Carbohydrate (Macronutrient) — OCR GCSE Food Preparation and Nutrition

Carbohydrates are one of the three macronutrients essential for human health, providing the body's primary source of energy. In the OCR GCSE Food Preparation and Nutrition course, you will explore the chemical structure of carbohydrates, their classification into simple sugars (monosaccharides and disaccharides) and complex carbohydrates (polysaccharides like starch and fibre), and their roles in the body. Understanding carbohydrates is crucial for designing balanced diets, managing energy levels, and preventing diet-related diseases such as type 2 diabetes and obesity.

This topic also covers the functional properties of carbohydrates in food preparation, including gelatinisation (thickening sauces), dextrinisation (browning of toast), and caramelisation (production of sweet, brown compounds). You will learn how different carbohydrates behave during cooking and how they contribute to the sensory qualities of food. Mastery of this content is vital for both the written examination and the non-exam assessment (NEA), where you must apply scientific principles to practical cooking tasks.

Carbohydrates are a core component of the 'Nutrition' section of the specification, linking to energy balance, dietary guidelines, and the Eatwell Guide. By studying this topic, you will be able to critically evaluate food choices, understand food labelling, and make informed recommendations for different life stages and health conditions. This knowledge forms the foundation for more advanced topics such as the role of carbohydrates in sports nutrition and the management of metabolic disorders.

• →Classification: Monosaccharides (glucose, fructose), disaccharides (sucrose, lactose), and polysaccharides (starch, glycogen, fibre).
• →Energy provision: Carbohydrates provide 3.75 kcal per gram; glucose is the body's preferred energy source, stored as glycogen in liver and muscles.
• →Functional properties: Gelatinisation (starch granules swell and thicken when heated with liquid), dextrinisation (dry heat breaks down starch into dextrins, causing browning), and caramelisation (sugars break down under heat to produce colour and flavour).
• →Dietary fibre: Non-starch polysaccharides (e.g., cellulose) that aid digestion, prevent constipation, and reduce risk of bowel cancer; found in whole grains, fruits, and vegetables.
• →Glycaemic index (GI): A measure of how quickly carbohydrate-containing foods raise blood glucose levels; low-GI foods provide sustained energy release.

• Identification of sugar types: monosaccharides and disaccharides
• Understanding of starch as a complex carbohydrate
• Knowledge of dietary fibre
• Functions of carbohydrates in the body
• Symptoms and consequences of carbohydrate deficiency
• Identification of food sources for sugar, starch, and fibre

• 💡Ensure you can distinguish between simple sugars and complex carbohydrates
• 💡Be prepared to link carbohydrate intake to energy balance and health
• 💡Know the specific functional properties of carbohydrates in food science, such as gelatinisation, dextrinisation, and caramelisation
• 💡Use specific terminology: In exam answers, always use correct scientific terms like 'monosaccharide', 'polysaccharide', 'gelatinisation', and 'dextrinisation'. This demonstrates depth of understanding and secures higher marks.
• 💡Link to practical examples: When explaining functional properties, always give a food example (e.g., 'gelatinisation occurs when making a roux for a cheese sauce'). This shows application of knowledge.
• 💡Discuss health implications: For higher marks, relate carbohydrate intake to health conditions such as diabetes, obesity, and dental caries. Reference the Eatwell Guide and current dietary recommendations.

• Misconception: All carbohydrates are bad for you. Correction: Carbohydrates are essential for energy; the key is choosing complex carbohydrates (whole grains, pulses) over refined sugars and starches.
• Misconception: Fibre is not a carbohydrate. Correction: Fibre is a type of carbohydrate (non-starch polysaccharide) that the body cannot digest, but it is crucial for digestive health.
• Misconception: Gelatinisation and dextrinisation are the same process. Correction: Gelatinisation occurs when starch is heated with liquid (e.g., making a white sauce), while dextrinisation occurs when starch is dry-heated (e.g., toasting bread).