WACE ATAR Food Science and Technology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Water activity (aw)

The ratio of vapour pressure of water in food to that of pure water. It predicts microbial growth better than moisture content; most bacteria require aw above 0.91.

Gelatinisation

Heating starch with water causes granules to swell and burst, releasing amylose. On cooling, retrogradation sets a gel, as in custard or white sauce.

Maillard reaction

A non-enzymatic browning reaction between reducing sugars and amino groups of proteins, producing brown pigments and flavours when food is heated above roughly 140 degrees C.

Emulsion

A dispersion of one liquid in another that does not normally mix. Emulsifiers such as lecithin stabilise droplets by lowering interfacial tension, as in mayonnaise.

Indispensable amino acids

Amino acids the body cannot synthesise in adequate amounts and must obtain from food. Nine are essential for adults, including lysine, methionine and tryptophan.

HACCP

Hazard Analysis Critical Control Point: a seven-principle system identifying biological, chemical and physical hazards and controlling them at critical points with monitoring and records.

Critical control point

A step in a food process where control can prevent, eliminate or reduce a significant hazard to an acceptable level, such as cooking to a specified core temperature.

Temperature danger zone

The range between 5 and 60 degrees Celsius in which food-poisoning bacteria multiply rapidly. High-risk foods should spend minimal time in this range.

Cross-contamination

Transfer of harmful microorganisms from raw food, surfaces, equipment or hands to ready-to-eat food, prevented by colour-coded boards, separation and handwashing.

Two-hour four-hour rule

Food held in the danger zone under two hours may be refrigerated; two to four hours it must be used immediately; beyond four hours it must be discarded.

Design brief

A statement defining the target consumer, need or opportunity, constraints and success criteria that guides the development of a food product.

Sensory evaluation

Controlled testing of food using human senses. Discriminative tests detect differences, descriptive tests profile attributes and hedonic scales measure liking.

Product specification

Measurable requirements a product must meet, including mass, pH, water activity, texture, colour, shelf life and cost per serve, used to judge conformance.

Modified atmosphere packaging

Packaging in which the internal gas mix is altered, usually lowering oxygen and raising carbon dioxide or nitrogen, to slow respiration and microbial growth and extend shelf life.

Pasteurisation

Heat treatment, typically 72 degrees C for 15 seconds, that destroys vegetative pathogens and reduces spoilage organisms to extend chilled shelf life without sterilising.

Blanching

Brief heating of food, usually vegetables, in water or steam to inactivate enzymes and fix colour before freezing, drying or further processing.

Fermentation

Microbial conversion of sugars into acids, gases or alcohol. It lowers pH and produces preservative metabolites, as in yoghurt, sauerkraut and sourdough.

Extrusion cooking

A continuous process using heat, pressure and shear to gelatinise starch and texturise protein, producing snacks, cereals and meat analogues.

Nutrient Reference Values

Australian and New Zealand intake standards including Estimated Average Requirement, Recommended Dietary Intake, Adequate Intake and Upper Level of Intake.

Glycaemic index

A ranking of carbohydrate foods from 0 to 100 by the blood glucose rise they cause over two hours compared with a reference food such as glucose.

Nutrition Information Panel

A mandatory label panel showing energy, protein, total and saturated fat, carbohydrate, sugars and sodium per serve and per 100 grams.

Health Star Rating

An Australian front-of-pack system scoring products from half a star to five stars using an algorithm balancing energy, saturated fat, sodium and sugar against positive nutrients.

Food security

Reliable physical, social and economic access to sufficient, safe and nutritious food. Its pillars are availability, access, utilisation and stability.

Lifecycle assessment

A method quantifying environmental impacts of a product across its whole supply chain, from production and processing through distribution, use and disposal.

Food waste hierarchy

A ranked preference for managing surplus food: prevent waste, redistribute to people, feed animals, recycle through composting or digestion, then dispose.

Mise en place

French term for preparing and organising all ingredients, equipment and workspace before cooking begins, improving efficiency, accuracy and safety.

Controlled variable

A factor held constant across all trials in an investigation so that changes in the dependent variable can be attributed to the independent variable.

Denaturation

Unfolding of a protein's three-dimensional structure by heat, acid, salt or mechanical action, altering solubility and texture without changing amino acid sequence.

Soluble fibre

Fibre that dissolves or swells in water, such as pectin and beta-glucan. It slows glucose absorption and lowers blood cholesterol.

Cleaning versus sanitising

Cleaning removes visible soil and grease using detergent; sanitising then reduces microorganisms on a clean surface using heat or an approved chemical sanitiser.

Food recall

Removal of a food from sale and distribution when it poses a safety risk, supported by traceability records showing one step back and one step forward.

Quality control

Testing samples and processes against established specifications, such as measuring pH or micro counts, to confirm products meet defined standards before release.