Posted by kathryn in Fats & oils

A question from rgh

“when you fry food, but you don’t use oil, why is there such a difference in flavour, to when you do use it? Or put more succinctly, what effect does oil have on the food you fry?

To answer this question, I’m going to have to refer to the great Mr Harold McGee. According to On Food & Cooking when you are pan-frying the oil is doing a number of different things. Firstly it lubricates the surface between the pan and the food, preventing sticking, but more importantly it enables the food to be cooked at a higher temperature.

McGee calls this the browning reaction. If you think about the difference between cooking something in oil and cooking it dry, or in water, the food will brown quickly in the oil. Food cooked in water or dry-fried either doesn’t brown, or it takes a lot longer.

The browning reaction relies on a high temperature, at least 154°C. At this point there is enough energy to force carbohydrates in the food to react with amino acids, resulting in a number of chemical reactions that lead to the brown colouration and an intensification of flavour. It only happens on the outside of the food, because the inside doesn’t reach the same temperature (typically it remains about 100°C).

Therefore by using oil you are inducing the browning reaction in the food you’re pan frying. It’s this that changes the flavour of your food, in ways that are intrinsic to the process, rather than to the food itself.

21 June, 2007