Preparation Of Raw Materials For Processing

All the incoming raw materials, including packaging materials, should be evaluated and monitored to prevent potential contamination of the food  product manufactured. Incoming materials must be received into an area, which is separated from processing areas. The raw materials are then processed as soon as possible in order to avoid deterioration. Healthy and sound commodities  without any infection are selected for processing. Preliminary preparation of raw materials includes cleaning, peeling, cutting, trimming and grating, sieving, soaking,  processing, coating, blanching, marinating, sprouting, fermenting, grinding, drying and filtering.

• Cleaning: Cleaning is applicable to vegetables, fruits and many other foodproducts. One of the aspect of cleaning is soaking or washing and is applicable tofruits, vegetables, cereals, pulses and non-vegetarian foods. Washing fruits renderthem free from dirt, twigs, stalks, sand, soil, insects, pesticides and fertilizerresidues. Soaking helps to loosen the adhered soils particularly on root crops.Washing cereals or  dhals help to remove husk, mud and any other unwanted matter. Hard vegetables are scrubbed under cold running water.

• Sorting: The purpose of sorting is to separate the ripe fruits from the underripe orover ripe fruits. At the same time, parts of damaged fruits will be removed. Some fruits are cut in two to check the inside.

• Peeling and stringing: These methods involve the removal of non-edible orfibrous portion of fruits or vegetables. It may be done (a) by hand ;(b) with steam or boiling water ;(c) with  lye or alkalis (NaOH, KOH) ; and (d) by mechanical means.  Peeling facilitates the operation of cutting the raw material into pieces or into slices before processing.  

• Cutting and grating: Dividing the food into smaller pieces is cutting. This helps in easy cooking. Various terms used under this are cut, chop, mince, dice and slice.

• Blanching: Blanching is plunging food commonly fruits and vegetables into boiling liquid and immersing in cold water. This destroys the enzymes present in food which otherwise causes browning and off-flavor hence, used as pre-preparation for preservation. Generally tomatoes, potatoes, almonds, carrots and beans are blanched.

• Sieving: Sieving is done to remove coarse fibres and insects and also in preparing cakes for blending of flour with baking powder.

• Grinding: The term implies to reduce to powder by friction, as in a mill, or with the teeth; to crush into small fragment. 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 and other cereal grains to flour.

• Processing: Processing includes all the things to get food ready for cooking and serving. The various processes included under this are: mixing, blending, binding,beating, whipping, folding, mashing, rolling and stuffing.

• Marinating: Marinating is nothing but soaking a food in a marinade, which is a seasoned liquid, usually containing an acid, such as vinegar, lemon juice, or wine to add flavour or to tenderize it or  both. Vegetables, fruits and meats are marinated with many flavour combinations like oil, flavour and acid. Oil helps to hold natural juices  of meat. Acid is used to tenderize by breaking own connective tissue. Vegetables like brinjals, onions, radish,  bittergourd, potatoes and chillies are normally marinated.

• Sprouting or Germination: It is defined as the process whereby the seeds sprout and begin to grow. 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.

• Fermentation: Fermentation is the process of breaking down of complex matter into simpler ones with the aid of enzymes and bacteria. This can be under aerobic or anaerobic conditions. Fermented foods  are often more  nutritious than their unfermented counterparts.

• Drying: Drying or dehydrating is removal of moisture from food products.Removal of moisture helps to prolong the shelf life of the food.

• Filtering: This process is generally done to remove dirt, unwanted particles or to remove moisture from foodstuff. Foodstuffs filtered are coffee, tea, rice, soups,fruit juices and tamarind water.