FOOD9102 Chap.9 How We Taste: Physiology and Product Design
How We Taste: Physiology and Product Design
The Week 4 lecture explains what panellists are detecting when they taste. This chapter sets out flavour as taste plus smell, the three chemosensory pathways, the five taste modalities with their receptors, and the chain from receptor activation to perception, cognition and preference.
It then follows the Week 4 workshop method for building a food concept on taste physiology, with a measurable target, a test plan and a success threshold set before testing.
For the quizzes, focus on the definitions, the pathways and the receptor for each modality. For the workshop and later laboratory design, focus on the habit of setting a measurable target and a success threshold before any test is run.
What this chapter covers
- 01
Flavour as taste plus smell
- 02
Gustation, olfaction and chemesthesis
- 03
Sweet and umami receptors from the T1R family
- 04
Bitter T2R receptors and adaptation
- 05
Salt taste through the ENaC sodium channel
- 06
From stimulation to perception and preference
- 07
Designing and testing a taste-led product concept
Worked example · free
Match five stimuli to their sensing pathway
- 1(a) Sugar: sweet taste, detected by the T1R2 and T1R3 receptor pair.
- 1(b) MSG: umami taste, detected by T1R1 and T1R3.
- 1(c) A bitter compound: bitter taste, detected by the T2R receptor family.
- 1(d) Sodium chloride: salty taste, with sodium passing through the ENaC channel.
- 1(e) Chilli heat: chemesthesis, an irritation pathway rather than one of the five tastes.
Key terms
- Gustation
- Gustation is the sense of taste proper, covering the five modalities sweet, sour, salty, bitter and umami.
- Retronasal olfaction
- Retronasal olfaction is smelling aromas that travel from the mouth to the nose during eating.
- Taste receptor
- A taste receptor is a protein in a taste cell that binds a stimulus and starts the signal for one modality.
- ENaC channel
- The ENaC channel is the epithelial sodium channel through which sodium and lithium produce salty taste.
- Sensory profile
- A sensory profile is a multi-attribute description of a product, often drawn as a spider diagram.
- Labelled-line model
- The labelled-line model proposes that each taste quality is carried by its own dedicated nerve pathway.
How We Taste: Physiology and Product Design FAQ
What is the difference between taste and flavour?
Taste is gustation alone: sweet, sour, salty, bitter and umami. Flavour combines taste with smell, including aromas reaching the nose from the mouth, which is why the lecture writes flavour as taste plus smell.
Why does a sensory scientist need to know about receptors?
Because receptors explain what a product change will do to perception and offer tools for innovation. Different modalities use different receptors, and those receptors can be used to screen for new flavour molecules, such as compounds that boost sweetness or umami in reformulated foods.
Can a taste test prove a health benefit?
No. The Week 4 workshop is explicit that a taste test measures liking. A health or performance benefit needs separate evidence, and any claim on a label must meet the Food Standards Code.
How do umami and sweet receptors relate to each other?
Both belong to the T1R family and share the T1R3 subunit. Sweet taste uses T1R2 paired with T1R3, while umami uses T1R1 paired with T1R3. The lecture also shows a synergy between MSG and nucleotides in umami taste, which makes umami a target for flavour enhancement.
Assessment move
Draw the five taste modalities with their receptors from memory, then add the two other pathways around them. For the workshop, practise one concept summary in six lines: problem and consumer, product and mechanism, benefit and evidence, consumer proposition, feasibility and test, and the decision the result would trigger. Then practise the three-minute pitch structure aloud with a friend.
Link each modality to a product example you know, such as a reduced-sugar drink for sweet or a stock cube for umami, to make the receptors memorable.
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