The term used to describe the tasks done before or ahead the final preparation of food is preliminary preparation.
Preliminary treatment of food includes cleaning, peeling and stringing, cutting and grating, sieving, soaking, processing, coating, blanching, marinating, sprouting, fermenting, grinding, drying and filtering.
The term cleaning is applicable to vegetables, fruits and many other food products. Many food products may have portions to be discarded, for example, withered or discoloured leaves in green leafy vegetables.
Other aspect of cleaning is washing. This term is applicable to fruits, vegetables, cereals, pulses and non-vegetarian foods.
Washing fruits renders them dirt-free. Washing cereals or dais helps to remove husk, mud and any other unwanted matter. Hard vegetables are scrubbed under cold running water.
(i) Insecticides, sprays, chemicals and dirt are removed.
(ii) Washing in warm water helps to kill the worms e.g., worms in cauliflower.
(iii) Washing flesh food products helps to remove blood, dirt and unwanted impurities.
(iv) Cleaning process helps to remove gills from fish, hard shells from prawns and crab.
(i) Washing cereals like rice causes loss of B complex vitamins especially thiamine. This can however be reduced by quick and thorough washing.
(ii) Water-soluble vitamins are lost when fruits and vegetables are cut and then washed.
Peeling and stringing:
Both these methods involve the removal of non-edible or fibrous portion of fruits or vegetables e.g., peeling of banana and potato, stringing of beans.
Peeling brings about loss of nutrients present under the surface of food, hence the product should be boiled or blanched and then peeled e.g., vitamin C in potatoes.
Colour of beetroot can be preserved better when it is cooked with the skin.
(i) Non-edible or fibrous portion is removed.
(ii) Dirt and chemicals which is retained after cleaning on the skin can be removed.
(iii) Appeals better to the eye after peeling and stringing e.g., potatoes and beans.
(i) Some nutrients might be lost e.g., peeling and exposing fruits can bring loss of vitamin C.
(ii) Some edible portion might be removed along with peel.
Cutting and grating:
This is dividing the food into smaller pieces, thus helping in easy cooking. Various terms under this are:
To divide into pieces or to shape with knife.
To cut into no specified shape.
To chop very fine.
To cut into small uniform cubes.
To cut into uniform slices. .
To cut finely with a grater.
Cutting is a general term which includes all the others. Apart from knife, various other machines are used to cut like food slicer, chopper, grinder and vertical cutter.
(i) The product is easily cooked.
(ii) It is easily consumed.
(iii) Spoiled portion of the food can be discarded.
(iv) Appearance of the food can be improved, e.g., salads.
(v) Grating helps in proper blending of the product.
Smaller the size, greater the surface area, greater the loss of nutrients, hence cutting is preferred to grating but, however, certain recipes need grating.
Sieving is done to remove coarse fibres and insects. It is also done in preparing cakes for blending of flour with baking powder.
(i) Helps in removal of dirt, worms, fibre and stones from the whole grains.
(ii) The shelf life of food products can be improved.
(iii) Flour becomes fine.
(iv) Helps in blending.
Bran is lost, thereby some nutrients like fibre, protein and B vitamins may be lost.
It involves time.
Soaking is done in water either plain or salted with sodium chloride or sodium bicarbonate.
Hastens the process of cooking.
(i) It facilitates grinding e.g., in making idli or dosa.
(ii) Texture of food softens.
(iii) Peel can be easily removed from soaked products like whole grams.
(iv) Make the extraction of tamarind easier.
(v) Reduces pungency in onions.
(vi) It initiates fermentation process, e.g., idli and dosa batter.
(i) Water-soluble nutrients may be leached into the water.
(ii) It involves time.
Processing includes all the things to get food ready for cooking and serving. The various processes included under this are:
To combine ingredients in such a way that the parts of each ingredient are evenly
dispersed in the total product.
To mix two or more ingredients so completely that they lose their separate identities.
Ingredients in ice-creams and milkshake blend so well that individual ingredients cannot be seen.
To cause a mixture of two or more ingredients to cohere as a homogeneous product.
Binding agents like starches and eggs are used in making custards. Dough making comes under this category.
To move an instrument back and forth to blend ingredients together to achieve a smooth texture.
To beat with a rapid lifting motion to incorporate air into a food e.g., eggs.
To mix a whipped ingredient lightly with another ingredient by gently turning one over the other with a flat implement e.g., egg white in souffle preparation.
Crushing the food products to a smooth structure e.g., mashing of vegetables in cutlet preparation.
Introducing or filling a foodstuff e.g., stuffing mashed potatoes in parathas.
(i) All the processes mentioned above help in the enhancement of flavour of the product.
(ii) Beating and whipping help in incorporation of air thereby lightening the texture.
(iii) In process of binding, dough becomes elastic and thus can be easily rolled, thereby helping in preparation of chapatis and puris.
The term coating refers to covering a food with a layer of crumbs, flour or other fine substances before cooking it. There are different ways of coating a food.
This means passing a food through a fine dry or powdery substance in order to coat it. Substances often used are flour, powdered almonds and bread crumbs.
3 steps are involved. The product is first dredged with flour, then dipped in egg mixture liquids then in crumbs.
This is dipping the food product in batter. Batter is semi liquid. It usually consists of an egg liquid mixture thickened with flour to achieve a smooth consistency.
Bengal gram flour or rice flour can also be used for this purpose.
(i) Coating adds colour and flavour to the finished product.
(ii) The coat of breading helps in transmission of heat to the food product.
(iii) It brings less-fat absorption.
(iv) Produces a crunchy texture.
(v) Helps the food to retain moisture.
(vi) They help in binding the food substances.
(i) Battered or dredged food cannot be held long, otherwise the product becomes soggy.
(ii) Breading may not stick to food.
(iii) The breading may break during frying.
This is plunging food into boiling liquid and immersing in cold water. This destroys enzymes present in food hence used as preparation for preservation.
Food products normally blanched are tomatoes, potatoes, almonds, carrots and beans.
(i) Peel can be removed easily.
(ii) It is a preliminary method for canning and freezing.
(iii) Micro-organisms present on the surface are partially removed.
(iv) Enzymes bringing spoilage can be inactivated.
(v) Blanching causes better exposure of pigment, hence improves the colour of the food product.
(i) Part of water-soluble nutrients may be lost.
(ii) Long-time blanching undesirably softens the food.
Marinating is soaking a food in a marinade to add flavour or to tenderize it or both. A marinade is any liquid made up for purpose of marinating.
Vegetables, fruits and meats are marinated with many flavour combinations. Meat marinade made up of oil, flavour builders and acid.
Oil helps to hold natural juices of meat. Acid is used to tenderize by breaking down connective tissue. Vegetables normally marinated are brinjal, onions, radish, bittergourd, potatoes and chillies.
(i) Prevents browning reaction e.g., in potatoes and apples.
(ii) Adds flavour to the food.
(iii) Texture of product is improved.
(iv) Eve irritation due to cutting of onions can be reduced by marinating.
Water-soluble nutrients may leach into marinade.
Sprouting or Germination:
All kinds of grams like green gram, Bengal gram, peas and cereals like ragi and wheat are generally sprouted. Sprouted pulses are used in making salads and curries.
(i) Digestibility can be increased as complex substances are converted to simple substances e.g., starch to amylose.
(ii) Discomfort due to flatulence can be reduced.
(iii) This decreases cooking time as grain becomes tender.
(iv) Water-soluble vitamins are increased.
(v) Dehusking is easier.
(vi) Thickening power of starch is reduced.
(vii) Availability of proteins and amino acids is increased.
Fermentation is the process of breaking down of complex matter into simpler ones with aid of enzymes and bacteria.
This can be under aerobic or anaerobic conditions. Fermented foods are often more nutritious than their unfermented counterparts. Some fermented food products are idli, bread and dhokla.
(i) Texture and taste is improved.
(ii) Quality of protein is improved as availability of some amino acids increase.
(iii) B vitamins are synthesized by micro-organisms.
(iv) Shelf life of food product can be prolonged e.g., milk is converted to curds.
(v) Fermented foods are easily digestible.
(i) Sometimes unwanted micro-organisms can develop and bring about spoilage of food.
(ii) Acidity of the product is increased.
This includes both wet and dry grinding. Wet grinding includes the grinding idli batter and preparations of chutneys.
Dry grinding is grinding spices for masala powders and wheat for wheat flour.
(i) Grinding facilitates fermentation in case of idli, dosa and dhokla.
(ii) Proper blending of flavour is ensured.
(iii) There is enhancement in taste and flavour.
(iv) This is helpful in preparing gravy preparations.
(v) Extraction of flavouring compounds is better when coffee seed is ground.
(i) Infestation chances are more in flours than in whole food substances.
(ii) Flavour is lost easily e.g., coffee powder.
(iii) Vitamin C content may be reduced due to oxidation.
Drying or dehydrating is removal of moisture from food products. Removal of moisture helps to prolong the shelf life of the food.
Foodstuffs generally dried are mango and gongura for pickles. Cereals, pulses and spices that are normally used are dried products only.
(i) Shelf life can be prolonged.
(ii) Dried food grinds easily.
(iii) In vegetables like ladyfinger, removal of moisture helps in reducing stickiness.
This process is generally done to remove dirt, unwanted particles or to remove moisture from foodstuff.
In the preparation of cottage cheese or paneer, whey water is extracted. Foodstuffs filtered are coffee, tea, rice, soups, fruit juices and tamarind water.
(i) Removal of dirt and unwanted particles.
(ii) Better extraction of flavour compounds in making tea and coffee.
(iii) Improves taste.
Nutrients are lost e.g., in whey water, and rice kanji. This loss can be compensated by utilizing the liquids for some other purposes rather than discarding them.
This process should be grouped under actual cooking methods but certain recipes however demand roasting as preparation. Foods generally roasted are rava and vermicelli.
(i) It prevents lump formation, e.g., upma.
(ii) Gives characteristic flavour to a food product.
(iii) Infestation can be reduced.