eChapters

Materials Required

Sample, reagents, beakers, conical flasks, pestle and mortar, funnels, volumetric flasks, pipettes, hot plate, weighing balance, spectrophotometer/colorimeter.

Reagents

    1.    0.1 N NaOH: Dissolve 4 g NaOH (AR) crystals in sufficient water to make up the final volume 1 Litre.
    2.    1 % Phenolphthalein: Dissolve 1 g in 100 ml water. Readymade indicator solutions are more commonly used.
    3.    Alkaline copper Tartarate
        a.    Dissolve 12.5 g anhydrous sodium carbonate, 10 g sodium bicarbonate, 12.5 g potassium sodium tartarate and 100 g anhydrous sodium sulphate in about 400 ml of distilled water and make up the final volume to 500 ml.
        b.    Dissolve 15 g copper sulphate in distilled water. Add one drop of sulphuric acid and make up to 100 ml in distilled water.
    4.    Always prepare fresh Alkaline Copper Tartarate reagent by mixing 96 ml of sol. a. and 4 ml of sol. b. and before use.
    5.     Arsenomolybdate Reagent: Dissolve 5.0 g ammonium molybdate (AR) in 90 ml of distilled water. Add about 5.0 ml of concentrated sulphuric acid and mix well. Add 600 mg of disodium hydrogen arsenate dissolved in 50 ml water. Mix well and incubate the prepared reagent at 37ºC for 24-48 hr or 55ºC for 30  min. with constant stirring.

Materials Required

Sample, 0.1 N NaOH solution, 1% phenolphthalein indicator solution, beakers, conical flasks, pestle and mortar, funnels, volumetric flasks, pipettes, pH meter, shaker.

Reagents

    1.    0.1 N NaOH: Dissolve 4 g NaOH (AR) crystals in sufficient water to make up the final vol. 1 litre.

    2.    1 % Phenolphthalein: Dissolve 1 g in 100 ml water. Readymade indicator solutions are more commonly used.  

Procedure

Preparation of sample: For fresh fruits and vegetables, prepare a well blended, uniform pulp in a pestle and mortar and for processed products, take out a representative sample and blend it well so that it becomes uniformly soluble when added to water. Filter through a fine muslin cloth or coarse filter paper if felt necessary. The liquid samples can be taken directly for estimation.
    1.    Take out a known weight / vol. (say 20 g) of sample in a beaker (in 3 replicates).
    2.    Make it to a known vol. (say 100 ml) with added distilled water.
    3.    Take 10 ml of this aliquot in a conical flask.
    4.    Add 1-2 drops of phenolphthalein indicator into the aliquot.
    5.    Titrate against 0.1 N solution of NaOH till light pink coloured end point is obtained.
    6.    For coloured products, i.e. tomato products where judgment of light pink colour is difficult, titration may be done over a shaker, and digital pH meter may be used for continuously measuring pH of aliquot which would show a steady increase with more and more addition of 0.1 N NaOH. Titre value may be recorded when pH of 8.3 is obtained.
    7.    Record the titre value and calculate the acidity of the sample as per the given formula.

Materials Required

Fruit/ sample, refractometers, thermometers, standard solutions of known TSS, temperature correction Tables.

Procedure

    1.    Calibrate refractometers of all ranges to be used.
    2.    The TSS of the juices/pulps/fresh fruits can be measured with the one having lowest range i.e. 0-32º Brix while, for measuring the TSS of concentrates, syrups, squashes, jams, jellies etc. refractometers of the higher ranges are made use of.
    3.    Put a drop of material on to the glass surface of refrectrometer’s prism, cover gently with the lid and observe the TSS against light.
    4.    Measure the temperature of the liquid which is being evaluated and apply temperature corrections (Annexure III).
    5.    Record the corrected value as the TSS of the sample.

Materials Required

Sample, hot air oven, weighing balance, crucibles, muffle furnace, lead pencil / marker etc.

Procedure

    1.    After following the procedure for the determination of moisture (in silica crucibles as given in previous chapter) the same sample can be used for the determination of ash. 
    2.    Heat the dried sample in the silica crucibles over a heater/hot plate/burner to burn the carbon.
    3.    When it becomes completely black and no more smoke comes out of the sample, shift them to muffle furnace.
    4.    After heating the samples in muffle furnace, all the marks of pen / pencil/ marker are lost, so one would not be able to identify the samples and error of weights may occur. Therefore, it is advised to place the samples in the furnace in one or two rows and draw the diagram on a piece of paper for identification purpose.

Materials Required

Fruit, vegetable or product sample, hot air oven, weighing balance, crucibles, petri plates, lead pencil / marker etc.

Procedure

    1.    Take crucibles  or petri plates and record the tare weight of crucibles / petri plates (C) and mark them
    2.    Cut the sample into small and thin pieces (if solid)
    3.    Put the sample into the crucibles / petri plates in three replications
    4.    Record the weight of crucibles + sample (C + S)
    5.    Put in hot air oven for drying at 70 + 2ºC.
    6.    Record the loss in weight after every 1-2 hrs till it becomes constant
    7.    Calculate the moisture and total solids. 

Materials Required

Cut flowers, 1000 ml conical flasks, scissor, tape, distilled water, chemicals, weighing balance, volumetric flasks, labels, thermometer (max. & min. type) and hygrometer. 

Procedure

    1.    Collect fresh spikes of flowers
    2.    Cut at the base keeping about 25-60 cm of the cut flowers stick (uniformly for each flower).
    3.    Prepare Pulsing/ Vase solutions.
    4.    Put the prepared flower spikes in labeled conical flasks containing different Pulsing/ Vase solutions (for a known period of time).
    5.    Record the weight of the spikes and other observations daily.
    6.    Record the temperature and relative humidity of the storage chamber daily.
    7.    Analyse the recorded data and draw conclusion about the best vase solutions for the selected cut flower.

Materials Required

Apple (or any local fruit), fruit mill, hydraulic press, weighing balance, Refractometer/sugar pectinol, diammonium hydrogen phosphate, Saccharomyces cerevisiae culture, Potassium metabisulphite (KMS) etc.

Procedure

    1.    Take a known quantity of apple (or any other fruit) say 20 Kg
    2.    Extract the juice as discussed in earlier exercises.
    3.    Add about 200 ppm of kms.
    4.    Add sugar syrup to increase the TSS to about 20 – 24ºBrix.
    5.    To about 10 Kg of juice diammonium hydrogen phosphate (10 g) and pectinol (20-25 g are added).
    6.    Take about 500 ml of this mixture in a conical flask and add pure Saccharomyces cerevisiae culture @ 1 % and plug the neck with cotton. Keep at 22-24ºC to complete the fermentation within one day and yeast culture is ready.
    7.    Add this culture to about 10 Kg of must for further fermentation (i.e. culture is added @ 5% therefore 500 g is added to 10 Kg must).
    8.    Record the TSS of the must before fermentation.
    9.    Keep must for fermentation in big jars (narrow mouth) filled to about 75 % of their volume. Close the mouth of jars or bottles with cotton plug.
    10.    Allow fermentation to take place at 22-24ºC for about 10–15 days.
    11.    When no more bubbles are coming out of the jars, fermentation is complete. At this stage the TSS reaches about 7º Brix.
    12.    Siphon the wine. Add filter aids if wine is not clear.
    13.    Blend the wine with sweetening agents if required.
    14.    Fill in beer bottles by keeping a head space of about 2.5 cm followed by crown corking them.
    15.    Pasteurize the bottles by keeping at 62.5ºC for 20 min.

Materials Required

Dehydrator, balance, thermometer, sulphur dioxide, blanching pan, fruits / vegetables, polythene or aluminium bags.

Procedure

    1.    Select sound fruits or vegetables 
    2.    Record their initial weight and wash them properly in plain water to remove any dirt or extraneous matter. 
    3.    Peel with stainless steel knife (as the case may be) and cut into thin uniform pieces or slices of  0.2-0.5 mm thickness
    4.    Blanch the slices in boiling water for 1-2 min. to inactivate the enzymes followed by immediate cooling.
    5.    Treat the slices with sulphur (sulphuring or sulphiting) in order to prevent darkening of the product during drying. 
    6.    Dry the slices in a mechanical air dehydrator at about 55 + 5oC temperature.
    7.    Record the weight of the product after every 2 hr till it becomes (almost) constant i.e. when there no more (significant) loss of moisture from the product.
    8.    Pack the product in ploythene or aluminium laminated pouches and seal them air tight. 
    9.    If it is to be converted into powder, the dried product can be ground in a grinder before packing.
    10.    Label the packages and store them in a cool dry place.
    11.    Plot the drying rate curve of the product on a graph paper and analyse it.
    12.    Record the initial and final moisture content of the product (as discussed in Exercise No. 19). 

Materials Required

Canned product, weighing balance, can cutter, vacuum/pressure guage, seam checking guage, Refractometer / Salometer etc. 

Procedure

    1.    Take a canned product say canned peach.
    2.    Record the weight of the can (A)
    3.    Record the information marked on the label i.e net  weight, date of packing, etc
    4.    Observe the can externally for the concavity of the lid.
    5.    Record the vacuum of the can by using a vacuum guage
    6.    Cut the lid of the can with a can cutter
    7.    Record the head space
    8.    Put all the contents over a sieve and let the liquid drain
    9.    Record the weight of empty can (B) to calculate net contents
    10.    Record the drained weight of the pieces.
    11.    Record whether the liquid is syrup or brine
    12.    Record the TSS of the salometer reading of the liquid (as the case may be)

Materials Required

Fruits or vegetables, stainless steel knife, steel pans, Can Body Reformer, Flanger, Double seamer, weighing balance, Refractometer / Salometer, sugar or salt etc. 

Procedure

    1.    Wash the selected fruit or vegetable (as the case may be) 
    2.    Cut into pieces or slices (the size and shape may depend on the fruit/ vegetable but it should not be too large or too small)
    3.    Blanch the material in boiling water for 1-2 min for effective inactivation of enzymes. 
    4.    Prepare the sugar syrup of strength 40o Brix or brine of 1-3 % strength.
    5.    Prepare the can body using a can body reformer and flange the ends in a flanger.
    6.    Seal the base plate using first and second roller operations of the double seamer. 
    7.    Transfer the prepared fruits / vegetables into the cans. 
    8.    Pour in hot syrup or brine into the cans.
    9.    Place the lid over the top of filled can. (follow the first roller operation of the double seamer, if the cans are OTS cans)
    10.    Exhaust the cans in boiling water for about 10 min. to exclude any dissolved air out of the tissues or syrup/brine.
    11.    When the temperature of the centre of can reaches 79-80 ºC for fruits or 82ºC for vegetables, remove the cans from the exhaust box and seal them properly (follow the second roller operation of the double seamer, if the cans are OTS can).
    12.    Process the sealed cans at 100ºC and 115-121ºC for fruits and vegetables respectively for 15-30 min in case of fruits and 25-45 min. in case of vegetables.
    13.    Cool the cans immediately in cold water and air dry them at room temperature.
    14.    Label and store in a cool dry place.

Materials Required

Tomato fruits, pulper, steel pans, weighing balance, refractometer, sugar, salt, spices, acetic acid, citric acid, muslin cloth etc.

Procedure
I. Puree

    1.    Extract fruit pulp by Hot process as told by the teacher.
    2.    Record the TSS of the pulp.
    3.    Concentrate the pulp by heating to 12º Brix (heavy puree)
    4.    Hot fill the boiling puree into pre-sterilized glass bottles (200 ml cap.)
    5.    Seal the bottles by crown corking
    6.    Heat process in boiling water in a big aluminium pan for 15-20 min. 
    7.    Cool the bottles to room temperature as quickly as possible.
    8.    Label and store at a dry place.

Materials Required

Fruits or fruit pulp, steel pans, weighing balance, refractometer, sugar, salt, spices, acetic acid, citric acid etc. 

Procedure

    1.    Extract fruit pulp as told in earlier exercises. 
    2.    Take a known quantity of freshly extracted or preserved pulp.
    3.    Weigh sugar (about half the weigh of pulp).
    4.    Heat pulp and sugar over a gas flame.
    5.    Add spices, chillies, salt, citric acid (if required) etc. and cook
    6.    Record the TSS to judge the end point. It should be more than 50o Brix.
    7.    Add measured quantities of acetic acid and sodium benzoate at the end.
    8.    Cool and pack in pre-washed and sterilized glass jars
    9.    Label and store.

Materials Required

Lime fruits, green chillies, ginger salt (common), stainless steel pans, kinives, weighing balance, spices etc. 

Procedure

    1.    Select sound and mature fruits of lime, mature but green chillies having good size and ginger rhizomes.
    2.    Wash the lime fruits, ginger and chillies properly in running cold water.
    3.    Cut the lime fruits into pieces / halves. 
    4.    Remove the stalks of the chillies and cut into longitudinal slices. Peel ginger and cut into long thin slices.
    5.    Put the lime pieces, chilli and ginger slices in a wide mouthed pre-sterilized glass jar 
    6.    Add common salt @ 250g / Kg of material.
    7.    Squeeze some of the juice over the slices
    8.    Stir the mass well mixing thoroughly
    9.    In case the juice does not cover the material completely, add pre-boiled and cooled 5% solution of citric acid.
    10.    Keep the jar in Sun for about a week with occasional shaking of the material.
    11.    When the lime pieces start turning light brown, the pickle is ready for consumption.

Materials Required

Fruit extract, cane sugar, potable water, essence, citric acid, colours, preservatives, weighing balance, glass jars (500 ml capacity), jar closures, hand refractometer, steel pan, ladle etc.

Procedure for Jelly

    1.    Select sound and fresh fruits, free from any blemishes. Generally a mixture of ripe and unripe fruits shouldbe taken as the ripe fruits impart good flavour and the unripe fruits are rich in pectin, required for a good set.
    2.    Wash the fruits thoroughly. Cut into 4-8 pieces depending upon the fruit and size
    3.    Boil the fruit pieces in water (about ½ to an equal weight of fruits for fruits like apple and 2-3 times the weight of sliced fruits in case of citrus fruits) for about 30 min. with occasional stirring. Strain the boiled mixture through coarse muslin cloth to get a clear pectin extract
    4.    A second extract may also be taken by boiling the same mass again and straining.
    5.    Add sugar (usually 3/4th to one part of the extract or in 45:55 ratio) to the pectin extract and boil in a stainless steel pan. Add required quantities of acid towards the end of boiling.
    6.    Remove the scum rising on the top of boiling mass occasionally.
    7.    To avoid charring, occasional stirring is also done.
    8.    To avoid destruction of pectin the cooking should be completed fast
    9.    Determine the end point of jelly as detailed ahead.
    10.    Fill in hot dry glass jars and cool rapidly
    11.    Pour a thin layer of hot molten paraffin wax seal to avoid moulding.   
    12.    Label and store in a cool place.

Materials Required

Fruit pulp, cane sugar, potable water, essence, citric acid, colours, preservatives, weighing balance, glass jars (500 ml capacity), jar closures, hand refractometer, steel pan, ladle etc.

Procedure

    1.    Select sound and fresh fruits, free from any blemishes. Generally a mixture of ripe and unripe fruits should be taken as the ripe fruits impart good flavour and the unripe fruits are rich in pectin, required for a good set.

    2.    Wash the fruits thoroughly. Cut into 4-8 pieces depending upon the fruit and size
    3.    Boil the fruit pieces for about 20-25 min in boiling water and pass through pulper to get a good pulp.
    4.    Weigh known quantity of fresh or preserved pulp and add about equal quantity of sugar (preferably in 45:55 ratio)
    5.    Cook the mixture on gas flame by occasional stirring. 
    6.    When the mixture becomes thick, perform sheet test.
    7.    Citric acid is added generally towards the end of cooking. Addition of all the acid in the beginning may result in stickiness and poor set. 
    8.    Remove from the flame when the mixture gives a clear sheet
    9.    Flavours, colours etc may also be added towards the end of boiling. 
    10.    Fill the jam in glass jars (preferably pre-warmed in hot air).
    11.    Close the jars with lug caps and allow to cool overnight.
    12.    Label and store in a cool place.

Materials Required

Fruits juice, enzymes (pectinase, cellulase, pectinase CCM etc.), filter press, buchner filter apparatus, water bath, filter paper pulp, buchhi type rotary vacuum evaporator, freeze concentrator, membrane concentrator (whichever available), vacuum grease.

Procedure

    1.    Extract the juice as discussed in earlier exercises. Take a known quantity of juice in a conical flask.
    2.    Add enzymes i.e. pectinase @ 0.2% to the juice and keep in a water bath at temperature of 40-50ºC for 2 hrs.
    3.    Shake the flasks occasionally for uniform mixing of enzyme all throughout the flask during the enzymatic treatment.
    4.    Leave the flasks undisturbed for 10-12 hrs for allowing the insoluble solids to settle at the bottom of the flask.
    5.    Siphon the clear juice from the top of the flask.
    6.    Pass this siphoned juice through filter press or through a 0.4-0.5 cm thick bed of filter paper pulp in a Buchner filter apparatus or filter press.
    7.    Record the volume of the clarified juice obtained. Calculate the wastage.
    8.    Concentrate the juice in rotary vacuum evaporator at 50+2ºC temperature and at 28-30” Hg vacuum to a TSS of about 50 to 70º Brix. Record the exact TSS.
    9.    Record the volume of condensate obtained in the round bottom flask of the buchhi apparatus.
    10.    Calculate the folds of concentration

Materials Required

Fruit juice/ pulp, cane sugar, potable water, essence, citric acid, colours, preservatives, weighing balance, bottling and sealing facilities, hand refractometer, homogenizer etc.  

Procedure

    1.    Extract the juice as discussed in previous exercise.
    2.    Filter the fresh or preserved juice through muslin cloth.
    3.    Calculate the quantities of juice, sugar, water, acid (if required), preservatives, colour, essence etc. required for preparation of a known quantity of                      squash as per FPO specifications.
    4.    Prepare the beverage as directed by instructor
    5.    Pack the beverage in bottles 
    6.    Seal the bottles and label them
    7.    Take out one of the bottles and measure its TSS and titratable acidity.

Materials Required

Fruit, pulper, fruit mill, hydraulic press, screw type juice extractor, stainless steel pans, chemical preservatives, glass bottles, closures, crown corks, crown corking machine, plastic barrels.

Procedure

    1.    Select and weigh sound fruits/vegetables for extraction of juice/pulp.    
    2.    Wash and peel the fruits as required.
    3.    Extract the juice by hot or cold process.
    4.    Pasteurize the juice/pulp to inactivate the enzymes and partially kill microorganisms.
    5.    Preserve the juice/pulp by heat processing after hot filling and hermetic sealing or by addition of permissible quantities of suitable preservatives.
    6.    Label the bottles properly and keep them for storage

Materials Required

Fruits/ vegetables, weighing balance, plastic crates, CFB boxes or other packaging material fruit pressure tester, hand refractometer, markers etc.

Procedure

    1.    Harvest the fruits
    2.    Subject them to various pre-treatments (as discussed in previous exercise).
    3.    Record their initial parameters i.e. weight, firmness, surface colour, TSS, rotting etc. 
    4.    Place properly packed commodity in storage alongwith a check under ambient conditions
    5.    Record the observations regarding changes in quality during storage
 

Materials Required

Fruits/ vegetables, washing tanks/ containers, size grader, fruit waxes, packaging material, neem based fungicides etc. 

Procedure

    1.    Take available fruits or vegetables 
    2.    Wash them in plain water or chemical solution as told by the teacher
    3.    Shade dry the fruits / vegetables
    4.    Prepare suitable wax solution
    5.    Apply wax on to the fruits as told
    6.    Record the fruit weight before packing
    7.    Pack the fruits properly in the trays / boxes depending upon the type and purpose
    8.    Do curing if required 
    9.    Do pre-packaging, if desired
    10.    Label the package for desired information
    11.    Keep the fruits for storage
    12.    Record the observations pertaining to weight loss and rotting periodically depending upon the commodity and its shelf life.