Many vegetables are eaten in their natural raw state. But if they require cooking, then care must be taken to retain their nutritive value as much as possible. This is attained only if we take certain precautions. First of all pick the vegetables that are in season. Then vegetables are washed thoroughly in clean water under a tap. The nutrients in vegetables and fruits are mainly concentrated just below the skin, so it is better to eat vegetables and fruits, unpeeled so that we do not loose any fibres or essential nutrients. The papery peel of carrot, reddish can be scraped away by using knife. Vegetables should be peeled as thinly as possible. Vegetables like potato, sweet potato should be boiled first and then peeled.
Due to this, the nutrients move to centre of the vegetable and thereby helping in better retention of nutrients. Vegetables are cut or chopped into large pieces and then boiled in water. Pinch of salt is added to the water which helps in preserving vitamin B-complex and vitamin C.
Baking powder is never added as they decreases juices. Then the vegetables are cooked slowly over a low flame. Due to this the natural flavour of vegetable is preserved and it makes them easier to digest also. Moreover, quick cooking over high heat, also destroys the essential nutrients. Minimum quantity of water is used, necessary just to cover the vegetables. The cooking used is tightly covered during cooking. Cooking is done as possible and vegetable and is served hot. Vegetables as cooked in earthen ware or copper vessels. Aluminium vessels are not used for cooking vegetables as the function of pancreatic juices are decreased if the vegetables are cooked in it.
While cooking grains, mainly pulses, they soaked just for half an hour before cooking. The main advantage of soaking is that, it softens them and thus saves the cooking time.
Sprouting of grains is also preferred. Sprouted grains are more nutritions than unsprouted ones. For this, any pulse is soaked overnight in water. Next morning, the water is drained and the pulses seeds are placed in a wet muslin cloths and hung. Little water is sprinkled over it twice a day. When them sprouts attain a length of two to three centimeters, then they are used.
During cooking of vegetables, the less oil should be used. One can also make use of the palak puree, tomato puree, onion puree, etc to make low calorie gravies.