Quick Tests for some adulterants in the food

Quick Tests for some adulterants in the food

Name of Food Article	Adulterant	Simple Method for detection of Common Adulterants	Remarks
Oils and Fats	Argemone oil	Take some quantity of oil in a test tube. Add equal quantity of concentrated Nitric acid and shake carefully. Red to reddish brown color in lower (acid) layer would indicate the presence of Argemone oil
Milk	Water	The presence of water can be by putting a drop of milk on a polished slanting surface. The drop of pure milk either or flows lowly leaving a white trail behind it, whereas milk adulterated water will flow immediately without leaving a mark.
Milk	Starch	Add a few drops of tincture of Iodine or Iodine solution. Formation of blue colour indicates the presence of starch.	Iodine solution is easily available in the medical stores.
Milk	Urea	Take a teaspoon of milk in a test tube. Add ½ teaspoon of soybean or arhar powder. Mix up the contents thoroughly by shaking the test tube. After 5 minutes, dip a red litmus paper in it. Remove the paper after ½ a minute. A change in colour from red to blue indicates the presence of urea in the milk.
Milk	Vanaspati	Take 3 ml of milk in a test tube. Add 10 drops of hydrochloric acid. Mix up one teaspoonful of sugar. After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the milk.
Milk	Formalin	Take 10 ml of milk in a tests tube and add 5 ml of con sulphuric acid from the sides of the wall without shaking. If a violet or blue ring appears at the intersection of two layers then it shows presence of formalin.	Formalin enhances the life of milk and thus is added for preservationpurpose.
Milk	Synthetic milk	Synthetic milk has a bitter after taste, gives a soapy feeling on rubbing between the fingers and turns yellowish on heating
Milk	Synthetic milk -test for protein	The milk can easily be tested by Urease strips (available in the Medical stores) because Synthetic milk is devoid of protein.
Milk	Test for Glucose/inverted sugar	Milk does not contain glucose /invert sugar, if test for glucose with urease strip found positive. It means milk is adulterated.	If it is made synthetically by adding while colour water paint. Oils, alkali, urea and detergent etc. Glucose, inverted sugar syrup is added in milk to increase the consistency and test.
Ghee, cottage cheese, condensed milk, khoa, milk powder etc,	Coal Tar Dyes	Add 5 ml of dil. H2SO4 or conc. HCL to one teaspoon full of melted sample in a test tube. Shake well. Pink colour (in case of H2SO4) or crimson colour (in case of HCl) indicates coal tar dyes. If HCl does not give colour dilute it with water to get the colour.
Sweet Curd	Vanaspati	Take1 teaspoon full of curd in a test tube. Add 10 drops of hydrochloric acid. Mix up the contents shaking the test tube gently. After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the curd.
Rabdi	Blotting paper	Take a teaspoon of rabri in a test tube. Add 3 ml of hydrochloric acid and 3 ml of distilled water. Stir the content with a glass rod. Remove the rod and examine. Presence of fine fibres to the glass rod will indicate the presence of blotting paper in rabri.
Khoa and its products	Starch	Boil a small quantity of sample with some water, cool and add -a few drops of Iodine solution. Formation of blue colour indicates the presence of starch .
Chhana or Paneer	Starch	Boil a small quantity of sample with some water, cool and add a few drops of Iodine solution. Formation of blue colour indicates the presence of starch.
Ghee	Vanaspathy or Margarine	Take about one tea spoon full of melted sample of Ghee with equal quantity of concentrated Hydrochloric acid in a stoppered test tube and add to it a pinch of sugar. Shake for one minute and let it for five minutes. Appearance of crimson colour in lower (acid) of Vanaspati or Margarine.	The test is specific for seasame oil which is compulsorily added to Vanaspati and Mrgarine. Some coal tar colours also give a positive test. If the test is positive i.e. red colour develops only by adding strong Hydrochloric acid (without adding crystals of sugar) then the sample is adulterated with coal tar dye. If the crimson or red colour develops after adding and shaking with sugar, then alone Vanaspati or Margarine is present
Ghee	Mashed Potatoes, Sweet Potatoes and other starches.	The presence of mashed potatoes and sweet potatoes in a sample of ghee can easily be detected by adding a few drops of Iodine, which is brownish in colour turns to blue if mashed potatoes/sweet potatoes/other starches are present.
Butter	Vanaspati or Margarine	Take about one teaspoon full of melted sample of butter with equal quantity of concentrated Hydrochloric acid in a stoppered test tube and add to it a pinch of sugar. Shake for one minute and let it for five minutes. Appearance of crimson colour in lower (acid) of Vanaspati or Margarine.	The test is specific for seasame oil which is compulsorily added to Vanaspati and Mrgarine. Some coal tar colours also give a positive test. If the test is positive i.e. red colour develops only by adding strong Hydrochloric acid (without adding crystals of sugar) then the sample is adulterated with coal tar dye. If the crimson or red colour develops after adding and shaking with sugar, then alone Vanaspati or Margarine is present
Edible oil	Prohibited colour	Take 20 drops of the edible oil in each of the four test tubes. Make 3 different solutions, mixing up 1 part of distilled water, 3 parts of distilled water and 4 parts of distilled water. Add 2 ml of each solution in each of the test tubes and add 2 ml of hydrochloric acid in the mixture of any tube, indicates the presence of prohibited colour in the edible oil..
Coconut oil	Any other oil	Place a small bottle of oil in refrigerator. Coconut oil solidifies leaving the adulterant as a Separate layer.
Whole spices	Dirt, dust, straw, insect, damaged seeds, other seeds, rodent hair and excrete	These can be examined visually
Black pepper	Papaya seeds	Papaya seeds can be separated out from pepper as they are shrunken, oval in shape and greenish brown or brownish black in colour.
Black pepper	Light black pepper	Float the sample of black pepper in alcohol (rectified spirit). The black pepper berries sink while the papaya seeds and light black pepper float.
Black pepper	Coated with mineral oil	Black pepper coated with mineral oil gives Kerosene like smell.
Cloves	Volatile oil extracted (exhausted cloves)	Exhausted cloves can be identified by its small size and shrunken appearance. The characteristic pungent of genuine cloves is less pronounced in exhausted cloves.
Mustard seed	Argemone seed	Mustard seeds have a smooth surface The argemone seed have grainy and rough surface and are black and hence can be separated out by close examination. When Mustard seed is pressed inside it is yellow while for Argemone seed it is white	Use magnifying glass for identification
Powdered spices	Added starch	Add a few drops of tincture of Iodine or Iodine solution. Indication of blue colour shows the presence of starch.	Iodine test for added starch is not applicable for turmeric powder.
Turmeric powder	Coloured saw dust	Take a tea spoon full of turmeric powder in a test tube. Add a few drops of concentrated Hydrochloric acid. Instant appearance of pink colour which disappears on dilution with water shows the presence of turmeric If the colour persists, metanil yellow (an artificial colour) a now permitted coal tar colour is present.	This test is only for Metanil yellow .
Turmeric powder	Chalk powder or yellow soap stone powder	Take a small quantity of turmeric powder in a test tube containing small quantity of water. Add a few drops of concentrated Hydrochloric acid, effervescence (give off bubbles) will indicate the presence of chalk or yellow soap stone powder .
Chillies powder	Brick powder, salt powder or talc, powder	Take a tea spoon full of chillies powder in a glass of water. Coloured water extract will show the presence of artificial colour. Any grittiness that may be felt on rubbing the sediment at the bottom of glass confirms the presence of brick powder/sand, soapy and smooth touch of the white residue at the bottom indicates the presence of soap stone. To a little powder of chilli add small amount of conc HCl and mix to the consistency of paste, dip the rear end of the match stick into the paste and hold over the flame, brick red flame colour due to the presence of calcium slats in brick powder.	This test is only for earthy material
Chillies powder	Artificial colours	Sprinkle the chilli powder on a glass of water. Artificial colorants descend as coloured streaks.
Chillies powder	Water soluble coal tar colour	Water soluble artificial colour can be detected by sprinkling a small quantity of chillies or turmeric powder on the surface of water contained in a glass tumbler. The water soluble colour will immediately start descending in colour streaks
Asafoetida (Hing)	Soap stone or other earthy material	Shake little portion of the sample with water and allow to settle. Soap stone or other earthy mailer will settle down at the bottom.	In compounded asafoetida due to presence of starch, a slight turbid solution may be produced. However, this will settle down after keeping
Asafoetida (Hing)	Starch	Add tincture of iodine, appearance of blue colour shows the presence of starch.	Compound of asafoetida contains starch which is declared on the label. This test is not applicable for compound asafoetida.
Asafoetida (Hing)	Foreign resin	Burn on a spoon, if the sample burns like camphor, it indicates the sample is pure.	Pure hing burns like aromatic camphor
Spices	Powdered bran and saw dust	Sprinkle on water surface. Powdered bran and sawdust float on the surface.
Cinnamon	Cassia bark	Cinnamon barks are very thin and can be rolled. It can be rolled around a pencil or pen. It has a distinct smell. Whereas cassia ark comprise of several layers in between the rough outer and inner most smooth layers. On examination of the ark loosely, a clear distinction can be made.
Cumin seeds	Grass seeds coloured with charcoal dust	Rub the cumin seeds on palms. If palms turn black adulteration is indicated.
Green chilli and green vegetables.	Malachite green	Take a cotton piece soaked in liquid paraffin and rub the outer green surface of a small part of green vegetable. If the cotton turns, green, we can say the vegetable is adulterated with malachite green.
Green peas	Artificially coloured	Take a little amount of green peas in a 250 ml beaker add water to it and mix well. Let it stand for half an hour. Clear separation of colour in water indicates adulteration.
Saffron	Dried tendrils of maizecob	Genuine saffron will not break easily like artificial. Artificial saffron is prepared by soaking maize cob in sugar and colouring it with coal tar colour. The colour dissolves in water if artificially coloured. A bit of pure saffron when allowed to dissolved in water will continue to give its saffron colour so long as it lasts.

OLIVE OIL

OLIVE OIL IS A FAT OBTAINED FROM THE OLIVE, A TRADITIONAL TREE CROP OF THE MEDITERRANEAN BASIN. THE OIL IS PRODUCED BY PRESSING WHOLE OLIVES AND IS COMMONLY USED IN COOKING, COSMETICS, PHARMACEUTICALS  AND SOAPS, AND AS A FUEL FOR TRADITIONAL OIL LAMPS. OLIVE OIL IS USED THROUGHOUT THE WORLD AND IS OFTEN ASSOCIATED WITH MEDITERRANEAN COUNTRIES.

COMPOSITION:-

OLIVE OIL SEED NOT EXCEED 3% OF THE WEIGHT OF THE FRUIT. AT FULLY MATURITY, THE MESOCARP CONTAIN 6-10% SOLUBLE SOLID AND15-40% OE EVEN MORE OIL, DEPENDING ON VARIETY. THE PERICARP CONTAINS 96-98% OF THE TOTAL AMOUNT OF OIL, WHILE THE REMAINING 2-4% OF THE OIL IS IN THE KERNEL.

EXTRACTION OF OIL:-

OIL IS EXTRACTED TRADITIONALLY BY SIMPLE EQUIPMENT INVOLVING CRUSHING, PRESSING AND SEPARATION OF OIL FROM THE LIQUOR. IT IS NOW BEING REPLACED BY MODERN MECHANICAL EQUIPMENT OF WIDELY VARIEING  DESIGNS EITHER AS SEPARATE UNIT OR COMBINED AS A SINGLE STAGE PROCESS.

THE OIL EXTRACTION OBTAINED FROM SOUND FRUIT BY PRESSING WITHOUT FURTHER TREATMENT IS CALLED VIRGIN OIL. AFTER THE FIRST PRESSING, THE RESIDUAL PULP IS STILL RICH IN OIL AND IS USUALLY RECRUSHED AND REPRESSED WITH OR WITHOUT THE ADDITION OF WARM WATER.

OIL OBTAINED FROM THE SECONDARY PRESSING TENDS TO HAVE A MORE INTENSE COLOUR AND HIGHER ACID CONTENT, AS WELL AS A WEAK AROMA. VIRGIN OIL IS FURTHER SUBJECTED TO REFINING TREATMENT AND WINTERIZATION, THIS HELPS IN REMOVING ACID, COLOR AND ODOUR. THEOIL SO OBTAINED IS CALLED REFINED OLIVE OIL, WHICH IS LARGELY USED FOR MIXING WITH THE FIRST EXTRACTION TO PRODUCE EDIBLE GRADE. THE REMAINING PRESS CAKE STILL RETAIN ABOUT 4-5% OIL BUT MORE THAN 50% OF THE TOTAL OIL IN THE CAKE CAN BE OBTAINED IN SINGLE STEP BY DIRECT EXTRACTION INA CONTINUOUS CENTRIFUGATION SYSTEM, AFTER ADDING ABOUT 1% NaCO3 BY WEIGHT OF CAKE.

THE EXTRACTION WITH HEXANE RESULT IN AN OIL WITH HIGHER ACIDITY AND MOISTURE CONTENT BUT A LOW PERCENTAGE IMPURITIES.

USES:-

THE USE OF OLIVE OIL, WHETHER IN MEDIUM AS A SOURCE OF NUTRITION HAS ITS ROOTS IN ANCIENT HISTORY.

THE OIL IS USED LARGELY FOR CULINARY PURPOSE IN WOOL COMBING, THE MANUFACTURE OF TRILET PREPARATION AND IN THE PHARMACEUTICAL INDUSTRY.

BESIDES IT PHYSIOLOGICAL ADVANTAGES IS BEING RAPIDLY AND COMPLETELY DIGESTED, THE OIL ALSO HAS CLINICAL IMPORTANCE . Eg- ANTI-ULCER ACTIVITY, EFFECTIVENESS IN COMBATING GALL BLADDER DISEASE AND LOWERING PLASMA CHOLESTEROL LEVEL.

OIL-SEEDS

OIL-SEEDS COMPRISES AN ESSENTIAL PART OF OUR COUNTRIES ECONOMY. INDIA OCCUPIES A PROMINENT POSITION IN THE WORLD. BOTH REGARD TO AVERAGE AND PRODUCTION BY PRODUCING AN AVERAGE 20 MILLION TONNES OF OIL-SEEDS EVERY YEAR.

INDIA IMPARTS OUT OF WORLD RS. 12000 CRORES EVERY YEAR. THE PER CAPITA AVAILABILITY OF OIL AND FAT IN INDIA IS ABOUT 5KG WHICH IS FAR BELOW THAN RECOMMENDED AVERAGE REQUIREMENT OF 18KG. THE IMPROVEMENT IN OIL MILLING TECHNOLOGY CAN CERTAINLY CONTRIBUTE TO INCREASE AVAILABILITY OF EDIBLE OILS.

THE MAJOR OIL SEEDS ARE- OLIVE SEEDS, SUNFLOWER, COTTON SEEDS, GROUNDNUT, COCONUT AND MUSTARD SEED ETC.

OIL EXTRACTION:-

TO SUIT SPECIFIC CONDITIONS ONE OF THE THREE BASIC METHODS CAN BE MODIFIED OR COMBINED TO OBTAIN OIL FROM OIL SEEDS. COMMERCIALLY BASIC METHODS ARE-

1- BASIC HYDROLIC PRESSING:-

IN THIS OIL IS EXPRESSED BY HYDROLIC PRESSURE FROM MASS OF OIL BEARING MATERIAL.

2- CONTINUOUS MECHANICAL PRESSING:-

IN THIS THE OIL BEARING MATERIAL IS SQUEEZED THROUGH A TAPOURING OUTLET, BEING EXPRESSED BY THE INCREASING PRESSURE.

3- SOLVENT EXTRACTION:-

IN THIS OIL BEARING MATERIAL IS TAKE INTO SOLUTION WITH A SOLVENT. THE SOLUTION IS SEPARATED FROM INSOLUBLE RESIDUE AND OIL RECOVERED FROM THE SOLVENT SOLUTION. THE COMBINATION OF THESE PROCESS IS COMMERCIAL.

OPERATIONS ARE CONTINUOUS, MECHANICAL PRESSING (EXPELLING) WITH CONTINUOUS SOLVENT EXTRACTION AND BATCH HYDRAULIC PRESSING AND SOLVENT EXTRACTION WITH THE EXCEPTION OF COASTER WHICH REQUIRES SPECIAL TREATMENT AND EQUIPMENT CLEANING PROCEDURES AND OTHER OIL SEEDS CAN BE SIMILARLY PROCESSED.

WHEAT

WHEAT

NEXT TO RICE, WHEAT IS THE SECOND LARGEST IMPORTANT FOOD GRAIN OF INDIA.NEARLY  1/10 OF CROPPED AREA IS DEVOTED TO WHEAT. THE COUNTRIES PRODUCING MORE WHEAT THAN INDIA ARE- USA AND CHINA OVER 83% OF THE COUNTRIES. TOTAL WHEAT OUTPUT COMES FROM UP, PUNJAB, BIHAR, MP, HARYANA AND RAJASTHAN. DURING 1890-91 IT IS OCCUPIED AN AREA OF 240 LAKH TONNES OF WHEAT GRAIN.

STRUCTURE OF WHEAT GRAIN:-

THE GRAIN OF WHEAT CONSIST OF AN OUTER COVERING THE PERICARP AND TESTA WHICH IS HARD AND INDIGESTIBLE, AN ALLEURONE LAYER, WHICH CONTAINS A HIGHER PROPORTION OF PROTEIN THAN FLOUR, AN EMBRYO ATTACKED TO A SMALL STRUCTURE, THE SCHUTELUM AT THE LAYER END OF GRAIN AND FINALLY THE ENDOSPERM COMPERISING OF 85% OF THE WHOLE GRAIN FROM WHICH THE FLOUR IS DERIVED.

IT IS IMPORATANT TO MENTION THAT THE MILLING OF WHEAT IS A PHYSICAL PROCESS. THE COMPOSITION OF BRAN, EMBRYO AND ENDOSPERM IN WHEAT IS GIVEN BELOW-

BRAN – 12%

GERM – 3%

ENDOSPERM – 85%

COMPOSITION OF WHEAT:-

MOISTURE – 10-13%

CARBOHYDRATE – 69%

PROTEIN – 8-13%

FAT – 2%

FIBRE – 3%

QUALITY TEST FOR WHEAT:-

1)- TEST WEIGHT:-

IT IS MOST WIDELY USED CRITERIA FOR FINDING WHEAT QUALITY FACTORS AFFECTING WEIGHT IN WHEAT.

SHAPE

SIZE

DENSITY

MOISTURE CONTENT

IN INDIA THE WEIGHT IS MEASURED IN TERMS OF KG/HECTO LITRE.

TEST WEIGHT= WEIGHT/UNIT VOLUME

VOLUME IS MEASURED IN TERMS OF WINCHESTER BUSHEL.

1 KG HECTO LITRE= 1 WINCHESTER BUSHEL * 1.287

2)- THOUSAND KERNEL WEIGHT:-

IT IS DEFINED AS THE WEIGHT OF 1000 KERNELS OF WHEAT. THE PROPERTY GIVEN AN IDEA ABOUT THE SOUNDNESS OF WHEAT.

PROCEDURE:-

RANDOMLY SELECT 1000 KERNELS FROM THE GIVEN SAMPLE WEIGH THEM AND WEIGHT BY 100. TAKE ATLEAST 5 READING AND THEN TAKE AVERAGE.

3)- GRAIN HARDNESS:-

HARDNESS CAN BE MEASURED BY GRAIN HARDNESS OR BY PEARLING INDEX. HARD THE WHEAT MEANS CONTAIN MORE PROTEIN CONTENT.

HARDNESS α PROTEIN CONTENT

WHEAT MILLING:-

THE WHEAT MILLING PROCESS CONSISTS OF 5 MAIN PRODUCTS.

1-       RECEPTION AND STORAGE OF WHEAT.

2-      CLEANING

3-      TEMPRING OR CONDITIONING

4-      MILLING OF WHEAT INTO FLOUR

5-      STORAGE OF FINISHED PRODUCTS.

1)-  RECEPTION AND STORAGE OF WHEAT:-

WHEAT SELECTION IS IMPORTANT TO THE FLOUR MILLER WITHOUT SOUND WHEAT (DRY UNSPOTTED AND FREE FROM CONTAMINATION) THE MILLER IS PRWERLESS TO PRODUCE ADEQUATE PRODUCED.

WHEAT IS STORED AT MILL IN LARGE CONCRETE. BEFORE STORAGE THE WHEAT IS UNDERGOES A PRELIMINARY CLEANING AND DRYING TO REMOVE THE GROSS IMPURITIES AND FOREIGN MATERIAL AND TO REMOVE MOISTURE IF NECESSARY SO THAT THE WHEAT CAN BE STORED WITHOUT HEATING.

WHEAT MUST BE KEPT DRY NORMALLY NOT HIGHER THAN 14.5% MOISTURE.

2)- CLEANING:-

SINCE THE GRAIN IMPURITIES HAVE ALREADY BEEN REMOVED AT THE STORAGE LINES THE TECHNIQUES USED IN THE CLEANING HOUSE IS MORE REFINED. HERE, THE WHEAT IS CLEANED BY REMOVING LOOSE FOREIGN MATERIAL AND DIRT, ADHERING TO SURFACE OF THE GRAIN. WHEAT IS WEGHED AS IT ENTERS THE CLEANING HOUSE AND THERE FORE GOES THROUGH A SEPARATOR, WHICH IS SET TO REMOVE FINE IMPURITIES AND DUST, SMALL PIECES OF STICKS, STONES, SAND AND DUST ARE SHIFTED AWAY AND LIGHT IMPURITIES SUCH AS WHEAT CHOFF ARE REMOVED BY AIR CURRENT. AFTER THIS WHEAT IPASSES OVER MAGNETIC SEPARATOR TO RAMOVE BITS OF ADVENTITIOUS METAL WHICH MAY HAVE FORMED THEIR WAY INTO THE WHEAT MIX. NEXT STEP OF DIRT FROM SURFACE OF WHEAT BY SCORING.

THE FINAL CLEANING STEP IS A WATERMARK. THE WATER DISSOLVES THE DIRT AND PERMITS STONES AND BITS OF MEATAL TO SINK.

3)- TEMPERING OR CONDITIONING:-

TEMPERING REFERS TO THE ADDITION OF WATER TO THE BRAN AND ENDOSPERM. THE BRAN BECOMES TOUGH AND RUBBERY WHILE THE ENDOSPERM BECOME LESS VITEROUS. THIS IMPROVES MILLING EFFICIENCY.

TEMPERING INVOLVES ADDING WATER TO VOICE THE MAOISTURE TO 15-18% FOR HARD WHEAT AND 14.5-17% FOR SOFT WHEAT AND ALLOWING WHEAT TO BE INTEMPERING BINS FOR PERIOD OF 18-72 HOURS. DURING THIS TIME THE WATER ENTERS THE BRAN AND DIFFUSE INWARDS CAUSING. THE BRAN TO LOOSE ITS VIABLE CHARACTERISTICS AND TO BECOME LEATHERY IN TEXTURE.

CONDITIONING IN CONTRAST TO TEMPERING ALWAYS INVOLVES THE USE OF WHEAT SINCE QUICK DIFFUSION OF WATER INTO ENDOSPERM AS WELL AS THE BRAN IS THE PURPOSE. WHEAT CONDITIONERS INVOLVE  FOR SECTIONS. THE FIRST SECTION HEATS THE WHEAT TO THE PROPER TEMPERATURE (AS HEAT AFFECTS QUALITY OF GLUTEN, SO NORMALLY TEMPERATURE OF 45⁰C CANNOT BE EXCEES).

THE SECOND SECTION ADDS MOISTURE AND HOLDS THE WHEAT FOR THE PROPER TEMPERATURE. THE THIRD SECTION COOLS THW WHEAT AT ROOM TEMPERATURE AND THE FINAL SECTION ROVIDES A HOLDING BIN WHERE THE MOISTURE IN WHEAT IS ALLOWED TO EQUILIBRATE BEFORE MILLING.

4)- WHEAT GRINDING:-

THE GRINDING OF WHEAT IS DONE BETWEEN PAIRS OF ROLLS SINCE THEY ARE MOVING IN OPPOSITE DIRECTIONS MOVING AT DIFFERENT RATE OF SPEED ONE FROM THE OTHER AND SET WITH AN APPRECIABLE GAP BETWEEN THEM, DO NOT GRIND THE WHEAT PRIMARILY BY CRUSHING THE REDUCTION OF WHEAT SIZE BY SHEARING FORCES WHICH BECAUSE OF THE SET OF THE ROLL RUNS ABOUT 25 TIMES FASTER THAN THE SLOWER ONE AND AT SPEEDS FROM 250-450 RPM.

HERE, THE ROLLER MILLING AREA IS DIVIDED INTO 2 SECTIONS, THE BREAK SECTION AND THE REDUCTION SECTION. IN THE FIRST SYSTEM, THE BRAN IS BROKEN OPEN AND THE ENDOSPERM IS MILLED AWAY. ROLLS IN SECOND SYSTEM ARE REDUCTION ROLLS WHICH ARE SIMILAR TO THE BREAK ROLLS EXCEPT THAT THEIR SURFACES IS NORMALLY SMOOTH RATHER THAN CORRUPTED. AFTER EACH REDUCTION OF ENDOSPERM THE FLOUR IS SHIFTED AWAY FROM THE UNDERGROUND ENDOSPERM CHANNELS WHICH ARE RETURN TO THE SECOND ROLL AND PROCESS IS REPEATED.

5)- STORAGE OF FINISHED PRODUCT:-

NOW ATLEAST FLOUR IS PACKAGED IN WELL MANNER ANS STORE IN STORE HOUSE.

PHYSIOCHEMICAL TEST OF WHEAT FLOUR:-

THE GENERAL TEST WHICH ARE CONDUCTED TO SPECIFY THE WHEAT FLOUR ARE-

1- MOISTURE CIONTENT

2- PROTEIN

3- FIBRE

4- COLOUR

5- GLUTEN CONTENT

6- AMYLOSE ACTIVITY

7- SEDIMENTATION VALUE

8- POLSHENKE VALUE

USE OF FLOUR:-

1- WHEAT FLOUR IS USED TO PREPARE VARIOUS WHEAT PRODUCTS SUCH AS BREAD, COOKIE, BISCUITS, CRUCKER, CAKES, PARTY ETC.

2- FOR MAKING READY TO EATEN EASY TO MAKE OR OTHER CONVENIENT FOODS.

RICE GRAIN

RICE GRAIN- QUALITY, TEST, MILLING AND 

USES OF RICE

STRUCTURE OF RICE

THE RICE GRAIN CONSIST OF AN OUTER PROTECTIVE COVERING, THE HULL (HUSK) AND THE EDIBLE RICE CARYOPSIS OF FRUIT (BROWN, CARGO, DEHULLED OR DEHUSKED RICE). BROWN RICE CONSISTS OF THE OUTER LAYERS OF PERICARP SEED COAT AND NUCELLUS, THE GERM OR EMBRYO WHICH ARE MATERNAL TISSUE AND THE ENDOSPERM. THE ENDOSPERM CONSISTS OF THE ALEURSOME LAYER, THE SUBALLEURONE LAYER AND THE STARCHY  OR INNER ENDOSPERM PIGMENT IS CONFINED TO PERICARP. THE ALLEURONE LAYER ENCLOSES THE EMBRYO.

THE INEDIBLE HULL CONSTITUTE 16-20% (MEAN 20%) OF THE ROUGH RICE WEIGHT. BROWN RICE CONSISTS OF 1-2% PERICARP, 4-5% ALLEURONE, NUCELLUS AND SEED COAT, 1% EMBRYO, 2% SCUTELLUM AND 90-91% ENDOSPERM. THE ALLEURONE AND EMBRYO CELLS ARE RICH IN PROTEIN BODIES CONTAINING GLOBOIDS AND PHYTATE BODIES AND IN LIPID BODIES.

THE ENDOSPERM CELLS ARE THIN WALLED AND PACKED WITH AMYLOPLASTS CONTAINING POLYHEDRAL COMPOUND. STARCH GRANULES ABOUT 3-9 MICRO METER IN SIZE. PROTEIN OCCURS MAINLY IN THE FORM OF LARGE(1-2 MICRO METER) AND SMALL (0.5-0.8 MICROMETER) SPHERICAL; PROTEIN BODIES AND CRYSTALLINE PROTEIN BODIES SPHERICAL PROTEIN BODIES ARE RICH IN PROLAMINE (ALCOHOL SOLUBLE PROTEIN) & CRYSTALLINE PROTEIN BODIES ARE RICH IN GLUTELIN (ALKALI SOLUBLE PROTEIN), SPHEROSOMES ARE PRESENT IN SUBALLEURONE OR TWO OUTERMOST CELL LAYER.

VARIOUS PARAMETERS USED TO JUDGE THE QUALITY OF RICE ARE:-

·          

      ALKALI SCORE

·         WATER UPTAKE

·         COOKING QUALITY

·         DIMENSIONS

·         COLOR

·         1000 KERNEL WEIGHT

·         BULK DENSITY

·         TRUE DENSITY

·         PERCENT POROSITY

·         SURFACE AREA

ALKALI SCORE:-

IT HELPS IN DETERMINING THE APPROXIMATE GELATINIZATION TEMPERATURE OF THE GIVEN VARIETY OF RICE. IN THIS 8 OR 10 KERNALS ARE PLACED IN KOH SOLUTION, FOR 24 HOURS OR OVERNIGHT. KOH TRIES TO BREAK THE KERNEL. OBSERVED HOW MANY  KERNELS ARE DISINTEGRATED & CALCULATE PERCENT DISINTEGRATION. IF DISINTEGRATION IS MORE , GELATINIZATION TEMPERATURE IS LESS & RICE IS OF LOW QUALITY.

PROCEDURE:-

·         TAKE 8 RICE KERNALS AND KEEP THEM SYMMETRICALLY ON THE PETRIPLATE.

·         ADD 1.8% KOH SOLUTION ENOUGH TO COVER THE KERNELS OR IMMERSE THE KERNEL.

·         PLACE THE COVER OF PETRIPLATE.

·         KEEP IT FOR OVERNIGHT.

·         NOTE DOWN THE MICRO-ORGANISMS OF KERNELS DISINTEGRATED.

FORMULA USED:-

ALKALI SCORE= NUMBER OF KERNEL DISINTEGRATED/TOTAL NUMBER OF KERNELS*100

GELATINIZATION TEPERATURE α 1/ALKALI SCORE

COOKING QUALITY:-

COOKING QUALITY REVEALS THE QUALITY DEPENDING UPON THE TYPE OF KERNELS. COOKING QUALITY IS DEFINED W.R.T MANY CHARACTERISTICS SUCH AS TIME OF COOKING, SWELLING CHARACTERISTICS, COLOR, PASTYNESS. RAW RICE TAKES 15-20 MINUTES TO BECOME FULLY COOK IN BOILING WATER WHEREAS PARBOILED RICE TAKE 30 MINUTES FOR SOME DEGREE OF SOFTNESS. RAW RICE COOKED BEYOND 20 MINUTE BECOME PASTY.

PROCEDURE:-

·        SIX BEAKERS HAVING 50 ML OF WATER ARE TAKEN AND BOILED OVERFLAME.

·         WHEN WATER STARTS BOILING ADD 2 GM OF RICE IN EACH.

·         WITHDRAW IT FROM FLAME AFTER TIME INTERVALS OF 4, 8, 12, 20, 22, AND 24.

·         NOTE THE NATURE OF THE RICE KERNELS.

WATER UPTAKE:-

WATER UPTAKE IS DEFINED AS GRAMS OF WATER OBSERVED BY ONE GM OF RICE. IT IS A PARAMETER USE TO FIND OUT COOKING QUALITY.

PROCEDURE:-

·         TAKE 4 TEST TUBES HAVING 20 ML OF WATER IN EACH.

·         IMMERSE IT IN WATER BOTH TILL THE TEMPERATURE OF THE TEST TUBE WATER REACHES TO 80⁰C.

·         ADD 2 GM OF RICE IN EACH TEST TUBE AND KEEP IT FOR 25 MINUTES.

·         TEST TUBES ARE COOLED AND EXCESS OF WATER ID DRAINED.

·         WEIGH THE RICE TO CALCULATE WATER ABSORBED.

FORMULA USED:-

WATER UPTAKE= FINAL WEIGHT- INITIUAL WEIGHT/INITIAL WEIGHT*100

% WATER ABSORBED= GM OF H2O ABSORBED/GM OF RICE*100

DIMENSIONS:-

THIS INCLUDES LENGTH AND BREADTH OF RICE. DIMENSIONS GIVE AN IDEA ABOUT THE QUALITY OF RICE. LONG AND THIN RICE IS OF GOOD QUALITY AS COMPARED TO THICK AND SMALL RICE.

PROCEDURE:-

LENGTH:-

FOR FINDING THE LENGTH WE USE VERNIER CALLIPER. TAKE 10 KERNELS FROM EACH OF THE SAMPLE AND FIND THE LENGTH THEN TAKE THE AVERAGE. THE LEAST COUNT OF VERNIER CALLIPER IS 0.1.

BREADTH:-

FOR FINDING THIS SCREW GUAGE IS USE. TAKE 10 KERNELS FROM EACH SAMPLE AND THEN TAKE THE AVERAGE. THE LEAST COUNT OF SCREW GUAGE IS 0.001.

COLOUR:-

COLOR IS A HERIDATORY NFACTOR AND DEPENDS UPON THE TYPE OF PROCESSING AND DEGREE OF MILLING COLOR OF RICE IS WHITE TO YELLOWISH.

1000 KERNEL WEIGHT:-

IT IS DEFINED AS THE WEIGHT OF 1000 KERNELS OF RICE. THE PROPERTY GIVES AN IDEA ABOUT THE SOUNDNESS OF RICE.

PROCEDURE:-

RANDOMLY SELECT 1000 KERNELS FROM THE GIVEN SAMPLE WEIGH THEM AND THE WEIGHT BY 100. TAKE ATLEAST 5 READINGS AND THEN TAKE AVERAGE.

BULK DENSITY:-

BULK DENSITY IS A WEIGHT OF KNOWN QUANTITY OF CEREALS. IT GIVES THE SOUNDNESS OF GRAIN WITH THE HELP OF BULK DENSITY, ONE CAN CALCULATE THE SURFACE AREA REQUIRED TO STORE A PARTICULAR OF RICE.

PROCEDURE:-

TAKE A MEASURING CYLINDER WITH THE RICE BY FIRST FILLING THE CYLINDER UPTO 25 ML, THEN TO 50 ML AND ATLEAST 75 ML AS THE DENSITY IS MASS/VOLUME. PUTTING THE  VALUE IN THE FORMULA FIND THE VALUES FOR BULK DENSITY.

TRUE DENSITY:-

TRUE DENSITY IS FOUND BY DIPPING 10 GM OF SAMPLE TO 50 ML TOULENE SOLUTION.

FORMULA USED:-

TRUE DENSITY= WEIGHT OF SAMPLE/ FINAL VOLUME-INITIAL VOLUME

% POROSITY:-

IT IS CALCULATED BY USING TRUE DENSITY AND BULK DENSITY.

FORMULA USED:-

% POROSITY= TRUE DENSITY- BULK DENSITY/ TRUE DENSITY* 100

MILLING OF RICE:-

STEPS OF RICE MILLING:-

RECEIVING:-

ROUGH RICE (PADDY RICE) WHICH CONSISTSOF 50% OR MORE KERNELS FROM WHICH THE HULL HAVE NOT BEEN REMOVED IS RECEIVED AT RICE MILL IN BULK OR SACKS.

DRY CLEANING:-

INCOMING RECEIPTS MUST BE CAREFULLY SORTED SO THAT DIFFERENT GRADES, VARIETIES AND GRAIN SIZES CAN BE PROCESSED IN A SEPARATE LOTS. PROCESSING MACHIENERY IS ADJUSTABLE SO THAT VARYING CHARACTERISTICS OF THE INCOMING MATERIAL CAN BE ACCOMODATED IN A SERIES OF MECHANICAL AND PNEUMATIC OPERATIONS CHAFF, LUMPS OF MUD AND DIRT, FOREIGNSUBSTANCES, GRAVEL, WEEDSEEDS AND ANY OTHER DEBSIS LEFT OVER FROM PRIOR THRESHING ARE REMOVED.

SHEILLING:-

THE RICE IS PASSED THROUGH SHELLER FOR THE REMOVAL OF HULLS. ALTHOUGH HULLING STONES MAY BE USED, MOST (MODERN FACILITIES), THE SHELLER CONSISTS OF PAIRED RUBBER ROLLS WHICH TURN AT DIFFERENT SPUDS SO THAT AS THE KENELS PASS THROUGH THE MACHINE A TEARING OR PULLING AND SLIGHT CRUSHING (CRACKING) ACTION TAKES PLACE. SHELLERS ARE USED IN TANDOM WITH RECYCLING BETWEEN MACHINES TO EFFECT FINAL QUALITY CONTROL. IN THESE OPERATIONS AND THROUGH OUT ALL MILLING OPERATIONS, A MAJOR CONCERN IS THAT OF AVOIDING KERNEL BREAKAGE. AFTER HULLING THE PRODUCT IS KNOWN AS BROWN RICE.

SEPERATING:-

DUST AND HUSKS ARE REMOVED PNEUMATICALLY IN WHAT IS CALLED A FANNING MACHINE. THE HULLS MAY BE CONSUMED AS FUEL AT THE MILLING FACILITY OR COLLECTED AND MARKETED FOR USE AN INSULATION AS A SOURCE OF FURFURAL FOR CHEMICAL MANUFACTURER, AS PACKING AND SOIL MULCHING MATERIAL. EVEN WIH PRIOR SHELLING IN TANDOM SOME UNHULLED KERNELS WILL GET THROUGH. THESE ARE RECYCLED BACK TO THE SHELLING LINE. THE SEPARATION MACHINE IS SOME TIME CALLED AS PADDY MACHINE.

BRAN REMOVAL:-

THE BRAN LAYERS ARE REMOVED. THE INNERMOST OR POLISH LAYER MAY REMAIN. THIS MACHINE IS AN ADAPTATION OF THE MACHINE USED TO HULL COFFEE AND HENCE IN THE TRADE IT IS COMMONLY REFERRED TO, THROUGH INCORRECTLY AS A HULLER. IN A SERIES OF RUBBING ACTIONS, THE BROWN COAT IS REMOVED AND ASPIRATED AWAY TO A BRAN COLLECTOR. AT THIS POINT THE PRODUCT IS KNOWN AS UNDERMILLED RICE. IN SOME PLANTS,  PEARLING OPERATION MAY FOLLOW. THIS ESSENTIALLY IS A REFINEMENT OF BRAN REMOVAL OPERATION. MOST RICE BRAN IS USED IN ANIMAL FEEDS.

BRUSHING:-

THE RICE PRODUCTS TO BRUSHING MACHINE WHERE IT IS SCOURED TO REMOVE THE INNER MOST BRAN COAT, ALSO KNOWN AS POLISH. THIS MACHINE CONSISTS OF A RAPIDLY REVOLVING VERTICAL CYLINDER EQUIPPED WITH OVERLAPPING PIECES OF HIDE.  A HIGH POLISH IS IMPOTED TO THE SURFACE OF RICE AND THE PRODUCT IS CALLED POLISHED RICE. THE POWDERY POLISH SUBSTANCES (MOSTLY CHO) IS COLLETED AND IS ALSO USED IN ANIMAL FEED.

TRUMBLING:-

POLISHED OR UNCOATED RICE MAY BE MARKETED AT THIS POINT, OR THE PRODUCT MAY BE PASSED TO TRUMBLING MACHINES, WHERE THE KERNELS ARE COATED WITH GLUCOSE AND TALE. THE COATING IS PREFERRED BY SOME MARKETS AND DOES NOT DETRACT FROM THE NUTRITIONAL VALUE OF THE PRODUCT.

SCREENING AND SEPERATNG:-

IN SCREENING AND SEPERATING THE WHOLE RICE KERNELS, BROCKERS AND RICE FLOUR ARE SEPERATED, THEN THEY ARE GRADED PACKAGED SEPERATELY AND MARKETED.

USES OF RICE:-

1.       RICE IS USED AS A STAPLE FOOD IN MANY COUNTRIES.

2.       RICE WITH A LOW STARCH GELATINIZATION IS  PREFERRED  IN RICE PUDDING, BREADS & CAKES & BEER ADJUNCTS, THIS ALLOWS STARCH GELATINIZATION AT LOWER PROCESSING TEMPERATURES, PARTICULARLY IN THE PRESENCE OF SUCROSE.

3.       WARY AND LOW AMYLOSE RICES ARE PREFERRED FOR RICE WINE(FOR HIGHER ETHANOL YEILD) AND IN FROZEN SAUCES, DESSERTS AND SWEETS BECAUSE OF THE SLOW STALING RATE.

4.       RICE BY PRODUCTS INCLUDING THE OUTER BRAN LAYERS, GERM AND POLISH ARE THE POTENTIAL SOURCE OF FOOD FOR HUMANS, THESE BY PRODUCTS ACCOUNTS FOR APPROX 10% OF PADDY RICE WEIGHT.

5.       THE HULLS OF THE RICE MAY BE CONSUMED ASFUEL AT THE MILLING FACILITY, OR COLLECTED AND MARKETED FOR USE AS INSULATION, AS A SOURCE OF FURFURAL FOR CHEMICAL MANUFACTURES, AS PACKING AND SOIL MULCHING MATERIAL.

6.       RICE-BRAN IS USED AS ANIMAL FOOD.

7.       RICE-FLOUR (GLUTINOUS AND WARY) IS USED FOR THICKENING OF VARIOUS PRODUCTS SUCH AS GRAVIES, WHITE SAUCES ETC.

8.       IN INDIA, SEVERAL TYPES OF DISHES ARE PREPARED FROM RICE FLAVORED WITH SPICES AND OTHER INGREDIENTS . OTHER RICE PREPARATIONS INCLUDE PARCHED RICE, PUFFED RICE AND FERMENTED PREPARATION LIKE IDLI AND DOSA.