Food & Cooking · Unit 16
Food Science
The chemistry and physics happening in every pan
This unit explains the mechanisms behind everything the technique units describe, and it is the point where cooking becomes predictable rather than superstitious.
It covers heat transfer, browning reactions, what heat does to protein, starch and gels, and emulsions and foams.
This unit breaks down into 20 short steps and 118 questions, starting at difficulty 4 and building to 5. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.
- Steps
- 20
- Questions
- 118
- Difficulty
- 4-5
What this unit covers
- Protein and Heat
- Starch and Gels
- Browning Reactions
- Emulsions and Foams
- Heat Transfer in Cooking
Where this fits
Best after Cooking Methods and Baking and Pastry. Connects to Chemistry.
Where people slip
The Maillard reaction and caramelisation are different processes. One involves protein and sugar together, the other sugar alone, and they need different conditions.
How the unit is structured
Food Science runs as 20 short steps that unlock in order. 15 are practice rounds and 5 are challenge rounds that pull together everything before them. Questions start at difficulty 4 and climb to 5 as you progress.
Challenge rounds
Example questions
30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 118 in the unit altogether.
Browning Reactions
- Choose all that applyLevel 4
1. Which speed up Maillard browning? Pick all that apply.
- Higher surface temperaturecorrect
- A dry surfacecorrect
- Slightly alkaline conditionscorrect
- Adding cold water
Higher temperature, dry surface, alkalinity and available sugar all speed it.
- Multiple choiceLevel 4
2. Which two classes of molecule react together in Maillard browning?
- Reducing sugars and amino groupscorrect
- Fats and water
- Salt and acid
- Starch and minerals
Reducing sugars react with amino groups from proteins and amino acids.
- Picture questionLevel 4
3. 🍞 What reaction created the brown crust on this toast?
- The Maillard reactioncorrect
- Fermentation
- Freezing
- Emulsification
Dry heat drove the Maillard reaction on the bread surface.
- Sort into groupsLevel 4
4. Sort each reaction by what it needs.
Answer: Maillard reaction = Needs sugar and amino groups; Crust browning on bread = Needs sugar and amino groups; Caramelisation = Needs sugar alone; Caramel sauce = Needs sugar alone
Browning reactions differ in their requirements.
- Fill the blankLevel 5
5. The brown polymers formed late in Maillard browning are called ____.
- melanoidinscorrect
- emulsifiers
- amylopectins
- tannins
Melanoidins give roasted foods their colour.
- Put in orderLevel 5
6. Put the Maillard cascade in order.
Answer: Sugar reacts with an amino group -> Amadori compounds form -> Fragments rearrange into aroma compounds -> Brown melanoidins accumulate
Sugar and amine react, Amadori compounds form, fragments rearrange, melanoidins appear.
Emulsions and Foams
- Choose all that applyLevel 4
7. Which are emulsions? Pick all that apply.
- Mayonnaisecorrect
- Milkcorrect
- Buttercorrect
- Sugar syrup
Mayonnaise, milk and butter are all emulsions.
- Fact or fibLevel 4
8. Oil and water mix on their own if you stir long enough.
Answer: False
False. Without an emulsifier they separate again.
- Multiple choiceLevel 4
9. Why does an emulsifier work?
- It has both water-loving and fat-loving endscorrect
- It dissolves fat completely
- It removes water
- It heats the mixture
It has a water-loving end and a fat-loving end, so it sits at the boundary between them.
- Sort into groupsLevel 4
10. Sort each system by whether it disperses liquid or gas.
Answer: Mayonnaise = Liquid in liquid; Vinaigrette = Liquid in liquid; Whipped cream = Gas in liquid; Meringue = Gas in liquid
Emulsions and foams differ in the dispersed phase.
- True or falseLevel 4
11. Mayonnaise is oil dispersed in a water-based liquid.
Answer: True
True, stabilised by the emulsifiers in egg yolk.
- Put in orderLevel 5
12. Put these stages of emulsion breakdown in order.
Answer: Droplets flocculate into clusters -> The clusters cream to the top -> Droplets coalesce -> The phases fully separate
Droplets cluster, cream, merge and finally separate.
Heat Transfer in Cooking
- Build the sentenceLevel 4
13. Build a sentence about cooking heat.
Answer: Heat travels inwards from the food surface
Heat travels inwards from the food surface.
- Choose all that applyLevel 4
14. Which affect how fast heat penetrates food? Pick all that apply.
- Thickness of the piececorrect
- Moisture contentcorrect
- Starting temperaturecorrect
- The name of the dish
Thickness, moisture, density and starting temperature all matter.
- Multiple choiceLevel 4
15. Why does a thick piece of meat cook unevenly?
- Heat travels inwards slowly from the surfacecorrect
- The centre repels heat
- The outside stays cool
- It cooks perfectly evenly
Heat has to travel inwards, so the outside is far hotter for far longer.
- True or falseLevel 4
16. Water conducts heat into food far more effectively than still air at the same temperature.
Answer: True
True, which is why a hot bath feels hotter than a hot room.
- Type the answerLevel 4
17. What continues to raise a food's internal temperature after it leaves the heat?
Answer: carryover heat
Carryover heat moves inwards from the hot exterior.
- Choose all that applyLevel 5
18. Which raise the rate of heat transfer to food? Pick all that apply.
- Moving hot air or liquidcorrect
- Direct contact with a hot surfacecorrect
- A larger temperature differencecorrect
- An insulating air gap
Moving fluid, direct contact, higher temperature difference and thin pieces all help.
Protein and Heat
- Choose all that applyLevel 4
19. Which foods are set by protein networks? Pick all that apply.
- Baked custardcorrect
- Cooked egg whitecorrect
- Set yoghurtcorrect
- Melted butter
Custard, cooked egg and set yoghurt all rely on protein gels.
- Fill the blankLevel 4
20. When a protein loses its folded shape it has been ____.
- denaturedcorrect
- fermented
- caramelised
- emulsified
Denaturation unfolds the structure.
- Match the pairsLevel 4
21. Match each change to what it does to protein.
Answer: Heating = Denatures protein; Whisking egg white = Unfolds protein at air surfaces; Overcooking = Squeezes out water
Different conditions affect protein structure in different ways.
- Multiple choiceLevel 4
22. What happens to a protein when it denatures?
- Its folded structure unravelscorrect
- It gains new amino acids
- It becomes a sugar
- It evaporates
Its folded three-dimensional structure unravels, exposing parts that were buried.
- Build the sentenceLevel 5
23. Build a sentence about food structure.
Answer: Proteins unfold and link to set cooked food
Proteins unfold and link to set cooked food.
- Sort into groupsLevel 5
24. Sort each phenomenon by whether it involves proteins or starch.
Answer: Syneresis in a custard = Protein behaviour; Egg white foam = Protein behaviour; Gelatinisation = Starch behaviour; Retrogradation = Starch behaviour
Food structure comes from several different polymer systems.
Starch and Gels
- Build the sentenceLevel 4
25. Build a sentence about starch.
Answer: Starch granules swell and thicken hot liquid
Starch granules swell and thicken hot liquid.
- Choose all that applyLevel 4
26. Which are common thickeners? Pick all that apply.
- Wheat flourcorrect
- Cornflourcorrect
- Arrowrootcorrect
- Table salt
Flour, cornflour and arrowroot are all starch thickeners.
- Multiple choiceLevel 4
27. What are the two main molecules that make up starch?
- Amylose and amylopectincorrect
- Glucose and fructose
- Casein and whey
- Pectin and cellulose
Amylose is largely linear and amylopectin is highly branched.
- True or falseLevel 4
28. A high amylose starch tends to set into a firmer gel on cooling.
Answer: True
True. Linear chains realign more readily.
- Type the answerLevel 4
29. Which branched starch molecule contributes to a smooth thick texture?
Answer: amylopectin
Amylopectin is highly branched.
- Fact or fibLevel 5
30. All starches thicken sauces in exactly the same way.
Answer: False
False. Amylose and amylopectin content and modification change the behaviour completely.
Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.
How you practise
This unit mixes 11 different question formats, so you are recalling and applying rather than recognising the same layout every time.
- Build the sentence
- Choose all that apply
- Fact or fib
- Fill the blank
- Match the pairs
- Multiple choice
- Picture question
- Put in order
- Sort into groups
- True or false
- Type the answer
Practise Food Science
118 questions across 20 steps. Start with step one and crawl at your own pace.
Play this unitRead about Food Science
Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.
- What Is Emulsification in Cooking?How oil and water are forced to mix in mayonnaise and vinaigrette, and why sauces split and how to rescue them.August 28, 2026 · 5 min read
- What Is the Maillard Reaction?The browning that gives roast meat, bread crust and coffee their flavour, and how to make it work in your kitchen.August 28, 2026 · 6 min read
More units in Food & Cooking
- What We EatFood groups, meals and where our food comes from
- Fruit and VegetablesGrowing, picking and eating plants
- In the KitchenTools, hygiene and staying safe while you cook
- From Farm to PlateThe journey food takes before it reaches you
- Grains and BreadThe crops that feed the world and the loaves they become
- Dairy and EggsMilk, cheese, butter and the remarkable egg
- Meat, Fish and ProteinProtein foods, how they cook and how they are caught or raised
- Herbs and SpicesFlavour, aroma and the trade that moved the world