Nutrition, Food Science and Technology

The One Thing

Nutrition and food technology are applied sciences concerned with protecting and improving health through appropriate diets, safe food systems and controlled processing. Effective practice must integrate nutritional requirements, disease management, food safety, cultural suitability, affordability, evidence and environmental responsibility.

Reactions, Processes and Experiments

Key Terms

• Clinical nutrition: The application of nutrition knowledge to assess nutritional needs and plan diets for individuals who are healthy, ill or recovering from disease.
• Medical Nutrition Therapy: A planned diet intervention used under professional guidance to treat or manage a medical condition, such as diabetes, hypertension or kidney disease.
• Nutritional assessment: Systematic evaluation of a person's nutritional status using dietary, anthropometric, biochemical, clinical and socioeconomic information.
• Anthropometry: Measurement of body dimensions, such as weight, height, body mass index, waist circumference and mid-upper-arm circumference, to assess nutritional status.
• Body Mass Index: A screening measure relating body weight to height and calculated as weight in kilograms divided by height in metres squared.
• Diet therapy: Modification of the normal diet in quantity, quality, texture or meal pattern to meet the needs of a particular health condition.
• Therapeutic diet: A diet designed to support treatment, reduce symptoms, correct nutrient deficiencies or prevent complications of disease.
• Public nutrition: The study and application of nutrition strategies to improve the health and nutritional well-being of populations and communities.
• Malnutrition: A condition caused by deficiency, excess or imbalance of energy and nutrients, including undernutrition, micronutrient deficiencies and overnutrition.
• Nutrition intervention: An organised action intended to improve nutritional status, such as supplementation, food fortification, nutrition education or supplementary feeding.
• Food security: A situation in which all people have regular physical, social and economic access to sufficient, safe and nutritious food for an active and healthy life.
• Food science: The scientific study of food composition, structure, properties, processing, storage, safety and consumer acceptability.
• Food technology: The practical application of food science and engineering to produce, preserve, package, store and distribute food safely and efficiently.
• Food processing: Any physical, chemical or biological operation that changes raw food into a safer, more stable, convenient or acceptable product.
• Preservation: Methods used to delay spoilage and extend the usable life of food by controlling microorganisms, enzymes, moisture, oxygen, temperature or light.
• Pasteurisation: Controlled heating of a food, commonly milk, to destroy disease-causing microorganisms while causing relatively little change in quality.
• Sterilisation: High-temperature treatment intended to destroy microorganisms and spores, producing a commercially sterile product when properly packaged.
• Blanching: Brief heating of fruits or vegetables, usually followed by rapid cooling, to inactivate enzymes before freezing or drying.
• Dehydration: Removal of moisture from food to reduce water activity and slow the growth of microorganisms.
• Fermentation: A process in which useful microorganisms convert food components, often sugars, into acids, gases or alcohol, improving flavour, digestibility or preservation.
• Refrigeration and freezing: Low-temperature methods that slow microbial growth and chemical reactions; freezing preserves food by converting much of its water into ice.
• Canning: Preservation by filling food into airtight containers and applying heat to destroy microorganisms and enzymes.
• Food irradiation: Controlled use of ionising radiation to reduce microorganisms, insects or sprouting in food without making the food radioactive.
• Food additives: Substances deliberately added in small amounts to maintain or improve colour, flavour, texture, stability, safety or shelf life.
• Food fortification: Addition of essential nutrients to a food to prevent or correct nutrient deficiencies in a population.
• Food adulteration: The lowering of food quality or safety by adding inferior, harmful or unnecessary substances or by removing valuable components.
• Food safety: The assurance that food will not cause harm when prepared, handled, stored and consumed as intended.
• HACCP: Hazard Analysis and Critical Control Point, a preventive system that identifies hazards and controls them at important stages of food production.
• Cross-contamination: Transfer of harmful microorganisms or allergens from one food, surface, utensil or person to another.
• Water activity: The amount of available water in food that can support microbial growth and chemical reactions; lowering it helps preserve food.
• Shelf life: The period during which a food remains safe and retains acceptable quality under specified storage conditions.
• Packaging: The use of containers and protective materials to protect food from contamination, damage, moisture, oxygen, light and temperature changes.
• Sensory evaluation: Scientific assessment of food using human senses to judge characteristics such as appearance, aroma, taste, texture and acceptability.
• Nutrient loss: Reduction in the amount or availability of nutrients caused by harvesting, storage, preparation, processing or cooking.

Easily Confused

• Clinical nutrition and public nutrition: Clinical nutrition focuses on individuals, whereas public nutrition focuses on populations and communities.
• Diet therapy and therapeutic diet: Diet therapy is the modification process; a therapeutic diet is the resulting diet designed for a health condition.
• Pasteurisation and sterilisation: Pasteurisation reduces harmful microorganisms but does not produce complete sterility; sterilisation is a higher-temperature treatment intended to destroy microorganisms and spores.
• Blanching and cooking: Blanching is brief heating primarily to inactivate enzymes before freezing or drying, whereas cooking is intended to make food ready for consumption.
• Refrigeration and freezing: Refrigeration slows spoilage, whereas freezing converts much of the water into ice and slows microbial growth more substantially.
• Dehydration and preservation by salt or sugar: Dehydration removes moisture directly; salt or sugar preserves food by reducing available water.
• Food fortification and food adulteration: Fortification deliberately adds essential nutrients for a nutritional purpose; adulteration lowers quality or safety through inferior, harmful or unnecessary additions or removal of valuable components.
• Best-before and use-by or expiry dates: Best-before mainly indicates expected quality; use-by or expiry dates relate more directly to safety or permitted use according to the product and regulation.
• Food science and food technology: Food science explains food composition, properties and changes; food technology applies that knowledge to production, preservation, packaging, storage and distribution.
• Food safety and food quality: Food safety concerns prevention of harm; quality includes characteristics such as taste, texture, appearance, acceptability and nutrient retention.
• Food irradiation and radioactivity: Irradiation uses controlled ionising radiation to reduce hazards but does not make food radioactive.
• Nutrient loss and nutrient deficiency: Nutrient loss occurs during food handling or processing; nutrient deficiency is an inadequate nutritional status in a person or population.

What Gets Asked

• Define and distinguish major fields and systems: Questions may ask for clinical nutrition, public nutrition, food science, food technology, HACCP or food security. Marks are lost by confusing individual clinical care with population-level public nutrition.
• Calculate or interpret BMI and energy values: Students may be asked to use BMI = weight in kilograms divided by height in metres squared or apply 4 kcal per gram for carbohydrate and protein and 9 kcal per gram for fat. BMI must be identified as a screening tool rather than a complete clinical diagnosis.
• Outline the nutrition care process: A question may require the sequence assessment, nutrition diagnosis, intervention, monitoring and evaluation. Omitting nutrition diagnosis or monitoring and evaluation loses marks.
• Explain dietary management of disease: Diabetes questions may require total carbohydrate, portion control, fibre, meal timing, physical activity and blood-glucose monitoring; hypertension questions may require reduced excess sodium, fruits and vegetables, healthy body weight and fewer highly processed foods; anaemia questions may require iron-rich foods, vitamin C and awareness that tea or coffee with meals may reduce non-haem iron absorption.
• Compare food-preservation methods: Questions may compare pasteurisation, sterilisation, blanching, dehydration, fermentation, refrigeration, freezing, canning and food irradiation. The key slips are stating that pasteurisation makes food sterile, that freezing destroys all microorganisms, or that irradiation makes food radioactive.
• Explain food-safety hazards and controls: Questions may require biological, chemical and physical hazards, cross-contamination, the temperature danger zone, or HACCP. Marks are lost by treating food safety as final-product testing alone rather than preventive control during production and handling.
• Discuss processing and nutrient retention: Students may be asked how prolonged heating, repeated reheating or excess cooking water affect vitamin C, B vitamins and water-soluble nutrients. The specific preservation or preparation method must be linked to its stated effect rather than assuming that all processing is harmful or beneficial.