•When barbecuing, you can either put the food directly above the flames; what is called direct heat or further away for indirect heat.
•This reaction and the flavours it produces are influenced by many variables.
The mere thought of barbecue’s smokey scents and intoxicating flavors of mahindi choma (roasted corn) is enough to get most mouths watering.
What we probably do not understand is the science behind the flavour. What makes us prefer barbecue beef to boiled stew or roasted maize to boiled maize?
Cooking on a grill may seem so simple, but there is a lot of chemistry that sets barbecuing apart from other cooking methods.
How the flavour is achieved:
Barbecuing is essentially cooking food over an open flame. What distinguishes barbecuing from other cooking methods is how the heat reaches the food.
When barbecuing, you can either put the food directly above the flames; this is called direct heat or further away known as indirect heat.
On a barbecue, the hot grill grates heat the food in direct contact through a process known as conduction.
Here the food gets warm and cooks by absorbing radiation directly from the flames below.
This resulting range of temperatures produces a complex mixture of flavors and aromas.
In contrast, when cooking on a stovetop, there is much less radiation and most of the cooking occurs where the food is in direct contact with the pan.
According to Kristine Nolin, Associate Professor of Chemistry, University of Richmond, over direct heat on a barbecue, the first thing to happen is boiling of the water near the surface of the meat.
“Once the surface is dry, the heat causes the proteins and sugars on the outside of the meat to undergo a reaction called the Maillard Reaction,” Nolin says.
“This reaction produces a complex mixture of molecules that make food taste more savory or “meaty” and adds depth to scents and flavors.”
This reaction and the flavours it produces are influenced by many variables, including temperature and acidity as well as the addition of any sauces, rubs or marinades.
She says a similar process occurs with vegetables. Such as with roasted maize or corn.
Barbecuing allows the water to evaporate or drip down without getting trapped by a pan. This keeps the vegetables from becoming soggy and promotes caramelization reactions.
These reactions turn carbohydrates and sugars into smaller compounds like maltol, with a more toasty, nutty, meaty and caramel-like flavour.
Next time you enjoy your barbecue or roasted maize, at least you know what happened behind the scenes to achieve the flavour.
