Food Science and Nutrition Fundamentals
This domain tests how food composition relates to nutrition and to processing behaviour. Expect questions on macro- and micronutrients, energy values, balanced diets, deficiency disorders, and nutrient changes during processing.
Core concepts
- Macronutrients: carbohydrate and protein supply about 4 kcal/g; fat supplies about 9 kcal/g. Water and fibre are essential but are not counted as major energy sources in routine calculations.
- Micronutrients: vitamins and minerals. Water-soluble vitamins such as B-complex and C are heat- and leaching-sensitive; fat-soluble vitamins A, D, E and K are sensitive to oxidation and light.
- Balanced diet: supplies energy and all nutrients in required amounts. Cereals, pulses, milk or meat, fruits and vegetables, and fats and sugars each contribute different nutrients.
- Processing effects: milling removes bran and some B vitamins; blanching leaches water-soluble vitamins; severe heating can reduce lysine availability and destroy vitamin C.
Worked example
A 100 g snack contains 50 g carbohydrate, 20 g protein and 10 g fat. Energy = (50 × 4) + (20 × 4) + (10 × 9) = 200 + 80 + 90 = 370 kcal. The remaining 20 g is moisture, fibre and minerals, so it should not be multiplied by 4 kcal/g. If a label claims 400 kcal, suspect a calculation or rounding error.
Traps
Using 9 kcal/g for carbohydrate; counting all non-fat mass as protein; ignoring moisture; confusing kwashiorkor (protein deficiency) with marasmus (energy deficiency); assuming cooking always lowers every nutrient equally.