Introduction

Cooking is the process of preparing food by applying heat, selecting, measuring and combining of ingredients in an ordered procedure for producing safe and edible food. The process encompasses a vast range of methods, tools and combinations of ingredients to alter the flavour or digestibility of food. Factors affecting the final outcome include the variability of ingredients, ambient conditions, tools, and the skill of the individual doing the actual cooking. The diversity of cooking worldwide is a reflection of the natural polynormal nutritional, aesthetic, agricultural, economic, cultural, social and religious considerations that impact upon it. Applying heat to a food usually, though not always, chemically transforms it, thus changing its flavour, texture, consistency, appearance, and nutritional properties. Methods of cooking that involve the boiling of liquid in a receptacle have been practiced at least since the 10th millennium BC, with the introduction of pottery.
Effects of cooking:
Cooking prevents many foodborne illnesses that would otherwise occur if the raw food was eaten. Also, cooking increases the digestibility of many foods, especially meat. But in most cases if not cooked properly food can lose its flavor as well as its nutrients.
Source: http://en.wikipedia.org/wiki/Cooking