As a food scientist, I have carried series of research and practice on this topic.
The one major reason is the temperature difference.
our food contains water, So when the food is kept inside the water. and the water temperature increases, water present both inside and outside the food start to boil. There is a lot of exchange of water molecules from inside to outside the FOOD and vice versa since this type of cooking is done just by boiling, so we said the Food is boiled.
Frying is done at around 170 C. what that does is high heat changes the food surface and prevents food juice to come out. so you get a crispy outside (due to the high heat) and soft inside ). This is a quality acceptable in a fried food
Now, remember that oil has a high boiling point as compared to water. For cooking purposes, oil has a higher smoke point (the temperature at which oil starts to burn) is chosen.
so when food is kept in oil and the temperature is gradually increased, the Oil becomes hot and the water inside the food starts to boil. water present at the surface of the food evaporates first i.e, converts to gas,.and hence we see the gas Bubbles coming out of the food.
Now as this process goes on, Water on the surface of the food decreases, and water inside the food slowly comes in contact with oil, and that too evaporates. so we see bubbles till there is water present in the food.
so this frying process not just boils the food but also removes water from the food. so we can say that the frying process involves dehydration.
NOW almost all food items contain Amino acids and Sugar at 140 to 165 C temperature these two types of compounds react with each other, thus resulting in the Browning of the food item. the reaction between the Amino acid and reducing sugar at the above-mentioned temperature range is known as the Maillard reaction. There is another process known as Caramelization which is the breakdown of sugar.
Wealth
1 year agoWow , am literally getting my bed to sleep on this website of yours , great article sir , perfect explanations
Godstime
5 months agoNice 👍
Chioma
1 year agoThanks for this lecture.learnt alot