Food Quality
What you must understand
Food quality covers the sensory, nutritional, functional and safety characteristics of food and how they are preserved or changed. Know the sensory properties: appearance (colour, shape, size, gloss), flavour (taste and aroma), texture (mouthfeel, consistency), and sound. Understand how each is assessed - taste panels, consumer testing, objective instruments (colorimeters, texture analysers) versus subjective sensory evaluation.
Know the functional properties of food components: emulsification, gelation, coagulation, gelatinisation, dextrinisation, caramelisation, Maillard browning, aeration, and fermentation. Understand food spoilage agents - microorganisms, enzymes, oxidation, moisture, temperature, pests - and the preservation principles that control them: temperature (chilling, freezing, heat), moisture (drying, concentration), pH (pickling, fermentation), atmosphere (vacuum, modified atmosphere), and additives.
Traps in questions
- Mixing up caramelisation (sugar only) with Maillard browning (sugar plus protein).
- Naming a preservation method without linking it to the spoilage agent it controls.
- Confusing subjective sensory testing with objective measurement.
- Describing "quality" as only taste - nutritional quality and safety count too.
Rule of thumb
For every preservation question, write: agent controlled → principle → method → quality effect. Example: microorganisms → low temperature slows growth → freezing → retains nutrients but may change texture.
Worked example
"Why does bread brown in the oven?" Answer: Maillard reaction between reducing sugars and amino acids at high temperature produces brown colour and aroma compounds; caramelisation of sugars also contributes.