Food in its natural state contains many nutrients.

Post-cooking, the

food that we eat must not only be palatable, it should also be
nutritious. But the process of preparing food for cooking, as well as
the actual cooking process, results in a great loss of nutrients. 
 
Vitamin
B and Vitamin C, which are water-soluble, are the most affected as
they leach into the water used for soaking and cooking and are affected
by exposure to sunlight and air and by prolonged heating.
 
Here are some tips by which you can minimise nutrient losses from food.

i. Eat fresh

Repeated
refrigerating and reheating of food results in the loss of nutrients.
Hence, it is best to buy small quantities and cook for a day or two.

The
other option is to cook food once a week and store it in the
refrigerator. At mealtimes, remove the desired quantity of food and
warm either on the gas or in a microwave.

ii. Preserve the skin

The
nutrients in vegetables and fruits are mostly concentrated just below
the skin; it is important to eat fruits and vegetables unpeeled so that
you don't lose out on fibre and vital nutrients.

~
The papery peel of carrot, radish and beetroot can be scraped away
using a plastic scrubber or knife. Other vegetables should be peeled as
thinly as possible.

~ Root vegetables like potato, sweet potato, colocasia (arbi), yam, suran,
etc, should be boiled with their skins on and then peeled. This helps
the nutrients to move to the centre of the vegetable, thereby helping
better retention of nutrients.

~ Fruits and vegetables should be
soaked in water without peeling or cutting to remove any pesticide
residues that are present in them. You must remember never to wash,
soak or store cut vegetables as it results in the loss of Vitamin B and
Vitamin C.

~ Fruits should be cut just before eating in order to
prevent excessive exposure to air, which results in the destruction of
Vitamin C.

~ Salads should be prepared just before serving and should be served in closed dishes to avoid excessive exposure to air.

iii. Soaking 
 
Soak grains, particularly pulses, in just enough water overnight. Soak dals
for half an hour before cooking. Soaking helps soften them, thereby
saving on cooking time. It also helps to remove some of the
anti-nutritional factors present in pulses (these anti-nutritional
factors, which do not allow the protein to be digested properly, are
destroyed by soaking, cooking or sprouting).

iv. Sprouting

Sprouted grains are more nutritious than unsprouted ones.

~ Take any pulse or a mixture of seeds, clean, wash well and soak overnight in water.

~ Next morning, drain the water and place the seeds in a strainer basket and cover with a lid.

~ Sprinkle a little water twice a day.

~ Use when sprouts are about two to three centimetres in length or longer (this takes approximately after about 36-48 hours).

~ Instead of placing the seeds in a strainer basket, they can be placed in a wet muslin or cheesecloth and hung up.

Dampen the cloth twice a day and use the sprouts as mentioned above. 

One kilo of dry seeds = six kilos of sprouts.
 
v. Food combinations

The proteins of cereals and pulses -- except for soyabean and alsande (local bean available in Goa - lack certain essential amino acids and are said to be incomplete proteins.

However,
the proteins of cereals and pulses have a natural supplementary effect
on each other when eaten together; the lack of amino acids in one is
made up by an excess in the other. This provides a protein comparable
to animal protein, with respect to the essential amino acid content.

Our traditional diet consisted of foods like rice and dal, khichdi, dhokla, idli, dosa, curd rice, etc, which provides quality protein, particularly in vegetarian diets.

Other
ways to increase the protein content, particularly in a vegetarian
diet, is to add two and a half kilogrammes of roasted soyabean, soya
granules or a combination of pulses to five kilogrammes of wheat then
grind it to obtain flour.

Use milk or leftover dal instead of water to knead dough. 
 
vi. Recycle nutrients

~ Do not throw away the excess water drained after boiling rice or vegetables or cottage cheese (while making paneer).

~ Use it to knead dough, prepare curry, dal or soup.

vii. Use the pressure-cooker

Preferably,
use your pressure cooker for cooking or cook foods in covered pans.
Pressure cooking food is quicker and helps you save gas; it also leads
to greater conserving of nutrients than open boiling or cooking.

viii. Use less oil

~
Season onions and other ingredients with just one teaspoon of oil
and keep adding a tablespoon of water at a time until they have cooked.

~ The other alternative to preparing low calorie gravies is to use palak puree, tomato puree, bottle gourd puree or onion puree instead of the mava or nuts needed to prepare dishes containing kadai or makhani gravies.

All you have to do is to grind any of the above into a puree and then fry it in a teaspoon of oil before adding the masala powders and vegetable, chicken or paneer to obtain rich and thick gravy. Add a tablespoon of milk cream for flavour.

~ For biryanis, finely slice onions and sundry. Bake in the oven till golden brown and use in place of the traditional fried onions.