Food Science and Cooking

What heat does to food

Cooking is food science in action. When you heat food, real changes happen inside it: proteins set, starch thickens a liquid, sugars brown, and air trapped in a mixture makes it rise. Understanding these changes lets you cook on purpose rather than by luck, put right a dish that goes wrong, and keep as much goodness in the food as you can. This module covers the main changes that heat causes, the ways heat travels into food, and how cooking affects how healthy the food stays.

Food science words

Learn these before you cook. They name the changes that heat causes in food and the ways heat reaches it.

Match the process to its result

Conduction against convection

Heat has to travel into food before it can cook it, and it does so in different ways. Two of them matter most in everyday cooking.

Why does the egg set?

You heat a raw egg white and it changes from a clear liquid into a firm white solid. Which food-science process is this?

• Coagulation
• Gelatinisation
• Caramelisation
• Emulsification

Explain the science, not just the recipe

In the exam, do not only say what you did. Say what happened inside the food and why. Name the process, describe the change, and link it to the result on the plate. For example, do not write that you heated the sauce. Write that the starch gelatinised, swelling and thickening the liquid, which is why the sauce went from thin to smooth and thick. Process, change, result: that chain is food science, not just a recipe.

Pick what heat can do

Select every change that heat can cause in food.

• Set protein so it becomes firm
• Thicken a starchy liquid
• Brown sugar and develop flavour
• Turn oil into water
• Add vitamins that were not there before

Order making a sauce thicken

Put the steps of thickening a sauce with starch in the right order.

• Mix the starch with a little cold liquid
• Add it to the rest of the liquid in the pan
• Heat the pan gently and keep stirring
• The starch grains absorb liquid and swell
• The sauce thickens as the starch gelatinises
• Take it off the heat once it is smooth and thick

Complete the food-science facts

When protein sets from a liquid into a solid as it heats, it has undergone _____. When starch swells and thickens a liquid, it has undergone _____. When sugar browns and develops flavour, it has undergone _____. Heat that passes through a solid pan by direct contact travels by _____.

One egg, three science ideas

Think about how many food-science ideas hide in a single egg. Whisk the white on its own and you trap air in it, which is aeration, so the foam grows light and stiff. Heat the white in a pan and its protein coagulates, setting from clear liquid to firm white. Beat the yolk into oil a little at a time and it holds the oil and water together in one smooth mixture, which is emulsification, the science behind mayonnaise. One everyday ingredient shows aeration, coagulation and emulsification. Naming the process each time is what turns cooking into food science.

Spot the science at work

Tap the TWO sentences that correctly name a food-science process at work.

• The egg white set because its protein coagulated
• The sugar turned golden because it caramelised
• The sauce thickened because the water turned into starch
• The cake rose because heat added new air to it

Choose the cooking method

For each aim, choose the method that fits the food science.

• You want to keep as much vitamin C as possible in green vegetables. What is the best choice?
• You want a crisp, golden-brown surface on a piece of food. Which effect are you after?
• Your sauce is thin and you want it thick and smooth. What should you use?

Build a food-science point

Choose the word for each gap to complete one correct food-science point.

Quick-fire food-science check

Answer each question. You have three lives, and losing them all restarts the run.

Explain the science of cooking

A friend can follow a recipe but does not understand why the steps work. Explain the science behind cooking, using the processes from this module.

• Explain what happens when protein coagulates
• Explain what happens when starch gelatinises
• Explain what caramelisation adds to food
• Explain how heat travels into food
• Explain one way cooking can reduce the goodness in food