkali refining”) generally is performed on vegetable

oils to reduce the free fatty acid content and to remove

other impurities such as phosphatides, proteinaceous,

and mucilaginous substances. By far the most important

and widespread method of refining is the treatment of

the fat or oil with an alkali solution. This results in a

large reduction of free fatty acids through their

conversion into high specific gravity soaps. Most

phosphatides and mucilaginous substances are soluble in

the oil only in an anhydrous form and upon hydration

with the caustic or other refining solution are readily

separated. Oils low in phosphatide content (palm and

coconut) may be physically refined (i.e., steam stripped)

to remove free fatty acids. After alkali refining, the fat or

oil is water-washed to remove residual soap.

Operation involve

·        The raw material is heated up to 45C.

·        After this check its FFA%

·        Then phosphoric acid is shower according to the batch almost 10 kg is given to 20Ton batch, its remove the gums.

·         Then caustic soda is shower according to the FFA% in the batch. Almost 5 to 8 inch are given. (20 to 22 baumi solution of caustic soda).

·        Then heat the batch up to  70 to 75C. 20kg of salt is given to 20 Ton batch

·        Then wash with hot water (several  wash till the soaps removed)

·        After the first wash wait for 2 to 3 hours to settle down the soaps and the soaps should be removed.

·        Again the batch heated  up to 95 to 98C and at 90C again give 20kg of salt after 3^rd wash.

·        Check the soaps content after every wash …..

Bleaching tank :

The term “bleaching” refers to the process for

removing color producing substances and for further

purifying the fat or oil. Normally, bleaching is

accomplished after the oil has been refined.

The usual method of bleaching is by adsorption

of the color producing substances on an adsorbent

material. Acid-activated bleaching earth or clay,

sometimes called bentonite, is the adsorbent material

that has been used most extensively.

This substance consists primarily of hydrated aluminum silicate.

Anhydrous silica gel and activated carbon also are used

as bleaching adsorbents to a limited extent.

Operation involve

After from neutralizer tank the batch goes to bleaching tank

·        First the sample is charged in bleacher.

·        Then dry the batch in bleacher for 10 to 15 mints.

·        Then according to the color the bleaching earth is given at 100C and 280 to 300mmHg pressure about 500kg is given to per 20 Ton batch.

·        The bleaching process remain for 45mints .

·        From bleacher the batch goes to filter where the color is checked.

·        After the filtration the batch goes to pre tank which taks about 2 to 3 hours.

Deodorization

Deodorization is a vacuum steam distillation

process for the purpose of removing trace constituents

that give rise to undesirable flavors, colors and odors in

fats and oils. Normally this process is accomplished after

refining and bleaching.

The deodorization of fats and oils is simply a

removal of the relatively volatile components from the

fat or oil using steam. This is feasible because of the

great differences in volatility between the substances that

give flavors, colors and odors to fats and oils and the

triglycerides. Deodorization is carried out under vacuum

to facilitate the removal of the volatile substances, to

avoid undue hydrolysis of the fat, and to make the most

efficient use of the steam.

Deodorization does not have any significant

effect upon the fatty acid composition of most fats or

oils. Depending upon the degree of unsaturation of the

oil being deodorized, small amounts of trans fatty acids

may be formed. In the case of vegetable oils, sufficient tocopherols remain in the finished oils after

deodorization to provide stability.

Operation involve

^·         At 110C about 2.5kg citric acid is given before entering to D tank

^·         From pre tank the batch goes to D tank. Where the batch is heated up to 150C.

^·         Than high vacuum valve is open to remove the moisture contents and dust particles  etc.

^·         The high vacuum is start for 4 hours , this process is carried in heating which means that the heater is on.

^·         At 130C the high vacuum is closed.

^·         At 80 to 90 C the cooling is start in the presence of low vacuum .

^·         When the batch is cool then its goes to final filter.

^·         In final filtration unit the flavors vitamins(A&D) are given.

Hydrogenation process

 This process is used to control the melting pointing of ghee.

It maintains the temperature from 35 to 37C.

It also gives granular stricture to ghee.In this process Nickel is used as a catalyst and hydrogen gas is passed for 2 to 3 hours at 140 to 145C.

Block diagram for whole process

Tanker => feed tank => neutralizer tank1=>  neutralizer tank2 =>  bleaching tank B1 => filter unit => pre tank => hydrogenation tank =>  cooler => neutralizer tank3 =>  cooler =>  bleaching tank2 (post tank) =>  filter unit => storage tank => deodorization tank D1(ghee) => cooler => deodorization tank D2 (oil) =>  cooler => polish filter => filling tank => filling section => cooling of packing => storage room.

For quality assessment involves in edible oil industries click here.