(a) Select sound fruits and vegetables and discard rotten parts, or pieces.
(b) The fruits and vegetables should be washed after cutting them. If the vegetables and fruits are washed after cutting, there are chances of losing some amount of water-soluble vitamins like ascorbic acid and ‘B’ vitamins.
(c) Cut as big pieces as your recipe permits. Cutting into smaller pieces leads to extra loss of watre-soluble vitamins.
(d) Put vitamin ‘C’ rich foods in boiling water, if these are to be cooked.
(e) Use minimum water required.
(f) Do not throw away extra water. The water in which vegetables boiled frequently contain water soluble minerals and vitamins. Therefore instead of throwing it away, it can be used in some other recipes.
(g) Complete the cooking in a shorter duration so that there is minimum loss of heat-sensitive vitamins.
(h) Do not overcook any food. It destroys flavour, color, and vitamins.
(i)Cook foods in covered vessel so that there is minimum loss of volatile substances.
(j) To retain different colours of fruits and vegetables; do not cook green coloured vegetables in acidic medium as the acidic medium changes natural green colour to unattractive olive-green colour. Never overcook green-colour vegetables.
(k) Do not cook high protein food at high temperature, as high temperature leads to denaturing of proteins. The denatured protein becomes insoluble in water,losing its original properties and becoming an irreversibly changed or denatured protein.
Dryness of cooked frozen fish is also an aspect of denaturation. Specially in case of meat which is high in protein, at high temperatures, muscle protein gets hard due to coagulation making protein less readily digestible.
(l) Ascorbic acid gets destroyed by oxidation also, therefore, foods rich in ascorbic acid should not be cut and kept exposed to air much before cooking time.
(m) Fruits and vegetables which become brown on cutting when exposed to air due to enzymatic browning, should be covered with salt, water or acidic or basic medium when cut.
(n) Do not add soda to foods while cooking as it destroys ‘B’ vitamins.
(o) Do not add too many spices at a time in one single recipe as it suppresses the natural flavour of the food.
(p) Do not add two types of flavouring agents in one single recipe as it leads to interference of two different flavours. For example addition of curry leaves and coriander leaves at the same time.
(q)Always measure the ingredients in right amounts.
(r) In case of baking, put the food stuff in the oven only when it reaches required temperature and do not open it frequently during the process of cooking.
(s) Always take out fried foods on a brown paper so that extra fat is soaked by the paper.
(t) Do not overheat the fat used for frying because once fat decomposes, it is no longer suitable for frying.
(u) Keep the fried foodstuffs in airtight container so that rancidity does not occur.