Improves the taste and food quality:
Cooking improves natural flavour and texture of food. For example roasting groundnuts, frying onions and papads, cooking rice and roasting coffee seeds improve the flavour.
Cooking meat with spices, rice with spices in making pulav, frying cashewnuts in ghee, addition of turmeric, curry leaves, pepper in pongal, blend flavour with one another during cooking.
Too much of cooking lowers the flavour as flavouring compounds are volatile. Over-cooked pulav, does not taste as good as well cooked pulav.
Destruction of micro-organisms :
Micro-organisms are present everywhere and some are useful in making curd, cheese and bread.
Some are harmful and cause infections or produce toxins, e.g., Clostridium botulism and salmonella.
Some moulds produce toxins. Aspergillus flavus produces aflatoxin in groundnuts, cereals and spices. This aflatoxin is a health hazard.
One of the most important methods of protection of food against harmful micro-organisms is by the application of heat.
Cooking food to the required temperature for a required length of time can destroy all harmful microorganisms in food e.g., pasteurised milk.
Tapeworm or its larvae which infest pork can be killed by proper application of heat. By cooking, food is made safe for consumption.
Improves digestibility :
Cooking softens the connective tissues of meat and the coarse fibres of cereals, pulses and vegetables so that the digestive period is shortened and gastrointestinal tract is less subjected to irritation.
Cooking improves the texture hence it becomes more chewable. Cooking also bursts the starch granules of pulses and cereals so that the starch digestion is more easier, rapid and complete.
When dry heat is applied to starches they are converted to easily digestible dextrins. Cooking increases the access to enzymes and improves digestibility.
Increases variety :
By cooking, same food can be made into different dishes. For example, rice can be made into plain, pulav, lemon rice, biryani, or combination with pulses and idli. Wheat can be made into chapatis, puri, paratha or halwa.
Increases consumption of food :
Cooking improves the texture and makes the food chewable. Improvement in texture and flavour by cooking increases the consumption of food to meet our nutritional requirement.
Increases availability of nutrients :
Raw egg contains avidin which binds biotin making biotin unavailable to the body. By cooking, avidin gets denatured and biotin is available to the body.
Trypsin inhibitors present in soyabean and duck egg get denatured on cooking and availability of protein is improved.
Toxic substances from kesari dhal can also be removed by boiling it and throwing away the water. Cooking increases the quality of protein by making some amino acids available to the body.
Increases antioxidant value :
Cooked tomatoes are associated with greater health benefits, compared to uncooked, because the heating process makes lycopene more easily absorbed by the body.
Lycopene – the pigment present in tomatoes – reduces the risk of some cancers.
Concentrates nutrients :
This may be due to removal of moisture or using combination of foods or due to cooking procedures, e.g., sweets.
Limitations of cooking :
i. Thiamin, which is heat sensitive, may be lost during cooking. Water soluble nutrients are leached into the water during cooking. Vitamin A and C content may be reduced due to oxidation and heat.
ii. Quality of protein may be reduced due to destruction of certain aminoacids during cooking e.g., bread crust has less quality of protein compared to the inside portion.